title: Effects of ultraviolet light disinfection on tetracycline-resistant bacteria in wastewater effluents.
abstract: The ubiquitous use of antibiotics has led to an increasing number of antibiotic-resistant bacterial strains, including strains that are multidrug-resistant, pathogenic, or both. There is also evidence to suggest that antibiotic resistance genes (ARGs) spread to the environment, humans, and animals through wastewater effluents. The overall objective of this study was to investigate the effect of ultraviolet (UV) light disinfection on antibiotic-resistant bacteria. Wastewater effluent samples from a wastewater treatment plant (WWTP) in Texas were evaluated for differences in tetracycline-resistant bacteria before and after UV treatment. The effects of photoreactivation or dark repair on the reactivation of bacteria present in WWTP effluent after UV disinfection were also examined. Culture-based methods were used to characterize viable heterotrophic, tetracycline-resistant heterotrophic, Escherichia coli, and tetracycline-resistant E. coli bacteria present before and after UV treatment. UV disinfection was found to be as effective at reducing concentrations of resistant heterotrophs and E. coli, as it was at reducing total bacterial concentrations. The lowest survival ratio following UV disinfection was observed in tetracycline-resistant E. coli showing particular susceptibility to UV treatment. Photoreactivation and dark repair rates were found to be comparable to each other for all bacterial populations.
authors.affiliation: Department of Biological and Agricultural Engineering, Texas A&M University, 2117 TAMU, College Station, TX 77843-2117, USA E-mail: karthi@tamu.edu.
authors.forename: H
authors.initials: H
authors.lastname: Childress
authors.affiliation: Department of Biological and Agricultural Engineering, Texas A&M University, 2117 TAMU, College Station, TX 77843-2117, USA E-mail: karthi@tamu.edu.
authors.forename: B
authors.initials: B
authors.lastname: Sullivan
authors.affiliation: Department of Biological and Agricultural Engineering, Texas A&M University, 2117 TAMU, College Station, TX 77843-2117, USA E-mail: karthi@tamu.edu.
authors.forename: J
authors.initials: J
authors.lastname: Kaur
authors.affiliation: Department of Biological and Agricultural Engineering, Texas A&M University, 2117 TAMU, College Station, TX 77843-2117, USA E-mail: karthi@tamu.edu.
authors.forename: R
authors.initials: R
authors.lastname: Karthikeyan
mesh_terms: D001419:Bacteria / Q000528:radiation effects*; D015169:Colony Count, Microbial; D004203:Disinfection / Q000379:methods*; D004926:Escherichia coli / Q000528:radiation effects; D013753:Tetracycline Resistance; D013781:Texas; D014466:Ultraviolet Rays; D062065:Wastewater / Q000382:microbiology*
chemical_list: D062065:Wastewater