Specific PCR Primers for the Identification of Salmonella enterica Serovar Enteritidis in Chicken-Related Samples
SHU-JEN WANG1*, DONG-BOR YEH2 AND CHENG-I WEI3
1.Department of Food Science and Technology, Chia Nan University of Pharmacy and Science, Taiwan (R.O.C.)
2.Department of Biotechnology, Chia Nan University of Pharmacy and Science, Tainan, Taiwan (R.O.C.)
3.College of Agriculture and Natural Resources, University of Maryland, Maryland 20742, U.S.A.
(Received: December 10, 2007; Accepted: March 27, 2009)
ABSTRACT
In this study, a designed pair of PCR primers, SefB127L-SefB661R, based on the sefb gene (accession number L11009) sequences was used in polymerase chain reaction (PCR) for rapid evaluation of Salmonella enterica serovar Enteritidis in chickenrelated samples. The specificity of this method was checked with 85 Salmonella strains and 17 non-Salmonella strains. The results showed that only 24 isolates of S. enterica serovar Enteritidis exhibited 535 bp PCR product. The detection limit of this PCR method were evaluated using 40 spiked samples under enrichment protocols. The data revealed that microbial extract from as few as 101 target cells per gram of the sample culture was required for this assay. Before PCR amplification, pre-culture and the cell lysates, rather than the DNA extracts, were used directly for all tested samples. To verify the usefulness of this PCR process for S. enterica serovar Enteritidis examination, 285 endogenous samples including chicken meats, eggs and swabs of chicken-related samples and coop’s facilities were tested and compared with that obtained by conventional BAM (Bacteriological Analytical Manual) method. About 1% (three in 285) of the S. enterica serovar Enteritidis samples was contaminated, approximately the same as that obtained from BAM method.
Key words: PCR, Salmonella enterica serovar Enteritidis, cell lysates