Unveiling the Bacteriophage Reservoir of the Ganga River: Ecological Roles, Environmental Drivers, and Biotechnological Potential

Introduction

The River Ganga has long been venerated for its intrinsic self-cleansing and therapeutic properties, sustaining more than 450 million people who rely on its waters for diverse livelihood and cultural needs. The river originates from the melting of India’s Himalayan permafrost. Several researchers have hypothesized that bacteriophages entrapped within Himalayan permafrost may be progressively liberated during thawing processes, thereby establishing a phage reservoir at Gaumukh- the source of the Ganga. Although this hypothesis remains empirically untested within the Ganga basin, it is grounded in established permafrost virology research conducted in Siberia and Antarctica. [1]. A distinct research team has identified a temperate bacteriophage from the Antarctic Dry Valley, which targets Psychrobacter, an extremophilic bacteria, and has analyzed its genetic attributes [2]. These findings together emphasize the need for further exploration of innovative opportunities for bacteriophages and their possible resurgence in the frozen Himalayan permafrost.

Water constitutes the most essential and invaluable resource for sustaining life on Earth [3]. India is abundantly endowed with water resources through its extensive network of rivers, which collectively fulfill the country’s diverse water requirements [4]. The Ganga (Ganges) River is the world’s third biggest river in terms of total water discharge. It originates in the western Himalayas from the Gaumukh ice cave (30°36′N; 79°04′E) in the Gangotri Glacier system, at an elevation of 4,100 m in Uttarkashi district, Uttarakhand. The river flows about 2,550 kilometres across the plains of Uttarakhand, Uttar Pradesh, Bihar, Jharkhand, and West Bengal, passing through several important towns such as Haridwar, Kanpur, Prayagraj (Allahabad), Patna, and Farakka before emptying into the Bay of Bengal [5] [6], [7], [8]. After passing through the Shivalik hills, the Ganga joins the plains near Haridwar and travels southward toward the plains of Uttar Pradesh. After leaving Uttar Pradesh, the river borders Bihar in the Rohtas district. It starts in Bihar and flows into Jharkhand’s Sahibganj district before entering West Bengal and heading south. Approximately 40 kilometers downstream of Farakka, the river divides into two arms: the left arm flows eastward into Bangladesh, and the right branch, known as the Bhagirathi, flows southward through West Bengal. The Hooghly River is a part of the Bhagirathi that flows west and southwest of Kolkata. After entering Diamond Harbour, the river turns southward and divides into two streams before flowing into the Bay of Bengal [5], [9]. The Ganga River provides a key freshwater supply for almost 400 million people who live in its watershed and rely on it for their daily livelihoods. The river has deep cultural and religious importance in India, and it is said to cleanse the soul. Additionally, it has been found to have antibacterial and therapeutic qualities[10], [11], [12].

For geographical, historical, sociological, and economic purposes, it is one of the most significant river for the Indian people [8], [13]. Ganga river water is frequently utilized for drinking and outdoor bathing by millions of people who become involved in ceremonial bathing rituals at least once annually along the whole length of the river, from Gangotri to Ganga Sagar, because of its profound socio-religious importance [5]. The Ganga encompasses a drainage basin of 861,404 km² within India, ranking 15th in Asia and 29th globally [4]. The Ganga River has the seventh greatest average annual water output on Earth, with 18,700 m³/s. The Ganga has significant flow variance within its catchment region, with a mean maximum flow of 468.7 × 10⁹ m³, accounting for 25.2% of India’s total water resources [14]. The river system relies heavily on tributaries for freshwater flow, resulting in significant regional variation in water availability, ranging from 59,000 million m³ at Prayagraj (before confluence with the Yamuna) to 459,000 million m³ at Farakka in the lower reaches [4].

In recent decades, the Ganga River has faced escalating pollution driven by anthropogenic activities, rapid urbanization, open defecation, and the direct discharge of untreated wastewater through small drains into the river [15]. Despite anthropogenic pollution, the River Ganga supports extensive biodiversity owing to its intrinsic self-cleaning and regenerative properties. In 1896, British bacteriologist Ernest Hankin demonstrated the antimicrobial properties of Ganga water against Vibrio cholerae, the causative agent of cholera, observing that the pathogen was rapidly destroyed in Ganga water while thriving in tap water. Hankin proposed that a heat-labile, unknown substance capable of passing through fine porcelain filters was responsible for preventing cholera epidemics in downstream villages [16], [17]. To preserve the purity of the River Ganga, the Government of India launched the Ganga Action Plan (GAP) in 1986 with the objective of reducing pollution in the Ganga River [18]. The Ganga Action Plan was relaunched in 2009, with a rebuilt National Ganga River Basin Authority (NGRBA). The Ganga’s water quality is decreasing due to excessive nutrient loading and eutrophication, which is causing the expansion of bacterial species that are detrimental to both aquatic ecosystems and human health [19]. River pollution is a critical and rising issue in most developing nations today. Rapid industrialization has led to a substantial increase in effluent discharge into natural water bodies. Industrial effluents and sewage that enter water bodies are significant causes of environmental toxicity, harming aquatic biota and decreasing water quality [5], [20]. Major contaminants found in water include volatile, biodegradable, and recalcitrant organic chemicals, poisonous metals, plant nutrients, suspended particles, microbial pathogens, and parasites [5].

Bacteriophages are associated with the distinctive properties of the River Ganga, and certain bacteriophages may remain stable under environmentally favorable conditions for extended periods [21], [22], [23]. Bacteriophages occupy all habitats worldwide where bacteria thrive. It has been estimated that for each bacterial cell, there exist ten bacteriophage particles. Viruses are considered obligate intracellular parasites that require a specific host cell for replication [23], [24].

In this review, we synthesize peer-reviewed studies through December 2025, prioritising research from the past decade, available data on PubMed, Web of Science, and Google Scholar by searching keywords such as “Ganga/Ganges bacteriophage,” “Ganga metagenomic,” and “river phage ecology,” while also integrating seminal historical investigations of Ganga water and bacteriophages.

Microbial and Environmental Ecosystem of the Ganga River

2.1 Geographical, Hydrological and Physicochemical Features

Environmental pollution in the Ganga is caused by anthropogenic, agricultural, and industrial activities near aquatic environments. Given the crucial relevance of these ecosystems for varied water-based activities, aquatic systems are particularly susceptible, and such pollution has a negative impact on bacteriophage populations [25]. Compared to other examined riverine ecosystems, the Ganga River displays a significantly higher proportion of human population along its banks, leading to potentially larger pollution from industrial and human waste. Due to pollution, regular consumption of Ganga water or immersion in it today may cause serious illness in humans. We are approaching the solution to water pollution by microbial pathogens, including its impacts and implications, through the application of bacteriophage therapies [23]. Organization such as WHO, CPCB, BIS, ICMR, provide standards for the drinking water (Table 1) [26], [27]. According to standards established by WHO, CPCB, BIS, ICMR, ISI, and USEPA, water quality assessments revealed that approximately 70% of river water in India was contaminated, with some portions being too poor for human consumption [26], [27].

The principal reasons worsening the water quality of the River Ganga are the disposal of dead corpses, discharge of sewage and industrial waste, agricultural runoff, and the direct disposal of different veneration items into the river. To effectively maintain water quality through suitable management methods, continual monitoring of physicochemical parameters such as pH, temperature, turbidity, conductivity, total dissolved solids, dissolved oxygen, and biochemical oxygen demand is required. [28], pH is the most critical factor as it determines the alkalinity and acidity of river water. If the pH value falls below 6.5, it impairs the absorption of vitamins and minerals in aquatic organisms [28].

Abbreviations: ICMR = Indian Council of Medical Research; WHO = World Health Organization; CPCB = Central Pollution Control Board; BIS = Bureau of Indian Standards; ISI = Indian Standards Institution; USEPA = United States Environmental Protection Agency; BOD = Biochemical Oxygen Demand; DO = Dissolved Oxygen; TDS = Total Dissolved Solids; NTU = Nephelometric Turbidity Unit
CPCB Surface Water Classification: (Class A: Drinking water source without conventional treatment but after disinfection), (Class B: Outdoor bathing), (Class C: Drinking water source after conventional treatment and disinfection)

2.2 Microbial Diversity and Dynamics

Microorganisms in freshwater environments can be classified based on their feeding habits into two major groups: (1) autotrophs, which synthesize complex carbon compounds from environmental CO₂, this group includes microalgae and photosynthetic bacteria; and (2) heterotrophs, which include saprotrophs that acquire their food from non-living material either through direct uptake of dissolved molecules or indirect uptake via discharge of external enzymes followed by absorption of hydrolytic products. Biological analysis of the environment is instrumental in determining ecosystem health, as there exists a correlation between the chemical constituents (both organic and inorganic) and physical attributes of the water body with the microbial profile. One of the most effective approaches to determine this relationship is through the calculation of a diversity index, specifically the Shannon-Wiener diversity index, as it provides a mathematical framework to quantify species diversity within a particular ecosystem and further correlates this with the pollution level of the ecosystem.

(Table 2).

This clear that the diversity level and pollution level is inversely proportional to each other i.e. when the diversity level is high then pollution level is less and when diversity level is low pollution level is high, the study conducted by Sood et al; 2010 [30] The diversity index of the lower Ganga River was identified as 1.5, and their study additionally demonstrated that the water quality of the river was correspondingly low. Hence, the microbial profile of the Ganga River reflects the pollution status of the river; therefore, the microbial profile of the Ganga has been determined several times, Mishra and Tripathi, 2008 [31], evaluated seasonal and temporal patterns in the bacteriological parameters of the River Ganga in Varanasi and revealed that the downstream stretch indicated a high bacterial concentrations, comprised of Aerobacter aerogenes, A. cloacae, Micrococcus sp., Salmonella sp., Staphylococcus aureus, Bacillus sp., and Shigella sp., indicating higher levels of fecal contamination in the water. Rai et al; 2010 [32] studied the microbial pollution if river Ganga at Varanasi during rainy and winter seasons. Kumar Singh et al. 2014 [33] studied the diversity of aquatic fungi in Ganga River at threebanks of Varanasi in their study 23 microflora were identified to be dominant. Chauhanand Dhiman, 2015 [34] analysed the microbial diversity of river Ganga at Haridwar and Rishikesh and reported the presence of Staphylococcus aureus, Salmonella sp., Escherichia coli, Pseudomonas aerugionosa, Enterobacter aerogenes and Shigella sp. Sinha and Paul, 2015 [35] analyzed the population of pollution indicator bacteria in river Ganga at Ichapore, West Bengal in their study all the bacterial populationwere abundant, Balagurunathan and Shanmugasundaram, 2015 [36] studied microbialdiversity of major river basin of India and identified that Ganga has maximummicrobial diversity followed by Cauvery, Krishna and Godavari basins. Basu et al.,2016 [37] they focused on the assessment of microbes (Coliform and Enterobacteriaceae) in and around Dakhshineswar area of West Bengal. Niveshikaet al., 2016 [38] isolate and characterized bacteria from Ganga River at Varanasi thathave a capability to tolerate heavy metals. Vats, 2017 [39] analyzed microbiologicalcharacteristic of Ganga River from Kankhal to Bhogpur. Bisht et al., 2018 [40] studiedbacterial diversity of Alaknanda River at Rudraprayag which give rise to riverGanga when unit with Bhagirathi at Devprayag and isolated bacterial species wereidentified as Pseudomonas extremoriental, Bacillus licheniformis, Paenibacillus glucanolyticus, Bacillus badius, Pseudomonas fulva, Pseudomonas azotoforman, Paenibacillus thiaminolyticus. The latest comprehensive data is shown in the Table 3.

