Characterization of microbial ecology, Listeria monocytogenes, and Salmonella sp. on equipment and utensil surfaces in Brazilian poultry, pork, and dairy industries.

This study aimed to evaluate the level of counting by indicator microorganisms, identify the microbial ecology, detect Listeria monocytogenes and Salmonella sp., and determine the presence of virulence genes and biofilm formation. A total of 480 samples were collected from the surfaces of the equipment and utensils using sterile swabs for the detection of L. monocytogenes and Salmonella sp. and counting mesophilic aerobes, Enterobacteriaceae, Escherichia coli, and Pseudomonas sp. The microbial ecology was evaluated by sequencing the 16S rRNA gene. Genes for virulence and biofilm formation were analyzed and adhesion capacity was evaluated for L. monocytogenes and Salmonella sp. The mesophilic aerobe count was the highest in the dairy processing facility, followed by the pork and poultry slaughterhouses. L. monocytogenes was detected in all facilities, with the highest detection in the pork slaughterhouse, followed by the poultry and dairy facilities. Salmonella sp. was only detected in the dairy. Isolates of L. monocytogenes and Salmonella sp. showed poor adhesion to polystyrene surfaces, virulence genes, and biofilm formation. The frequent contaminants in the slaughterhouses were Pseudomonas, Acinetobacter, and Aeromonas in poultry, Acinetobacter, Pseudomonas, and Brevundimonas in pork, and Pseudomonas, Kocuria, and Staphylococcus in dairy. Our results provide useful information to understand the microbiological risks associated with contamination.

Transfer of Salmonella Enteritidis to four types of surfaces after cleaning procedures and cross-contamination to tomatoes.

The objectives of the present study were to evaluate the spread of Salmonella Enteritidis to different cutting boards (wood, triclosan-treated plastic, glass, and stainless steel) from contaminated poultry skin (5 log CFU/g) and then to tomatoes and to analyze the effect of different protocols used to clean these surfaces to control contamination. The following procedures were simulated: (1) no cleaning after handling contaminated poultry skin; (2) rinsing in running water; (3) cleaning with dish soap and mechanical scrubbing; and (4) cleaning with dish soap and mechanical scrubbing, followed by disinfection with hypochlorite. The pathogen was recovered from all surfaces following procedure 1, with counts ranging from 1.90 to 2.80 log, as well as from the tomatoes handled on it. Reduced numbers of S. Enteritidis were recovered using the other procedures, both from the surfaces and from the tomatoes. Counts were undetectable after procedure 4. From all surfaces evaluated, wood was the most difficult to clean, and stainless steel was the easiest. The use of hypochlorite as a disinfecting agent helped to reduce cross-contamination.

Safety issues of raw milk: evaluation of bacteriological and physicochemical characteristics of human milk from a bank in a teaching hospital, focusing on Staphylococcus species.

Many infants are nurtured with milk supplied by human banks, whose bacteriological and physical-chemical profiles are a major issue. We investigated the bacteriological and physical-chemical characteristics, as well as genotypic and phenotypic and profiles of Staphylococcus species isolated from 240 samples of breast milk from a bank in a teaching hospital. Dornic acidity of milk revealed that 95.4% (229/240) had acceptable limits (< 8.0 oD). Caloric intake showed a wide variation in cream content (4%), fat (4%) and energy values (559.81 Kcal/L). Staphylococcus (105/186 or 56.5%) and Enterobacter (25/186 or 13.4%) were the most prevalent genera, although other microorganisms were identified, including Klebsiella pneumoniae and Pseudomonas aeruginosa. Amoxicillin/clavulanic acid (125/157 or 79.6%), vancomycin (115/157 or 73.2%), and cephalexin (112/157 or 71.3%) were the most effective antimicrobials. High resistance rates of isolates were found to penicillin G (141/157 or 89.8%), ampicillin (135/157 or 86%), and oxacillin (118/157 or 75.2%). Multidrug resistance to ≥ 3 antimicrobials occurred in 66.2% (123/186) of the isolates. Residues of microbial multiplication inhibitory substances were found in 85% (204/240) of samples. Among the coagulase-positive-CPS and negative-CoNS staphylococci, the mecA gene was detected in 53.3% (8/15) and 75% (30/40), respectively. Genes sea, seb and sec were detected in 20% (3/15) of CPS, while tsst-1 was detected in 13.34% (2/15). In addition, 13.3% (2/15) of S. aureus were toxin-producers. Genes sea, seb and sec were detected in 90% (36/40), 5% (2/40) and 15% (6/40) CoNS, respectively. Enterotoxin production was identified in 5% (2/40) of CoNS. The identification of multidrug-resistant bacteria, staphylococci species toxin-producers harboring methicillin-resistance genes, and residues of microbial multiplication inhibitory substances reinforce the need for a continuous vigilance of milk quality offered to infant consumption by human banks.

