Isolation and Identification of Antibiotic Resistance in Bacterial Samples from Lake Ontario

Antibiotic-resistant bacteria are an increasing public health concern and recently the Food and Drug administration has been pressured to withdraw approval of the use of subtherapeutic doses of antibiotics in livestock. In upstate New York, sewage and agricultural run-off may contain microbes that are selected for by antibiotics excreted in humans and livestock waste. Monthly water samples were collected from six different locations in Lake Ontario over the summer of 2011 to isolate and characterize antibiotic resistance in bacteria. Samples were taken from near a treated sewage outflow pipe and the mouth of the Genesee River. Water temperature and clarity were measured for each sample location. Water samples were filtered to collect bacteria and the resulting filtrate was grown on R2A medium. Gram character and resistance to five clinically relevant antibiotics (gentamicin, ampicillin, erythromycin, ciprofloxacin and sulfamethoxazole trimethoprim) was assessed.