家养观赏地图鱼肺炎克雷伯氏菌、维氏气单胞菌与黏质沙雷氏菌的分离鉴定及耐药性分析

Isolation,Identification and Drug Resistance of Klebsiella pneumoniae,Aeromonas veronii and Serratia marcescens Isolated from Domesticated Ornamental Astronotus ocellatus

本试验旨在通过细菌分离鉴定,明确家养观赏地图鱼的死因,筛选敏感药物。采用常规方法分离纯化细菌后,进行细菌形态学观察,并通过小白鼠致病性试验、细菌主要生化鉴定、16SrDNA序列测定分析、药敏试验及耐药基因检测等方法对分离的细菌进行鉴定及耐药分析。分离出3株革兰氏阴性短杆菌,根据细菌形态特征及理化特性,结合16SrDNA序列测定与系统发育分析结果,判定其分别为肺炎克雷伯氏菌(Klebsiella pneumoniae)、维氏气单胞菌(Aeromonas veronii)和黏质沙雷氏菌(Serratia marcescens),其中肺炎克雷伯氏菌具有较强致病性。3株细菌均对洛美沙星、氧氟沙星、阿米卡星、卡那霉素敏感,对阿莫西林、氟苯尼考、克林霉素、甲硝唑等具有较强耐药性。结果表明,肺炎克雷伯氏菌、维氏气单胞菌、黏质沙雷氏菌的混合感染是家养观赏地图鱼的死亡原因。

The study was aimed to determine the cause of death of a domesticated ornamental Astronotus ocellatus and screen sensitive drugs via isolation and identification of related bacteria.First,the bacteria were isolated and purified by conventional methods for observation of bacterial morphology.Then,identification and drug resistance analysis were performed through methods of pathogenicity test on mice,bacteria biochemical identification,16 SrDNA sequencing and analysis,drug susceptibility test and resistance gene detection.Three Gram-negative short bacilli were isolated and identified,according to their morphological characteristics and physical and chemical characteristics as well as the results of 16 SrDNA sequencing and phylogenetic analysis,as Klebslella pneumoniae,Aeromonas veronii and Serratia marcescens.Among them,Klebsiella pneumoniae had strong pathogenicity.The three bacteria were sensitive to lomefloxacin,ofloxacin,amikacin,kanamycin,but had a strong resistance to amoxicillin,florfenicol,clindamycin,metronidazole.A mixed infection of Klebsiella pneumoniae,Aeromonas veronii and Serratia marcescens was the cause of death of domesticated ornamental Astronotus ocellatus.