Genes encoding tetracycline resistance in a full-scale municipal wastewater treatment plant investigated during one year.
Tetracycline-resistant bacteria and genes encoding tetracycline resistance are common in anthropogenic environments. We studied how wastewater treatment affects the prevalence and concentration of two genes, tetA and tetB, that encode resistance to tetracycline. Using real-time polymerase chain reaction (PCR) we analysed wastewater samples collected monthly for one year at eight key-sites in a full-scale municipal wastewater treatment plant (WWTP). We detected tetA and tetB at each sampling site and the concentration of both genes, expressed per wastewater volume or per total-DNA, decreased over the treatment process. The reduction of tetA and tetB was partly the result of the sedimentation process. The ratio of tetA and tetB, respectively, to total DNA was lower in or after the biological processes. Taken together our data show that tetracycline resistance genes occur throughout the WWTP, and that the concentrations are reduced under conventional operational strategies.
Börjesson
Stefan
S
Division of Medical Microbiology, Department of Clinical and Experimental Medicine, Linköping University, SE-581 85, Linköping, Sweden.
Mattsson
Ann
A
Lindgren
Per-Eric
PE
Lindgren
Per-Eric
PE
D017920:Antiporters / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D004755:Enterobacteriaceae / Q000235:genetics*; D004784:Environmental Monitoring; D005798:Genes, Bacterial; D006801:Humans; D016133:Polymerase Chain Reaction; D013752:Tetracycline / Q000494:pharmacology*; D013753:Tetracycline Resistance / Q000235:genetics*; D018508:Water Purification; D014881:Water Supply / Q000032:analysis*
D017920:Antiporters; D001426:Bacterial Proteins; C079051:tetA protein, Bacteria; D013752:Tetracycline