Prevalence, antibiotic resistance, PFGE and MLST characterization of Salmonella in swine mesenteric lymph nodes.

This study evaluated 250 animals from 25 different processing lots, processed in four slaughterhouses in São Paulo state, Brazil for the presence of Salmonella in the mesenteric lymph nodes (10 g sample of each animal) and characterized the antibiotics resistance profile, the Pulsed Field Gel Electrophoresis - PFGE and Multi Locus Sequence Typing - MLST profiles of selected strains. The pathogen was present in 36.4% (n = 91, CL 95% 30.4-43.4) of samples and 72% (n = 18, CL 95% 50.6-87.9%) of the analyzed lots. The main serovars were S. Typhimurium (n = 23), Salmonella enterica subsp. enterica 1.4,5,12:i:- (n = 17), followed by S. Infantis (n = 12) and S. Havana (n = 11). Twenty-eight strains (30%) were classified as other serovars. Sixty-eight percent of the strains were resistant to Streptomycin and tetracycline, followed by ampicillin and sulphonamides (62.6%), chloramphenicol (56.0%), trimethoprim-sulfamethoxazole (41.8%) and nalidixic acid (40.7%). The antibiotics with lower resistance rates were cephalothin and aztreonam (both with 3.3% resistant), and ceftriaxone and cefepime (both with 7.7%). Multidrug-resistant strains (MDR) accounted for 70.3% of the isolates. Eight strains were submitted to MLST: four S. Typhimurium and one S.1.4,5,12:i:-, all belonging to the ST 19, two Salmonella Infantis, belonging to the ST 32 and one S. Derby, belonging to ST 40. Twenty-one isolates with different antibiotics resistance profiles from the most prevalent serovars were selected for PFGE analysis. Serovar S. Typhimurium (n = 11) revealed 4 pulsotypes and 1 cluster and S. 1.4,5,12:i:- (n = 10) revealed 5 pulsotypes and 4 clusters. The high prevalence of the pathogen, with its high rates of antibiotics resistance and belonging to genetic groups that are often associated with disease in humans, shows that the production chain of pork is a potential source of infection in salmonellosis cases. Therefore, effective preventive measures for pathogen control are needed to reduce the risk of foodborne diseases.

Multidrug resistance and ESBL-producing Salmonella spp. isolated from broiler processing plants.

The aim of this study was to investigate the occurrence of multidrug-resistant, extended spectrum beta-lactamase (ESBL) producing Salmonella spp. isolated from conveyor belts of broiler cutting rooms in Brazilian broiler processing plants. Ninety-eight strains of Salmonella spp. were analyzed. Multidrug resistance was determined by the disk diffusion test and the susceptibility of the isolated bacteria was evaluated against 18 antimicrobials from seven different classes. The double disk diffusion test was used to evaluate ESBL production. Of the 98 strains tested, 84 were multidrug resistant. The highest rates of resistance were against nalidixic acid (95%), tetracycline (91%), and the beta-lactams: ampicillin and cefachlor (45%), followed by streptomycin and gentamicin with 19% and 15% of strain resistance, respectively. By contrast, 97% of the strains were sensitive to chloramphenicol. 45% of the strains were positive for the presence of ESBL activity. In this study, high rates of multidrug resistance and ESBL production were observed in Salmonella spp.

Assessment of the microbiological quality of pattern minas cheese commercialized in Uberlândia and Patos de Minas, Minas Gerais / Avaliação microbiológica de queijo minas padrão comercializado em Uberlândia e Patos de Minas, Minas Gerais

Pattern minas cheese is a product developed with pasteurized milk, fermented with mesophilic cultures, and with the final addition of rennet. This cheese undergoes an artisanal maturation process and possesses a firm shell of yellowish color and striking and acidic flavor. Our study objective was to evaluate the microbiological quality of pattern minas cheese. We collected 40 samples from two micro regions (Uberlândia and Patos de Minas) of the Triângulo Mineiro and Alto Paranaíba mesor regions of the State of Minas Gerais, Brazil. The microbiological test results were recorded as counts of enterobacteria, Escherichia coli, coliforms at 35°C, coagulase-positive Staphylococcus and Salmonella spp. In the Patos de Minas micro region, the results were 45%, 35%, 20%, and 20% higher than 103 CFU/g for the counts of enterobacteria, Escherichia coli, coliforms at 35°C, and Staphylococcus coagulase-positive, respectively. Five percent of the analyzed samples were positive for Salmonella spp. in the Uberlândia micro region. Based on the findings of the microbiota in the cheese analyzed from the micro regions (Uberlândia and Patos de Minas), we concluded that the hygiene conditions in the manufacturing, handling, transport, and storage stages were precarious, requiring the implementation of Good Manufacturing Practices (GMP) systems, including Hazard Analysis and Critical Control Points (HACCP).(AU)

