Escherichia coli genes (uidA, mutS) from phylogroup B2 isolates from aquatic systems in a subtropical environment.. Escherichia coli from aquatic systems in a subtropical environment.

Escherichia coli is widely used as an indicator of faecal contamination as it is assumed that faeces from warm-blooded animals is the primary source of E. coli in the environment. However, recent studies have shown that E. coli can survive and multiply in environmental niches including soil, sand and sediment. E. coli can be assigned to seven phylogroups; environmental E. coli are usually associated with phylogroups A and B1. Phylogroup B2 is the most divergent, with a high diversity in gene content. In this study E. coli was isolated from different niches within two peri-urban reservoirs; Rietvlei and Roodeplaat dams. To represent the E. coli circulating within the human population, E. coli was also isolated from sewage before treatment and release into these reservoirs. To determine the diversity and to identify possible environmental E. coli, β-D-glucuronidase (uidA) and mismatch repair (mutS) genes were sequenced using Sanger sequencing. The uidA and mutS genes were concatenated and used to perform population STRUCTURE analysis.