Surveillance of Salmonella in population in Chongqing,2007

Objective To conduct surveillance of Salmonella in population and study of drug resistance and PFGE typing of Salmonella strains isolated in Chongqing.Methods The surveillance case definition was determined,the surveillance schema was developed and implemented,Salmonella strains were isolated and identified.The drug susceptibility test of isolated Salmonella strains was conducted by Kirby-Bauer method,and the molecule typing was performed by PFGE.Results A total of 835 cases of Salmonella infection were under surveillance in 2007,these cases distributed in 9 districts /counties.Ten Salmonella infection outbreaks were detected(175 cases).Seventy nine strains of Salmonella were isolated,which belonged to 11 serotypes and B serogroup.All the strains were resistant to one antibiotics at least,9 strains(75%) were resistant to ≥3 antibiotics,2 strains(16.67%) were resistant to 6 antibiotics.Particularly,Salmonella reading,Salmonella infantis,Salmonella thompson were highly resistant to antibiotics.The Salmonella strains isolated were divided into 9 PFGE types with 14 subtypes.Conclusion No predominating strains were detected among the isolates of Salmonella in population in Chongqing in 2007;the PFGE types were same for the strains in an outbreak;the drug resistances of the strains isolated were high and the drug resistance spectrum and PFGE type of isolated strains did not related with each other obviously.