China Animal Husbandry and Veterinary Medicine ›› 2023, Vol. 50 ›› Issue (12): 5114-5122.doi: 10.16431/j.cnki.1671-7236.2023.12.033

• Basic Veterinary Medicine • Previous Articles     Next Articles

Isolation and Identification of Pathogenic Bacteria Associated with Neurological Signs of Jinding Ducks

LIU He1,2, LI Qiong2, HUANG Jingjing2, HU Xiaoyang2, WANG Xiaoyan2, ZHAO Hui3   

  1. 1. Centre for Animal Disease Prevention and Control in Fushun City, Fushun 113006, China;
    2. College of Veterinary Medicine, China Agricultural University, Key Laboratory of Animal Epidemiology and Zoonoses of Ministry of Agriculture and Rural Affairs, Beijing 100193, China;
    3. Liaoning Academy of Agricultural Sciences, Shenyang 110161, China
  • Received:2023-06-06 Online:2023-12-05 Published:2023-11-28
  • Contact: 国家现代农业产业技术体系(CARS-42-16、CARS-42-32) E-mail:wxy320@cau.edu.cn;zhaohui_sy@126.com

Abstract: 【Objective】 The aim of the present study was to determine the pathogenic bacteria responsible for neurologic signs of Jinding ducks.【Method】 Twenty-two sick ducks,which displayed neurologic signs and lesions of fibrinous pericarditis,perihepatitis and airsacculitis,were randomly selected from four 24- to 48-day-old flocks of Jinding ducks from a region with intensive egg-laying duck production in Liaoning province.Brain tissues were sampled and bacterial isolation were performed by using tryptic soy agar (TSA) and MacConkey’s agar (MCA),and identified by Gram and Wright’s staining,biochemical testing,and 16S rDNA gene sequencing.【Result】 The 19 strains of bacteria isolated from the brain tissue of Jinding duck were all Gram-negative bacteria.Among them,17 (named H1-H17) failed to grow in MCA and tested negative in the biochemical assays,whereas other 2 isolates (named H18 and H19) formed red colonies in MCA,fermented glucose,lactose,and maltose,and were methyl red and indole positive.On the basis of comparative analyses of the 16S rDNA amplicon sequences,the 17 isolates represented by H1 shared 99.1%-100% identities with reference strains of RA serotypes 1 to 19.The H18 and H19 isolates were 99.2%-99.9% identical to the selected eight reference Escherichia coli strains.Phylogenetic analysis based on the amplified 16S rDNA amplicon sequences further demonstrated that the 17 isolates represented by H1 belonged to RA and that isolates H18 and H19 belonged to Escherichia coli.【Conclusion】 In the studied cases,RA was responsible for neurologic signs in Jinding ducks,and that Escherichia coli could also cause neurologic signs in Jinding ducks.

Key words: Jinding duck; Riemerella anatipestifer; Escherichia coli; neurologic signs

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