天鹅维氏气单胞菌、弗氏柠檬酸杆菌与大肠埃希氏菌混合感染的诊断

Diagnosis of Co-infection of Aeromonas veronii,Citrobacter freundii and Escherichia coli in Swan

为对饲养于某人工湖的1只病死天鹅进行病原诊断,在临床检查和病理剖检的基础上,无菌采集该天鹅病变组织进行细菌学检测,并对分离菌株进行小鼠致病性试验和药敏试验。经细菌分离培养、革兰氏染色、镜检、生化鉴定和分子生物学鉴定,成功分离到3种革兰氏阴性杆菌分别为维氏气单胞菌、弗氏柠檬酸杆菌和大肠埃希氏菌,小鼠致病性试验结果表明,3株分离菌株均有致病性。纸片扩散法药敏试验结果表明3株分离菌株均对链霉素、庆大霉素敏感,对阿莫西林、泰乐菌素等有耐药性。病例最终确诊该天鹅为维氏气单胞菌、弗氏柠檬酸杆菌和大肠埃希氏菌混合感染致死,能够为珍稀野生保护动物的相关病原研究和防治提供参考。

To diagnose the pathogens of the dead swan raised in a artificial lake,pathological tissues of the swan were collected aseptically for bacteriological diagnosis based on clinical examination and pathological anatomy,and the isolated strains were tested for pathogenicity to mice and antimicrobial susceptibility.After bacterial isolation and culture,Gram staining,microscopic examination,biochemical identification and molecular biological identification,three kinds of Gram-negative bacillus were successfully isolated,namely Aeromonas veronii,Citrobacter freundii and Escherichia coli,and the pathogenic trial in mice showed that all of the three isolated strains were pathogenic.The results of antimicrobial susceptibility testing performed by disk diffusion method showed that the three isolated strains were all sensitive to streptomycin and gentamicin,and showed resistance to a variety of antibacterial drugs,such as amoxicillin,tylosin,and so on.It was finally confirmed that the swan in this case died of co-infection of Aeromonas veronii,Citrobacter freundii and Escherichia coli,which could provide reference for etiological research,clinical prevention and treatment for the related pathogens of rare wild protected animals.