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Zhai L, Li J, Tao T, Lu Z, Lv F, Bie X. Propidium monoazide real-time PCR amplification for viable Salmonella species and Salmonella Heidelberg in pork. Can J Microbiol 2019; 65:477-485. [PMID: 30865841 DOI: 10.1139/cjm-2018-0547] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Salmonella enterica serovar Heidelberg causes foodborne infections and is a major threat to the food chain and public health. In this study, we aimed to develop a rapid molecular typing approach to identify Salmonella enterica serovar Heidelberg. Using comparative genomics, four serovar-specific gene fragments were identified, and a real-time polymerase chain reaction (PCR) combined with a propidium monoazide (PMA) pretreatment method was developed for simultaneous detection of viable Salmonella sp. (invA) and Salmonella Heidelberg (SeHA_C3258). The assay showed 100% specificity for all strains tested. The assay was able to distinguish effectively viable or dead cells with the PMA. The detection limit was 2.4 CFU/mL following 6 h of incubation in enrichment Luria-Bertani medium, and the assay could detect 1.7 × 102 CFU/mL in the presence of pork background flora. In artificially contaminated pork, real-time PCR detected inoculum levels of 1.15 CFU/25 g of pork after a 6 h enrichment. Thus, our findings indicated that this comparative genomics approach could be used to screen for serovar-specific fragments and that real-time PCR with PMA was a simple and reliable method for detecting viability of Salmonella species and Salmonella Heidelberg.
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Affiliation(s)
- Ligong Zhai
- a College of Food Science and Technology, Nanjing Agricultural University, Key Laboratory of Food Processing and Quality Control, Ministry of Agriculture of China, Nanjing, Jiangsu Province, China.,b College of Food Engineering, Anhui Science and Technology University Chuzhou, Anhui Province, China
| | - Junjie Li
- a College of Food Science and Technology, Nanjing Agricultural University, Key Laboratory of Food Processing and Quality Control, Ministry of Agriculture of China, Nanjing, Jiangsu Province, China
| | - Tingting Tao
- a College of Food Science and Technology, Nanjing Agricultural University, Key Laboratory of Food Processing and Quality Control, Ministry of Agriculture of China, Nanjing, Jiangsu Province, China
| | - Zhaoxin Lu
- a College of Food Science and Technology, Nanjing Agricultural University, Key Laboratory of Food Processing and Quality Control, Ministry of Agriculture of China, Nanjing, Jiangsu Province, China
| | - Fengxia Lv
- a College of Food Science and Technology, Nanjing Agricultural University, Key Laboratory of Food Processing and Quality Control, Ministry of Agriculture of China, Nanjing, Jiangsu Province, China
| | - Xiaomei Bie
- a College of Food Science and Technology, Nanjing Agricultural University, Key Laboratory of Food Processing and Quality Control, Ministry of Agriculture of China, Nanjing, Jiangsu Province, China
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