2.3 Anthropogenic Influences and Faecal Pollution Load

The Ganga River serves a method of sustaining livelihood for approximately 400 million citizens who live around and along its banks and depend on the stream for their necessities. Meanwhile, driven by anthropogenic activities, habitual drinking of Ganga water or religious immersion in it may have significant deleterious health impacts [6]. The Ganga encompasses a drainage basin of 861,404 km² within India, ranking 15th in Asia and 29th globally. The river encompasses nearly one-quarter (26.2%) of India’s geographic region. [4].

The Ganga River is predominantly polluted from three distinct sources: agriculture, industry, and city waste. Municipal sewage is the largest contribution, subsequent to industrial effluents and agricultural runoff. The river also hosts religious events, animal washing and watering, corpse disposal, and cremation procedures. Consequently, pollutants that originate in the Ganga may be generally classified into four categories: sewage pollution, industrial effluents, agricultural runoff, and religious activities. Bacteriophage abundance exhibits a positive relationship with fecal pollution load across riverine sites. Elevated concentrations of fecal indicator bacteria in sewage-impacted stretches provide a larger host reservoir for phage replication, resulting in increased phage density. This finding supports the utility of bacteriophages as complementary indicators of fecal contamination and microbial dynamics in river ecosystems.

2.3.1 Sewage pollution

Sewage pollution is one of the primary factors influencing bacteriophage abundance and diversity in river ecosystems, as it introduces large numbers of bacteria into rivers, creating favorable conditions for bacteriophage proliferation. The emission of untreated wastewater sewage from urban settings is the primary source of Ganga water microbiological degradation. Effluent water contains organic materials, nutrients, inorganic matter, harmful compounds, and pathogens [53]. Several studies have demonstrated that water quality in the upper stretch of the Ganga (from Gaumukh to Haridwar), including at Rishikesh, does not meet criteria for safe consumption. Although water quality in Rishikesh is classified as “B category” (suitable for outdoor bathing) from 2019–2023, it exceeds permissible limits for drinking water due to elevated E. coli and total coliform levels [54], In the upper Ganga, water quality deviations are minimal; however, in multiple locations along the middle and lower reaches, physicochemical and biological parameters exceed safe thresholds, rendering the water unsuitable for bathing and other livelihood-related uses [6]. About 75% of the pollutant load in the Ganga is derived from untreated or poorly treated municipal wastewater. Class I and II towns along the river contribute roughly 3,000 million liters per day (MLD) of sewage to the main stem, while installed sewage‑treatment capacity falls far short of this input. Consequently, over three‑quarters of the wastewater produced across India’s northern plains is discharged into the Ganga without adequate treatment [55]. According to the Central Pollution Control Board (CPCB), in 1985 the 25 identified Class‑I towns in Uttar Pradesh, Bihar, and West Bengal generated about 1,340 million liters per day (MLD) of municipal sewage. In response, the Ganga Action Plan (GAP) was launched in 1986; GAP Phase‑I proposed construction of 35 sewage‑treatment plants—3 in Uttarakhand, 10 in Uttar Pradesh, 7 in Bihar, and 15 in West Bengal—to reduce sewage pollution in the river [12]. GAP Phase‑II, initiated in 1993, extended sewage‑treatment interventions to several tributaries within the Ganga basin, resulting in the establishment of multiple STPs. Despite these investments, the programme did not meet its objectives for a range of technical, institutional, and operational reasons. The National Ganga River Basin Authority (NGRBA) was constituted in 2009 to coordinate basin‑scale restoration and conservation efforts. Nonetheless, recent Central Pollution Control Board (CPCB) assessments indicate that the disparity between sewage generation and treatment capacity has widened substantially, with over half of the generated sewage still entering the Ganga—either directly or via tributaries—without adequate treatment, Table 4. According to Dwivedi et al; 2018 [6], the Ganga basin generates an estimated 8,250 MLD of municipal wastewater across 222 towns, while installed treatment capacity is approximately 3,500 MLD. Of the generated wastewater, about 2,538 MLD is discharged directly to the main stem of the Ganga, 4,491 MLD is delivered via tributaries, and the remainder is disposed of onto land or in low‑lying areas. Among Class‑I cities, West Bengal produces the largest proportion of sewage (~50%, ≈1,311 MLD), largely attributable to Kolkata (≈618 MLD), followed by Uttar Pradesh (~34%, ≈874 MLD), primarily from Kanpur (≈339 MLD) and Prayagraj (≈208 MLD). For Class‑II towns, Uttar Pradesh contributes the greatest share (~52%, 63.5 MLD), followed by Bihar and Uttarakhand. Untreated sewage discharges are highest in West Bengal (≈548 MLD; 42% of its generated sewage) and Uttar Pradesh (≈461 MLD; 52% of its generated sewage) [6]. The Ganga basin produces roughly 12,000 MLD of municipal sewage, while installed treatment capacity is only about 4,000 MLD. Approximately 3,000 MLD of sewage enters the main stem from Class I and II towns situated along the river, but only about 1,000 MLD of treatment capacity has been established to handle this input. Industrial effluents account for roughly 20% of the pollutant load by volume; however, because they frequently contain toxic and non‑biodegradable constituents, their ecological and public‑health impacts are disproportionately large. Key industrial pollution hotspots include the Ramganga and Kali catchments and the Kanpur industrial area, with tanneries in Kanpur and distilleries, paper mills, and sugar factories in the Kosi, Ramganga, and Kali basins identified as principal contributors [56]. According to Dwivedi et al. 2018 [6], Urban sewage generation across the five states of the Indo‑Gangetic Plain (IGP) is estimated at 15,435 MLD, whereas installed treatment capacity amounts to only 3,458 MLD. Despite substantial financial investments, the volume of untreated sewage discharged into the Ganga in 2025 has increased by more than an order of magnitude relative to 1985, Table 4 [57].

2.3.1.2 Temporal changes in microbial contamination of the Ganga River

The escalating discharge of untreated municipal wastewater into the Ganga has markedly elevated microbial loads throughout the river. Domestic sewage is the dominant source of these microbial contaminants, and progressive urbanization along the basin has driven pronounced declines in water quality. Faecal and total coliform counts (reported as MPN/100 ml) were highest in West Bengal and next highest in Uttar Pradesh in both pre‑ and post‑NGRBA periods. Within Uttar Pradesh, Kanpur and Varanasi exhibited the greatest faecal coliform concentrations, reaching approximately 93,000 and 50,000 MPN/100 ml, respectively. In West Bengal, the most heavily impacted sites were Dakshineswar and Howrah, with peak faecal coliform levels of about 425,313 and 237,059 MPN/100 ml, respectively [6], [58]. Temporal trends indicate a modest decline in microbial contamination in Uttar Pradesh, Bihar, and West Bengal before the establishment of the NGRBA, whereas Uttarakhand exhibited a sustained upward trend. Measured microbial counts exceed regulatory thresholds by orders of magnitude relative to drinking‑water (50 MPN/100 ml) and bathing‑water (500 MPN/100 ml) standards. Spatially and temporally, the middle stretch (Uttar Pradesh) and lower stretch (West Bengal) consistently show the highest contamination levels, which correlate with the magnitude of wastewater inputs to those reaches. The pre‑NGRBA reductions likely reflect STPs installed under the Ganga Action Plan; however, in recent years the divergence between sewage generation and treatment capacity has widened, driving renewed increases in microbial loads across states. Current analyses also show an expanded range (minimum to maximum) for most contaminants, indicating persistent hotspots with inadequate treatment infrastructure.

2.3.2. Industrial Effluent

Numerous industrial facilities discharge a variety of wastes into the Ganga basin; 956 of these units are concentrated in Uttar Pradesh alone. Reported industrial sectors include thermal power generation, electro‑processing, textiles, wood and jute processing, sugar and distillery operations, pulp and paper production, synthetic rubber manufacturing, dairy processing, coal washeries (source of fly ash), pesticide production, dyeing operations, and tanneries [6]. Estimated industrial wastewater generation across the Ganga basin is approximately 2,500 MLD [59]. According to Dwivedi et al; 2018 [6], A total of 764 highly polluting industrial units—predominantly located in Uttar Pradesh—are reported to discharge effluents directly to the Ganga. The river stretch between Kannauj and Varanasi contributes the largest share of industrial wastewater inputs. Key industrial centres in Uttar Pradesh include Kanpur (tanneries), Prayagraj (engineering), and Varanasi (carpets and locomotive manufacturing), with the tannery sector accounting for the largest fraction (≈58%) of grossly polluting industries. Two of India’s three major tanning complexes are situated on the Ganga banks (Kanpur and Kolkata), and numerous small‑scale tanneries across the basin further exacerbate contamination. In Kanpur, 151 tanneries are concentrated at Jajmau on the southern bank, discharging an estimated 5.8–8.8 MLD of wastewater; approximately 62 of these facilities use chrome‑based tanning processes [60].

2.3.3 Agricultural Runoff

Agricultural runoff can significantly influence bacteriophage abundance, diversity, and distribution in river ecosystems. Runoff from croplands, livestock farms, and manure-amended fields transports bacteria, nutrients, organic matter, and associated bacteriophages into adjacent water bodies. The Indo‑Gangetic Plain (IGP) is one of the world’s largest fluvial plains. In India, it comprises approximately 13% of the national land area and includes the states of Uttarakhand, Uttar Pradesh, Bihar, Jharkhand, and West Bengal. These regions produce approximately 50% of India’s total food grains, which feed 40% of the country’s population [61]. In 2020, global agricultural pesticide use was approximately 3.39 million tonnes, of which India accounted for about 61,702 tonnes per year. India ranks fourth worldwide in pesticide production, after the United States, Japan, and China [62], [63]. Extensive pesticide application in agricultural areas of the river basin promotes environmental bioaccumulation via multiple pathways. These residues pose toxic risks to non‑target biota, enable long‑range transport, and degrade natural ecosystem conditions [64], [65], [66]. The total pesticide usage in the Ganga basin between 2012 and 2017 was 72,741 million tons, accounting for 27% of the country’s total consumption [64]. In 2014, the pesticide consumption pattern was dominated by insecticides at 80%, followed by herbicides at 15% and fungicides at 2%. The most commonly used pesticides include phosphamidon, butachlor, mancozeb, quinalphos, monocrotophos, paraquat, endosulfan, and isoproturon [67]. Given the extensive pesticide application, the probability of pesticides entering aquatic systems via surface runoff, subsurface leaching, and flood events is elevated. Volatilized pesticides from soil and crops can be scavenged by precipitation, resulting in rainwater that, despite generally being regarded as safe, may carry pesticide residues and thus act as an additional pathway for contamination, as reported by Kumari et al. 2007 and Sakai 2002 [68], [69].

