title: The capability of non-native strains of Bacteroides bacteria to detect bacteriophages as faecal indicators in a tropical area.
abstract: OBJECTIVE
  To evaluate the use of nonlocal, already-available strains of phages to indicate faecal contamination in Thailand waters.
  
  
  RESULTS
  Phages of Bacteroides fragilis strains ATCC 700786 (RYC2056PH) and ATCC 51477 (HSP40PH) were measured in 71 human and animal wastewater samples in Thailand using a double-layer agar assay. Bacteriophage RYC2056PH was detected at concentrations comparable to representative human and animal wastewater samples from European and Mediterranean countries, with 61·7 and 33·3% above the threshold value of 100 PFU 100 ml(-1) in wastewater samples of human and animal origins, respectively. On the other hand, HSP40PH was detected at low concentrations in both human- and animal-polluted wastewaters. Moreover, RYC2056PH was found in 12 canal waters with human-influenced pollution and was not detected in 6 nonpolluted river waters being tested in this study.
  
  
  CONCLUSIONS
  The presence of RYC2056PH could indicate nonsource-specific faecal contamination in Thailand.
  
  
  CONCLUSIONS
  This study provided the first evidence that bacteriophages of the European-isolated B. fragilis strain RYC2056 could be used as nonsource-specific faecal indicators in the Southeast Asian region. The results of this study support the worldwide use of Bacteroides phages as faecal indicators.
authors.affiliation: Translational Research Unit, Chulabhorn Research Institute, Bangkok, Thailand; Center of Excellence on Environmental Health and Toxicology, CHE, Ministry of Education, Bangkok, Thailand.
authors.forename: K
authors.initials: K
authors.lastname: Sirikanchana
authors.forename: B
authors.initials: B
authors.lastname: Wangkahad
authors.forename: S
authors.initials: S
authors.lastname: Mongkolsuk
mesh_terms: D000818:Animals; D001435:Bacteriophages / Q000302:isolation & purification*; D001441:Bacteroides fragilis / Q000821:virology*; D005243:Feces / Q000821:virology*; D005618:Fresh Water / Q000821:virology; D006801:Humans; D013785:Thailand; D014329:Tropical Climate; D062065:Wastewater / Q000821:virology*; D014871:Water Microbiology; D014876:Water Pollution
chemical_list: D062065:Wastewater
keywords: Bacteroides; bacteriophages; developing countries; faecal indicator; water quality