O queijo minas padrão é um produto elaborado com leite pasteurizado, fermentado com culturas mesófilas e adição de coalho. Esse queijo passa por um processo de maturação artesanal, possui uma casca firme de cor amarelada e sabor ácido. O presente trabalho avaliou a qualidade microbiológica de queijo minas padrão comercializado em duas microrregiões (Uberlândia e Patos de Minas) da mesorregião do Triângulo Mineiro e Alto Paranaíba do estado de Minas Gerais, Brasil. Foram examinadas 40 amostras de queijo. Os ensaios microbiológicos foram contagens de enterobactérias, Escherichia coli, coliformes a 35 oC, Staphylococcus coagulase positiva e pesquisa de Salmonella spp. Na microrregião de Patos de Minas, os resultados foram de 45%, 35%, 20% e 20% superiores a 103 CFU/g para as contagens de enterobactérias, Escherichia coli, coliformes a 35oC e Staphylococcus coagulase positiva, respectivamente. Cinco por cento das amostras analisadas foram positivas à pesquisa de Salmonella spp. Considerando a microrregião analisada (Uberlândia e Patos de Minas), a conclusão obtida foi que na região estudada, as condições de higiene nas etapas de fabricação, manuseio, transporte e armazenamento do queijo minas padrão são precárias, sendo necessária a implementação de sistemas de Boas Práticas de Fabricação (GMP), incluindo Análise de Perigos e Pontos Críticos de Controle (HACCP).(AU)

Assessment of the microbiological quality of pattern minas cheese commercialized in Uberlândia and Patos de Minas, Minas Gerais / Avaliação microbiológica de queijo minas padrão comercializado em Uberlândia e Patos de Minas, Minas Gerais

Pattern minas cheese is a product developed with pasteurized milk, fermented with mesophilic cultures, and with the final addition of rennet. This cheese undergoes an artisanal maturation process and possesses a firm shell of yellowish color and striking and acidic flavor. Our study objective was to evaluate the microbiological quality of pattern minas cheese. We collected 40 samples from two micro regions (Uberlândia and Patos de Minas) of the Triângulo Mineiro and Alto Paranaíba mesor regions of the State of Minas Gerais, Brazil. The microbiological test results were recorded as counts of enterobacteria, Escherichia coli, coliforms at 35°C, coagulase-positive Staphylococcus and Salmonella spp. In the Patos de Minas micro region, the results were 45%, 35%, 20%, and 20% higher than 103 CFU/g for the counts of enterobacteria, Escherichia coli, coliforms at 35°C, and Staphylococcus coagulase-positive, respectively. Five percent of the analyzed samples were positive for Salmonella spp. in the Uberlândia micro region. Based on the findings of the microbiota in the cheese analyzed from the micro regions (Uberlândia and Patos de Minas), we concluded that the hygiene conditions in the manufacturing, handling, transport, and storage stages were precarious, requiring the implementation of Good Manufacturing Practices (GMP) systems, including Hazard Analysis and Critical Control Points (HACCP).(AU)

O queijo minas padrão é um produto elaborado com leite pasteurizado, fermentado com culturas mesófilas e adição de coalho. Esse queijo passa por um processo de maturação artesanal, possui uma casca firme de cor amarelada e sabor ácido. O presente trabalho avaliou a qualidade microbiológica de queijo minas padrão comercializado em duas microrregiões (Uberlândia e Patos de Minas) da mesorregião do Triângulo Mineiro e Alto Paranaíba do estado de Minas Gerais, Brasil. Foram examinadas 40 amostras de queijo. Os ensaios microbiológicos foram contagens de enterobactérias, Escherichia coli, coliformes a 35 oC, Staphylococcus coagulase positiva e pesquisa de Salmonella spp. Na microrregião de Patos de Minas, os resultados foram de 45%, 35%, 20% e 20% superiores a 103 CFU/g para as contagens de enterobactérias, Escherichia coli, coliformes a 35oC e Staphylococcus coagulase positiva, respectivamente. Cinco por cento das amostras analisadas foram positivas à pesquisa de Salmonella spp. Considerando a microrregião analisada (Uberlândia e Patos de Minas), a conclusão obtida foi que na região estudada, as condições de higiene nas etapas de fabricação, manuseio, transporte e armazenamento do queijo minas padrão são precárias, sendo necessária a implementação de sistemas de Boas Práticas de Fabricação (GMP), incluindo Análise de Perigos e Pontos Críticos de Controle (HACCP).(AU)

