Genomic sequencing of E. coli strains grown in chemostat reactors.

What are the effects of nutrient levels in river and growth rates of bacteria on the conjugation frequency of antibiotic resistance genes (ARGs) from bacteria in WWTP effluent to river bacteria, as well as on the resulting resistance level of the river bacteria?Two Escherichia coli strains were used as donor and recipient cells to simulate bacteria in WWTP effluents and river bacteria, respectively. Chemostat reactors were built to simulate surface waters receiving WWTP effluent, and were operated under different growth rates and nutrient levels. Antibiotic tetracycline was also present in the chemostat reactors at an environmentally relevant concentration (i.e., 10 ug/L). Both culture-based and whole genome sequencing (WGS) approaches were employed to understand phenotypic and genotypic changes, respectively, resulting from conjugation events under continuous flow conditions.