Population similarity of enterococci and Escherichia coli in surface waters: A predictive tool to trace the sources of fecal contamination

Abstract

A biochemical fingerprinting method (the PhPlate system) was used to compare similarities between Escherichia coli and enterococci populations from surface water samples with those found in different animal species during the wet and the dry seasons in order to predict the dominant source(s) of fecal contamination in a local creek. A significant increase in the number and diversity of enterococci was observed in the creek during the wet season. Enterococci population from water samples also showed a higher population similarity with animal species than did E. coli. A higher population similarity was found between both indicator bacteria and animal species during the wet season with highest population similarities found in dogs, horses, cows and kangaroos. In contrast, a low population similarity was found for both fecal indicator bacteria from humans with water samples during the wet and the dry seasons, indicating that humans are not a major source of contamination in the studied creek. The results also indicate that the population similarity analysis of enterococci population has an advantage over E. coli in tracing the possible source(s) of contamination in the studied creek and that population similarity analysis as used in this study can be used to predict the source(s) of fecal contamination in surface waters.

Persistence and diversity of faecal coliform and enterococci populations in faecally polluted waters

“…This observation was supported by a decrease in the Sp index, which is more significant in the summer season. The Sp index was higher for ENT in both seasons than for FC, which is in agreement with the work of Ahmed et al. (2006) in which ENT and E. coli persistence was analysed by biochemical fingerprinting.…”

Assessment of the decay rates of microbial source tracking molecular markers and faecal indicator bacteria from different sources

“…; Ahmed et al . ). Furthermore, certain strains isolated from diverse sources showed different adaptations to the environment, with contrasting persistence times (Anderson et al .…”

“…They also showed smaller differences between the seasons, thus suggesting that other factors play a key role in the inactivation of the markers and have to be considered. For example, other studies reported differences between strains of EC and ENT of various animal sources (McLellan et al 2003;Ahmed et al 2006). Furthermore, certain strains isolated from diverse sources showed different adaptations to the environment, with contrasting persistence times (Anderson et al 2005;He et al 2015).…”

Environmental Health Threats Associated with Drainage from a Coastal Urban Watershed

“…Because water samples from the Seeps were collected at the soil surface, the samples may have been exposed directly to pet and wildlife waste, thus influencing the concentrations of E. coli in the samples. Research by Wright et al (2009) in coastal Florida and Ahmed et al (2006) in Queensland Australia also reported that pets such as dogs may be dominant sources of fecal indicator bacteria to soil and/or surface waters. The results of this study indicate that E. coli concentrations commonly exceed the water quality standards during baseflow and stormflow, and drainage from TC may be a threat to public and environmental health via exposure to recreational waters with elevated E. coli concentrations.…”