Evaluation of Bacteroides fragilis Bacteriophages as Indicators of the Virological Quality of Water

Jofre, Juan; Bosch, Anna; Lucena, F.; Gironés, R.; Tartera, Carmen

doi:10.2166/wst.1986.0126

Cited by 87 publications

(53 citation statements)

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“…In contrast to coliform bacteria and many other commonly used bacterial indicators of water quality (Grabow, 1996), Bacteroides bacteria themselves have limited value as indicators because they are Gram-negative bacteria which produce no spores, and they are rapidly inactivated by environmental oxygen levels. However, the phages of Bacteroides bacteria are resistant to unfavourable conditions and may, therefore, prove to be valuable indicators (Tartera and Jofre, 1987;Tartera et al, 1988;Jofre et al, 1986Jofre et al, , 1995. Even when using B. fragilis indicator strains with a relatively broad phage susceptibility, the percentage of individuals in human populations which excrete these phages has been reported to be only 5% (Kai et al, 1985) to 10% (Tartera and Jofre, 1987).…”

Section: Bacteroides Fragilis Phagesmentioning

confidence: 99%

Bacteriophages: update on application as models for viruses in water

Grabow¹

2004

WSA

184

230

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Phages are valuable models or surrogates for enteric viruses because they share many fundamental properties and features. Among these are structure, composition, morphology, size and site of replication. Even though they use different host cells, coliphages and Bacteroides fragilis phages predominantly replicate in the gastro-intestinal tract of humans and warm-blooded animals where enteric viruses also replicate. A major advantage of phages is that, compared to viruses, they are detectable by simple, inexpensive and rapid techniques. In view of these features, phages are particularly useful as models to assess the behaviour and survival of enteric viruses in the environment, and as surrogates to assess the resistance of human viruses to water treatment and disinfection processes. Since there is no direct correlation between numbers of phages and viruses, phages cannot to a meaningful extent be used to indicate numbers of viruses in polluted water. The presence of phages typically associated with human and animal excreta indicates the potential presence of enteric viruses. However, the absence of these phages from water environments is generally a meaningful indication of the absence of enteric viruses. This is because phages such as somatic coliphages, F-RNA coliphages and B. fragilis phages generally outnumber enteric viruses in water environments, and they are at least as resistant to unfavourable conditions including those in water treatment and disinfection processes. However, using highly sensitive molecular techniques viruses have been detected in drinking water supplies which yielded negative results in conventional tests for phages. Initially, data on phages were rather confusing because a wide variety of techniques was used. However, techniques for the detection of phages are being standardised internationally. This applies in particular to somatic and F-RNA coliphages, and B. fragilis phages, which are most commonly used in water quality assessment. Reliable and practical techniques now available include direct quantitative plaque assays on samples of water up to 100 ml, and qualitative tests on 500 ml or more using highly sensitive enrichment procedures.

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Section: Bacteroides Fragilis Phagesmentioning

confidence: 99%

Bacteriophages: update on application as models for viruses in water

Grabow¹

2004

WSA

184

230

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“…Havelaar & Nieuwstad (1985) have also demonstrated that very high doses of chlorine are required to reduce concentrations of F male-specific phages. Phages of the anaerobic bacterium Bacteroides fragilis also show promise as indicators, because they appear to be specific to human faeces and to be more closely correlated than coliphages with counts of both enteroviruses and rotaviruses (Jofre et al 1986). These and other studies of bacteriophages as faecal indicators have been reviewed by IAWPRC (1991).…”

Section: Alternatives To Faecal Streptococcimentioning

confidence: 99%

Faecal streptococci as faecal pollution indicators: A review. Part II: Sanitary significance, survival, and use

Sinton

Donnison²,

Hastie

1993

New Zealand Journal of Marine and Freshwater Research

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Some New Zealand regional councils are examining the use of faecal streptococci (or the subset, enterococci) to assist in identifying pollution sources, or as better indicators of disease risk in bathing waters than faecal coliforms. However, in spite of worldwide investigation, faecal streptococci have largely failed to fulfil their potential as pollution source (human versus animal) indicators in receiving waters. Many qualifications accompany the use of faecal coliform : faecal streptococci (FC : FS) ratios, and the species identification approach (using biochemical and DNA-based methods) has produced inconclusive results. Nevertheless, the FC : FS shift method (in which the ratio changes under sample storage) may M92025 Received 6 May 1992 ; accepted 18 January 1993 warrant further investigation. Although reported results vary widely, most studies indicate that faecal streptococci outlive faecal coliforms in receiving waters and are more resistant to sunlight-induced inactivation. USEPA epidemiological studies showed that enterococcus concentrations were better correlated than faecal conform concentrations with disease risk associated with bathing in sewage-polluted waters. These results, which implied that the enterococci better represented viral hazard, led the USEPA to recommend the use of enterococci (or Escherichia coli in freshwaters) as bathing water quality indicators. These recommendations have largely been followed in provisional New Zealand Department of Health guidelines. However, adoption of the USEPA criteria should be approached cautiously, because of doubts about their epidemiological applicability in New Zealand, and a lack of information about streptococcal concentrations and species profiles in local effluents and receiving waters.

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“…Indeed, phages may be a more appropriate indicator of the presence of enteric viruses in water and wastewaters than the bacterial indicators that continue to be widely used (Jofre et al, 1986;Gantzer et al, 1998;Purnell et al, 2011;Ebdon et al, 2012;Jofre et al, 2014) et al (2013) demonstrated that reductions in levels of somatic coliphages and F-RNA specific phages were 2.7 and 1.7 log higher as a result of MBR treatment than by conventional activated sludge treatment. Zanetti et al (2010) observed that, despite the smaller diameter of F-RNA specific phages (21-30nm), their levels in the permeate were lower than those of somatic coliphages (30-100nm).…”

Section: Introductionmentioning

confidence: 99%

Bacteriophage removal in a full-scale membrane bioreactor (MBR) – Implications for wastewater reuse

et al. 2015

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The aim of this study was to assess the potential removal efficacy of enteric viruses in a fullscale membrane bioreactor (MBR) wastewater reuse system, using a range of indigenous and 'spiked' bacteriophages (phages) of known size and morphology. Samples were taken each week for three months from nine locations at each treatment stage of the water recycling plant (WRP) and tested for a range of microbiological parameters (n=135). Mean levels of faecal coliforms were reduced to 0.3 CFU/ 100ml in the MBR product and were undetected in samples taken after the chlorination stage. A relatively large reduction (5.3 log) in somatic coliphages was also observed following MBR treatment. However, F-RNA and humanspecific (GB124) phages were less abundant at all stages, and demonstrated log reductions post-MBR of 3.5 and 3.8, respectively. In 'spiking' experiments, free-swimming 'spiked' phages (MS2 and B14) displayed post-MBR log reductions of 2.25 and 2.30, respectively.The removal of these 'free-swimming' phages, which are smaller than the membrane pore size (0.04 µm), also highlights the possible role of the membrane biofilm as an effective additional barrier to virus transmission. The findings from this study of a full-scale MBR

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Evaluation of Bacteroides fragilis Bacteriophages as Indicators of the Virological Quality of Water

Cited by 87 publications

References 0 publications

Bacteriophages: update on application as models for viruses in water

Bacteriophages: update on application as models for viruses in water

Faecal streptococci as faecal pollution indicators: A review. Part II: Sanitary significance, survival, and use

Bacteriophage removal in a full-scale membrane bioreactor (MBR) – Implications for wastewater reuse

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