Grant Award Year:
2013 - 2014
Triclosan is an antimicrobial agent added to a variety of medical and consumer care products such as soaps, deodorants, and cleaning supplies. These chemicals are then discharged into rivers, exposing native bacteria to triclosan. We have previously shown bacterial exposure to triclosan may have led to chlorine resistance. Since chlorination is the standard method used to disinfect drinking water, municipal water sources may not be sterilized from native bacteria. Previous work has identified 33% (112/336) of bacterial strains increased chlorine resistance after one triclosan exposure. 52% (87/168) of the strains isolated downstream an urban wastewater treatment plant increased chlorine resistance while only 15% (26/168) of strains in a rural reference site increased chlorine resistance. This proposal will focus on expanding the number of sites to include sampling just prior to and after municipal wastewater enters into four different MA rivers. By comparing the same watershed in close proximity, we will eliminate biases of different environmental conditions as well as test several new waterways for triclosan and chlorine tolerant bacteria. The number of chlorine resistant bacteria colonies will also be compared to triclosan measured in each of these waterways.