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Objective: To evaluate the adsorption capacity of magnetic beads for common foodborne pathogens., Methods: Escherichia coli, Staphylococcus aureus, Listeria monocytogenes and Cronobacter sakazakii were used as targets, the suitable conditions were obtained by optimization the incubation time, bead size, reaction temperature and so on. The adsorption efficiency of the magnetic beads in analog samples was also tested., Results: The optimum conditions were as follows: 2.0 - 3.0 microm diameter magnetic beads 50 microl, incubation for 60 min under 37 degrees C. In analog samples, the adsorption efficiency of the magnetic beads for Escherichia coli, Staphylococcus aureus, Listeria monocytogenes and Cronobacter sakazakii in juice, milk, duck meat were 50% - 84%, 46% - 66%, 54% - 74%, respectively., Conclusion: Magnetic beads enrichment technique has high adsorption efficiency, simple to operate, which is meet the requirement for PCR detection.

Objective: To establish a real-time PCR assay for the rapid detection of Listeria monocytogenes in simulated milk specimens., Methods: Based on part fragments of hlyO gene, a pair of primers and Taq-Man probe were designed for quantitative detection of L. monocytogenes. The specificity of the primers and probe were tested by using different L. monocytogenes strains and other common pathogenic bacteria., Results: L. monocytogenes strains were positive in the detection and other tested strains were negative. The sensitivity of assay was 9 copies per PCR reaction., Conclusion: The specificity and sensitivity of Taq Man real-time PCR technology for detecting L. monocytogenes in simulated dairy specimens were high, and the assay could be completed within 1.5 h. This method could be used to detect other food samples contaminated by L. monocytogenes and identify the cause of food-borne Listeriosis outbreaks.

Enterobacter sakazakii, one of the major pathogens affecting the safety of infant formula powder was defined as a species in 1980. However, the new names and new combinations about Enterobacter sakazakii notified in volume 58, part 6, of the International Journal of Systematic and Evolutionary Microbiology (IJSB). The taxonomic relationship of strains described as E. sakazakii, biological characteristics of its new genus and species, the development related to its isolation and identification were reviewed in this paper, in order to facilitate the related personnel to keep in touch with the latest developments on E. sakazakii. It's also conducive to unify and standardize the Chinese name for E. sakazakii.