Open AccessEvaluation of viable Mycobacterium avium subsp. paratuberculosis in milk using peptide‐mediated separation and Propidium Monoazide qPCR
Author(s) -
Ricchi Matteo,
De Cicco Caterina,
Kralik Petr,
Babak Vladimir,
Boniotti Maria B.,
Savi Roberto,
Cerutti Giulia,
Cammi Giuliana,
Garbarino Chiara,
Arrigoni Norma
Publication year - 2014
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/1574-6968.12480
Subject(s) - paratuberculosis , propidium monoazide , pasteurization , biology , mycobacterium avium subsp. paratuberculosis , mycobacterium , food science , microbiology and biotechnology , bacteria , real time polymerase chain reaction , biochemistry , genetics , gene
The causative agent of paratuberculosis in ruminants, Mycobacterium avium subsp. paratuberculosis (MAP), although still a matter of debate, has been linked with Crohn's and other human diseases. The availability of rapid methods for assessing the viability of MAP cells in food, in particular milk, could be of great use for risk management in food safety. MAP viability is generally assessed using culture techniques that require prolonged incubation periods for the growth of MAP. To differentiate between viable and nonviable MAP cells in milk samples, this study explores the combination of two already described techniques: peptide magnetic bead separation followed by Propidium Monoazide qPCR . Using an Ordinal Multinomial Logistic Regression model to analyze the results obtained after spiking milk samples with mixtures containing different percentages of viable/dead cells, we were able to assess the probability of the viability status of MAP found in milk. This model was applied to contaminated pasteurized milk to ascertain the efficacy of heat treatment in MAP killing. The method reported herein can potentially be used for direct detection of MAP viability in milk.