Simultaneous detection of Salmonella strains and Escherichia coli O157:H7 with fluorogenic PCR and single-enrichment-broth culture.
A multiplex fluorogenic PCR assay for simultaneous detection of pathogenic Salmonella strains and Escherichia coli O157:H7 was developed and evaluated for use in detecting very low levels of these pathogens in meat and feces. Two sets of primers were used to amplify a junctional segment of virulence genes sipB and sipC of Salmonella and an intragenic segment of gene eae of E. coli O157:H7. Fluorogenic reporter probes were included in the PCR assay for automated and specific detection of amplified products. The assay could detect <10 CFU of Salmonella enterica serovar Typhimurium or E. coli O157:H7 per g of meat or feces artificially inoculated with these pathogens and cultured for 6 to 18 h in a single enrichment broth. Detection of amplification products could be completed in </=4 h after enrichment.
Sharma
V K
VK
Pre-Harvest Food Safety and Enteric Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, Iowa 50010, USA. vsharma@nadc.ars.usda.gov
Carlson
S A
SA
D000818:Animals; D001431:Bacteriological Techniques; D002417:Cattle; D015169:Colony Count, Microbial; D019453:Escherichia coli O157 / Q000235:genetics* / Q000302:isolation & purification* / Q000472:pathogenicity; D005243:Feces / Q000382:microbiology; D006801:Humans; D008460:Meat / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods* / Q000706:statistics & numerical data; D012475:Salmonella / Q000235:genetics* / Q000302:isolation & purification* / Q000472:pathogenicity; D012680:Sensitivity and Specificity; D014774:Virulence / Q000235:genetics