Development of PMAxxTM-Based qPCR for the Quantification of Viable and Non-viable Load of Salmonella From Poultry Environment

• Published in: Frontiers in microbiology 2020-09, Vol.11, p.581201-581201
• Main Authors: Zhang, Jiawei, Khan, Samiullah, Chousalkar, Kapil K.
• Format: Article
• Language: English
• Subjects: Microbiology; PMAxx-based qPCR; poultry production; Salmonella contamination; Salmonella load; viability assay
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2020.581201

Determining the viable and non-viable load of foodborne pathogens in animal production can be useful in reducing the number of human outbreaks. In this study, we optimized a PMAxx TM -based qPCR for quantifying viable and non-viable load of Salmonella from soil collected from free range poultry environment. The optimized nucleic acid extraction method resulted in a significantly higher ( P < 0.05) yield and quality of DNA from the pure culture and Salmonella inoculated soil samples. The optimized primer for the amplification of the invA gene fragment showed high target specificity and a minimum detection limit of 10 2 viable Salmonella from soil samples. To test the optimized PMAxx TM -based qPCR assay, soil obtained from a free range farm was inoculated with Salmonella Enteritidis or Salmonella Typhimurium, incubated at 5, 25, and 37°C over 6 weeks. The survivability of Salmonella Typhimurium was significantly higher than Salmonella Enteritidis. Both the serovars showed moisture level dependent survivability, which was significantly higher at 5°C compared with 25°C and 37°C. The PMAxx TM -based qPCR was more sensitive in quantifying the viable load compared to the culture method used in the study. Data obtained in the current study demonstrated that the optimized PMAxx TM -based qPCR is a suitable assay for quantification of a viable and non-viable load of Salmonella from poultry environment. The developed assay has applicability in poultry diagnostics for determining the load of important Salmonella serovars containing invA .