China Animal Husbandry and Veterinary Medicine ›› 2023, Vol. 50 ›› Issue (3): 1250-1258.doi: 10.16431/j.cnki.1671-7236.2023.03.039

• Basic Veterinary Medicine • Previous Articles     Next Articles

Isolation,Identification and Drug Sensitivity of 3 Strains of Riemerella anatipestifer

CHEN Dong1, ZHANG Yanhao1, ZHANG Yang1, LI Sen1, ZHOU Zutao1,2,3, LI Zili1,2,3   

  1. 1. Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China;
    2. Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Wuhan 430070, China;
    3. State Key Laboratory of Agricultural Microbiology, Wuhan 430070, China
  • Received:2022-09-25 Online:2023-03-05 Published:2023-03-02

Abstract: 【Objective】 The purpose of this study was to understand the distribution and prevalence and drug resistance of Riemerella anatipestifer (R.anatipestifer) in some areas of Hubei,and further to provide a reference for the clinical medication of this disease on duck farms in these regions.【Method】 The suspected cases of R.anatipestifer from meat duck farms in districts and counties around Wuhan (Jiangxia district,Huangpi district,Huangmei county) were sampled and the pathogenic bacteria were isolated.The morphology,dyeing characteristics,biochemical characteristics and 16S rRNA of the isolated bacteria were identified.The serotype and drug resistance of the isolated strains identified as R.anatipestifer were analyzed.The genomes of the isolated strains were identified by specific primer PCR of marker gene integrase to determine whether 50K gene island was integrated.【Result】 A total of three R.anatipestifer strains were identified.All the three strains could grow as the morphology of smooth translucent colonies on TSA plate medium.The results of Gram staining for the three isolated strains were negative,and the results of Wright staining showed bipolar dyeing.Biochemical test results showed that the three strains of R.anatipestifer did not ferment glucose,were catalase positive,did not produce hydrogen sulfide,and could not liquefy gelatin.16S rRNA identification results showed that the target band with a size of 1 480 bp was obtained,and the serotype was type 1.PCR amplification results showed that only the isolated HM strain contained the 50K genomic island.Minimum inhibitory concentration and Kirby-Bauer tests showed that these strains were sensitive to penicillin,amoxicillin,ceftriaxone,cefotaxime,florfenicol and gentamicin,and vary degrees of resistance to nalidixic acid,spectinomycin,enrofloxacin and polymyxin B.【Conclusion】 In this study,three strains of serotype 1 R.anatipestifer strains were isolated and identified,the results of drug sensitivity could provide some theoretical guidance for the prevention,treatment and epidemiological study of R.anatipestifer in these regions.

Key words: Riemerella anatipestifer; isolation; identification; serotype; 50K genomic island; drug sensitivity

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