title: Class 1 integronase gene and tetracycline resistance genes tetA and tetC in different water environments of Jiangsu Province, China.
abstract: Class 1 integronase gene (intI1) and tetracycline resistance genes (tetA and tetC) from various environmental sites in Jiangsu Province (China) were detected using qualitative PCR (polymerase chain reaction) and quantified with SYBR Green-based qRT-PCR (quantitative real-time PCR) in this study. Qualitative PCR assays demonstrated that intI1, tetA and tetC occurred in the water environments of Taihu Lake, the Nanjing section of the Yangtze River, a sewage treatment plant (STP) in Nanjing City, and two drinking water treating bioreactors. qRT-PCR results showed that abundance of intI1 in lake water and sediments was lower than the tet genes, for a given sample site and date (P < 0.05). On a volumetric basis, lake sediments contained higher concentrations of the three genes by four to five orders of magnitude than water samples, and lake water and sediments sampled in April contained fewer copies of all the genes than the samples collected in June and August (P < 0.05). The levels of intI1, tetA and tetC in the Yangtze River water increased significantly after the river flowed through Nanjing City (P < 0.05). 94.1% integron, 97.2% tetA and 98.3% tetC were removed by the activated sludge process in the STP, and more than 80% of each gene was removed in both of the two biofilters in terms of relative concentration based on sample volume. However, on the basis of DNA mass, lower removals were obtained for both the activated sludge and biofiltration processes.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 210093 Nanjing, China.
authors.forename: Xuxiang
authors.initials: X
authors.lastname: Zhang
authors.forename: Bing
authors.initials: B
authors.lastname: Wu
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Tong
authors.initials: T
authors.lastname: Zhang
authors.forename: Liuyan
authors.initials: L
authors.lastname: Yang
authors.forename: Herbert H P
authors.initials: HH
authors.lastname: Fang
authors.forename: Tim
authors.initials: T
authors.lastname: Ford
authors.forename: Shupei
authors.initials: S
authors.lastname: Cheng
mesh_terms: D017920:Antiporters / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D002681:China; D004269:DNA, Bacterial / Q000235:genetics; D004784:Environmental Monitoring; D005618:Fresh Water / Q000032:analysis* / Q000382:microbiology; D005798:Genes, Bacterial; D019015:Geologic Sediments / Q000032:analysis / Q000382:microbiology; D019426:Integrases / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012722:Sewage / Q000032:analysis / Q000382:microbiology; D013753:Tetracycline Resistance / Q000235:genetics*; D014871:Water Microbiology; D018508:Water Purification
chemical_list: D017920:Antiporters; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D012097:Repressor Proteins; D012722:Sewage; C107173:TetC protein, Bacteria; C079051:tetA protein, Bacteria; D019426:Integrases; C115006:integron integrase IntI1