title: Changes of bacterial diversity and tetracycline resistance in sludge from AAO systems upon exposure to tetracycline pressure.
abstract: Two lab-scale anaerobic-anoxic-oxic (AAO) systems were used to investigate the changes in tetracycline (TC) resistance and bacterial diversity upon exposure to TC pressure. High-throughput sequencing was used to detect diversity changes in microorganisms at the level of class in sludge from different bioreactors with and without TC. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used to detect the abundances of eight tetracycline resistance genes (TRGs), tetA, tetB, tetC, tetE, tetM, tetO, tetS and tetX. The results showed that the diversities of the microbial communities of anoxic, anaerobic and aerobic sludge all increased with the addition of TC. TC substantially changed the structure of the microbial community regardless of oxygen conditions. Bacteroidetes and Proteobacteria were the dominant species in the three kinds of sludge and were substantially enriched with TC pressure. In sludge with TC added, almost all target TRGs proliferated more than those in sludge without TC except tetX, which decreased in anaerobic sludge with TC addition. The concentration of efflux pump genes, tet(A-C, E), was the highest among the three groups of TRGs in the different kinds of sludge.
authors.affiliation: College of Environmental Science and Engineering, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 201620, China. Electronic address: egghmh@163.com.
authors.forename: Manhong
authors.initials: M
authors.lastname: Huang
authors.affiliation: College of Environmental Science and Engineering, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 201620, China.
authors.forename: Fangfang
authors.initials: F
authors.lastname: Qi
authors.affiliation: College of Environmental Science and Engineering, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 201620, China.
authors.forename: Jue
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Environmental Science and Engineering, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 201620, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Xu
authors.affiliation: College of Environmental Science and Engineering, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 201620, China.
authors.forename: Li
authors.initials: L
authors.lastname: Lin
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D000900:Anti-Bacterial Agents / Q000633:toxicity*; D001419:Bacteria / Q000235:genetics* / Q000378:metabolism; D041963:Bacteroidetes / Q000378:metabolism; D044822:Biodiversity; D019149:Bioreactors; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004350:Drug Residues / Q000633:toxicity*; D005798:Genes, Bacterial / Q000235:genetics; D059014:High-Throughput Nucleotide Sequencing; D016133:Polymerase Chain Reaction; D020560:Proteobacteria / Q000378:metabolism; D012722:Sewage / Q000382:microbiology*; D013752:Tetracycline / Q000633:toxicity*; D013753:Tetracycline Resistance / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D012722:Sewage; D013752:Tetracycline
keywords: Anaerobic/anoxic/aerobic sludge; Bacterial diversity; High-throughput sequencing; Resistance genes; Tetracycline