Evaluation of five antibiotic resistance genes in wastewater treatment systems of swine farms by real-time PCR

Antibiotics are widely used in livestock for infection treatment and growth promotion. Wastes from animal husbandry are a potential environmental source of antibiotic-insensitive pathogens, and the removal efficiency of the resistance genotypes in current wastewater treatment plants (WWTPs) is unkno...

Full description

Saved in:
Bibliographic Details
Published in:The Science of the total environment 2014-10, Vol.496, p.116-121
Main Authors: Tao, Chi-Wei, Hsu, Bing-Mu, Ji, Wen-Tsai, Hsu, Tsui-Kang, Kao, Po-Min, Hsu, Chun-Po, Shen, Shu-Min, Shen, Tzung-Yu, Wan, Terng-Jou, Huang, Yu-Li
Format: Article
Language:English
Subjects:
Animal Husbandry
Animals
Antibiotic resistance genes
Antibiotics
Bacteria
Drug Resistance, Microbial - genetics
Farms
Genes
Genes, Bacterial
Livestock
Real-Time Polymerase Chain Reaction
Removal efficiency
Reproduction
Swine
Swine farms
Waste Disposal, Fluid
Waste Water - microbiology
Wastewater treatment
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Antibiotics are widely used in livestock for infection treatment and growth promotion. Wastes from animal husbandry are a potential environmental source of antibiotic-insensitive pathogens, and the removal efficiency of the resistance genotypes in current wastewater treatment plants (WWTPs) is unknown. In this study, quantitative PCR was used for evaluating antibiotic resistance genes in wastewater treatment processes. Six wastewater treatment plants in different swine farms were included in this study, and five antibiotic resistance genes (ARGs) were tested for each treatment procedure. All of the tested ARGs including tetA, tetW, sulI, sulII, and blaTEM genes were detected in six swine farms with considerable amounts. The results showed that antibiotic resistance is prevalent in livestock farming. The ARG levels were varied by wastewater treatment procedure, frequently with the highest level at anaerobic treatment tank and lowest in the activated sludge unit and the effluents. After normalizing the ARG levels to 16S rRNA gene copies, the results showed that ARGs in WWTP units fluctuated partly with the quantity of bacteria. Regardless of its importance in biodegradation, the anaerobic procedure may facilitate bacterial growth thus increasing the sustainability of the antibiotic resistance genotypes. After comparing the copy numbers in influx and efflux samples, the mean removal efficiency of ARGs ranged between 33.30 and 97.56%. The results suggested that treatments in the WWTP could partially reduce the spread of antibiotic-resistant bacteria, and additional procedures such as sedimentation may not critically affect the removal efficiency. •Antibiotic resistance is prevalent in livestock farming.•ARG levels varied by wastewater treatment procedures.•Anaerobic procedure may increase the sustainability of ARGs.•Current wastewater treatment plants may partially reduce ARGs.•Procedures like sedimentation may not critically affect the removal efficiency.
ISSN:0048-9697
1879-1026
DOI:10.1016/j.scitotenv.2014.07.024