Human origin of Bacteroides fragilis bacteriophages present in the environment

Abstract

Bacteroidesfragilis HSP40 phages have been detected in waters with various levels of fecal contamination of human origin. The average numbers of B. fragilis phages present in sewage water reached 5.3 x 103 per 100 ml of water. We found a number 1,000 times lower in a river contaminated with domestic sewage only, in which the levels of fecal coliforms and fecal streptococci were 10,000 times lower than those found in raw sewage. In addition, B. fragilis phages were not found in significant numbers in slaughterhouse wastewaters. They were not present in fecal-polluted waters containing fecal contamination from wildlife only. Although the number of B. fragilis phages present in contaminated waters was lower than the number of coliphages, their presence indicated human fecal contamination. It is also shown that Bacteroides phages are only able to multiply under anaerobic conditions in the presence of nutrients, and they cannot multiply in natural waters and sediments.

Isolation of bacteriophage host strains of Bacteroides species suitable for tracking sources of animal faecal pollution in water

“…Among these methods, bacteriophages that infect Bacteroides are potential tools for MST (Tartera et al, 1989;Grabow et al, 1995;Puig et al, 1999;Blanch et al, 2006). Bacteroides host strains vary in their capacity to discriminate between phages from different sources.…”

Distribution of genotypes of F-specific RNA bacteriophages in human and non-human sources of faecal pollution in South Africa and Spain

“…Microbiological methods include: ratios of faecal coliforms to faecal streptococci (Geldreich and Kenner 1969); the presence of Rhodococcus coprophilus (Mara and Oragui 1981); the presence of some phenotypes of Bifidobacterium species (Mara and Oragui 1983); the presence of some phenotypes of Bacteroides species (Kreader 1995); ribotypes of Escherichia coli (Carson et al 2001;Parveen et al 1999); repetitive DNA sequences of E. coli (Dombek et al 2000); antibiotic resistance patterns (Wiggins 1996;Harwood et al 2000); serogrouping of F-specific RNA (F-RNA) bacteriophages (Furuse et al 1978); bacteriophages specific for various strains of Bacteroides fragilis (Tartera et al 1989;Puig et al 1999) and phage typing of Staphylococcus aureus (Zierdt et al 1980). The ideal would be to have a single test to determine the origin of faecal pollution.…”

Occurrence of phages infecting Escherichia coli O157:H7 carrying the Stx 2 gene in sewage from different countries

“…Somatic coliphages were enumerated in those samples that were frozen for transport to have an indication of the conservation of the sample during transport. Indeed, the numbers of somatic coliphages are relatively similar in raw sewage samples all over the world [12] and frozen in the presence of 10% w/v glycerol and kept in ice can be transported without signi¢cant losses of viability.…”