一株兔源耐药性肺炎克雷伯氏菌的分离与鉴定

Isolation and Identification of a Resistant K. peneumoniae Strain from Rabbits

本试验旨在对从患呼吸道感染和腹泻的仔兔血液中分离的1株疑似病原菌进行鉴定。采用分离培养、镜检、生化检测、荚膜染色、16S rDNA序列测序、药敏试验和动物体内感染等方法,对该疑似菌进行了分析。结果显示,该疑似菌呈杆状、含有丰富的荚膜多糖,其16S rDNA序列与肺炎克雷伯氏菌标准菌株序列相似性达到99%,且对链霉素、庆大霉素、氨苄青霉素、硫酸庆大霉素、硫酸卡那霉素和氯霉素均表现出不同程度的显著抗性。腹腔注射该菌(109CFU/mL),仔兔全部死亡;而口腔灌喂,仔兔有较强的耐受性(无死亡)。结果表明,从患病仔兔血液中分离到1株肺炎克雷伯氏菌且具有致病性。

A suspected pathogen was newly isolated from rabbits with diarrhea and respiratory tract infection by isolation and culture. To further understand some features of this suspected bacteria, microscopic examination, biochemical detection including capsular stain, drug sensitive test and 16S rDNA sequence analysis were performed. The results showed that the iso- lated bacteria was in rod containing rich capsular polysaccharide, and demonstrated a significant multi-drug resistance to strep- tomycin, gentamicin, ampicillin, gentamicin sulfate, kanamycin sulfate and chloramphenicol at different levels. Furthermore 16S rDNA sequence of this suspected bacteria was cloned by PCR and sequenced, the result showed that 16S rDNA sequence shared about 99% similarity to that of K. pneumonia standard strains provided by GenBank. In addition, infection of suspected bacteria （109 CFU/mL） resulted in mortality to rabbits by intraperitoneal injection, but not by oral administration. Altogeth- er, it could be concluded that the isolated bacteria was a member of K. pneumonia and contributed to the disease of rabbits.