Duplex PCR for detection of Salmonella and Shigella spp in cockle samples.
Salmonella and Shigella spp are important causative agents of foodborne diseases. A sensitive, specific and rapid method is essential for detection of these pathogens. In this study, a duplex PCR method was developed for simultaneous detection of Salmonella and Shigella spp in cockle samples and compared with the traditional culture method. Enrichment broths for Salmonella spp recovery were also compared. Sensitivity of the duplex PCR for simultaneous detection of Salmonella and Shigella spp from pure culture was 10(3) CFU/ml (40 CFU/PCR reaction), and that of sterile cockle samples spiked with these two pathogens was 1 CFU/10 g of cockle tissue after 9 hours enrichment [3 hours in buffered peptone water (BPW), followed by 6 hours in Rappaport Vasiliadis (RV) broth or tetrathionate (TT) broth for Salmonella spp and 6 hours enrichment in Shigella broth (SB) for Shigella spp]. There was no significant difference in detection sensitivity between enrichment in RV and TT broths. Salmonella spp detected in cockles in Khon Kaen, Thailand by duplex PCR and culture method was 17% and 13%, respectively but Shigella spp was not detected. The duplex PCR technique developed for simultaneous detection of Salmonella and Shigella spp in cockle samples was highly sensitive, specific and rapid and could serve as a suitable method for food safety assessment.
Department of Microbiology and Research and Diagnostic Center for Emerging Infectious Diseases, Faculty of Medicine, Khon Kaen University, Khon Kaen.
Pachara
P
Senachai
Department of Microbiology and Research and Diagnostic Center for Emerging Infectious Diseases, Faculty of Medicine, Khon Kaen University, Khon Kaen.
Chariya
C
Chomvarin
Department of Microbiology and Research and Diagnostic Center for Emerging Infectious Diseases, Faculty of Medicine, Khon Kaen University, Khon Kaen.
Warawan
W
Wongboot
Department of Microbiology and Research and Diagnostic Center for Emerging Infectious Diseases, Faculty of Medicine, Khon Kaen University, Khon Kaen.
Wongwarut
W
Boonyanugomol
Bureau of General Communicable Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand.
Waraluk
W
Tangkanakul
D000818:Animals; D049873:Cardiidae / Q000382:microbiology*; D004269:DNA, Bacterial; D005516:Food Microbiology / Q000295:instrumentation*; D016133:Polymerase Chain Reaction; D012475:Salmonella / Q000235:genetics / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D012760:Shigella / Q000235:genetics / Q000302:isolation & purification*; D013785:Thailand / Q000453:epidemiology
D004269:DNA, Bacterial