Salmonella en pollos y la contaminación cruzada a través de superficies de corte en cocinas domésticas / Salmonella in poultry and cross-contamination through cutting boards in domestic kitchens / Salmonella em frangos e a contaminação cruzada por meio de superficies de corte em cozinhas domésticas

Entre los agentes patógenos causantes de enfermedades transmitidas por alimentos, Salmonella es considerado el más importante para la salud pública, y el serotipo S. Enteritidis los más involucrados en los casos de infección humana. Por lo tanto, esta revisión se centra en aspectos relacionados con la epidemiología de la salmonelosis y Salmonella, así como la importancia de pollo crudo como fuente de contaminación para las superficies de corte utilizadas en las cocinas domésticas para la manipulación de los alimentos y su posterior propagación a través de la contaminación cruzada, los alimentos listos para el consumo.

Among the pathogens responsible for causing food-borne diseases, Salmonella is considered the most important for public health, and the serotype S. Enteritidis is the most involved in cases of human infection. Thus, this literature review focuses on aspects related to the epidemiology of salmonellosis and Salmonella, as well as the importance of raw chicken as a source of contamination for cutting boards used in domestic kitchens for food handling and its subsequent spread through cross contamination to ready to eat foods.

Dentre os patógenos responsáveis por doenças transmitidas por alimentos, Salmonella é considerado o de maior importância para a saúde pública, sendo o sorotipo S. Enteritidis o mais frequentemente envolvido nos casos de infecção em humanos. Esta revisão aborda aspectos relacionados à epidemiologia da salmonelose e Salmonella, assim como a importância do frango cru como fonte de contaminação para superfícies de corte utilizadas nas cozinhas domésticas para manipulação de alimentos e sua consequente disseminação, através da contaminação cruzada, para alimentos prontos para o consumo.

Salmonella en pollos y la contaminación cruzada a través de superficies de corte en cocinas domésticas / Salmonella in poultry and cross-contamination through cutting boards in domestic kitchens / Salmonella em frangos e a contaminação cruzada por meio de superficies de corte em cozinhas domésticas

Entre los agentes patógenos causantes de enfermedades transmitidas por alimentos, Salmonella es considerado el más importante para la salud pública, y el serotipo S. Enteritidis los más involucrados en los casos de infección humana. Por lo tanto, esta revisión se centra en aspectos relacionados con la epidemiología de la salmonelosis y Salmonella, así como la importancia de pollo crudo como fuente de contaminación para las superficies de corte utilizadas en las cocinas domésticas para la manipulación de los alimentos y su posterior propagación a través de la contaminación cruzada, los alimentos listos para el consumo.(AU)

Among the pathogens responsible for causing food-borne diseases, Salmonella is considered the most important for public health, and the serotype S. Enteritidis is the most involved in cases of human infection. Thus, this literature review focuses on aspects related to the epidemiology of salmonellosis and Salmonella, as well as the importance of raw chicken as a source of contamination for cutting boards used in domestic kitchens for food handling and its subsequent spread through cross contamination to ready to eat foods.(AU)

Dentre os patógenos responsáveis por doenças transmitidas por alimentos, Salmonella é considerado o de maior importância para a saúde pública, sendo o sorotipo S. Enteritidis o mais frequentemente envolvido nos casos de infecção em humanos. Esta revisão aborda aspectos relacionados à epidemiologia da salmonelose e Salmonella, assim como a importância do frango cru como fonte de contaminação para superfícies de corte utilizadas nas cozinhas domésticas para manipulação de alimentos e sua consequente disseminação, através da contaminação cruzada, para alimentos prontos para o consumo.(AU)

Microbiological vulnerability of eggs and environmental conditions in conventional and free-range housing systems / Vulnerabilidade microbiológica de ovos e ambiente de produção no sistema convencional e de pastejo livre

Although Brazil is currently the world’s eighth largest egg exporter, the shift of consumers towards free-range eggs may present new sanitary challenges. This study aims to evaluate the microbiological vulnerability of eggs and environmental conditions in a farm certified for both conventional and freerange systems using two standard methods (enterobacteria counting and Salmonella spp. survey). Two high-producing farms were selected for this study, one under both conventional and freerange systems at the same place as the test farm, and another under conventional system only as a control farm. Enterobacteriaceae counts were determined for eggshells; and detection of Salmonella spp. was conducted in eggs, nest box material, feeder, and sponge samples from water dispensers, feeders, production plant, besides water samples from nipple dispensers and artesian well. The average enterobacteria count (log CFUmL-1) was 0.09 for conventional and 1.73 for free-range systems (p < 0.001). While Salmonella spp. was not detected in the conventional system but was present in one feeder and three eggshells from the free-range system. Therefore, the conventional system demonstrated better hygiene-sanitary status than the free-range one. Moreover, controlling food safety should always be considered when improving animal welfare.