2.3.4 Pollution Due to Religious Activities

Religious activities along the Ganga River indirectly affect bacteriophage abundance and diversity by changing microbial loads, nutrient levels, and water quality. The Ganga is an integral part of Indian society, and its water is regarded as sacred, found in most Hindu households across the country, and strongly qualifies for inclusion in the Geographical Indication registry. Owing to its religious significance, Ganga water is incorporated into a wide range of yajña/homa and other ritual practices—such as Gangapūjā, Laghurudra, Maharudra, various Rudra and Chandi yagnas, Durgā and Gayatri rites, bhoomi pūjā, śilānyāsa, murti pratishṭhā, vāstu and grah śānti ceremonies, śrādḥa, nārāyanabali, śivliṅga abhiṣeka, and vivāha samskāra. For practicing Hindus, the river’s water retains profound spiritual value throughout the life cycle; traditionally even a few drops administered at the time of death are believed to confer mokṣa (liberation) [70]. The Ganga basin includes numerous historic towns—Rishikesh, Haridwar, Garhmukteshwar, Kannauj, Prayagraj, Mirzapur, Varanasi, and Gangasagar—that function as major pilgrimage centres with continuous riverbank religious activities. Large-scale gatherings during festivals such as the Maha Kumbh and Makar Sankranti result in millions of participants undertaking ritual baths (“Ganga snāns”). Ritual offerings (e.g., sweets, milk, flowers, leaves, and lit earthen lamps), as well as the disposal of worn religious texts and idols, introduce organic and solid waste to the river. Furthermore, traditional funerary practices in some communities—including immersion of human remains and bone fragments—contribute additional biological and material inputs to the Ganga [6], [12]. The effects of various religious practices on Ganga water quality have been extensively investigated and are summarized below.

2.3.4.1 Religious Bathing

Daily bathing by millions occurs along the Ganga, with episodic peaks on particular auspicious dates when large congregations perform ritual immersions. The Kumbh Mela represents the largest such event; it is held sequentially at four pilgrimage sites—Haridwar (Har Ki Pauri), Prayagraj (Sangam), Nashik (Godavari Ghat), and Ujjain (Shipra Ghat)—with each location hosting the festival once every 12 years. Individual Kumbh celebrations extend for approximately six weeks [6]. During the Kumbh Mela, mass bathing occurs on designated river stretches and large numbers of devotees and ascetics camp along the Ganga throughout the event. Peak attendance on specific auspicious days—such as Makar Sankranti, Poush Purnima, Mauni Amavasya, Vasant Panchami, Magh Purnima, and Maha‑Shivaratri—produces particularly dense bathing crowds. For example, the 2021 Haridwar Kumbh recorded an estimated 9.1 million bathers despite the concurrent COVID‑19 pandemic [71]. At the 2025 Maha Kumbh in Prayagraj, an estimated 600 million ritual baths were recorded over a 45‑day period. Peak attendance occurred on Mauni Amavasya, when approximately 50 million devotees undertook a holy dip in the Ganga [72]. Large-scale congregations substantially impair water quality through the introduction of surfactants (soaps, shampoos, detergents), solid wastes (plastic, fabric, general litter), and organic offerings (food items, flowers, milk, curd, ghee), all of which increase the pollutant load in the river. These ritual inputs therefore, represent a significant source of contamination to the Ganga. Environmental monitoring during the 2025 Maha Kumbh highlighted these impacts: Central Pollution Control Board (CPCB) data documented measurable deterioration in river-water quality, reflecting persistent systemic challenges in the management of India’s water resources.

The CPCB conducted daily water‑quality monitoring at five sites within Prayagraj and two upstream locations on the Ganga from 12 January to 4 February 2025. In a report to the National Green Tribunal, the agency documented markedly elevated faecal coliform concentrations during the Maha Kumbh, indicating the river was unsafe for bathing. Mean counts exceeded the regulatory limit by more than fourfold, reaching ~11,000 MPN/100 mL, and a peak measurement on 20 January attained ~49,000 MPN/100 mL—approximately 19 times the permissible threshold [73]. Another study by Mishra et al. 2025 [74] The study highlighted microbial contamination in the river water, showing a sharp increase in Total Coliforms, Faecal coliforms, E. coli, and Enterococci during the Kumbh—levels that far exceed CPCB and WHO limits. This rise indicates significant faecal contamination and poses public health risks linked to mass gatherings and ritual bathing. Although partial improvement was observed after the Kumbh, contamination levels remained above safe standards, (Table 5). The presence of faecal coliforms in Ganga water signals the presence of pathogenic microorganisms that can cause various waterborne diseases. Religious activities along the Ganga may indirectly affect bacteriophage abundance by increasing microbial and organic matter inputs into the aquatic environment. Mass bathing events, ritual offerings, and heightened human activity during pilgrimage seasons can raise bacterial host densities, which in turn promotes bacteriophage persistence and replication. As a result, river sites with intensive religious activity tend to show higher phage concentrations compared to less frequented stretches of the Ganga.

*Exceedance Factor = Observed concentration ÷ Permissible limit
Key Interpretation: (Total coliforms exceeded the permissible limit by 100-fold, indicating substantial microbial contamination); (E. coli concentrations were approximately 29 times higher than recommended limits, suggesting significant faecal pollution); (Enterococci levels exceeded guideline values by 9-fold, indicating increased health risks associated with recreational water use); Although faecal coliforms remained below the CPCB maximum permissible limit for bathing waters (2,500 MPN 100 mL⁻¹), they substantially exceeded the desirable limit (500 MPN 100 mL⁻¹).

2.3.4.2. Pollution associated with ritual idol immersion

Idol immersion activities may indirectly affect bacteriophage communities in the Ganga River through increased inputs of organic matter, suspended solids, and anthropogenic contaminants. The resulting changes in bacterial abundance and community composition can influence phage replication dynamics, leading to localized variations in bacteriophage abundance and diversity following immersion events. In India, numerous religious activities occur throughout the year. Durga Pujā is a major festival in West Bengal, Bihar, and Uttar Pradesh, and over the past 15 years celebrations of Lakshmi Pujā and Ganesh Chaturthi have also increased in Uttar Pradesh and Bihar. Idols used in these rituals are typically constructed from plaster of Paris, clay, cloth, metal rods, and bamboo, and are finished with varnishes and water‑based paints. Upon immersion, these materials can alter water quality: the pigments and coatings commonly contain heavy metals such as mercury (Hg), cadmium (Cd), arsenic (As), zinc (Zn), chromium (Cr), and lead (Pb). Certain colourants (red, blue, orange, green) often include Hg, ZnO, Cr, and Pb, which are associated with toxic and carcinogenic effects; lead and chromium are additionally introduced via sindoor (a traditional red cosmetic). As idols deteriorate in aquatic environments, released particulates and organic matter contribute to eutrophication, changes in pH, and elevated concentrations of heavy metals in the receiving water bodies, Table:6 (A and B) [75] [6], [76]. According to the Lal 2021 [76], An estimated 100,000 ritual idols are immersed annually in water bodies across India.

According to the recent reports of the State Pollution Control Board (SPCB) [76], A delayed monsoon has exacerbated pollution in the Ganga, with conditions projected to deteriorate further during winter. At Bithoor—where the river enters Kanpur—the water remains relatively clear (dissolved oxygen, DO = 7.6 mg L⁻¹), but DO declines downstream, reaching 6.3 mg L⁻¹ at the Jajmau stretch within the city, which is identified as the most contaminated segment. For context, the reported acceptable DO threshold for a drinking‑water reservoir is 4 mg L⁻¹. The report also attributes part of the observed water‑quality degradation to the mass immersion of idols during Ganesh Chaturthi. Another study by Das et al. 2025 [77], a delayed monsoon has intensified pollution in the Ganga, with conditions expected to deteriorate further during winter. At Bithoor, where the Ganga enters Kanpur, the water remains relatively clear, but pollution increases downstream. The most contaminated section is at Jajmau, within the city limits. Dissolved oxygen (DO) levels measure 7.6 mg per litre at Bithoor but decline to 6.3 mg per litre at Jajmau. The report notes that 4 mg per litre is the acceptable DO level for drinking water reservoirs. It also highlights that the immersion of numerous idols during Ganesh Chaturthi has already negatively impacted water quality.

2.3.4.3. Dead Body Cremation

Among anthropogenic activities, cremation practices represent a unique source of organic and nutrient inputs to the river ecosystem. Although their contribution is likely lower than that of municipal sewage, localized increases in microbial abundance near cremation ghats may create favourable conditions for bacteriophage persistence and replication. Therefore, cremation-related inputs should be considered as a potential factor influencing phage dynamics in culturally significant river stretches. Many Hindus believe that dying and being cremated on the banks of the Ganga—particularly in Varanasi—facilitates liberation from the cycle of rebirth. Consequently, thousands of cremations occur daily along the river. A study covering 2009–2011 reported that the two principal cremation grounds in Varanasi (Harishchandra Ghat and Manikarnika Ghat) averaged approximately 32,000 cremations per year [6], [75]. Study by Khwairakpam et al. 2018 [78] has shown an increase in the number of cremations, especially in Manikarnika ghat. The daily number of cremations rose from 410 in 2009 to 490 in 2012, indicating a clear upward trend. Following cremation, ashes and partially combusted remains are deposited in the Ganga, and family members often consign ashes from cremations performed elsewhere to the river for religious reasons. In addition, substantial numbers of uncremated human bodies (including women, children, ascetics, victims of envenomation, and persons with dermatological conditions) and numerous animal carcasses—predominantly cattle—are directly immersed. These practices contribute both to deterioration of water quality and to the visual degradation of the riverine environment.

Diversity and Ecology of Bacteriophages in the Ganga

The Ganga has long been celebrated for purported self‑purifying and therapeutic properties, a perception often attributed to its diverse assemblage of bacteriophages [79]. Bacteriophages are viruses that infect prokaryotes, including both eubacteria and archaea [80] that attacks on the bacteria at specific sites of their host organisms. They are abundantly present in Ganga water, where they thrive and demonstrate a strong capability to combat harmful bacteria [81], [82]. Their presence in the river has been documented historically, supporting the well-recorded self-cleansing and healing properties attributed to Ganga water. [83]. Under polluted conditions, the diverse bacteriophages in the Ganga interact with microbial hosts and can significantly influence bacterial populations [84]. Bacteriophages encapsulate their nucleic acid (DNA or RNA) within an icosahedral protein capsid and characteristically possess a tail structure composed of a helical contractile sheath surrounding a central core tube, terminating in a baseplate with tail fibers. Phage surface receptor proteins mediate specific recognition and attachment to complementary molecules on the bacterial host cell surface [85]. Bacteriophages are categorised according to the nature of their genomic nucleic acid into four principal groups: single‑stranded DNA (ssDNA) phages, double‑stranded DNA (dsDNA) phages, single‑stranded RNA (ssRNA) phages, and double‑stranded RNA (dsRNA) phages [85] (Figure 1). Bacteriophages are acellular biological agents devoid of intrinsic metabolic machinery and therefore function as obligate intracellular parasites. They depend on bacterial host cells for replication, deploying their genomes to subvert host biochemical pathways and synthesise progeny virions [85]. Morphologically, bacteriophages exhibit a defined three‑dimensional architecture: an icosahedral protein capsid enclosing the genome, a helical contractile tail surrounding a central core tube, and typically six tail fibers attached to a baseplate. The baseplate bears receptor‑binding proteins that mediate specific recognition of bacterial surface molecules. These viruses are host‑specific and can regulate bacterial populations in aquatic ecosystems, thereby contributing to microbial community balance and potentially lowering the risk of waterborne infections in humans exposed to the water [82], [86].

