Introduction: self-service restaurants in which food is served ready to be consumed are liable to have some products contaminated by pathogenic microorganisms causing food-transmitted diseases. Aim: evaluates the microbiological quality of lettuce salads in restaurants in Pelotas RS Brazil by counts of thermo-tolerant coliforms, E. coli, Staphylococcus spp. and detection of Salmonella spp. Antimicrobial resistance of Staphylococcus spp. isolates are also assessed. Methods: thirty-six samples of lettuce salads were collected from nine restaurants and thermotolerant coliforms, Escherichia coli and Staphylococcus spp. were quantified, coupled to a research on Salmonella spp., following methodology by the Bacteriological Analytical Manual. Staphylococcus spp. isolates underwent antimicrobial resistance test by the disc-diffusion method. Results and discussion: results showed that 61.1% of the salad samples contained more thermotolerant coliforms than allowed by Brazilian legislation and E. coli was confirmed in 5.6% of the samples. Positive and negative coagulase Staphylococcus occurred respectively in 5.6% and 77.8% of isolates, but no sample had Salmonella spp. Further, 56.7% of the thirty isolates of Staphylococcus spp. tested were resistant to penicillin; 46.7% to oxacillin; 26.7% to erythromycin and 23.3% were multi- resistant. Conclusion: inadequate quality of the salad was due to pathogenic microorganisms, while Staphylococcus spp. isolates had a high percentage of antimicrobial resistance.

Introducción: la procura por estabelecimientos que ofrecen alimentos prontos para consumo ha aumentado, sin embrago, los alimentos disponibles en estos locales pueden estar contaminados con microorganismos patogénicos, pudiendo causar enfermedades transmitidas por alimentos. Objetivos: evaluar la calidad microbiológica de las ensaladas de lechuga en los restaurantes de Pelotas RS Brasil, a través de los recuentos de coliformes termotolerantes, Escherichia coli, Staphylococcus spp. y la detección de Salmonella spp. Resistencia a los antimicrobianos de Staphylococcus spp. también se evalúan. Métodos: fueron colectadas 36 muestras de ensaladas de lechuga en nueve restaurantes y realizada la cuantificación de coliformes termotolerantes, Escherichia coli y Staphylococcus spp. e investigación de Salmonella spp., siguiendo la metodología del Bacteriological Analytical Manual. Los aislados de Staphylococcus spp. fueron sometidos al examen de resistencia a antimicrobianos por el método de difusión con discos. Resultados y discusión: de las 36 muestras de ensalada de lechuga, 61,1% presentaron cuantificación de coliformes termotolerantes superiores a lo permitido por la legislación brasileña, y hubo confirmación de E. coli en 5,6% de las muestras. La cuantificación de Staphylococcus coagulasa positiva representó 5,6% de los aislados y Staphylococcus coagulasa negativa representó 77,8%. Todas las muestras presentaron ausencia de Salmonella spp. De los 30 aislados de Staphylococcus spp. examinados, 56,7% fueron resistentes a penicilina, 46,7% a oxacilina, 26,7% a eritromicina y 23,3% fueron multirresistentes. Conclusión: la calidad microbiológica de las ensaladas de lechuga se mostró inadecuada debido a la presencia de microorganismos patogénicos, y los aislados de Staphylococcus spp. presentaron elevado porcentaje de resistencia antimicrobiana.

Sanitary conditions are essential for the production of meals and control of the presence of pathogensis important to guarantee the health of customers. The aim of this study was to evaluate the sanitary quality of food services by checking the presence of thermotolerant coliforms, Staphylococcus sp. and evaluate the toxigenic potential from the latter. The analysis was performed on water, surfaces, equipment, ready-to-eat foods, hands and nasal cavity of handlers in seven food services. The water used in food services proved to be suitable for the production of meals. Most food, equipment and surfaces showed poor sanitary conditions due to the presence of thermotolerant coliforms (60.6%). Twenty-six Staphylococcus species were identified from the 121 Staphylococcus isolates tested. Staphylococci coagulase-negative species were predominant in the foods, equipment and surfaces. In food handlers and foods, the predominant species was Staphylococcus epidermidis. Twelve different genotypes were found after PCR for the classical enterotoxin genes. The seb gene (19.8%) was the most prevalent among all Staphylococcus sp. Both coagulase-positive and coagulase-negative Staphylococci showed some of the genes of the enterotoxins tested. We conclude that there are hygienic and sanitary deficiencies in the food services analyzed. Although coagulase-positive Staphylococci have not been present in foods there is a wide dispersion of enterotoxigenic coagulase-negative Staphylococci in the environment and in the foods analyzed, indicating a risk to consumer health.

A seqüência da região polimórfica do gene iap foi analisada em 25 cepas de Listeria monocytogenes isoladas de queijo no Estado do Rio Grande do Sul e comparadas com cepas referências. Esta investigação distinguiu L. monocytogenes em dois grupos: I (20 cepas) e II (5 cepas).

The polymorphic region sequences in the iap gene were analyzed in 25 strains of Listeria monocytogenes isolated from cheeses in the state of Rio Grande do Sul, and compared with reference strains. This investigation distinguished two clusters of L. monocytogenes: I (20 strains) and II (5 strains).