Aquaculture Facilities As A Potential Source Of Antibiotic Resistance To The Aquatic Environment
The development and proliferation of antibiotic resistance in pathogenic, commensal, and environmental microorganisms is a major public health concern. The extent to which human activities contribute to the maintenance of environmental reservoirs of antibiotic resistance is poorly understood. Aquaculture facilities are one possible source of resistance to the environment because of their oxytetracycline (OTC) use to treat bacterial infections in fish. We investigated the diversity and distribution of antibiotic resistance genes in aquaculture facilities with a recent history of OTC treatment which increased the frequency of tetracycline resistance genes detected throughout the facility as compared to facilities with no recent OTC treatment. Water samples from facilities with recent OTC use had significantly higher tetR detection frequencies than did water samples from facilities without recent OTC use. We found that effluent samples from all aquaculture facilities had higher tetR detection frequencies but not different gene compositions than their corresponding influent samples. These findings suggest that both OTC treatment in aquaculture facilities, and the aquaculture facilities themselves, may be sources of tetR gene propagation to the environment.