title: [Development of modified molecular beacon based real-time PCR assay for the rapid detection of Salmonella choleraesuis and Salmonella paratyphi C].
abstract: OBJECTIVE
  To develop real-time PCR assay based on modified molecular beacon for simultaneous detection of S. choleraesuis and S. paratyphi C. The established method was applied to the rapid detection of S. choleraesuis in food and stool samples of food poisoning, and then was applied to the identification of Salmonella C.
  
  
  METHODS
  Based on the sequences (CP000857.1) published in GenBank, Two sets of primers and modified molecular beacon were designed. The Real-time PCR assay for the simultaneous detection of S. paratyphi C and S. choleraesuis was developed with optimized PCR procedures and PCR components, while other 11 different bacterial species were as the control. Then the sensitivity and specificity of the assay were tested using 77 Samonella strains. The assay was applied to the detection of 70 food samples.
  
  
  RESULTS
  The limit of detection achieved was 10 fg/reaction or 20 CUF/reaction, Only Salmonella paratyphi C and Salmonella choleraesuis strains generated fluorescent signals. No cross-reaction was observed with other 11 bacterium, the sensitivity and specificity were both 100%. No samples among 70 food samples were found Salmonella positive by both real-time PCR assay and traditional culture method. It could be finished within 2 hours from template preparation to detection and the overall test would be finished within one day.
  
  
  CONCLUSIONS
  The real-time PCR assay was rapid, sensitive and specific. It could be applied to the rapid diagnosis of S. paratyphi C and S. choleraesuis in food and stool samples of food poisoning and the identification of Salmonella C to guarantee food safety.
authors.affiliation: Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China.
authors.forename: Yiman
authors.initials: Y
authors.lastname: Lin
authors.forename: Xiaolu
authors.initials: X
authors.lastname: Shi
authors.forename: Yumei
authors.initials: Y
authors.lastname: Zhu
authors.forename: Yaqun
authors.initials: Y
authors.lastname: Qiu
authors.forename: Yinhui
authors.initials: Y
authors.lastname: Li
authors.forename: Dongyue
authors.initials: D
authors.lastname: Lv
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Hu
mesh_terms: D000818:Animals; D005506:Food Contamination / Q000032:analysis; D005516:Food Microbiology; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012478:Salmonella Food Poisoning / Q000382:microbiology*; D012476:Salmonella arizonae / Q000235:genetics / Q000302:isolation & purification*; D012479:Salmonella paratyphi C / Q000235:genetics / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D013552:Swine