In 1896, Ernest Hanbury Hankin reported bacteriophages in Indian river waters that exhibited antibacterial activity against Vibrio cholerae [87]. After Felix d’Hérelle’s work, he advocated using bacteriophages therapeutically and reported successful phage treatments for Shigella dysentery in France and for cholera control in India. Phage therapy has also been applied against Staphylococcus skin infections. These findings have motivated interest in the Ganga as a source for isolating phages and developing novel antimicrobials. Nevertheless, the diversity, abundance, and ecological functions of bacteriophages in aquatic environments remain largely uncharacterized. Recent research has therefore focused on characterizing phage diversity to evaluate their potential as biological control agents [18]. The phage population caused a rapid decline in the host bacterial population, after which phage abundances decreased—likely reflecting intraspecific competition among phages. Subsequent evolution of bacterial resistance permitted host populations to rebound, a process that was associated with an increase in phage diversity [88]. Subsequent work showed that parasite (phage) diversity exerts rapid effects on host–parasite population dynamics and evolutionary trajectories by selecting for diverse resistance mutations, thereby modulating the magnitude and tempo of bacterial suppression and recovery [88]. Since then, phage therapy has been regarded as a significant therapeutic tool and the sole treatment for bacterial infections [89].

In 1915 d’Hérelle advanced the lysis hypothesis—accounting for the observed plaque (halo) phenomenon—and proposed therapeutic applications for phage preparations. By 1917, he had reported successful use of bacteriophages in treating dysentery in France and in controlling cholera outbreaks in India [90]. Phage therapy subsequently developed as a clinical practice. The G. Eliava Institute of Bacteriophages in Tbilisi, Georgia—established in 1933 by George Eliava, a former collaborator of d’Hérelle—became and remains a principal centre for phage research. Initially regarded as a potent and, in some contexts, the sole treatment for bacterial infections, phage therapy was largely abandoned internationally after World War II following the widespread adoption of antibiotics. Nevertheless, geopolitical factors and constrained antibiotic access in some Eastern Bloc countries sustained phage therapy programs there, enabling the continued operation of institutions such as the Eliava Institute into the present day [89]. Commercial production of bacteriophage preparations active against Staphylococcus spp., Streptococcus spp., Pseudomonas spp., Proteus spp., and Shigella spp. persisted until the mid‑1950s at the G. Eliava Institute of Bacteriophages, Microbiology and Virology (EIBMV) and at Poland’s Hirszfeld Institute of Immunology and Experimental Therapy (HIEET) [91]. The advent of antibiotics—with their broad‑spectrum antibacterial efficacy—and apprehensions regarding the therapeutic use of bacteriophages precipitated a decline in phage therapy’s widespread adoption. Nonetheless, phage‑based treatments for human conditions (including skin infections, wound prophylaxis, burns, respiratory infections, and sepsis) have been employed intermittently for close to nine decades [92].

Multidrug‑resistant pathogenic bacteria presently constitute a major scientific and public‑health challenge, imposing substantial socio‑economic burdens [89]. To address multidrug resistance, researchers are investigating alternative antimicrobial strategies. Promising approaches include the use of predatory bacteria (e.g., Bdellovibrio bacteriovorus, Micavibrio aeruginosavorus), antimicrobial peptides derived from amphibians and reptiles (such as frogs, alligators, and cobras), and metal‑based agents (notably copper and silver) [93]. Among the emerging alternatives, bacteriophages—viruses that specifically infect and lyse bacteria—are especially promising. In natural ecosystems, most bacterial taxa are associated with specific predatory phages capable, in many instances, of causing host population collapse, which positions these viruses as potential biological control agents [94].

Phage-Host Interaction

Upon infection, bacteriophage–host interactions can result in host cell lysis or in non‑lytic associations such as lysogeny or chronic infection. Lytic (virulent) phages introduce their genomes into the bacterial cytoplasm, replicate using host machinery, and subsequently lyse the cell to liberate progeny virions. Temperate (lysogenic) phages, after genome entry, may follow a lytic pathway or integrate their nucleic acid into the bacterial chromosome, replicating passively with the host without immediate production of virions [95]. An integrated phage genome is termed a prophage; in response to specific induction signals, the prophage can reactivate and enter the lytic cycle. In pseudo‑lysogeny, phage nucleic acid persists as an episome rather than integrating into the host chromosome. When environmental conditions become favourable, the phage may proceed to either lytic replication or establish lysogeny. This flexibility is thought to support phage persistence and survival during adverse growth conditions in natural habitats [96], [97] (Figure 2).

Diversity of Bacteriophages in River Ganga

Surveys of the Ganga have revealed representation from multiple bacteriophage families. Over the past five decades, more than 5,100 phage isolates have been described, with over 90% being tailed phages that are taxonomically assigned to the Myoviridae, Siphoviridae, and Podoviridae groups [80], [99], [100], [101]. Over 2,200 complete bacteriophage genomes are deposited in the NCBI Genome database. Viral taxonomy is overseen by the International Committee on Taxonomy of Viruses (ICTV), with bacteriophage-specific guidance provided by its Bacterial and Archaeal Subcommittee. Phage classification integrates multiple attributes, including genome architecture, particle morphology, host range, sequence homology, and pathogenic potential (see Table 7). To date, the ICTV recognizes 19 families within the order Caudovirales; among these, Myoviridae, Podoviridae, Siphoviridae, Microviridae, and Inoviridae are the most extensively characterized, while Herelleviridae and Ackermannviridae have been more recently delineated [102]. According to Behera et al [18], In the Ganga River, two sampling sites were identified: a polluted site (Kanpur) and a non-polluted site (Farakka). At the polluted Kanpur site, higher numbers of bacteriophages belonging to Mimiviridae, Phycodnaviridae, Iridoviridae, Marseilleviridae, Papillomaviridae, Retroviridae, Myoviridae, and Podoviridae were abundantly present. In contrast, at the non-polluted Farakka site, bacteriophage diversity included Poxviridae, Baculoviridae, Caulimoviridae, Adenoviridae, and Tectiviridae. Besides these site-specific phages, some phages were commonly identified at both locations: Asfarviridae, Circoviridae, Herpesviridae, Nimaviridae, Geminiviridae, Ascoviridae, Hepadnaviridae, Bicaudaviridae, Alloherpesviridae, Polyomaviridae, Reoviridae, Inoviridae, and Anelloviridae. The Ganga River showed higher concentrations of Microviridae and ssDNA viruses in polluted areas near Kanpur, while non-polluted sites like Farakka exhibited more Myoviridae. Currently, scientists are using bacteriophages in several research areas. Similarly, research on the river Ganga for bacteriophages by Samson et al [103], conducted from Haridwar to Bhagalpur across two seasons explored nearly ten phage diversities in the Ganga River. Mimiviridae, Siphoviridae, Myoviridae, Podoviridae, Herpesviridae, Phycodnaviridae, Pithoviridae, Marseilleviridae, and Poxviridae were abundantly identified. The potential benefits of using bacteriophages isolated from Ganga water as an alternative to antibiotic treatment in phage therapy have increased, as antibiotic resistance in bacteria has risen due to the widespread use of antibiotics for treating bacterial infections [86], [104]. Additionally, 40 percent of the bacteria in the Ganga showed resistance to semisynthetic drugs such as ampicillin and amoxicillin. The river Ganga was also examined for the presence of multi-drug resistant (MDR) bacteria, Amp-C traits, and ESBL (extended-spectrum beta-lactamase) bacteria [86], [105].

The bacteriophage diversity in the Ganga River is markedly greater than in other Indian rivers. For example, while the Ganga harbors approximately 1,100 types of bacteriophages, rivers like the Yamuna and Narmada show significantly fewer varieties, with fewer than 200 types reported. This vast diversity is essential for maintaining the ecological balance and health of the river’s microbial ecosystem. The predominance of bacteriophages in the Ganga suggests a natural mechanism for environmental regulation. These viruses help mitigate the impact of pathogenic bacteria, which is crucial for preserving the river’s health, particularly in areas heavily affected by industrial pollution and urban waste [106]. Thus, the diverse bacteriophage community helps maintain ecosystem balance, supporting water quality and reducing health risks for communities that depend on the river [18]. The Ganga River hosts a diverse array of bacteriophages, including notable families such as Microviridae, Myoviridae, Mimiviridae, and Retroviridae. This diversity is shaped by environmental conditions, pollution levels, and the unique microbial communities in the river, especially at both polluted and non-polluted sites.

The Mimiviridae family is also present in the Ganga, recognized for its large size and complex structure. Mimiviruses possess unique characteristics that distinguish them from typical bacteriophages, and their presence in the Ganga contributes to the ecological complexity of the river’s virome. Their ecological role includes interactions with various microbial hosts, which can shape community dynamics [18].

Bacteriophages as Indicators of Water Quality

Faecal indicator microorganisms are widely used to assess microbiological water quality because their occurrence signifies faecal pollution and the possible presence of enteric pathogens. Common faecal indicator bacteria (FIB) comprise total coliforms, faecal coliforms, Escherichia coli, streptococci, and enterococci [109]. Bacteriophages targeting enteric bacteria have been proposed as surrogate indicators of faecal and viral contamination. Relative to conventional bacterial indicators, these phages are often more abundant and more persistent in the environment, and they can better reflect risks associated with viral pathogens. Because they are excreted in faeces and generally do not replicate outside of metabolically active hosts, bacteriophages reliably signal recent faecal inputs. Moreover, phages that infect intestinal bacteria disperse and persist in the environment in ways analogous to human enteric viruses, so their occurrence and fate can serve as a proxy for viral contamination. Routine monitoring of every specific viral pathogen is neither practical nor cost‑effective—especially in low‑resource settings—so readily detectable bacteriophages have been adopted in many water‑quality guidelines as operational indicators of faecal and viral pollution [110], [111], [112].

6.1 Families of Bacteriophages Used as Indicators of Faecal Pollution

Bacteriophages infecting enteric bacteria are typically categorised into three taxonomically distinct groups: somatic coliphages, F‑specific (or male) coliphages, and phages that target Bacteroides spp. [110], [113]. Enterophages—phages that infect Enterococcus spp.—are less commonly used but represent promising indicator organisms because they are abundant in wastewater, exhibit survival characteristics comparable to enteric viruses, and display prevalence patterns that vary between human and animal gut microbiota [114], [115]. Somatic coliphages comprise a heterogeneous collection of phages that infect Escherichia coli and other coliforms by binding to receptors on the bacterial outer membrane and subsequently breaching the cell wall [116]. Under favorable physiological conditions, lysis typically follows ~30 minutes after adsorption, yielding on the order of 100 to 1,000 progeny virions per infected cell [117]. In contaminated wastewaters, four principals somatic coliphage families have been detected, with Myoviridae and Siphoviridae predominating, and Podoviridae and Microviridae occurring at lower abundances [118].

F‑specific bacteriophages constitute the second most prevalent group of indicator phages detected in environmental samples [119]. F‑specific bacteriophages infect Escherichia coli and other coliforms by binding to sex pili, which are encoded by the F plasmid and may be transferred among enteric bacteria via conjugation [120]. This group comprises two families: Leviviridae, single‑stranded RNA phages with isometric, tailless capsids of roughly 25 nm, and Inoviridae, single‑stranded DNA phages characterized by flexible, filamentous capsids about 800 nm in length [121]. The third proposed indicator group targets Bacteroides spp.; their abundances in feces and fecally contaminated matrices are generally lower than those of coliphages. Most members of this morphologically uniform group are Siphoviridae and infect host cells by binding to cell‑wall receptors [122], [123], [124].

