锦鲤厦门希瓦氏菌的分离鉴定及药敏试验

摘要

[目的]明确引起锦鲤发病死亡的原因及其病原菌的药敏特性,为生产中有效防治该病提供科学依据.[方法]采用常规方法从患病锦鲤的肝脏中分离病原菌,经形态观察、生理生化鉴定和16SrDNA序列分析确定其种属,通过人工感染试验判断病原菌的致病性,并以纸片扩散法测定其药物敏感性.[结果]综合分离菌株的形态特征、生理生化特性及16SrDNA序列分析结果,可确定其为厦门希瓦氏菌(Shewanella xiamenensis).人工感染试验证明,从患病锦鲤肝脏分离获得的厦门希瓦氏菌具有较强毒力,其对斑马鱼的半数致死量(LD50)为2.30×104CFU/mL.厦门希瓦氏菌对阿莫西林、红霉素、头孢克肟、头孢哌酮、头孢噻肟、美罗培南、亚胺培南、阿奇霉素、克林霉素、氯霉素、庆大霉素、卡那霉素、新霉素和氟苯尼考等14种药物高度敏感,但对氨苄西林、左氧氟沙星、诺氟沙星、恩诺沙星、利福平、链霉素、依诺沙星、磺胺异恶唑和甲氧嘧啶等抗生素已产生耐药性.[结论]厦门希瓦氏菌可感染引起锦鲤发病死亡,且具有较强毒力,实际生产中可选用阿莫西林、美罗培南、亚胺培南、庆大霉素、新霉素、卡那霉素、头孢哌酮、头孢克肟、头孢噻肟和阿奇霉素等抗生素进行防治.%[Objective]The cause of death for Cyprinus carpio var.Koi and antibiotic susceptibility of its pathogens were clarified to provide reference for effective prevention and control of this disease in breeding.[Method]The pathogenic bacteria were isolated from the diseased fish using the conventional method.The species of the isolated strain was identi-fied according to the morphological observation,physiological and biochemical characteristics identification and 16S rD-NA sequences analysis.Then,an artificial infection experiment was carried out to identify its pathogenicity.Kirby-Bauer method was used for antibiotic susceptibility test.[Result]Taking the morphological characteristics,physiological and biochemical characteristics and 16S rDNA sequences analysis into consideration,the bacterial strain isolated was finally identified as Shewanella xiamenensis.Results of artificial infection experiment showed that the isolated S.xiamenensis strain from liver of diseased fish was highly virulent.Its median lethal dosage(LD50)for the zebra fish was calculated as 2.30×104CFU/g.The results of antibiotic susceptibility test showed that the S.xiamenensis was highly susceptible to 14 drugs such as amoxicillin,meropenem,imipenem,gentamicin,neomycin,kanamycin,cefoperazone,cefixime,cefo-taxime,azithromycin,erythromycin,clindamycin,chloramphenicol,and florfenicol.While it was resistant to ampicil-lin,levofloxacin,norfloxacin,enrofloxacin,rifampicin,streptomycin,enoxacin,sulfisoxazole and trimethoprim.[Con-clusion]S.xiamenensis can infect C.carpio and cause the death of it.The virulence of S.xiamenensis is strong.Some anti-biotics such as amoxicillin,meropenem,imipenem,gentamicin,neomycin,kanamycin,cefoperazone,cefixime,cefo-taxime and azithromycin can be used for prevention and treatment of this disease in breeding.