中华鳖(Pelodiscus sinensis)摩氏摩根菌(Morganella morganii)的鉴定及致病性研究

ISOLATION AND IDENTIFICATION OF PATHOGENIC MORGANELLA MORGANII ISOLATES FROM CHINESE SOFT-SHELLED TURTLE PELODISCUS SINENSIS

从3只患有头面部疖疮中华鳖(Pelodiscus sinensis)的肝脏、肾脏、头面部病灶干酪样组织,分离得到12株细菌。综合菌落形态观察、16S rRNA序列分析与生化特性分析方法,所有分离株均为摩氏摩根菌(Morganella morganii)。稚鳖和小鼠感染试验提示该菌具有较强的致病力,其对小鼠的半数致死量(LD50)为107.24。同时采用常规琼脂扩散(K-B)法进行8类14种常用药物的抗菌敏感性测定,结果表明,分离株对氨基糖苷类、β-内酰胺类、四环素类、林可酰胺类、多肽类、喹诺酮类、磺胺类等中的8种药物耐药,对氨曲南、氟苯尼考、头孢哌酮则较为敏感。本研究为中华鳖以头面部疖疮为主要临床特征的摩氏摩根菌病的首例报道,旨在为该病的确诊与防治提供科学依据和参考。

An outbreak of Chinese soft-shelled turtle （Pelodiscus sinensis） disease with typical symptoms of head and facial furuncle sore happened in a large-scale breeding farm in Zhejiang Province, 2012. A total of 12 isolates were col-lected from livers, kidneys and facial loci of these diseased turtles. Based on the colony morphology, biochemical reactions and the sequence analysis of 16S rRNA gene, these isolates were identified as Morganella morganii. These isolates dem- onstrated virulence potential both in Chinese soft-shelled turtle and mouse models, with the median lethal dose （LDso） in mice at 10TM. The susceptibity test to antibiotics using Kirby-Bauer Sagar diffusion method showed these M. morganii isolates were resistant to aminoglycosides, beta-lactams, tetracyclines, lincomycin amides, polypeptides, quinolones, sul- fonamides, and sensitive to aztreonam, florfenicol, cefoperazone. This study represents the first report of M. mor-ganii-mediated disease with the typical signs of head and facial furuncle sore in Chinese soft-shelled turtles, and paves the way for the prevention and treatment program of this disease.