RESUMO

This study evaluated the prevalence of the populations and serotypes of Listeria monocytogenes in 552 refrigerated samples of ground beef, chicken leg, hot dog, and pork sausage collected in supermarkets in the city of Sao Paulo, SP, Brazil, between May 2008 and July 2009. The supermarkets were selected after stratification by geographical region and by random draw. Tests for presence and enumeration of L. monocytogenes were based on ISO 11290-1:1996/Amd.1:2004 and ISO 11290-2:1998 methods, respectively. Listeria spp. were detected in 469 (85.0%) of the studied meat products. The most frequently isolated species was L. innocua (64.1%), followed by L. monocytogenes (48.7%), L. welshimeri (13.4%), L. seeligeri (7.1%), L. ivanovii (0.2%), and L. grayi subspecies murrayi (0.2%). L. monocytogenes was detected in 269 (48.7%) samples, with highest prevalence in ground beef (59.4%) followed by chicken legs (58.0%), pork sausages (39.8%), and hot dogs (37.7%). The populations were <10(2) colony-forming units/g in the majority of samples (62.5%). Prevalence of serotypes varied according to the type of meat product. These data are relevant for estimating the risks of listeriosis associated with consumption of meat products in Sao Paulo, and for establishing science-based intervention strategies aimed at reducing these risks, especially for pregnant women and immunocompromised individuals.

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RESUMO

As micobactérias de crescimento rápido anteriormente classificadas como complexo micobacterium fourtuitum foram recentemente designadas M.fortuitum, M. peregrinum, M. chenonae e M. abcessus. A identificaçäo dessas micobactérias é importante para estabelecer a terapêutica adequada, visto que possuem diferentes padröes de resistência às drogas. Dentre 3.441 culturas de micobactérias recebidas em 1999 no Setor de micobactérias do Instituto Adolfo Lutz, foram selecionadas 13 cepas, classificadas como complexo M. fortuitum. O estudo incluiu o isolamento das colônias para certificar-se da pureza das culturas, a adiçäo de testes com carboidratos e citrato de sódio que separam as quatro espécies citadas e o uso da técnica de PCR restriction analysis do gene hsp65 (PRA) para elucidaçäo de resultados duvidosos dos tstes fetípicos. Na análise das 13 culturas, observou-se que oito apresentaram dois tipos de colônias (lisa e rugosa) e as cinco restantes apenas um tipo. As identificaçöes feitas com a técnica de PRA e c om os testes fenotípicos foram concordantes na maioria das cepas. Os resultados desse estudo de referência e implementada com testes específicos para cada espécie, que possibilitem a elucidaçäo rápida do diagnóstico

The rapidly growing mycobacteria, previously classified as Mycobacterium fortuitumcomplex, has recently been designated M. fortuitum, M. peregrinum, M. chelonae and M. abscessus. Theidentification of these mycobacteria is important for establishing the proper treatment, because they havedifferent patterns to drugs. Among 3,441 cultures of mycobacteria received in 1999 by the MycobacteriaLaboratory of the Adolfo Lutz Institute, 13 cultures classified as M. fortuitum complex were selected to bestudied. The study included isolation of colonies in order to ensure the purity of the cultures, the additionof tests with carbohydrate and citrate, which differentiate the four previously mentioned species and theuse of the PCR restriction analysis of hsp65 (PRA) for the analysis of dubious results in conventionaltests. In the analysis of the 13 cultures, it was observed that eight showed two types of colonies (smoothand rough) and the remaining five showed only one type. The identification by PRA technique and byconventional tests agreed to the majority of the strains. The results of this study suggest that theidentification of mycobacteria, due to its complexity, should be centralized in Reference Laboratories andimplemented with specific tests for each specie in order to give a rapid diagnosis

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