title: Analysis of antimicrobial resistance genes in Aeromonas spp. isolated from cultured freshwater animals in China.
abstract: The development of resistance to antimicrobials used in aquatic animals is an increasing concern for aquaculture and public health. To monitor the occurrence of antimicrobial resistance and resistance genes in Aeromonas, a total of 106 isolates were collected from cultured freshwater animals in China from 1995 to 2012. Antimicrobial susceptibilities were determined by the disk diffusion method. The highest resistance percentage occurred with ampicillin, rifampin, streptomycin, and nalidixic acid. Most strains were sensitive to fluoroquinolones, doxycycline, cefotaxime, chloramphenicol, and amikacin. The isolates from turtle samples had the highest levels of resistance to 11 of the 12 tested antimicrobials when compared with those from fish or shrimp. Polymerase chain reaction and DNA sequence results showed that all trimethoprim/sulfamethoxazole-resistant strains contained sul1, and 37.0% were positive for tetA in tetracycline-resistant strains. ant(3″)-Ia was identified in 13 (24.5%) streptomycin-resistant strains. Plasmid-borne quinolone resistance genes were detected in five Aeromonas hydrophila (4.7%), two of which carried qnrS2, while the other three strains harbored aac(6')-Ib-cr. Two cefotaxime-resistant A. hydrophila were positive for bla(TEM-1) and bla(CTX-M-3). To our knowledge, this is the first report characterizing antimicrobial resistance in Aeromonas isolated from cultured freshwater animals in China, and providing resistance information of pathogen in Chinese aquaculture.
authors.affiliation: 1 Key Laboratory of Fishery Drug Development, Ministry of Agriculture, Pearl River Fisheries Research Institute , Chinese Academy of Fishery Sciences, Guangzhou, People's Republic of China .
authors.forename: Yu-Ting
authors.initials: YT
authors.lastname: Deng
authors.forename: Ya-Li
authors.initials: YL
authors.lastname: Wu
authors.forename: Al-Ping
authors.initials: AP
authors.lastname: Tan
authors.forename: Yu-Ping
authors.initials: YP
authors.lastname: Huang
authors.forename: Lan
authors.initials: L
authors.lastname: Jiang
authors.forename: Hui-Juan
authors.initials: HJ
authors.lastname: Xue
authors.forename: Wei-Li
authors.initials: WL
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Luo
authors.forename: Fei
authors.initials: F
authors.lastname: Zhao
mesh_terms: D016980:Aeromonas hydrophila / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017756:Aquaculture; D002681:China; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D005399:Fishes; D005798:Genes, Bacterial; D008460:Meat / Q000382:microbiology*; D033561:Penaeidae; D010957:Plasmids; D014426:Turtles
chemical_list: D000900:Anti-Bacterial Agents