Use of PFGE to analyze an outbreak of food poisoning caused by Salmonella enteritidis

Objectives To isolate and identify the pathogen responsible for an outbreak of food poisoning in a district of Wuhan in 2014 and to analyze the homology of those pathogens. Methods The pathogen was isolated and cultured in accordance with the methods in GB 4789-2012 and WS/T 13-1996,and the pathogen was typed and identified.Pulsedfield gel electrophoresis(PFGE)was used to molecularly type the pathogen and strains of Salmonella enteritidis from the laboratory,and PFGE was used to analyze the epidemiological characteristics of the pathogen and strains of S.enteritidis.Susceptibility testing was carried out using the modified K-B method recommended by the WHO. Results Results of an epidemiological study and laboratory testing indicated that the outbreak of food poisoning was caused by S.enteritidis.In total,18 strains were isolated.Strains isolated from suspected food sources had 100% similarity to S.enteritidis from anal swabs of patients who suffered food poisoning and 90% similarity to clinical isolates from patients during the same period.The isolated strains were least similar(similarity of less than 90%)to isolates from physical exams conducted in2012 and clinical isolates from patients in 2013-2014.Strains that were responsible for the outbreak of food poisoning were more sensitive to antibiotics than other strains. Conclusion The pathogens responsible for the outbreak of food poisoning are dominant strains of S.enteritidis that are prevalent in this region.PFGE can be used to analyze the origins of bacterial food poisoning.