Novel duplex real-time Taqman PCR assay for rapid detection of Enterobacter sakazakii in powdered infant formula

Abstract

To develop a dulplex real-time Taqman polymerase chain reaction(PCR)assay for the detection of Enterobacter sakazakii. Primers and probes were designed based on the sequences of the macromolecular synthesis(MMS)operon and outer member protein A(ompA). Sensitivity and specificity of the assay were evaluated. Detection limit of the assay in pure culture was 4.3×103 CFU/mL and as few as 2 CFU/100 g of Enterobacter sakazakii could be detected in artificially contaminated infant formula through 24 h of enrichment. All of 15 Enterobacter sakazakii strains were successfully identified,no specific amplification were presented when 24 non-Enterobacter sakazakii were tested. The duplex real time Taqman PCR assay developed in study was sensitivity,specific and rapid. It could be used for detection of Enterobacter sakazakii from infant milk powder for food safety.