Applications of Bacteriophages

7.1 Bacteriophages as Faecal Indicators in Water

Faecal indicator bacteria (FIB) are commonly employed to evaluate water microbiological quality, but they may not reliably predict the occurrence of enteric viruses. Enteric viruses typically exhibit greater resistance to wastewater and drinking‑water treatment processes and persist longer in environmental waters than bacterial indicators [125], [126], [127], [128], [129]. Thus, exclusive reliance on bacterial indicators may lead to underestimation of microbial contamination and associated public‑health risks. Incorporating at least one viral indicator yields a more representative appraisal of water quality and bolsters confidence in its safety. Coliphages originate primarily from human and animal feces and enter aquatic environments via untreated or treated wastewater discharges, septic‑tank overflows, sewer leaks, and the application or runoff of wastes such as sewage sludge, slurry, manure, and feces from pets, livestock, and wildlife [119]. Guelin’s 1948 study first highlighted coliphages as potential indicators of enteric contamination, reporting a strong correlation with coliform counts in both freshwater and marine environments. Since that work, numerous investigations have assessed bacteriophages as markers of faecal pollution across a variety of aquatic settings [109].

Wastewater treatment plants: Bacteriophages are useful indicators for assessing wastewater treatment performance because their removal by common treatment processes mirrors that of human enteric viruses, whereas conventional faecal indicator bacteria (FIB) are typically reduced to a much greater extent [111], [125], [130], [131], [132], [133]. Coliphage levels in wastewater do not exhibit clear seasonal variation and remain persistently high year‑round worldwide, mirroring the patterns observed for bacterial indicators [133], [134]. Coliphage concentrations in wastewater are highly variable; however, the generally lower abundance of F‑specific coliphages relative to somatic coliphages in both raw and treated effluents may constrain their applicability as wastewater indicators [135].

Drinking water: Detection of coliphages or phages infecting Bacteroides spp. in drinking‑water sources is indicative of faecal contamination or insufficient treatment [136]. Bacterial indicators, human viruses, and bacteriophages are generally present at low concentrations in drinking‑water sources and are infrequently detected after treatment. Limited studies that have evaluated phages for drinking‑water monitoring indicate they may be superior to conventional faecal indicator bacteria (FIB), because phages tend to be less effectively removed by common drinking‑water treatment processes [137], [138], [139], [140], [141].

Recreational water: The sanitary quality of recreational waters is assessed using faecal indicator bacteria (FIB) in accordance with EU Directive 2006/7/EC [142]; Alternative markers, including Clostridium perfringens and various bacteriophages, have likewise been suggested [143]. Somatic coliphages are detected in recreational water [143], and at beaches with unknown sources of faecal contamination, the presence of coliphages correlates more frequently with disease occurrence than the presence of faecal indicator bacteria (FIB) [144], [145]. Epidemiological studies have found that the presence of coliphages in recreational waters is associated with an elevated risk of gastrointestinal illness among swimmers when faecal contamination is likely, but not when it is absent. Correlations with illness were comparable between enterococci and somatic coliphages, and were stronger for F‑specific coliphages [146]. These findings indicate that coliphages may be suitable for application as indicators of bathing water quality.

Groundwater: Groundwater supplies a substantial fraction of water for domestic, municipal, agricultural, landscape‑irrigation, and industrial uses. Surface‑water contaminants can reach groundwater via pathways such as septic‑system failures, leaking sewer lines, and transport through soils and fractures. One study demonstrated that combining a bacterial indicator with a phage indicator yields more informative assessments of groundwater microbiological quality than relying on two bacterial indicators alone [128]. However, as summarized in Table 8, only a single regulation (dating from 2006) currently lists bacteriophages as indicators of enteric viral contamination in groundwater, underscoring the need for further research in this domain.

Abbreviations: WA = Western Australia; QLD = Queensland; QC = Quebec; NC = North Carolina; I&AR = Irrigation and Agricultural Reuse; UV = Ultraviolet Disinfection; – = No specific guideline or application reported
Footnote* Indicates that bacteriophage monitoring recommendations were incorporated through risk-based water safety frameworks or referenced from WHO guidance rather than established as standalone regulatory standards.

7.2 Bacteriophages as Faecal Indicators in Solid Matrices

Solid and semisolid matrices are important reservoirs for pathogen persistence and dissemination within the water cycle; when contaminated with faecal material they can concentrate large numbers of pathogens, particularly viruses[112], [147]. To maximize the utility of bacteriophages as indicators in solid matrices, standardized procedures for extraction, detection, and enumeration are required. Available studies generally report that somatic coliphages occur in solids at higher concentrations than conventional faecal indicator bacteria and F‑specific RNA coliphages, persist longer in soils and sediments, and are more resistant to treatments applied to sludge and manure. For a comprehensive review and additional data on solid matrices, consult the relevant literature [112].

Future Prospects

Future research on Ganga River bacteriophages should prioritize systematic, longitudinal mapping of phage diversity and abundance from Gaumukh to the Bay of Bengal across seasons, integrating culture-dependent isolation with high‑throughput metaviromics and parallel host community profiling. Particular emphasis is needed on phages infecting multidrug-resistant bacteria prevalent in the basin (for example ESBL‑producing Enterobacteriaceae, Pseudomonas and Acinetobacter), including characterization of their genomes, host range, and potential for horizontal gene transfer of resistance and virulence factors. Another priority is to evaluate somatic and F‑specific coliphages and Bacteroides phages as routine viral indicators within existing CPCB and NMCG monitoring frameworks, through coordinated pilot studies at major urban and pilgrimage centres such as Haridwar, Kanpur, Prayagraj, Varanasi and the Hooghly stretch. Finally, targeted exploration of glacier meltwater, permafrost and sediment at Himalayan source regions may reveal ancient or extremophile phage lineages, while experimental phage‑based biocontrol and bioremediation trials in controlled mesocosms could clarify both the promise and ecological risks of using Ganga‑derived phages for water quality management.

Conclusion

Bacteriophages constitute an integral yet underexplored component of the Ganga River ecosystem, tightly linked to the structure and dynamics of bacterial communities along its longitudinal and pollution gradients. Historical observations of the river’s self‑purifying properties and recent ecological and metagenomic studies together suggest that diverse phage assemblages contribute to microbial regulation, nutrient cycling and resilience under increasing anthropogenic stress. At the same time, intense inputs of sewage, industrial effluents, agricultural runoff and faecal contamination are reshaping both bacterial and phage populations, with important implications for the spread of antimicrobial resistance and water‑borne disease risks. Harnessing Ganga‑derived phages as tools for water‑quality monitoring, faecal pollution assessment, AMR control and targeted bioremediation will require coordinated efforts that combine basic virology, environmental microbiology, and public‑health surveillance. By integrating phage‑centric approaches into existing river management programmes, the ecological and biotechnological potential of Ganga bacteriophages can be translated into more effective and sustainable strategies for safeguarding this culturally and economically vital river system.

References

[1] K. Khairnar, ‘Ganges: Special at its origin’, 2016. doi: 10.1186/s40709-016-0055-6.

[2] T. L. Meiring, I. Marla Tuffin, C. Cary, and D. A. Cowan, ‘Genome sequence of temperate bacteriophage Psymv2 from Antarctic Dry Valley soil isolate Psychrobacter sp. MV2’, Extremophiles, vol. 16, no. 5, 2012, doi: 10.1007/s00792-012-0467-7.

[3] S. N. Sinha, D. Paul, and K. Biswas, ‘Effects of Moringa oleifera Lam. and Azadirachta indica A. Juss. leaf extract in treatment of tannery effluent’, Our Nature, vol. 14, no. 1, pp. 47–53, Jan. 2017, doi: 10.3126/on.v14i1.16440.

[4] D. M. Joshi, A. Kumar, and N. Agrawal, ‘Assessment of The Irrigation Water Quality of River Ganga in Haridwar District’, vol. 2, no. 2, pp. 285–292, 2009, [Online]. Available: http://www.rasayanjournal.com

[5] D. Paul, ‘Research on heavy metal pollution of river Ganga: A review’, Ann. Agrar. Sci., vol. 15, no. 2, pp. 278–286, Jun. 2017, doi: 10.1016/j.aasci.2017.04.001.

[6] S. Dwivedi, S. Mishra, and R. D. Tripathi, ‘Ganga water pollution: A potential health threat to inhabitants of Ganga basin’, Aug. 01, 2018, Elsevier Ltd. doi: 10.1016/j.envint.2018.05.015.

[7] M. Singh and A. K. Singh, ‘Bibliography of environmental studies in natural characteristics and anthropogenic influences on the Ganga River’, Environ. Monit. Assess., vol. 129, no. 1–3, pp. 421–432, Jun. 2007, doi: 10.1007/s10661-006-9374-7.

[8] S. Y. Zhang et al., ‘Intensive allochthonous inputs along the Ganges River and their effect on microbial community composition and dynamics’, Environ. Microbiol., vol. 21, no. 1, pp. 182–196, Jan. 2019, doi: 10.1111/1462-2920.14439.

[9] M. M. Rahaman, ‘Integrated Ganges basin management: Conflict and hope for regional development’, Water Policy, vol. 11, no. 2, pp. 168–190, 2009, doi: 10.2166/wp.2009.012.

[10] C. S. Nautiyal, ‘Scientific validation of incorruptible self-purificatory characteristic of Ganga Water’, Asian Agrihist., vol. 13, no. 1, 2009.

[11] C. S. Nautiyal, ‘Self-purificatory ganga water facilitates death of pathogenic escherichia coli O157:H7’, Curr. Microbiol., vol. 58, no. 1, pp. 25–29, Jan. 2009, doi: 10.1007/s00284-008-9260-3.

[12] B. Rai, ‘Pollution and Conservation of Ganga River in Modern India’, International Journal of Scientific and Research Publications, vol. 3, no. 4, 2013, [Online]. Available: www.ijsrp.org

[13] R. Bhutiani, D. R. Khanna, D. B. Kulkarni, and M. Ruhela, ‘Assessment of Ganga river ecosystem at Haridwar, Uttarakhand, India with reference to water quality indices’, Appl. Water Sci., vol. 6, no. 2, pp. 107–113, Jun. 2016, doi: 10.1007/s13201-014-0206-6.

[14] U. K. Sarkar et al., ‘Freshwater fish biodiversity in the River Ganga (India): Changing pattern, threats and conservation perspectives’, Rev. Fish Biol. Fish, vol. 22, no. 1, pp. 251–272, Mar. 2012, doi: 10.1007/s11160-011-9218-6.

[15] V. S. Baghel, K. Gopal, S. Dwivedi, and R. D. Tripathi, ‘Bacterial indicators of faecal contamination of the Gangetic river system right at its source’, Ecol. Indic., vol. 5, no. 1, pp. 49–56, Jan. 2005, doi: 10.1016/j.ecolind.2004.09.002.

[16] D. H. Duckworth, ‘“Who discovered bacteriophage?”’, Bacteriol. Rev., vol. 40, no. 4, 1976, doi: 10.1128/mmbr.40.4.793-802.1976.

[17] J. Rakonjac, N. J. Bennett, J. Spagnuolo, D. Gagic, and M. Russel, ‘Filamentous bacteriophage: biology, phage display and nanotechnology applications.’, 2011. doi: 10.21775/cimb.013.051.

