American Journal of Infectious Diseases

Isolation and Identification of Listeria monocytogenes in Processed Meat by a Combined Cultural-molecular Method

Angela Ingianni, Marta Quartuccio, Maria Antonietta Madeddu, Adriana Sanna, Sandro Dessì and Raffaello Pompei

DOI : 10.3844/ajidsp.2007.159.164

American Journal of Infectious Diseases

Volume 3, Issue 3

Pages 159-164

Abstract

The isolation and identification of Listeria monocytogenes in processed meat samples by a combined cultural-molecular method is described. It allows the identification of Listeria strains by means of a hybridization technique with a specific DNA probe directed to the listerial internalin gene. The specificity of this method was found to be 100% and sensitivity was as low as 1 CFU/2.5 g of food sample. A total of 278 meat samples were tested in comparison with PCR and conventional cultural assays. A total of 42 (15.4%) L. monocytogenes were detected. PCR analysis gave 3 false negative results and culture failed to detect the Listeria in 5 cases. With this cultural-molecular method the identification and quantitative detection of L. monocytogenes were achieved within 36 hours and no false positive or negative tests were obtained, thus fitting most food industry requirements.

Copyright

© 2007 Angela Ingianni, Marta Quartuccio, Maria Antonietta Madeddu, Adriana Sanna, Sandro Dessì and Raffaello Pompei. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.