Apesar do Brasil ser considerado o oitavo maior exportador mundial de ovos, mudanças nas preferências dos consumidores relacionadas a ovos produzidos em sistemas de pastejo livre, podem representar novos desafios sanitários. Neste estudo o objetivo foi avaliar a vulnerabilidade microbiológica dos ovos e ambiente de produção numa fazenda certificada para sistema convencional e de pastejo livre, utilizando dois métodos considerados padrão (contagem de Enterobactérias e pesquisa de Salmonella). Duas fazendas de alta produção de ovos foram selecionadas para o estudo, sendo que uma delas continha o sistema convencional e também o sistema de pastejo livre de criação na mesma localidade. A segunda fazenda (sistema convencional) foi utilizada como controle. A enumeração de enterobactérias foi realizada nas cascas dos ovos e a pesquisa de Salmonella nas cascas dos ovos, no material de ninho, nos comedouros, bebedouros, ração (comedouros e fábrica) e água (bebedouros e poço artesiano). A contagem média de enterobactérias (log UFCml-1) foi 0,09 para sistema convencional e 1,73 para sistema de pastejo livre (p < 0,001). Salmonella não foi detectada no sistema convencional, mas estava presente em comedouro e em três cascas de ovos do sistema de pastejo livre. Dessa forma, o sistema convencional apresentou melhor condição higiênico-sanitária que o sistema de pastejo livre. Além disso, controlar a segurança de alimentos é imperativo quando é melhorada a condição de bem-estar.

Microbiological vulnerability of eggs and environmental conditions in conventional and free-range housing systems / Vulnerabilidade microbiológica de ovos e ambiente de produção no sistema convencional e de pastejo livre

Although Brazil is currently the worlds eighth largest egg exporter, the shift of consumers towards free-range eggs may present new sanitary challenges. This study aims to evaluate the microbiological vulnerability of eggs and environmental conditions in a farm certified for both conventional and freerange systems using two standard methods (enterobacteria counting and Salmonella spp. survey). Two high-producing farms were selected for this study, one under both conventional and freerange systems at the same place as the test farm, and another under conventional system only as a control farm. Enterobacteriaceae counts were determined for eggshells; and detection of Salmonella spp. was conducted in eggs, nest box material, feeder, and sponge samples from water dispensers, feeders, production plant, besides water samples from nipple dispensers and artesian well. The average enterobacteria count (log CFUmL-1) was 0.09 for conventional and 1.73 for free-range systems (p < 0.001). While Salmonella spp. was not detected in the conventional system but was present in one feeder and three eggshells from the free-range system. Therefore, the conventional system demonstrated better hygiene-sanitary status than the free-range one. Moreover, controlling food safety should always be considered when improving animal welfare.(AU)

Apesar do Brasil ser considerado o oitavo maior exportador mundial de ovos, mudanças nas preferências dos consumidores relacionadas a ovos produzidos em sistemas de pastejo livre, podem representar novos desafios sanitários. Neste estudo o objetivo foi avaliar a vulnerabilidade microbiológica dos ovos e ambiente de produção numa fazenda certificada para sistema convencional e de pastejo livre, utilizando dois métodos considerados padrão (contagem de Enterobactérias e pesquisa de Salmonella). Duas fazendas de alta produção de ovos foram selecionadas para o estudo, sendo que uma delas continha o sistema convencional e também o sistema de pastejo livre de criação na mesma localidade. A segunda fazenda (sistema convencional) foi utilizada como controle. A enumeração de enterobactérias foi realizada nas cascas dos ovos e a pesquisa de Salmonella nas cascas dos ovos, no material de ninho, nos comedouros, bebedouros, ração (comedouros e fábrica) e água (bebedouros e poço artesiano). A contagem média de enterobactérias (log UFCml-1) foi 0,09 para sistema convencional e 1,73 para sistema de pastejo livre (p < 0,001). Salmonella não foi detectada no sistema convencional, mas estava presente em comedouro e em três cascas de ovos do sistema de pastejo livre. Dessa forma, o sistema convencional apresentou melhor condição higiênico-sanitária que o sistema de pastejo livre. Além disso, controlar a segurança de alimentos é imperativo quando é melhorada a condição de bem-estar.(AU)

