China Animal Husbandry and Veterinary Medicine ›› 2021, Vol. 48 ›› Issue (4): 1457-1465.doi: 10.16431/j.cnki.1671-7236.2021.04.034

• Basic Veterinary Medicine • Previous Articles     Next Articles

Isolation,Identification and Pathogenicity Analysis of a Strain of Non-O1/O139 Vibrio cholerae from Duck

ZHANG Tiantian1,2, WU Zhengzhuo1,4, CHEN Guoquan1,2, WANG Na1,2, ZHOU Bijun1,2,3, CHENG Zhentao1,2,3, WEN Ming1,2,3, WANG Kaigong1,2,3   

  1. 1. College of Animal Science, Guizhou University, Guiyang 550025, China;
    2. Institute of Animal Diseases, Guizhou University, Guiyang 550025, China;
    3. Guizhou Provincial Key Laboratory of Animal Diseases and Veterinary Public Health, Guiyang 550025, China;
    4. Sansui County Duck Industrialization Construction Management Office, Sansui 556500, China
  • Received:2020-08-19 Online:2021-04-20 Published:2021-04-16

Abstract: In order to find out the pathogen,pathogenicity and drug resistance of ducklings in a duck farm in Guizhou province,we dissected the ducks suspected of bacterial infection in the duck farm,tissues and organs such as nasal mucosa,heart and liver were inoculated in the culture medium for bacterial isolation and identification,and studied the drug resistance and pathogenicity of the isolate by drug sensitivity test,animal regression test and virulence gene detection.The results showed that the isolated bacteria grew on the blood agar medium for 16 h and showed a smooth and glossy milky white colony with β-hemolysis.The isolated bacteria were Gram-negative short bacilli with blunt round ends and irregular arrangement under the biological microscope,which was consistent with Vibrio cholera.The homology and phylogenetic tree of 16S rDNA gene sequence showed that the homology of the isolate and Vibrio cholerae were as high as 99.6% to 99.7% and were clustered into one branch.The results of drug sensitivity showed that the isolate was resistant to most drugs,including ampicillin,clindamycin,compound trimethoprim,oxacillin,clindamycin and so on,and the isolate was highly sensitive to cefoperazone and ceftriaxone.The results of animal regression test showed that the isolated strain could cause all ducklings to die within 5 days,which indicated that the isolate had strong pathogenicity to ducklings.PCR detection of virulence genes showed that hlyA,ompW and chxA genes of Vibrio cholerae were positive,while the O1 group rfb,O139 group rfb,tcpA and ctxA genes were negative,indicating that the Vibrio cholerae isolated in this study carried pathogenic genes,but did not belong to O1 and O139 serogroups.The results showed that the pathogen was non-O1/O139 Vibrio cholerae,which was highly pathogenic and resistant to many antibiotics.The results provided a reference for the prevention and control of duck Vibrio cholerae in Guizhou province.

Key words: duck; non-O1/O139 Vibrio cholerae; drug susceptibility test; virulence gene

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