斑点叉尾鮰腹水病病原菌分离鉴定及药敏试验

Isolation and identification of ascites disease pathogen from channel catfish and its drug sensitivity test

【目的】通过对广西龙州某养殖场患腹水病的斑点叉尾鮰进行病原菌分离鉴定及药敏试验,为生产中有效防治该病提供参考。【方法】以常规方法从病鱼的心脏、肝脏和腹水中分离病原菌,人工感染确定其致病性,以API20NE生化鉴定与16S rRNA基因序列分析相结合的方法鉴定病原菌,并采用K-B纸片扩散法进行药敏试验。【结果】从患病斑点叉尾鮰的肝脏和心脏中分离获得两株致病力很强的菌株GXCW01和GXCW02,经API20NE生化鉴定与16S rRNA基因序列分析确定,分离菌株GXCW01和GXCW02均属于温和气单胞菌(Aeromonas sobria),与Aeromonas sobri ATCC 43979(X74683)株和NCIMB 12065(X60412)株的亲源关系最近,相似性分别为99.0%和99.4%。菌株GXCW01和GXCW02的药敏试验结果基本相同,对复达欣、氧氟沙星、头孢呋肟、先锋噻肟、菌必治、呋喃妥因、先锋霉素Ⅵ、先锋必等8种药物极度敏感,对先锋霉素Ⅴ、妥布霉素、庆大霉素、利福平、链霉素、卡那霉素、阿米卡星等7种药物高度敏感,而对氨苄青霉素、苯唑青霉素、青霉素G、万古霉素等4种药物具有耐药性。【结论】引起广西龙州某养殖场斑点叉尾鮰腹水病的病原菌是温和气单胞菌,可选用复达欣、氧氟沙星、头孢呋肟、先锋噻肟、菌必治、呋喃妥因、先锋霉素Ⅵ、先锋必等8种极敏感的药物进行防治。

[Objective]Isolation and identification of ascites disease pathogen from channel catfish and its drug sensitivity test were conducted in a fish farm in Longzhou of Guangxi to provide references for effective prevention and treatment of the disease.[Method]Pathogen was separated from the heart,lever and ascites in diseased fish using routine method.Pathogen was determined by artificial infection experiment.Pathogen was identified using API 20NE and 16S rRNA gene sequence analysis.kirby-Bauer method was used to test drug sensitivity.[Result]Two separated Aeromonas sobria GXCW01 and GXCW02 possessed strong pathogenicity,and they had close relationship with Aeromonas sobri ATCC 43979（X74683） and NCIMB 12065 （X60412）.Similarity with GXCW01 was 99.0％,and similarity with GXCW02 was 99.4％.The two pathogens showed identical results to the drugs.They were extremely sensitive to eight medicines,such as ceftazidime,ofloxacin,cefuroxime,cefalotin,ceftriaxone sodium,macrodantin,cephalosporinⅥ and cefobid and highly sensitive to six medicines including cephalosporin Ⅴ,tobramycin,gentamicin,rifampicin,streptomycin,kanamycin and amikacin.They had drug resistance to four medicines,which were ampicillin,oxacillin,penicillin G and vancomycin.[Conclusion]The pathogen caused ascites diseased channel catfish was Aeromonas sobria in a fish farm in Longzhou of Guangxi.Eight extremely sensitive medicines （ceftazidime,ofloxacin,cefuroxime,cefalotin,ceftriaxone sodium,macrodantin,cephalosporinⅥ and cefobid）could be prescribed for prevention and treatment.