Open AccessDevelopment of a PCR test system for specific detection of Salmonella Paratyphi B in foods
Author(s) -
Zhai Ligong,
Yu Qian,
Bie Xiaomei,
Lu Zhaoxin,
Lv Fengxia,
Zhang Chong,
Kong Xiaohan,
Zhao Haizhen
Publication year - 2014
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/1574-6968.12443
Subject(s) - salmonella , salmonella enterica , serotype , microbiology and biotechnology , biology , pathogen , polymerase chain reaction , multiplex polymerase chain reaction , escherichia coli , real time polymerase chain reaction , enterobacteriaceae , virology , gene , bacteria , genetics
Salmonella enterica serotype Paratyphi B is a globally distributed human‐specific pathogen causing paratyphoid fever. The aim of this study was to develop a rapid and reliable polymerase chain reaction ( PCR ) assay for its detection in food. The SPAB _01124 gene was found to be unique to S . Paratyphi B using comparative genomics. Primers for fragments of the SPAB _01124 gene and the Salmonella ‐specific invA gene were used in combination to establish a multiplex PCR assay that showed 100% specificity across 45 Salmonella strains (representing 34 serotypes) and 18 non‐ Salmonella strains. The detection limit was 2.2 CFU mL −1 of S . Paratyphi B after 12‐h enrichment in pure culture. It was shown that co‐culture with S. Typhimurium or Escherichia coli up to concentrations of 3.6 × 10 5 CFU and 3.3 × 10 4 CFU, respectively, did not interfere with PCR detection of S . Paratyphi B. In artificially contaminated milk, the assay could detect as few as 62 CFU mL −1 after 8 h of enrichment. In conclusion, comparative genomics was found to be an efficient approach to the mining of pathogen‐specific target genes, and the PCR assay that was developed from this provided a rapid, specific, and sensitive method for detection of S . Paratyphi B.