Phenotypic diversity caused by differential RpoS activity among environmental Escherichia coli isolates.

ABSTRACT: Enteric bacteria deposited into the environment by animal hosts are subject to diverse selective pressures. These pressures may act on phenotypic differences in bacterial populations and select adaptive mutations for survival in stress. As a model to study phenotypic diversity in environmental bacteria, we examined mutations of the stress response sigma factor, RpoS, in environmental Escherichia coli isolates. A total of 2,040 isolates from urban beaches and nearby fecal pollution sources on Lake Ontario (Canada) were screened for RpoS function by examining growth on succinate and catalase activity, two RpoS-dependent phenotypes. The rpoS sequence was determined for 45 isolates, including all candidate RpoS mutants, and of these, six isolates were confirmed as mutants with the complete los

SUBMITTER: Chiang SM 

PROVIDER: S-EPMC3209002 | biostudies-literature | 2011 Nov

REPOSITORIES: biostudies-literature