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Demonstration of the effective performance of a combined enrichment /real‐time PCR method targeting the prfA gene of Listeria monocytogenes by testing fresh naturally contaminated acid curd cheese
Author(s) -
Rossmanith P.,
Mester P.,
Wagner M.,
Schoder D.
Publication year - 2010
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1111/j.1472-765x.2010.02925.x
Subject(s) - listeria monocytogenes , contamination , food science , listeria , biology , microbiology and biotechnology , gene , food contaminant , polymerase chain reaction , bacteria , food microbiology , chemistry , genetics , ecology
Aims: A rapid real‐time PCR‐based method for the detection of Listeria monocytogenes was applied to the examination of 44 Quargel cheese samples from a recent outbreak in Austria and compared to the standard method according to ISO‐16140. Methods and Results: The combined enrichment/real‐time PCR method amplifying the prfA locus was performed according to [Rossmanith et al. (2006) Res Microbiol , 157, 763–771]. Qualitative and quantitative examination of the samples was performed according to the standard method ISO‐11290. Comparison of the combined enrichment/real‐time PCR method with ISO‐11290 resulted in 100% relative accuracy, 100% relative sensitivity and 100% relative specificity. Conclusions: A previously published study describing the validation of the method, including samples after storage at −80°C, resulted in lower performance values. In contrast, the samples were stored at +4°C in this study. The results of this study indicate an effect of storage, thus masking the true performance of the method. Significance and Impact of the Study: The results of this study are discussed together with the previously published data to demonstrate the excellent qualities of this rapid (≤30 h) method when applied to fresh specimens stored at +4°C.