title: Comparative die-off of Escherichia coli O157:H7 and fecal indicator bacteria in pond water.
abstract: In situ and in vitro experiments were performed to assess the effects of solar radiation and predation by indigenous microflora on the relative die-off rates of a toxigenic strain of Escherichia coli O157:H7, commensal E. coli, and fecal enterococci in surface waters from ponds in agricultural watersheds. The objective of these experiments was to discern a mechanism of persistence of E. coli O157:H7 in surface waters compared to fecal indicator bacteria. Results of these experiments indicated that E. coli and fecal enterococci were affected by both insolation and apparent predation; whereas E. coli O157:H7 appeared to be resistant to both of these environmental stressors. The number of days to reach 99% die-off (T(99)-values) for E. coli O157:H7 was significantly greater than that for the indicator bacteria. The capacity to prolong die-off may be connected to the apparent persistence of E. coli O157:H7 in surface waters.
authors.affiliation: USDA Agriculture Research Service, J Phil Campbell, Sr Natural Resource Conservation Center, Watkinsville, Georgia 30677, USA. michael.jenkins@ars.usda.gov
authors.forename: Michael B
authors.initials: MB
authors.lastname: Jenkins
authors.forename: Dwight S
authors.initials: DS
authors.lastname: Fisher
authors.forename: Dinku M
authors.initials: DM
authors.lastname: Endale
authors.forename: Paige
authors.initials: P
authors.lastname: Adams
mesh_terms: D004784:Environmental Monitoring / Q000379:methods; D019453:Escherichia coli O157 / Q000254:growth & development* / Q000302:isolation & purification / Q000528:radiation effects; D005243:Feces / Q000382:microbiology; D005618:Fresh Water / Q000737:chemistry / Q000382:microbiology*; D013312:Stress, Physiological; D013472:Sunlight / Q000009:adverse effects; D013696:Temperature; D014871:Water Microbiology; D014873:Water Pollutants / Q000032:analysis; D014876:Water Pollution / Q000706:statistics & numerical data
chemical_list: D014873:Water Pollutants