China Animal Husbandry and Veterinary Medicine ›› 2021, Vol. 48 ›› Issue (3): 1084-1092.doi: 10.16431/j.cnki.1671-7236.2021.03.033

• Basic Veterinary Medicine • Previous Articles     Next Articles

Isolation,Identification and Virulence Gene Detection of a Strain of Proteus mirabilis from Ducks

YANG Xia1,2, ZHANG Piao1,2, ZENG Maoqin1,2, LIU Yanhan1,2, CHENG Zhentao1,2,3, WEN Ming1,2,3   

  1. 1. College of Animal Science, Guizhou University, Guiyang 550025, China;
    2. Institute of Animal Diseases, Guizhou University, Guiyang 550025, China;
    3. Key Laboratory of Animal Disease and Veterinary Public Health of Guizhou Province, Guiyang 550025, China
  • Received:2020-08-19 Online:2021-03-20 Published:2021-03-18

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Abstract: This experiment was aimed to study the drug resistance and pathogenicity of the duck isolate.Through isolation and identification of bacteria,drug sensitivity test,PCR detection of drug resistance genes and virulence genes,and animal pathogenicity test,a bacterial strain was successfully isolated.The purified bacteria had two forms of Gram staining,some looked like short rod-shaped,some were as long and thin as hair,and Gram-negative,the isolated strain was named as GZGY2020.The biochemical reaction showed that the isolated bacteria had obvious motility,M-R test and V-P test were positive,and the biochemical characteristics were consistent with Proteus mirabilis.The 16S rDNA gene phylogenetic tree showed that the isolate was in the same branch as Proteus mirabilis.The results of drug sensitivity test showed that the isolate was resistant to multiple drugs,it was resistant to 16 drugs including carbenicillin,cephalexin,and oxacillin among 18 drugs,and the drug resistance rate was as high as 88.9%,and only sensitive to ceftazidime and ciprofloxacin.PCR results showed that it contained sulfonamides resistance genes sul1 and sul2 and β-lactam resistance gene VIM,and 9 virulence genes including hpmA,rsmA,atfA,ucaA,ureC,zapA,pmfA,fliL and mrpA.The results of animal regression test showed that the isolated bacteria had strong pathogenicity to ducklings,1×108 CFU/mL bacterial solution could kill all ducklings within 1 day.In terms of drug sensitivity,the strain GZGY2020 isolated from dead ducks was different from Proteus mirabilis previously reported,which indicated that the strain might mutate and lead to increased virulence.However,only one of the 10 virulence genes detected had no corresponding bands,indicating that Proteus mirabilis was an important pathogen causing the death of the duck,which should be paid more attention.

Key words: duck; Proteus mirabilis; drug resistance gene

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