[18] B. K. Behera et al., ‘Bacteriophages diversity in India’s major river Ganga: a repository to regulate pathogenic bacteria in the aquatic environment’, Environmental Science and Pollution Research, vol. 30, no. 12, pp. 34101–34114, Mar. 2023, doi: 10.1007/s11356-022-24637-7.

[19] Khan, F.A., Ansari, A.A. Eutrophication: An ecological vision. Bot. Rev 71, 449–482 (2005). https://doi.org/10.1663/0006-8101(2005)071[0449:EAEV]2.0.CO;2

[20] Sankar, N. Sinha, and D. Paul, ‘Impact of Sewage Water on Seed Germination and Vigour Index of Cicer Arietinum L. And Pisum Sativum L’, 2013. [Online]. Available: http://www.cibtech.org/jfav.htm

[21] S. T. Abedon, C. Thomas-Abedon, A. Thomas, and H. Mazure, ‘Bacteriophage prehistory: Is or is not Hankin, 1896, a phage reference?’, Bacteriophage, vol. 1, no. 3, 2011, doi: 10.4161/bact.1.3.16591.

[22] F. D’Herelle, ‘Sur un microbe invisible antagoniste des bacilles dysenteriques (An invisible microbe that is antagonistic to the dysentery bacillus).’, Comptes rendus Acad. Sciences, vol. 165, 1917.

[23] A. Dimri, C. Awasthi, S. Uniyal, A. Nautiyal, and K. P. Singh, ‘Isolation and Characterization of Coliform Bacteria and Bacteriophages from Ganga River in Northern Himalayan Regions’, Int. J. Curr. Microbiol. Appl. Sci., vol. 8, no. 11, pp. 1582–1592, Nov. 2019, doi: 10.20546/ijcmas.2019.811.183.

[24] S. Menon, S. Shrivastava, and Z. Bhathena, ‘Harnessing Potential of Phage Cocktail for Bacterial Reduction in Wastewater Treatment: A Pilot-Scale Demonstration of a Sustainable Approach’, Indian J. Microbiol., 2025, doi: 10.1007/s12088-025-01484-x.

[25] T. M. Nolan et al., ‘Bacteriophages from faecal contamination are an important reservoir for AMR in aquatic environments’, Science of the Total Environment, vol. 900, Nov. 2023, doi: 10.1016/j.scitotenv.2023.165490.

[26] C. R. Ramakrishnaiah, C. Sadashivaiah, and G. Ranganna, ‘Assessment of water quality index for the groundwater in Tumkur taluk, Karnataka state, India’, E-Journal of Chemistry, vol. 6, no. 2, pp. 523–530, 2009, doi: 10.1155/2009/757424.

[27] R. Jindal and C. Sharma, ‘Studies on water quality of Sutlej River around Ludhiana with reference to physicochemical parameters’, in Environmental Monitoring and Assessment, 2011. doi: 10.1007/s10661-010-1466-8.

[28] N. S. Bhandari and K. Nayal, ‘Correlation study on physico-chemical parameters and quality assessment of Kosi river water, Uttarakhand’, E-Journal of Chemistry, vol. 5, no. 2, 2008, doi: 10.1155/2008/140986.

[29] A. K. Panja et al., ‘Interaction of physico-chemical parameters with Shannon-Weaver Diversity Index based on phytoplankton diversity in coastal water of Diu, India’, Mar. Pollut. Bull., vol. 190, 2023, doi: 10.1016/j.marpolbul.2023.114839.

[30] A. Sood, P. Pandey, S. Bisht, S. Sharma, M. P. Gusain, and O. P. Gusain, ‘Assessment of bacterial diversity in the Gangetic river system of Uttarakhand, India’, 2010.

[31] A. Mishra and B. D. Tripathi, ‘Assessment of water quality of the Ganga river at Varanasi using Trophic Diatom and water quality indexes’, Journal of Environmental Hydrology, vol. 16, 2008.

[32] P. K. Rai, A. Mishra, and B. D. Tripathi, ‘Heavy metal and microbial pollution of the River Ganga: A case study of water quality at Varanasi’, Aquat. Ecosyst. Health Manag., vol. 13, no. 4, 2010, doi: 10.1080/14634988.2010.528739.

[33] B. Kumar Sing, S. Singh, V. Srivastava, and D. N. Shukla, ‘Diversity of Aquatic Fungi in Three Bank of Ganga River in Varanasi District of Uttar Pradesh’, Plant Pathol. J. (Faisalabad)., vol. 13, no. 3, 2014, doi: 10.3923/ppj.2014.200.202.

[34] N. S. Chauhan and M. Dhiman, ‘Assessment of Microbial Biodiversity of River Ganga at Haridwar and Rishikesh’ ‘IJSR-International Journal of Scientific Research, 2015, https://www.doi.org/10.36106/ijsr

[35] S. Narayan Sinha, ‘Density of Pollution Indicator Bacteria in Relation to Physicochemical Factors During Diel Cycle of River Ganga at Ichapore, West Bengal, India’, Frontiers in Environmental Microbiology, vol. 1, no. 1, 2015, doi: 10.11648/j.fem.20150101.12.

[36] R. Balagurunathan and T. Shanmugasundaram, ‘Microbial Biodiversity of Selected Major River Basins of India’, 2015. doi: 10.1007/978-3-319-13425-3_27.

[37] J. Basu, S. Datta, and L. Bagchi, ‘A Geographical and Microbiological Assessment of Ganga Water in and Around Dakhshineswar Area, West Bengal’, IOSR J. Environ. Sci. Toxicol. Food Technol., vol. 10, no. 09, pp. 19–25, Sep. 2016, doi: 10.9790/2402-1009021925.

[38] Niveshika, S. Singh, E. Verma, and A. K. Mishra, ‘Isolation, characterization and molecular phylogeny of multiple metal tolerant and antibiotics resistant bacterial isolates from river Ganga, Varanasi, India’, Cogent Environ. Sci., vol. 2, no. 1, 2016, doi: 10.1080/23311843.2016.1273750.

[39] D. Vats, ‘Microbiological Characteristics of River Ganga In Between Khankhal to Bhogpur’, International Journal of Advance Research, Ideas and Innovations in Technology., vol., 3 issue 5., 2017. [Online]. Available: https://s3.ap-southeast-1.wasabisys.com/ijmanuscripts/manuscripts/v3i5/V3I5-1160.pdf

[40] R. Kumar, S. Bisht, R. C. Sharma, and S. Rawat, ‘Physico–chemical attributes and bacterial diversity of river water at Rudraprayag, Garhwal Himalaya’, MOJ Ecology & Environmental Sciences, vol. 3, no. 4, 2018, doi: 10.15406/mojes.2018.03.00100.

[41] B. K. Behera et al., ‘Metagenomic Analysis Reveals Bacterial and Fungal Diversity and Their Bioremediation Potential from Sediments of River Ganga and Yamuna in India’, Front. Microbiol., vol. 11, 2020, doi: 10.3389/fmicb.2020.556136.

[42] R. Kumar and R. C. Sharma, ‘Psychrophilic Microbial Diversity and Physicochemical Characteristics of Glaciers in The Garhwal Himalaya, India’, Journal of Microbiology, Biotechnology and Food Sciences, vol. 10, no. 5, pp. 1–6, Apr. 2021, doi: 10.15414/jmbfs.2096.

[43] A. Srivastava and D. Verma, ‘Ganga River sediments of India predominate with aerobic and chemo-heterotrophic bacteria majorly engaged in the degradation of xenobiotic compounds’, Environmental Science and Pollution Research, vol. 30, no. 1, pp. 752–772, Jan. 2023, doi: 10.1007/s11356-022-22198-3.

[44] D. Prakash, C. B. Tiwary, and R. Kumar, ‘Ecosystem Variability along the Estuarine Salinity Gradient: A Case Study of Hooghly River Estuary, West Bengal, India’, J. Mar. Sci. Eng., vol. 11, no. 1, Jan. 2023, doi: 10.3390/jmse11010088.

[45] A. Ghosh, Yash, C. Kumar, and P. Bhadury, ‘Metagenomic insights into the functional microbial diversity of the lower stretch of the River Ganga: mapping antibiotic and metal resistance genes’, Environ. Res. Commun., vol. 5, no. 9, Sep. 2023, doi: 10.1088/2515-7620/acddbc.

[46] N. Choudhury, T. K. Sahu, A. R. Rao, A. K. Rout, and B. K. Behera, ‘An Improved Machine Learning-Based Approach to Assess the Microbial Diversity in Major North Indian River Ecosystems’, Genes (Basel)., vol. 14, no. 5, May 2023, doi: 10.3390/genes14051082.

[47] A. K. Rout et al., ‘Metagenomics analysis of sediments of river Ganga, India for bacterial diversity, functional genomics, antibiotic resistant genes and virulence factors’, Curr. Res. Biotechnol., vol. 7, Jan. 2024, doi: 10.1016/j.crbiot.2024.100187.

[48] A. Katara, S. Chand, H. Chaudhary, H. Chandra, and R. C. Dubey, ‘Microbial diversity of river Ganga at Haridwar (Uttarakhand) through metagenomic approaches’, J. Appl. Biol. Biotechnol., vol. 12, no. 2, pp. 295–303, Mar. 2024, doi: 10.7324/JABB.2024.171556.

[49] A. Srivastava and D. Verma, ‘Diversity, antibiotic resistance, and biofilm profiling of the inhabitant bacteria of the Ganga River of India’, Microbe (Netherlands), vol. 7, 2025, doi: 10.1016/j.microb.2025.100404.

[50] N. Verma, N. Chavan, K. S. Aulakh, A. Sharma, Y. Shouche, and V. V. Ramana, ‘Temporal Dynamics of Microbial Community Composition and Antimicrobial Resistance in a Mass Gathering Setting Using Culturomics and Metagenomic Approaches’, J. Epidemiol. Glob. Health, vol. 15, no. 1, Dec. 2025, doi: 10.1007/s44197-025-00382-1.

[51] R. Samson, S. Kumar, S. Dastager, K. Khairnar, and M. Dharne, ‘Deciphering the comprehensive microbiome of glacier-fed Ganges and functional aspects: implications for one health’, Microbiol. Spectr., vol. 13, no. 8, Aug. 2025, doi: 10.1128/spectrum.01720-24.

[52] S. Vani, S. Shukla, S. Swati, A. Sheershwal, and B. Trivedi, ‘Isolation and Diversity Analysis of Heavy Metal-Tolerant Bacteria from Ganga River Across Seasonal Gradients’, Nov. 10, 2025. doi: 10.21203/rs.3.rs-7921720/v1.

[53] M. Vega, R. Pardo, E. Barrado, and L. Debán, ‘Assessment of seasonal and polluting effects on the quality of river water by exploratory data analysis’, Water Res., vol. 32, no. 12, 1998, doi: 10.1016/S0043-1354(98)00138-9.

[54] A. Chauhan and S. Singh, ‘Evaluation of Ganga water for drinking purpose by water quality index At Rishikesh, Uttarakhand, India’, Report and Opinion, vol. 2, no. 9, 2010.

[55] V. Dutta, D. Dubey, and S. Kumar, ‘Cleaning the River Ganga: Impact of lockdown on water quality and future implications on river rejuvenation strategies’, Science of the Total Environment, vol. 743, Nov. 2020, doi: 10.1016/j.scitotenv.2020.140756.

