Open AccessDirect Identification in Food Samples of Listeria spp. and Listeria monocytogenes by Molecular Methods
Author(s) -
Luca Simone Cocolin,
Kalliopi Rantsiou,
Lucilla Iacumin,
C. Cantoni,
Giuseppe Comi
Publication year - 2002
Publication title -
applied and environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.552
H-Index - 324
eISSN - 1070-6291
pISSN - 0099-2240
DOI - 10.1128/aem.68.12.6273-6282.2002
Subject(s) - listeria monocytogenes , listeria , biology , serotype , microbiology and biotechnology , food microbiology , identification (biology) , specific identification , polymerase chain reaction , food science , bacteria , gene , genetics , botany
A new molecular approach for the detection and identification of Listeria spp. and Listeria monocytogenes in food is presented here. The method is based on the PCR amplification of a fragment of the iap gene from the five species belonging to the genus and on the analysis of the PCR products obtained by denaturing gradient gel electrophoresis (DGGE). The protocol was first optimized by using strains from international collections. Based on the differences present in the sequences amplified, it was possible to obtain species-specific DGGE migration that allowed fast and easy identification of L. monocytogenes, L. innocua, L. welshimeri, L. seeligeri, and L. ivanovii. Moreover, for L. monocytogenes serotypes, partial differentiation was possible. The optimized protocol was used for identification of Listeria strains traditionally isolated from food and for direct detection and identification of Listeria members in food after an overnight enrichment. Identification of 48 food isolates and direct detection of Listeria spp. in 73 food samples show the potential of the method that can be used as a fast screening test to investigate the presence of Listeria spp. and L. monocytogenes in food.