Abstract: In this article, the species-specific PCR and real time PCR were developed to detect the 16S～23S rDNA internal transcribed spacer (ITS) of E. sakazakii. One pair of specific primers were designed by sequencing the ITS of six strains ofE. sakazakii and BLAST of GenBank. The specificity of the PCR and real time PCR methods were tested against a panel of 18 different bacterial strains. All of the E. sakazakii strains generated positive signal, and no cross-reaction was observed with non- E. sakazakii strains in the PCR and real time PCR. Sensitivity of the detections is (2.2～5.4) CFU/100g dehydrated powdered milk with the selective enrichment. The comparative tests indicated that both results of the PCR and real time PCR are consistent with those of the FDA BAM by detecting 110 pieces of dehydrated powdered milk. This study demonstrated that the PCR and real time PCR methods are reliable,rapid and deserved to be generalized and applied to routine detections.

Key words: dehydrated powdered milk, Enterobacter sakazakii, ITS, PCR(polymerase chain reaction), real time PCR