关键词: 地图鱼; 肺炎克雷伯氏菌; 维氏气单胞菌; 黏质沙雷氏菌; 分离鉴定; 药敏特性

Abstract: 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, 16S rDNA 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 16S rDNA 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.

Key words: Astronotus ocellatus; Klebsiella pneumoniae; Aeromonas veronii; Serratia marcescens; isolation and identification; drug susceptibility characteristics