Avaliação da qualidade higienicossanitária de hambúrgueres bovinos de marcas comerciais brasileiras / Evaluation higienic sanitary quality beef burgers sold in Brazil

O hambúrguer é um produto cárneo industrializado e potencial veículo de bactérias produtoras ou não de toxinas nas diversas fases de seu processamento, desde sua origem até as fases de transformação, armazenagem, transporte e distribuição para o consumo. Dentro deste contexto, o objetivo do trabalho foi a avaliação do aspecto higienicossanitário dos hambúrgueres bovinos comercializados no Brasil. Foram analisadas 110 amostras de hambúrgueres de carne bovina de 11 marcas comerciais brasileiras segundo a metodologia microbiológica descrita pela Instrução Normativa n° 62 de 26 de agosto de 2003. Todas as 11 marcas comerciais brasileiras apresentaram contagem bacteriana dentro do limite (5x103 UFC/g) para Coliformes a 45°C, enquanto os valores para Staphylococcus coagulase positiva estavam acima dos padrões permitidos (5x103 UFC/g) na marca H (amostras 1 e 7). As marcas B (amostra 5), D (amostra 5), E (amostra 5) e G (amostra 4) também apresentaram contagens acima do estipulado (3x103 UFC/g) para Clostridium sulfito redutor a 46°C e a amostra 6 da marca L foi positiva para Salmonella Infantis.

Multidrug resistance and ESBL-producing Salmonella spp. isolated from broiler processing plants

Abstract The aim of this study was to investigate the occurrence of multidrug-resistant, extended spectrum beta-lactamase (ESBL) producing Salmonella spp. isolated from conveyor belts of broiler cutting rooms in Brazilian broiler processing plants. Ninety-eight strains of Salmonella spp. were analyzed. Multidrug resistance was determined by the disk diffusion test and the susceptibility of the isolated bacteria was evaluated against 18 antimicrobials from seven different classes. The double disk diffusion test was used to evaluate ESBL production. Of the 98 strains tested, 84 were multidrug resistant. The highest rates of resistance were against nalidixic acid (95%), tetracycline (91%), and the beta-lactams: ampicillin and cefachlor (45%), followed by streptomycin and gentamicin with 19% and 15% of strain resistance, respectively. By contrast, 97% of the strains were sensitive to chloramphenicol. 45% of the strains were positive for the presence of ESBL activity. In this study, high rates of multidrug resistance and ESBL production were observed in Salmonella spp.

Multidrug resistance and ESBL-producing Salmonella spp. isolated from broiler processing plants

The aim of this study was to investigate the occurrence of multidrug-resistant, extended spectrum beta-lactamase (ESBL) producing Salmonella spp. isolated from conveyor belts of broiler cutting rooms in Brazilian broiler processing plants. Ninety-eight strains of Salmonella spp. were analyzed. Multidrug resistance was determined by the disk diffusion test and the susceptibility of the isolated bacteria was evaluated against 18 antimicrobials from seven different classes. The double disk diffusion test was used to evaluate ESBL production. Of the 98 strains tested, 84 were multidrug resistant. The highest rates of resistance were against nalidixic acid (95%), tetracycline (91%), and the beta-lactams: ampicillin and cefachlor (45%), followed by streptomycin and gentamicin with 19% and 15% of strain resistance, respectively. By contrast, 97% of the strains were sensitive to chloramphenicol. 45% of the strains were positive for the presence of ESBL activity. In this study, high rates of multidrug resistance and ESBL production were observed in Salmonella spp. (AU)

Behavior of Staphylococcus aureus and autochthone microbiota in fresh sausages added of sodium nitrite and stored under refrigeration / Comportamento de Staphylococcus aureus e microbiota autóctone frente à ação de nitrito de sódio em linguiças frescais estocadas sob refrigeração

Fresh sausages are cured meat products that may be contaminated with Staphylococcus aureus during the manufacturing procedure, which is frequently related with inadequate handling practices. The use of nitrite in meat products has proven efficacy against Clostridium botulinum, and studies indicate that bactericidal action against S. aureus depends on factors that are intrinsic and extrinsic to the product. The objective of the present study was to evaluate the effect of nitrite concentration, and pH on S. aureus and psychrotrophic autochthone microbiota in fresh sausages stored at different times and temperatures. Fresh sausage were produced at nitrite concentrations 50, 150 and 200ppm and contaminated with S. aureus. The sausages were storage at refrigeration (7 and 12°C) and the quantification of S. aureus and psychrotrophic microorganisms was carried out on days 0, 2, 4, 7, and 10. Results showed that nitrite concentrations and the temperatures used had minimal effect on the multiplication of S. aureus and psychrotrophic autochthone microbiota. Final counts depended only on the length of storage: at the end of 10 days, counts were statistically similar in the different groups, showing that temperature and nitrite concentrations used did not control microbial growth effectively. It is suggested that the product should be stored below 7°C or at freezing temperatures for greater microbiological stability.(AU)

