P2-02 Listeria spp. and Listeria monocytogenes in Beef Cuts and in a Beef Processing Plant Located at Minas Gerais State, Brazil

Tuesday, July 24, 2012
Exhibit Hall (Rhode Island Convention Center)
Anderson Carlos Camargo, Universidade Federal de Vicosa, Vicosa, Brazil
Marcus Vinicius Coutinho Cossi, Universidade Federal De Vicosa, Vicosa, Brazil
Frederico Germano P. Alvarenga Lanna, Universidade Federal de Vicosa, Vicosa, Brazil
Mariane Rezende Dias, Universidade Federal de Vicosa, Vicosa, Brazil
Paulo Sergio de Arruda Pinto, Universidade Federal de Viçosa, Viçosa, Brazil
Luis Augusto Nero, Universidade Federal de Vicosa, Vicosa, Brazil
Introduction: Listeria monocytogenes is a foodborne pathogen frequently associated with beef and meat products, usually due to the utilization of several types of equipment and utensils during the processing. Thus, the environment of beef processing facilities can play an important role in the contamination route of this pathogen.

Purpose: Verify the occurrence of Listeria spp. and L. monocytogenes in end products (beef cuts) and in the environment of a beef processing facility.

Methods: A beef processing facility was selected for the present study, where the following 222 samples were collected by swabbing (400 cm²): shoulder (24 samples), tenderloin (24), rump (24), tables, knifes and workers hand before (11, 31, and 33, respectively), and during (11, 31, and 33, respectively) processing. All samples were subjected to Listeria spp. detection by ISO 11290-1, being the isolates submitted to biochemical identification.

Results: Listeria spp. was detected in 50 (22.5%) samples, being more frequent in tables and hands during processing (11/33 and 7/31, respectively) and shoulder (15/24). Based on biochemical results, 142 isolates were identified as Listeria spp., being 111 L. innocua, 26 L. monocytogenes, and 5 L. grayi. L. innocua was present in all samples at different frequencies, and L. grayi was detected only in tables during processing (3/33) and shoulder (1/24). L. monocytogenes, the main concern in this genus, was detected in knife before processing (1/11), hands and tables during processing (1/31 and 1/33, respectively), rump (1/24) and shoulder (5/24).

Significance: These data indicate that Listeria spp. and L. monocytogenes are present in the beef cuts and the processing environment of the analyzed facility, showing the shoulder as the cut with the highest frequency of L. monocytogenes. Further analyses are necessary to determine the molecular profiles of isolates, in order to establish their persistence in this environment and their contamination routes.