Abstract:Cronobacter sakazakii in infant and baby food can lead newborns and infants to infect meningitis, sepsis and necrotizing enterocolitis, and composed serious threat to their health. In this study, 3 molecular subtyping methods including pulse field gel electrophoresis(PFGE), multilocus sequence typing (MLST) and enterobacterial repetitive intergenic consensus sequence PCR(ERIC-PCR) were used for Cronobacter sakazakii subtyping for its quick and accurate epidemiological investigation and analysis. Cronobacter sakazakii was isolated from infant formula milk powder, rice flour and complementary food. The classification and subtyping efficiency of the 3 methods were evaluated by Simpson's diversity index (DI) value. The results indicated that PFGE, MLST and ERIC-PCR classified 37 Cronobacter sakazakii isolates into 35 PFGE genotypes, 23 ST types and 28 different ERIC-PCR subtypes, respectively. DI values of PFGE, MLST and ERIC-PCR were 99.55%, 96.40% and 98.05%, respectively. Three molecular methods had high classification ability for Cronobacter sakazakii subtyping, among which, PFEG showed the highest subtyping ability and efficiency.