Main content area

Rapid detection and specific differentiation of Salmonella enterica subsp. enterica Enteritidis, Typhimurium and its monophasic variant 4,[5],12:i:− by real-time multiplex PCR

Maurischat, Sven, Baumann, Beatrice, Martin, Annett, Malorny, Burkhard
International journal of food microbiology 2015 v.193 pp. 8-14
European Union, Salmonella enterica subsp. enterica, chickens, diseases and disorders (animals and humans), hosts, microbiological criteria, neck, pathogens, probability, quantitative polymerase chain reaction, rapid methods, raw meat, serotypes
Salmonella enterica is one of the most common zoonotic pathogens worldwide causing clinical diseases in human and animal hosts. Targeting a reduction of Salmonella prevalence in poultry, the EU set up a microbiological criterion that demands the absence of S. enterica subsp. enterica serovars Enteritidis and Typhimurium including its monophasic variant with seroformula 4,[5],12:i:− in 25g of poultry neck skin samples and fresh meat according to regulation (EU) no 1086/2011. We developed and in-house validated a method that detects and differentiates these Salmonella serovars based on a 5-plex real-time PCR assay within 24h after sampling. The inclusivity and exclusivity were between 98 and 99% analysing 456 bacterial strains. Validation according to ISO 16140:2003 against the traditional cultural reference method ISO 6579:2002 was performed using 60 artificially contaminated and 31 presumably naturally contaminated chicken neck skin samples resulting in a relative accuracy of 100%. The detection probability reached 100% between 3 and 5CFU/25g sample. We were also able to assign rough and non-motile strains to S. enterica subsp. enterica serovars Enteritidis and Typhimurium. In conclusion, we provide diagnostic laboratories a fast and accurate method to monitor these Salmonella serovars in chicken neck skin samples. Other matrices could be easily adapted.