兔源肺炎克雷伯氏菌和大肠埃希氏菌的分离鉴定及小鼠感染试验  

Isolation,Identification and Mouse Infection Tests of Klebsiella pneumoniae and Escherichia coli from Rabbits

作　　者：张鲁星 石晴晴 陶梦珂 李苗苗 赵恒 胡功政[1] 吴华[1] 刘建华[1] ZHANG Lu-xing;SHI Qing-qing;TAO Meng-ke;LI Miao-miao;ZHAO Heng;HU Gong-zheng;WU Hua;LIU Jian-hua(College of Veterinary Medicine,Henan Agricultural University,Zhengzhou,Henan,450000,China)

机构地区：[1]河南农业大学动物医学院,河南郑州450000

出　　处：《动物医学进展》2025年第1期55-61,共7页Progress In Veterinary Medicine

基　　金：国家自然科学基金项目(32072914);河南省重点研发项目(221111111300)。

摘　　要：为确定某规模化兔场仔兔呼吸道感染合并腹泻引起死亡的原因,无菌采集病兔气管、肺、肝组织进行病毒和细菌检测。通过细菌分离培养、革兰氏染色、生化鉴定、16S rRNA序列同源性比对分析,确定分离菌株种属。通过药物敏感性试验、耐药基因检测及动物回归对分离菌株的耐药性和致病性进行分析。结果显示,病毒检测结果均为阴性;从同一只仔兔的肺脏、气管中分离得到2株肺炎克雷伯氏菌,分别将其命名为KF1、KQ2,从肝脏中分离得到1株大肠埃希氏菌并将其命名为EG3。药敏试验结果显示,菌株KF1、KQ2和EG3均对黏菌素和氨苄青霉素钠耐药,对阿米卡星和氟苯尼考敏感。3株菌均检出耐药基因mcr-1和bla TEM。动物致病性试验显示,KF1组小鼠5 h后死亡50%,24 h全部死亡;混合组小鼠12 h后全部死亡;KQ2和EG3组48 h全部死亡。以上研究表明,大肠埃希氏菌和肺炎克雷伯氏菌的混合感染是引起仔兔死亡的主要原因,3株分离株单独及混合感染均能引起试验小鼠死亡。To investigate the pathogens of respiratory tract infection and diarrhea leading to mortality in rabbits in a large-scale rabbit farm in Liaocheng,Shandong province.Viral and bacterial pathogens were aseptically isolated and cultured from the trachea,lungs and liver.The strains were subjected to bacterial isolation and culture,Gram staining,biochemical identification,homology comparison analysis of the 16S rRNA sequence and construction of a phylogenetic tree in order to determine their species.The drug resistance and pathogenicity of the isolates were evaluated by conducting drug sensitivity testing,detecting of drug resistance genes and performing animal regression analysis.The results demonstrated that all of the viruses tested were negative and the isolation of two strains,Klebsiella pneumoniae KF1 and KQ2,from the lungs and trachea of a single rabbit.Additionally,a strain of Escherichia coli was obtained from its liver,designated as EG3.The drug susceptibility test results revealed that strains KF1,KQ2 and EG3 exhibited resistance to colistin and ampicillin sodium,while demonstrating sensitive to amikacin and flufenicol.The presence of drug resistance genes mcr-1 and bla TEM was observed in all three strains.Animal pathogenicity tests showed that in the KF1 group,50%of the SPF mice succumbed within 5 hours,exhibiting complete mortality at 24 hours;whereas all mice in the mixed group experienced total mortality after 12 hours.The mortality rate was 100%within 48 hours for all groups exposed to KQ2 and EG3 while the control group exhibited normal survival without any observed abnormalities.The above study indicated that the mixed infection of Escherichia coli and Klebsiella pneumoniae was the main reason of mortality of young rabbits,and the three isolates can cause death of mice by single and mixed infections.

关 键 词：兔 肺炎克雷伯氏菌 大肠埃希氏菌 分离鉴定 耐药基因 

分 类 号：S858.291[农业科学—临床兽医学]