一株多重耐药鳢源舒氏气单胞菌的分离、鉴定及其耐药性分析  

Isolation, identification and antimicrobial resistance of a multidrug-resistant Aeromonas schubertii isolated from snakehead fish

作　　者：张德锋 刘春[2] 可小丽[2] 常藕琴[2] 卢迈新[2] 石存斌[2] 袁伟[2] 郝贵杰[1] 梁丽[3] 

机构地区：[1]浙江省淡水水产研究所农业部淡水渔业健康养殖重点实验室/浙江省鱼类健康与营养重点实验室,浙江湖州313001 [2]中国水产科学研究院珠江水产研究所/农业部热带亚热带水产资源利用与养殖重点实验室/广东省水产动物免疫技术重点实验室,广东广州510380 [3]佛山市顺德区广盈生物技术有限公司,广东佛山528000

出　　处：《中国预防兽医学报》2017年第12期981-986,共6页Chinese Journal of Preventive Veterinary Medicine

基　　金：948计划"东南亚国家淡水养殖病害联合研究与防控"(2016-X57);农业部淡水渔业健康养殖重点实验室开放课题(ZJK2014002);现代农业产业技术体系专项资金项目(CARS-49);广东省自然科学基金项目(2014A030310097)

摘　　要：本实验室2016年7月从广东省佛山市某杂交鳢(Channa maculata×Channa argus)养殖场分离到一株编号为WL-23的细菌,为对该菌株进行鉴定与分析,本研究首先对该菌进行生理生化和分子生物学鉴定;将该菌株进行人工回归感染试验对其进行致病性分析,并对其耐药性和耐药基因进行检测与分析。结果显示,WL-23株为舒氏气单胞菌(Aeromonas schubertii),该菌株人工感染杂交鳢的临床症状与自然发病鱼的症状一致,且对杂交鳢的LD_(50)为2.6×10~6cfu/mL。药敏试验结果显示WL-23株具有8重耐药特征,该菌对大环内酯类、四环素类、氨基糖苷类、β-内酰胺类、氯霉素类、林可酰胺类、磺胺类和利福平等药物耐药。耐药基因检测结果显示,该菌株携带大环内酯类mph(A),四环素类tet(A),氨基糖苷类aad(A)、aacC4和aphA1,氯霉素类Flor,喹诺酮类qnrS、磺胺类sul1、sul2和dfra1以及利福平aar-2/3等耐药基因。WL-23菌株的耐药基因与其耐药表型之间具有良好的相关性,表明以上11种耐药基因是WL-23株具有耐药性的关键原因。近年来鳢源舒氏气单胞菌对四环素类和氨基糖苷类的耐药性明显增强,这与该菌获得了大量的耐药基因有关。本研究为鳢源舒氏气单胞菌的流行病学和耐药性等研究奠定了基础,也为对其科学防控提供指导意见。Abstract： In July 2016, a bacterial disease outbreak occurred in cultured snakehead fish （Channa maculataxChanna argus） in Foshan city, Guangdong province. A Gram-negative bacillus （strain WL-23） was isolated from the moribund fish. To identify the pathogen, detect the pathogenicity, determine the drug sensitivity spectrum, and detect the resistance genes of WL-23 strain. According to the results, the WL-23 isolate was identified as Aeromonas schubertii based on the biochemical and molecular identification tests. The clinical signs of artificially infected fish were similar to that of the natural infected fish, which indicated this strain exhibited strong virulence to snakeheads and the LDs0 value of WL-23 strain was 2.6x 106 cfu/mL to snakehead fish. The WL-23 strain was resistant to 24 antimicrobial agents （9 classes） including macrolides, tetracyclines, aminoglycosides, β-1actams, chloramphenicols, lincosamides, sulfonamides and rifampicin determined by disk diffusion method. PCR detection results revealed the presence of 11 resistance-related genes in the WL-23 strain, such as mph（A）, tet（A）, and（A）, aacC4, aphA1, Flor, qnrS, sull, sul2, dfral and aar-2/3. The results indicated that there were good correlation between the resistant phenotype and resistance genes in WL-23 strain and highlighted that the 11 resistance genes were the important reason of the resistance for the isolate. Recently, the resistance of A.schubertii to tetracycline and aminoglycosides was found to be significantly enhanced, which was probably correlated with the strains acquiring a large number of resistance genes. These results could provide a scientific basis for epidemiological studies and development of drugs against A.schubertii for snakehead fish, and could provide guidance for the prevention and control of A.schubertii infections.

关 键 词：杂交鳢 舒氏气单胞菌 药敏试验 耐药基因 

分 类 号：S917.1[农业科学—水产科学]