Abstract: 【Objective】 This study was conducted to explore the distribution of drug resistance and virulence genes of pathogenic Salmonella Enteritidis isolated from a commercial meat duck farm,and provide reference for the prevention,control and medication of the disease.【Method】 The livers of dead meat ducks were collected for bacterial isolation,and the serotype of the isolated strains was identified by separation and purification,Gram staining microscopy,biochemical test and PCR amplification.The drug sensitivity test was carried out by K-B disk method,and the drug resistance of the strain was analyzed by combining the drug resistance genes.The pathogenicity test of duckling was used to monitor the virulence,mortality and body weight changes of duckling anal swabs,and to evaluate the pathogenicity of strains combined with virulence genes.【Result】 The isolated strain showed purple colonies on the Salmonella chromogenic medium,and the results of Gram staining microscopy were Gram-negative brevis.The results of biochemical identification were negative for indigo matrix,amino acid decarboxylase control,urease,potassium cyanide test biochemical tube and potassium cyanide test control,and positive for lysine decarboxylase,which was consistent with the biochemical characteristics of Salmonella.The target fragment 304 bp was further amplified by PCR primer of Salmonella Enteritidis,which was consistent with the expected fragment size,and then the strain was identified as Salmonella Enteritidis.The results of drug sensitivity showed that the isolate was sensitive to fluoroquinolones and chloramphenicols,but resistant to tetracyclines and β-lactams.Meanwhile，tetA and bla_TEM were detected as drug resistance genes.Eleven virulence genes were detected:bcfC,avrA,sopE,spvR, spvB,spvC,spvD,sopB,siiD,mgtC and ssaQ.The pathogenicity test of ducklings showed that the mortality rate of 7-day-old ducklings was 90%.Salmonella pathogen was detected by anal swab 2 days after the challenge,and the weight of ducklings increased slowly.Anatomical symptoms showed varying degrees of cellulose exudates in the heart and liver.【Conclusion】 In this study,Salmonella Enteritidis were isolated and identified from commercial meat ducks.The strain had strong pathogenic ability to meat ducks,and there were two drug resistance genes and multiple virulence genes.The experimental results could lay a theoretical foundation for further research on the pathogenesis,prevention and treatment of Salmonella Enteritidis.

Key words: commercial meat ducks; Salmonella Enteritidis; isolation and identification; pathogenicity; drug resistance