China Animal Husbandry and Veterinary Medicine ›› 2020, Vol. 47 ›› Issue (2): 637-644.doi: 10.16431/j.cnki.1671-7236.2020.02.037

• Basic Veterinary Medicine • Previous Articles    

A Isolation,Identification and Drug Sensitivity Test of a Pathogen Causing Death of Taiwan Loach (Paramisgurnus dabryanus ssp.Taiwan)

XU Xiandong1, WANG Haihua1, WU Bin1, TAO Zhiying1, MA Benhe1, XI Hongbin2   

  1. 1. Jiangxi Fisheries Research Institute, Nanchang 330039, China;
    2. Fisheries Bureau of Xiajiang County in Jiangxi Province, Xiajiang 331400, China
  • Received:2019-08-06 Published:2020-02-28

Abstract: In order to determine the cause of death of Taiwan loach (Paramisgurnus dabryanus ssp.Taiwan) after the transfer of fishing,the pathological anatomy and pathogen isolation of Taiwan loach were carried out.Morphological observation,physiological and biochemical characteristics determination,16S rDNA gene sequencing and identification were carried out for the isolated bacteria,as well as artificial infection test and drug sensitivity test.The results showed that the dominant strains were isolated from the liver,spleen,kidney and intestine of loach and named as XJC after purification and preservation.The strain XJC was positive in glucose fermentation,D-glucose,ornithine,phenylalanine and urea utilization,and the other biochemical indexes were negative,which was consistent with Morganella morganii.The similarity of 16S rDNA gene sequence with Morganella morganii was 99.6%,which was identified as Morganella morganii.The results of infection test showed that XJC had pathogenicity to the loach,and the infected loach had typical pathological changes of intestinal congestion.The strain XJC was identified as the pathogen of loach.The results of drug sensitivity test showed that XJC was sensitive to aminoglycosides,quinolones and the third generation cephalosporins,and equally resistant to tetracycline,penicillin,erythromycin,polypeptide,furazolidone,lincomycin and the first and the second generation cephalosporins.Aminoglycosides and quinolones could be selected for the prevention and treatment of Morgan's disease.The results of this experiment could provide a reference for the diagnosis and control of Morganella morgensis in Taiwan loach.

Key words: Paramisgurnus dabryanus ssp.Taiwan; Morganella morganii; isolation and identification; drug sensitivity test

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