[56] NMCG, ‘Pollution Threat’. Accessed: May 14, 2026. [Online]. Available: https://nmcg.nic.in/pollution.aspx

[57] National Mission For Clean Ganga, ‘NMCG’, Dec. 2025. Accessed: May 14, 2026. [Online].Available:https://sansad.in/getFile/loksabhaquestions/annex/186/AU879_7nFWL2.pdf?source=pqals

[58] S. Pandey, and L. Prasad, ‘Pollution impact on Ganga river and fisheries’, Veterinary Science & Technology, vol. s1, no. 01, 2014.

[59] R. C. Trivedi, ‘Water quality of the Ganga River – An overview’, Aquat. Ecosyst. Health Manag., vol. 13, no. 4, 2010, doi: 10.1080/14634988.2010.528740.

[60] A. Agrawal, R. S. Pandey, and B. Sharma, ‘Water Pollution with Special Reference to Pesticide Contamination in India’, J. Water Resour. Prot., vol. 02, no. 05, 2010, doi: 10.4236/jwarp.2010.25050.

[61] D. K. Pal, T. Bhattacharyya, P. Srivastava, P. Chandran, and S. K. Ray, ‘Soils of the Indo-Gangetic Plains: Their historical perspective and management’, 2009.

[62] A. A. Reddy, M. Reddy, and V. Mathur, ‘Pesticide Use, Regulation, and Policies in Indian Agriculture’, Sustainability (Switzerland), vol. 16, no. 17, 2024, doi: 10.3390/su16177839.

[63] U. Kashyap, S. Garg, and P. Arora, ‘Pesticide pollution in India: Environmental and health risks, and policy challenges’, Toxicol. Rep., vol. 13, 2024, doi: 10.1016/j.toxrep.2024.101801.

[64] Z. U. Shah and S. Parveen, ‘Pesticides pollution and risk assessment of river Ganga: A review’, 2021. doi: 10.1016/j.heliyon.2021.e07726.

[65] S. Takatori et al., ‘A rapid and easy multiresidue method for the determination of pesticide residues in vegetables, fruits, and cereals using liquid chromatography/tandem mass spectrometry’, J. AOAC Int., vol. 91, no. 4, 2008, doi: 10.1093/jaoac/91.4.871.

[66] P. Carriquiriborde, P. Mirabella, A. Waichman, K. Solomon, P. J. Van den Brink, and S. Maund, ‘Aquatic risk assessment of pesticides in Latin America’, Integr. Environ. Assess. Manag., vol. 10, no. 4, 2014, doi: 10.1002/ieam.1561.

[67] C. Bhushan, A. Bhardwaj, and S. S. Misra, ‘State of Pesticide Regulations in India’, Centre for Science and Environment, JSTOR, no. 2013, 2013.

[68] B. Kumari, V. K. Madan, and T. S. Kathpal, ‘Pesticide residues in rain water from Hisar, India’, Environ. Monit. Assess., vol. 133, no. 1–3, 2007, doi: 10.1007/s10661-006-9601-2.

[69] M. Sakai, ‘Determination of pesticides and chronic test with Daphnia magna for rainwater samples’, J. Environ. Sci. Health B, vol. 37, no. 3, 2002, doi: 10.1081/PFC-120003102.

[70] NMCG 2016, ‘Cultural-Religious Aspects of Ganga Basin GRBMP: Ganga River Basin Management Plan Indian Institutes of Technology’. [Online]. Available: https://nmcg.nic.in/writereaddata/fileupload/14_culturalrelegiousaspects.pdf

[71] M. Bahuguna, ‘Harnessing Geospatial Technologies for Strategic Planning of Maha Kumbh Mela, Haridwar’, Int. J. Eng. Res. Appl., vol. 15, no. 6, 2025, doi: 10.9790/9622-15068290.

[72] Prakash S. Mahakumbh 2025: Balancing Spirituality, Sustainability, And the Sacred Rivers of India. Shodh Sarita. 2025;

[73] S. Tiwari, R. M. Jindal, and D. Mavalankar, ‘John Snow and the contaminated water of River Ganga at Kumbh Mela in India’, Int. Health, Mar. 2025, doi: 10.1093/inthealth/ihaf081.

[74] M. Mishra, K. Ahuja, and R. Rawat, ‘Assessment of Physicochemical, Heavy Metal, and Microbial Contamination in the Ganga River at Prayagraj Across Maha Kumbh Phases’, SSR Institute of International Journal of Life Sciences, vol. 11, no. 5, pp. 8320–8326, Sep. 2025, doi: 10.21276/ssr-iijls.2025.11.5.18.

[75] J. Das, ‘Impact of Durga Puja on River Ganga’, International Journal of Agriculture & Environmental Science, vol. 10, no. 3, 2023, doi: 10.14445/23942568/ijaes-v10i3p102.

[76] J. Lal, ‘Heavy Metal Pollution by Immersion of Idols: The Indian Scenario’, Journal of Water Resource Engineering & Pollution Studies, 2021.

[77] K. Das, B. Makal, R. Chakraborty, K. Bandyopadhyay, and P. P. Biswas, ‘Impact of Idol Immersion on the Water Quality of the Hooghly River and Review on the Use of Nanomembrane for Water Treatment in a Cost-Effective Manner’, 2025. doi: 10.1061/9780784485699.006.

[78] D. Khwairakpam, N. Kumar, K. Srivastava, ‘Environment Impact of Cremation Activities in Manikarnika Ghat, Varanasi, Uttar Pradesh’, International Journal for Scientific Research & Development, Vol. 6, Issue 04., 2018.

[79] K. Khairnar, ‘Ganges: Special at its origin’, 2016, BioMed Central Ltd. doi: 10.1186/s40709-016-0055-6.

[80] H. W. Ackermann, ‘5500 Phages examined in the electron microscope’, Feb. 2007. doi: 10.1007/s00705-006-0849-1.

[81] B. K. Behera et al., ‘Bacteriophages diversity in India’s major river Ganga: a repository to regulate pathogenic bacteria in the aquatic environment’, Environmental Science and Pollution Research, vol. 30, no. 12, 2023, doi: 10.1007/s11356-022-24637-7.

[82] Somrita Ghosh, ‘The Ganga bacteriophages could help against infection’, The Times of India. Available: The Ganga Bacteriophages could help against infection | Delhi News – Times of India

[83] Kalyan Ray, ‘Scientists take a deep dive to get to the bottom of Ganga mystery’, Deccan Herald. Available: Scientists take a deep dive to get to the bottom of Ganga mystery

[84] B. K. Behera et al., ‘Bacteriophages diversity in India’s major river Ganga: a repository to regulate pathogenic bacteria in the aquatic environment’, Environmental Science and Pollution Research, vol. 30, no. 12, pp. 34101–34114, Mar. 2023, doi: 10.1007/s11356-022-24637-7.

[85] L. K. Harada et al., ‘Biotechnological applications of bacteriophages: State of the art’, Jul. 01, 2018, Elsevier GmbH. doi: 10.1016/j.micres.2018.04.007.

[86] A. Kumar et al., ‘Bacteriophage Therapy in Hospitals: Unveiling the Potential of River Ganga Bacteriophages’, vol. 31, no. 02, pp. 175–184, 2024, doi: 10.53555/jptcp.v31i2.4322.

[87] H. E. White and E. V. Orlova, ‘Bacteriophages: Their Structural Organisation and Function’, in Bacteriophages – Perspectives and Future, IntechOpen, 2020. doi: 10.5772/intechopen.85484.

[88] A. Betts, D. R. Gifford, R. C. Maclean, and K. C. King, ‘Parasite diversity drives rapid host dynamics and evolution of resistance in a bacteria-phage system’, Evolution (N. Y)., vol. 70, no. 5, pp. 969–978, May 2016, doi: 10.1111/evo.12909.

[89] P. Domingo-Calap, P. Georgel, and S. Bahram, ‘Back to the future: Bacteriophages as promising therapeutic tools’, Mar. 01, 2016, Blackwell Publishing Ltd. doi: 10.1111/tan.12742.

[90] N. Chanishvili, ‘Phage Therapy-History from Twort and d’Herelle Through Soviet Experience to Current Approaches’, in Advances in Virus Research, vol. 83, Academic Press Inc., 2012, pp. 3–40. doi: 10.1016/B978-0-12-394438-2.00001-3.

[91] A. Sulakvelidze, Z. Alavidze, and J. Morris, ‘Bacteriophage therapy’, 2001. doi: 10.1128/AAC.45.3.649-659.2001.

[92] S. T. Abedon, S. J. Kuhl, B. G. Blasdel, and E. M. Kutter, ‘Phage treatment of human infections’, Bacteriophage, vol. 1, no. 2, pp. 66–85, Mar. 2011, doi: 10.4161/bact.1.2.15845.

[93] ‘Old dogma, new tricks-21st Century phage therapy’, 2004. doi: https://doi.org/10.1038/nbt0104-31.

[94] S. Reardon 2015, ‘Antibiotic alternatives rev up bacterial arms race’. Nature 521, 402–403, doi: https://doi.org/10.1038/521402a.

[95] L. Zeng, S. O. Skinner, C. Zong, J. Sippy, M. Feiss, and I. Golding, ‘Decision Making at a Subcellular Level Determines the Outcome of Bacteriophage Infection’, Cell, vol. 141, no. 4, pp. 682–691, 2010, doi: 10.1016/j.cell.2010.03.034.

[96] M. Łoś and G. Wegrzyn, ‘Pseudolysogeny’, in Advances in Virus Research, vol. 82, Academic Press Inc., 2012, pp. 339–349. doi: 10.1016/B978-0-12-394621-8.00019-4.

[97] W. Cenens, A. Makumi, S. K. Govers, R. Lavigne, and A. Aertsen, ‘Viral Transmission Dynamics at Single-Cell Resolution Reveal Transiently Immune Subpopulations Caused by a Carrier State Association’, PLoS Genet., vol. 11, no. 12, 2015, doi: 10.1371/journal.pgen.1005770.

[98] P. Singh and R. Singh, ‘Bacteriophage Therapy as a Next Generation Solution for Treating Drug Resistant Bacterial Infections’, Microbiology Archives, an International Journal, vol. 5, no. 2, 2023, doi: 10.51470/ma.2023.5.2.21.

[99] X. Wittebole, S. De Roock, and S. M. Opal, ‘A historical overview of bacteriophage therapy as an alternative to antibiotics for the treatment of bacterial pathogens’, 2014, Taylor and Francis Inc. doi: 10.4161/viru.25991.

[100] G. W. Hanlon, ‘Bacteriophages: an appraisal of their role in the treatment of bacterial infections’, Aug. 2007. doi: 10.1016/j.ijantimicag.2007.04.006.

[101] K. Dabrowska, K. Switała-Jelen, A. Opolski, B. Weber-Dabrowska, and A. Gorski, ‘A review: Bacteriophage penetration in vertebrates’, 2005, Blackwell Publishing Ltd. doi: 10.1111/j.1365-2672.2004.02422.x.

[102] C. Sieiro et al., ‘A hundred years of bacteriophages: Can phages replace antibiotics in agriculture and aquaculture?’, Aug. 01, 2020, MDPI AG. doi: 10.3390/antibiotics9080493.

