Premium
Evaluation of culture‐based and molecular detection methods for Campylobacter in New Zealand raw cows’ milk
Author(s) -
Kingsbury J.M.,
Soboleva T.K.
Publication year - 2021
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/jam.14798
Subject(s) - campylobacter , campylobacter jejuni , raw milk , food science , campylobacter coli , agar , biology , microbiology and biotechnology , bacteria , genetics
Aims This study evaluated the performance of a commercial molecular detection method (mericon Campylobacter triple kit real‐time/quantitative (q)PCR) and a selective plating medium (R&F Campylobacter jejuni/Campylobacter coli Chromogenic Plating Medium (CCPM)) against a culture‐based reference method (ISO 10272‐1:2017 detection procedure B) for the detection of Campylobacter from raw milk enrichment broths. Methods and Results New Zealand raw cows’ milk and Ultra‐High Temperature‐processed milk samples were inoculated with 50, 125 and 500 colony forming units of C. jejuni and C. coli cocktail per analytical unit. Samples were tested for Campylobacter after 0, 24‐ and 48 h refrigeration. ISO 10272‐1:2017 proved to be a sensitive detection method (77/80 positive samples); detection only failed for some milk samples tested 48 h postinoculation. CCPM was as effective as Cefoperazone Charcoal Deoxycholate Agar for selective plating of Campylobacter raw milk enrichments (78/80 positive samples). However, the qPCR detected Campylobacter in only 42/80 samples and qPCR reaction inhibition was observed. Conclusions The ISO 10272‐1:2017 method was a more sensitive method for Campylobacter detection from raw milk than the mericon Campylobacter triple kit qPCR, and CCPM was a useful complementary medium to mCCDA where one of these media is required by the standard. Significance and Impact of the Study In regions where testing is required or recommended, optimized methods for Campylobacter detection from raw milk will reduce risk to the raw milk consumer. Although molecular methods are generally touted as a rapid alternative to culture, issues with inhibition due to matrix components mean that culture‐based methods might provide the most sensitive option for Campylobacter detection in raw milk. Findings also emphasize the importance of minimizing the time between milk collection and testing for Campylobacter .