Pathogenic Analysis And Molecular Typing Of Salmonella Choleraesuis Causing An Outbreak Foodborne Infection

Objective:To carry out pathogenic analysis and molecular typing of Salmonella choleraesuis strain cultured in the feces of 6 diarrhea patients,to determine the nature of the foodborne infection,and to understand the pathogenic characteristics and tolerance of the pathogenic bacteria.Methods:1.Collect and analyze the clinical medical records of patients with acute diarrhea who came to our hospital for diarrhea clinics from May 10 to May 14.2.Bacterial culture and identification of stool specimens from patients with diarrhea.3.The strain was subjected to antibiotic susceptibility test using the disc diffusion method for the identified Salmonella choleraesuis.4.Pulsed Field Gel Electrophoresis(PFGE): Cluster analysis of the electrophoresis band spectra was performed using BioNumerics software.5.Detection of 9 virulence genes including invA,sitC,hilA,sifA,mgtC,siiE,spvB,Prot6 E and pefA in 6 strains of Salmonella choleraesuis by polymerase chain reaction.Results:1.Six patients(3 males and 3 females)presented to our hospital for different degrees of diarrhea.The consultation period was concentrated from May 10 to May 14,2016.All 6 patients came to eat at the same chain restaurant.,the pathogenesis and clinical manifestations are similar,suspected of eating contaminated raw meat.2.After pathogenic culture and identification of bacterial molecules,the results of 6strains of Salmonella choleraesuis.3.6 strains of Salmonella choleraesuis have the same antibacterial spectrum,sensitive to ceftriaxone,gentamicin,acarbamicin,tetracycline,ciprofloxacin,norfloxacin,chloramphenicol,and resistant to ampicillin.4.After restriction endonuclease digestion and pulsed field electrophoresis,the banding patterns of the 6 strains were consistent,and then BioNumerics7.6 software was used to study the banding patterns.The similarity of the bacterial strains was94.0~ 99.0%,which was confirmed to be homologous.5.Six strains of salmonella cholerae porcine carry the same virulence genes,invA,sitC,hilA,sifA and mgtC.The virulence genes spvB,pefA and prot6 E were not detected.Conclusions:1.According to the clinical experience of the patients,epidemiological data combined with the pfeg electrophoresis spectrum of pathogenic bacteria,virulence gene spectrum and antibiotic drug sensitivity spectrum analysis,it can be preliminarily determined that the foodborne event involved in this experiment is an outbreak of foodborne infection caused by salmonella cholerae.2.Great importance should be attached to food hygiene and safety to control outbreaks of foodborne infections at the source of food supply.