A linguiça frescal é um embutido curado que, devido à manipulação durante as etapas de produção, pode se tornar contaminado com S. aureus, patógeno frequentemente relacionado com práticas inadequadas de higiene durante a produção de alimentos. A utilização de nitrito em embutidos tem sua eficácia comprovada contra C. botulinum e, para o S. aureus, estudos indicam que a ação bactericida depende de fatores extrínsecos e intrínsecos. O objetivo do presente estudo foi avaliar o efeito da concentração de nitrito e do pH frente à contaminação por S. aureus e microbiota autóctone em linguiças frescais estocadas em diferente tempos e temperaturas. Linguiças foram produzidas com concentrações de 50, 150 e 200ppm de nitrito e contaminadas com S. aureus. As linguiças foram armazenadas sob refrigeração (7 e 12°C) e a quantificação de S. aureus e psicrotróficos foi realizada nos dias 0, 2, 4, 7 e 10. Os resultados demonstraram que a influência das concentrações de nitrito e temperaturas utilizadas sobre a multiplicação de S. aureus e da microbiota autóctone foi mínima, sendo dependente apenas do período de estocagem. Entretanto, ao final de dez dias, as contagens foram estatisticamente iguais nos grupos analisados, mostrando que as condições de temperatura e concentrações de nitrito utilizadas não exerceram controle efetivo no desenvolvimento destes micro-organismos. Sugere-se que este produto seja armazenado sob temperaturas inferiores a 7°C ou sob congelamento para maior estabilidade microbiológica.(AU)

Behavior of Staphylococcus aureus and autochthone microbiota in fresh sausages added of sodium nitrite and stored under refrigeration / Comportamento de Staphylococcus aureus e microbiota autóctone frente à ação de nitrito de sódio em linguiças frescais estocadas sob refrigeração

Fresh sausages are cured meat products that may be contaminated with Staphylococcus aureus during the manufacturing procedure, which is frequently related with inadequate handling practices. The use of nitrite in meat products has proven efficacy against Clostridium botulinum, and studies indicate that bactericidal action against S. aureus depends on factors that are intrinsic and extrinsic to the product. The objective of the present study was to evaluate the effect of nitrite concentration, and pH on S. aureus and psychrotrophic autochthone microbiota in fresh sausages stored at different times and temperatures. Fresh sausage were produced at nitrite concentrations 50, 150 and 200ppm and contaminated with S. aureus. The sausages were storage at refrigeration (7 and 12°C) and the quantification of S. aureus and psychrotrophic microorganisms was carried out on days 0, 2, 4, 7, and 10. Results showed that nitrite concentrations and the temperatures used had minimal effect on the multiplication of S. aureus and psychrotrophic autochthone microbiota. Final counts depended only on the length of storage: at the end of 10 days, counts were statistically similar in the different groups, showing that temperature and nitrite concentrations used did not control microbial growth effectively. It is suggested that the product should be stored below 7°C or at freezing temperatures for greater microbiological stability.

A linguiça frescal é um embutido curado que, devido à manipulação durante as etapas de produção, pode se tornar contaminado com S. aureus, patógeno frequentemente relacionado com práticas inadequadas de higiene durante a produção de alimentos. A utilização de nitrito em embutidos tem sua eficácia comprovada contra C. botulinum e, para o S. aureus, estudos indicam que a ação bactericida depende de fatores extrínsecos e intrínsecos. O objetivo do presente estudo foi avaliar o efeito da concentração de nitrito e do pH frente à contaminação por S. aureus e microbiota autóctone em linguiças frescais estocadas em diferente tempos e temperaturas. Linguiças foram produzidas com concentrações de 50, 150 e 200ppm de nitrito e contaminadas com S. aureus. As linguiças foram armazenadas sob refrigeração (7 e 12°C) e a quantificação de S. aureus e psicrotróficos foi realizada nos dias 0, 2, 4, 7 e 10. Os resultados demonstraram que a influência das concentrações de nitrito e temperaturas utilizadas sobre a multiplicação de S. aureus e da microbiota autóctone foi mínima, sendo dependente apenas do período de estocagem. Entretanto, ao final de dez dias, as contagens foram estatisticamente iguais nos grupos analisados, mostrando que as condições de temperatura e concentrações de nitrito utilizadas não exerceram controle efetivo no desenvolvimento destes micro-organismos. Sugere-se que este produto seja armazenado sob temperaturas inferiores a 7°C ou sob congelamento para maior estabilidade microbiológica.

