Listeria spp. associated to different levels of autochthonous microbiota in meat, meat products and processing plants

Abstract

High levels of microbial contamination, commonly found in animal origin foods and food processing environments, are able to hinder the growth of pathogens in these products and interfere in the results of laboratory analyses for detection of these pathogens. With the aim of verifying the possible interference of the autochthonous microbiota encountered in meat and meat products and processing plants over the presence of Listeria spp., 443 samples, collected from 11 meat retail establishments, were submitted to microbiological analysis to determine the levels of mesophilic aerobes, total coliforms and Escherichia coli and the presence of Listeria spp., according to the methodology proposed by the USDA. The results did not show evident interference of the autochthonous microbiota over Listeria spp., once the genus was detected even in the meat, meat products and environmental samples with high levels of contamination by mesophilic aerobes and coliforms.

Comparative evaluation of impedanciometry combined with chromogenic agars or RNA hybridization and real-time PCR methods for the detection of L. monocytogenes in dry-cured ham

“…The detection of L. monocytogenes could be influenced by the food's intrinsic and extrinsic characteristics. Dry-cured ham matrix is complex, with high NaCl and fat content, and possesses abundant background flora that could affect the detection of the pathogen (Barros et al, 2007;O´Grady et al, 2009;Suh & Knabel, 2001). In a previous study carried out by our research group, the pathogen was subjected to stressful conditions before inoculation in dry-cured ham.…”

Characterization of Listeria monocytogenes isolated from a fresh mixed sausage processing line in Pelotas-RS by PFGE

“…Beef, poultry, seafood and dairy processing plants can be contaminated by L. monocytogenes (3,5,7) and studies have shown that this bacterium can survive in the plant for extended periods of time (17,18,20,28).…”

Pesquisa de genes de virulência em cepas de Listeria monocytogenes e Listeria innocua originárias de carne suína e ambiente de abatedouros e açougues

“…Nas últimas duas décadas, o estudo da epidemiologia molecular do agente no país evoluiu muito, evidenciando possíveis rotas de contaminação ambiental e a alta similaridade genética existente entre os isolados de ambiente e alimento (DESTRO et al, 1996;BARROS et al, 2007;BRITO et al, 2008;CRUZ et al, 2008b) com os de origem humana (BARBALHO et al, 2005;BUENO et al, 2010;PAIXÃO, 2010).…”