Host Species-Specific Metabolic Fingerprint Database for Enterococci and Escherichia coli and Its Application To Identify Sources of Fecal Contamination in Surface Waters

Abstract

A metabolic fingerprint database of enterococci and Escherichia coli from 10 host groups of animals was developed to trace the sources of fecal contamination in surface waters. In all, 526 biochemical phenotypes (BPTs) of enterococci and 530 E. coli BPTs were obtained from 4,057 enterococci and 3,728 E. coli isolates tested. Of these, 231 Enterococcus BPTs and 257 E. coli BPTs were found in multiple host groups. The remaining 295 Enterococcus BPTs and 273 E. coli BPTs were unique to individual host groups. The database was used to trace the sources of fecal contamination in a local creek. The mean diversities (Di) of enterococci (Di ‫؍‬ 0.76 ؎ 0.05) and E. coli (Di ‫؍‬ 0.88 ؎ 0.04) were high (maximum 1) in water samples, indicating diverse sources of fecal contamination. Overall, 71% of BPTs of enterococci and 67% of E. coli BPTs from water samples were identified as human and animal sources. Altogether, 248 Enterococcus BPTs and 282 E. coli BPTs were found in water samples. Among enterococci, 26 (10%) BPTs were identical to those of humans and 152 BPTs (61%) were identical to those of animals (animal BPTs). Among E. coli isolates, 36 (13%) BPTs were identical to those of humans and 151 (54%) BPTs were identical to those of animals. Of the animal BPTs, 101 (66%) Enterococcus BPTs and 93 (62%) E. coli BPTs were also unique to individual animal groups. On the basis of these unique Enterococcus BPTs, chickens contributed 14% of contamination, followed by humans (10%), dogs (7%), and horses (6%). For E. coli, humans contributed 13% of contamination, followed by ducks (9%), cattle (7%), and chickens (6%). The developed metabolic fingerprint database was able to distinguish between human and animal sources as well as among animal species in the studied catchment.

Integrated Analysis of Established and Novel Microbial and Chemical Methods for Microbial Source Tracking

“…On the other hand, phenotyping with the Phene-Plate system has previously been proven to be useful to identify specific animal species as contamination sources in surface water in Australia (1).…”

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

“…While several genotypic and phenotypic methods have been used to trace the sources of contamination in surface waters (Simmons et al 1995;Parveen et al 1999;Wiggins et al 1999;Bernhard & Field 2000;Harwood et al 2000;Carson et al 2001;Hartel et al 2002;Ahmed et al 2005b), none of these methods are regarded as a gold standard or benchmark to date. For instance, genotypic methods, though highly discriminatory, can be laborious and/or expensive for bacterial source tracking/ ecological studies where a large number of isolates need to be tested (Kü hn et al 1995;Olive & Bean 1999;Hartel et al 2002).…”

Anthropogenic Activities as a Source of High Prevalence of Antibiotic Resistant Staphylococcus Aureus in the River Ganga

“…The surface waters in populous countries have become reservoirs of antimicrobialresistant pathogenic microbes due to indiscriminate use of antimicrobials in human and veterinary medicine and addition of faecal contamination through point as well as nonpoint sources, storm drain infrastructure and malfunctioning septic trenches [1]. The number of antimicrobial-resistant (AMR) bacteria in the environment increases exponentially with the misuse of antimicrobials, as a result of increasing selective pressure on bacterial populations [25,39].…”