Genetic Determinants of Escherichia coli Survival in Beach Sand.

Escherichia coli contain a high level of genetic diversity and are generally associated with the guts of warm-blooded animals but have also been isolated from secondary habitats outside hosts. We used E. coli isolates from previous microcosm experiments conducted under actual beach conditions and performed population-level genomic analysis to identify accessory genes associated with survival within the beach sand environment.

Selective survival of phylotypes in freshwater beach sand.

is used as an indicator of fecal pollution at beaches despite evidence of long-term survival in sand. This work investigated the basis for survival of through field microcosm experiments and phylotypic characterization of more than >1400 isolated from sand, sewage, and gulls, enabling identification of long-surviving populations and environmental drivers of their persistence. Microcosms containing populations of from each source (n=176) were buried in the backshore of Lake Michigan for 45 & 96 days under several different nutrient treatments, including unaltered native sand, sterile autoclaved sand and baked nutrient depleted sand.