[Study on a duplex specific detection of Salmonella spp. in foods by a duplex PCR].
OBJECTIVE
To develop a rapid duplex PCR assay for detection of Salmonella spp. in foods.


METHODS
Two sets of primers that specific amplified segments of the invA, hilA genes were designed to detect Salmonella spp. Sixteen Salmonella spp. and twenty-four non Salmonella spp. were amplified by PCR to confirm the specificity. The genomic DNA was serially diluted and subjected by PCR amplification to verify sensitivity. Various numbers of bacteria were added into pork. After different time of enrichment, DNA was extracted and amplified by PCR to verify detection limit. This method was applied to detect naturally contaminated samples.


RESULTS
The PCR system were specific. The detection limit of the sensitivity was 0.1332pg with genomic DNA and 2.5 cfu/ml in artificially contaminated pork. Fifty-three foods were detected by the duplex PCR and twenty-one were found to be positive.


CONCLUSIONS
A rapid, sensitive and specific duplex PCR assay could be used for detection of Salmonella spp. in foods such as meat, aquatic products and cake.
Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Institute of Microbiology, Guangzhou 510070, China. xuxiaoke209@163.com
Xiaoke
X
Xu
Qingping
Q
Wu
Jumei
J
Zhang
Yanhong
Y
Zhou
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D004269:DNA, Bacterial / Q000032:analysis*; D005516:Food Microbiology; D008460:Meat / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods*; D012475:Salmonella / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D013552:Swine; D015534:Trans-Activators / Q000235:genetics
D001426:Bacterial Proteins; D004269:DNA, Bacterial; C102236:HilA protein, Salmonella; D015534:Trans-Activators; C075518:invA protein, Bacteria