Navegando por Autor "Moraes, Paula Mendonca"
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Item Foodborne pathogens and microbiological characteristics of raw milk soft cheese produced and on retail sale in Brazil(Foodborne Pathogens and Disease, 2009) Moraes, Paula Mendonca; Vicosa, Gabriela Nogueira; Yamazi, Anderson Keizo; Ortolani, Maria Beatriz Tassinari; Augusto Nero, LuisThe consumption of raw milk soft cheeses (RMSC), which are typically manufactured in small dairy farms under unsatisfactory hygiene conditions, is common in Brazil. Due to these production characteristics, this type of cheese is a potential carrier of pathogenic microorganisms, such as Listeria monocytogenes, Salmonella, and enterotoxin-producing Staphylococcus spp. Considering these characteristics, in this work, we aimed to detect the presence of these pathogenic microorganisms in RMC and to evaluate their microbiological quality. Fifty-five samples of this product were collected from different noninspected commercial establishments and submitted to the enumeration of mesophilic aerobes (MA), total coliforms (TC), Escherichia coli, and coagulase-positive staphylococci (CPS), and detection of L. monocytogenes and Salmonella spp. All analyzed samples were negative for Salmonella spp. and L. monocytogenes. All samples presented counts of MA higher than [10.sup.6] colony forming units/g (CFU/g; range, 3.0 x [10.sup.6] to 4.0 x [10.sup.9]). TC were present at levels between 1.0 x [10.sup.3] and 1.8 x [10.sup.8] CFU/g, and E. coli between 1.0 x [10.sup.2] and 3.5 x [10.sup.6] CFU/g. CPS were detected in 17 (30.9%) samples at levels higher than [10.sup.4] CFU/g. These results confirm the poor microbiological quality of raw milk used in the manufacturing of RMC samples, and also the inadequate production conditions. Therefore, the evaluation of microbiological safety and quality of these products must be constantly reported to alert the official agencies about the significance of proper inspection.Item Microbiological quality and safety of raw milk and soft cheese and detection of autochthonous lactic acid bacteria with antagonistic activity against Listeria monocytogenes, Salmonella spp., and Staphylococcus aureus(Foodborne Pathogens and Disease, 2010) Ortolani, Maria Beatriz Tassinari; Yamazi, Anderson Keizo; Moraes, Paula Mendonca; Nero, Luis Augusto; Viçosa, Gabriela NogueiraThis study aimed to characterize the microbiological quality and safety of raw milk and soft cheese, verifying possible associations between microbial populations, and the detection of lactic acid bacteria (LAB) with antagonistic activity against foodborne pathogens. Raw milk (n = 36) and soft cheese (n = 18) samples were collected and submitted for the analysis of mesophilic aerobes, total coliforms, Escherichia coli, LAB, coagulase- positive Staphylococcus (CPS), Listeria monocytogenes, and Salmonella spp. In all, 389 LAB isolates were randomly selected and submitted for antagonistic tests against L. monocytogenes, St. aureus, Salmonella Typhimurium, and Lactobacillus sakei. The samples presented high counts of mesophilic aerobes, total coliforms, and LAB, and also high and significant correlation indices between these populations. Low levels of CPS and E. coli were observed, as well as an absence of Salmonella spp. and L. monocytogenes. A substantial portion of the analyzed samples presented LAB cultures with antagonistic activity, but not against Salmonella Typhimurium. The obtained results indicate the antimicrobial potential of the autochthonous microbiota of raw milk and soft cheese. Despite the spoilage potential, the LAB present in the studied food products can be isolated and properly characterized as antagonistic cultures, to be used in bioconservation studies for pathogen control in foods.