[103] R. Samson et al., ‘Spatio-temporal variation of the microbiome and resistome repertoire along an anthropogenically dynamic segment of the Ganges River, India’, Science of the Total Environment, vol. 872, 2023, doi: 10.1016/j.scitotenv.2023.162125.

[104] B. Tarsillo and R. Priefer, ‘Proteobiotics as a new antimicrobial therapy’, May 01, 2020, Academic Press. doi: 10.1016/j.micpath.2020.104093.

[105] S. Sharma et al., ‘Bacteriophages and its applications: an overview’, Jan. 01, 2017, Springer Netherlands. doi: 10.1007/s12223-016-0471-x.

[106] Jacob Koshy, ‘Ganga has higher proportion of antibacterial agents: study’, The Hindu. Available at: Ganga has higher proportion of antibacterial agents: study – The Hindu

[107] E. M. Adriaenssens et al., ‘ICTV Virus Taxonomy Profile: Duplodnaviria 2025’, Journal of General Virology, vol. 106, no. 9, 2025, doi: 10.1099/jgv.0.002139.

[108] Y. Zhou, Y. Wang, and M. Krupovic, ‘ICTV Virus Taxonomy Profile: Aoguangviridae 2023’, Journal of General Virology, vol. 104, no. 11, 2023, doi: 10.1099/jgv.0.001922.

[109] D. Toribio-Avedillo, A. R. Blanch, M. Muniesa, and L. Rodríguez-Rubio, ‘Bacteriophages as fecal pollution indicators’, Jun. 01, 2021, MDPI AG. doi: 10.3390/v13061089.

[110] J. Jofre, ‘Is the replication of somatic coliphages in water environments significant?’, 2009. doi: 10.1111/j.1365-2672.2008.03957.x.

[111] B. R. McMinn, N. J. Ashbolt, and A. Korajkic, ‘Bacteriophages as indicators of faecal pollution and enteric virus removal’, Jul. 01, 2017. doi: 10.1111/lam.12736.

[112] J. Martín-Díaz, F. Lucena, A. R. Blanch, and J. Jofre, ‘Review: Indicator bacteriophages in sludge, biosolids, sediments and soils’, 2020. doi: 10.1016/j.envres.2020.109133.

[113] S. Jebri, M. Muniesa, and J. Jofre, ‘General and host-associated bacteriophage indicators of faecal pollution’, in Water and Sanitation for the 21st Century: Health and Microbiological Aspects of Excreta and Wastewater Management (Global Water Pathogen Project), 2019. doi: 10.14321/waterpathogens.7.

[114] T. M. Santiago-Rodriguez, P. Marcos, S. Monteiro, M. Urdaneta, R. Santos, and G. A. Toranzos, ‘Evaluation of Enterococcus-infecting phages as indices of fecal pollution’, J. Water Health, vol. 11, no. 1, 2013, doi: 10.2166/wh.2012.100.

[115] N. Bonilla, T. Santiago, P. Marcos, M. Urdaneta, J. Santo Domingo, and G. A. Toranzos, ‘Enterophages, a group of phages infecting Enterococcus faecalis, and their potential as alternate indicators of human faecal contamination’, Water Science and Technology, vol. 61, no. 2, 2010, doi: 10.2166/wst.2010.815.

[116] M. Muniesa, L. Mocé-Llivina, H. Katayama, and J. Jofre, ‘Bacterial host strains that support replication of somatic coliphages’, Antonie van Leeuwenhoek, International Journal of General and Molecular Microbiology, vol. 83, no. 4, 2003, doi: 10.1023/A:1023384714481.

[117] A. Bosch, ‘Human viruses in water: perspectives in medical virology’, Elsevier, vol. 17, no. January 2010, 2007.

[118] M. Muniesa, F. Lucena, and J. Jofre, ‘Study of the potential relationship between the morphology of infectious somatic coliphages and their persistence in the environment’, J. Appl. Microbiol., vol. 87, no. 3, 1999, doi: 10.1046/j.1365-2672.1999.00833.x.

[119] J. Jofre, F. Lucena, A. R. Blanch, and M. Muniesa, ‘Coliphages as model organisms in the characterization and management of water resources’, 2016. doi: 10.3390/w8050199.

[120] J. E. Davis, ‘Bacteriophage MS2. Another RNA phage’, Science (1979)., vol. 134, no. 3, 1961.

[121] C. M. Fauquet and D. Fargette, ‘International Committee on Taxonomy of Viruses and the 3,142 unassigned species’, 2005. doi: 10.1186/1743-422X-2-64.

[122] M. R. McLaughlin and J. B. Rose, ‘Application of Bacteroides fragilis phage as an alternative indicator of sewage pollution in Tampa Bay, Florida’, Estuaries and Coasts, vol. 29, no. 2, 2006, doi: 10.1007/BF02781993.

[123] N. Queralt, J. Jofre, R. Araujo, and M. Muniesa, ‘Homogeneity of the morphological groups of bacteriophages infecting Bacteroides fragilis strain HSP40 and strain RYC2056’, Curr. Microbiol., vol. 46, no. 3, 2003, doi: 10.1007/s00284-002-3813-7.

[124] J. Jofre, A. R. Blanch, F. Lucena, and M. Muniesa, ‘Bacteriophages infecting Bacteroides as a marker for microbial source tracking’, 2014. doi: 10.1016/j.watres.2014.02.006.

[125] F. Lucena et al., ‘Reduction of bacterial indicators and bacteriophages infecting faecal bacteria in primary and secondary wastewater treatments’, J. Appl. Microbiol., vol. 97, no. 5, 2004, doi: 10.1111/j.1365-2672.2004.02397.x.

[126] A. Korajkic, B. R. McMinn, and V. J. Harwood, ‘Relationships between microbial indicators and pathogens in recreational water settings’, 2018. doi: 10.3390/ijerph15122842.

[127] N. Contreras-Coll et al., ‘Occurrence and levels of indicator bacteriophages in bathing waters throughout Europe’, Water Res., vol. 36, no. 20, 2002, doi: 10.1016/S0043-1354(02)00229-4.

[128] F. Lucena et al., ‘Occurrence of bacterial indicators and bacteriophages infecting enteric bacteria in groundwater in different geographical areas’, J. Appl. Microbiol., vol. 101, no. 1, 2006, doi: 10.1111/j.1365-2672.2006.02907.x.

[129] J. J. Borrego, R. Córnax, M. A. Moriñigo, E. Martínez-Manzanares, and P. Romero, ‘Coliphages as an indicator of faecal pollution in water. their survival and productive infectivity in natural aquatic environments’, Water Res., vol. 24, no. 1, 1990, doi: 10.1016/0043-1354(90)90072-E.

[130] J. Rose, ‘Reduction of Pathogens, Indicator Bacteria, and Alternative Indicators by Wastewater Treatment and Reclamation Processes’, Water Intelligence Online, vol. 4, no. 0, 2015, doi: 10.2166/9781780404370.

[131] F. Lucena and J. Jofre, ‘Potential use of bacteriophages as indicators of water quality and wastewater treatment processes’, in Bacteriophages in the Control of Food- and Waterborne Pathogens, 2014. doi: 10.1128/9781555816629.ch6.

[132] M. Yahya, F. Hmaied, S. Jebri, J. Jofre, and M. Hamdi, ‘Bacteriophages as indicators of human and animal faecal contamination in raw and treated wastewaters from Tunisia’, J. Appl. Microbiol., vol. 118, no. 5, 2015, doi: 10.1111/jam.12774.

[133] E. Dias, J. Ebdon, and H. Taylor, ‘The application of bacteriophages as novel indicators of viral pathogens in wastewater treatment systems’, Water Res., vol. 129, 2018, doi: 10.1016/j.watres.2017.11.022.

[134] J. Jofre, F. Lucena, and A. R. Blanch, ‘Coliphages as a complementary tool to improve the management of urban wastewater treatments and minimize health risks in receiving waters’, 2021. doi: 10.3390/w13081110.

[135] W. O. K. Grabow, ‘Bacteriophages: Update on application as models for viruses in water’, Water SA, vol. 27, no. 2, 2001, doi: 10.4314/wsa.v27i2.4999.

[136] R. Armon and Y. Kott, ‘Distribution comparison between coliphages and phages of anaerobic bacteria (Bacteroides fragilis) in water sources, and their reliability as fecal pollution indicators in drinking water’, Water Science and Technology, vol. 31, no. 5–6, 1995, doi: 10.1016/0273-1223(95)00269-S.

[137] J. Méndez et al., ‘Assessment of drinking water quality using indicator bacteria and bacteriophages’, J. Water Health, vol. 2, no. 3, 2004, doi: 10.2166/wh.2004.0018.

[138] R. Armon, ‘Bacteriophage monitoring in drinking water: Do they fulfil the index or indicator function?’, in Water Science and Technology, 1993. doi: 10.2166/wst.1993.0393.

[139] J. Heffron, B. McDermid, E. Maher, P. J. McNamara, and B. K. Mayer, ‘Mechanisms of virus mitigation and suitability of bacteriophages as surrogates in drinking water treatment by iron electrocoagulation’, Water Res., vol. 163, 2019, doi: 10.1016/j.watres.2019.114877.

[140] M. Abbaszadegan, P. Monteiro, N. Nwachuku, A. Alum, and H. Ryu, ‘Removal of adenovirus, calicivirus, and bacteriophages by conventional drinking water treatment’, J. Environ. Sci. Health A Tox. Hazard. Subst. Environ. Eng., vol. 43, no. 2, 2008, doi: 10.1080/10934520701781541.

[141] J. Jofre, E. Olle, F. Ribas, A. Vidal, and F. Lucena, ‘Potential usefulness of bacteriophages that infect Bacteroides fragilis as model organisms for monitoring virus removal in drinking water treatment plants’, Appl. Environ. Microbiol., vol. 61, no. 9, 1995, doi: 10.1128/aem.61.9.3227-3231.1995.

[142] C. Decision, ‘Directive 2006/7/EC of the European Parliament and of the Council of 15 February 2006 concerning the management of bathing water quality and repealing Directive 76/160/EEC’, Official Journal of the European Union, vol. L 064, no. 1882, 2006.

[143] L. Bonadonna et al., ‘Enteric viruses, somatic coliphages and Vibrio species in marine bathing and non-bathing waters in Italy’, Mar. Pollut. Bull., vol. 149, 2019, doi: 10.1016/j.marpolbul.2019.110570.

[144] J. M. Colford et al., ‘Water quality indicators and the risk of illness at beaches with nonpoint sources of fecal contamination’, Epidemiology, vol. 18, no. 1, 2007, doi: 10.1097/01.ede.0000249425.32990.b9.

[145] A. M. Abdelzaher et al., ‘Daily measures of microbes and human health at a non-point source marine beach’, J. Water Health, vol. 9, no. 3, 2011, doi: 10.2166/wh.2011.146.

[146] J. Benjamin-Chung et al., ‘Coliphages and Gastrointestinal Illness in Recreational Waters: Pooled Analysis of Six Coastal Beach Cohorts’, Epidemiology, vol. 28, no. 5, 2017, doi: 10.1097/EDE.0000000000000681.

[147] C. Guzmán, J. Jofre, M. Montemayor, and F. Lucena, ‘Occurrence and levels of indicators and selected pathogens in different sludges and biosolids’, J. Appl. Microbiol., vol. 103, no. 6, 2007, doi: 10.1111/j.1365-2672.2007.03487.x.

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