Uso de maltodextrina e prebiótico em rações de leitões desmamados / Use of maltodextrin and a prebiotic in the feed of weaned piglets

Dois experimentos foram conduzidos com o objetivo de avaliar o efeito da substituição da lactose pela maltodextrina e da adição de frutoligossacarídeos (FOS) nas rações de leitões desmamados. O primeiro experimento apresentou delineamento de blocos casualizados com arranjo fatorial 2 x 2 (duas fontes de carboidratos: maltodextrina e lactose na ração pré-inicial; com ou sem uso de 0,3% de frutoligossacarídeo, nas rações pré-inicial e inicial) com sete repetições de três animais. Foram avaliados o desempenho e parâmetros hematológicos. No segundo experimento foi empregado o delineamento de blocos casualizados em arranjo fatorial 2 x 2 x 2 + 1 (duas fontes de carboidratos: maltodextrina e lactose; com ou sem uso de 0,3% de frutoligossacarídeo; duas épocas de abate: sete e quatorze dias pós-desmame; e abate no dia do desmame) com oito repetições de um animal. Foram avaliados o pH e peso relativo de órgãos do sistema digestório, atividade enzimática e população microbiana. Na fase inicial a maltodextrina não compromete o desempenho e pode substituir com vantagem econômica a lactose, contudo, reduz a ingestão da ração pré-inicial I. A maltodextrina possui efeito prebiótico, pois reduz a população de coliformes totais e de E. coli no ceco e o pH do conteúdo do reto. O uso de frutoligossacarídeo não se justifica independente de se usar lactose ou maltodextrina nas rações.(AU)

Two experiments were conducted to evaluate the effect of replacing lactose with maltodextrin and adding fructooligosaccharides (FOSs) to the feed of weaned piglets. The first experiment was conducted using a randomized block design with a 2 × 2 factorial arrangement (2 sources of carbohydrates: maltodextrin and lactose in the pre-starter feed and with or without the use of 0.3% FOS in the pre-starter and starter feeds) with 7 repetitions in 3 animals. Performance and hematological parameters were evaluated. The second experiment was conducted using a randomized block design with a 2 × 2 × 2 + 1 factorial arrangement (2 sources of carbohydrates: maltodextrin and lactose and with or without the use of 0.3% FOS; 2 slaughter dates: 7 and 14 d post-weaning; and slaughter on the day of weaning) with 8 repetitions in 1 animal. The following parameters were evaluated: pH and relative weight of digestive organs, enzyme activity, and microbial population. In the initial phase, maltodextrin did not compromise performance and could replace lactose with economic benefits; however, it does reduce intake of the pre-starter I feed. Maltodextrin has a prebiotic effect because it reduces the total coliform and E. coli populations in the cecum and reduces the pH of the rectal contents. The use of FOSs is not justified, regardless of whether lactose or maltodextrin is added to the feed.(AU)

Análise microbiológica e físico-química de material proteico comestível derivado do processamento da gordura oriunda do abate de bovinos / Microbiological and Physical-Chemical Analysis of Edible Protein Obtained as a By-Product of Fat Rendering in Cattle Slaughter

Background: The use of all by-products of bovine slaughter is of high economic importance for the industries of products of animal origin. Among these products, fat has an important role, once fat rendering may generate several different products, such as protein material that may be used in the manufacture of meat products. However, in spite of the importance that the use of all by-products has for the economic balance of the industry, there are no reports on their use in Brazil, or studies that supply data on microbiological and physical-chemical local standards for this protein. Thus, the objective of this study was to evaluate microbiological and physical-chemical characteristics of protein material obtained from fat rendering, as well as to provide support for companies to use fat rendering to generate protein material, adding value to industrialized meat products. Materials, Methods & Results: The experimental production of edible protein obtained of fat rendering was conducted in slaughterhouse with supervision of the Brazilian Ministry of Agriculture, Livestock and Food Supply. Protein material was obtained in a continuous, humid heat system at high temperatures. Fat scraps containing protein were ground and cooked at high temperature (85°C), and placed in a three phase decanter centrifuge. After centrifugation, protein material was ground again and packed. Samples were collected from 15 batches of protein material, and the following microbiological analyses were carried out: counts of aerobic mesophilic and psychrotrophic microorganisms, coliforms at 35ºC, Escherichia coli, sulfite-reducing Clostridium, and Staphylococcus aureus, besides presence or absence of Salmonella and Listeria monocytogens. The following physical-chemical analyses were also carried out: protein, total lipid, moisture, ash, carbohydrate, and energy content. Mean counts of mesophiles, psychrotrophs, and coliforms at 35ºC were 4.17; 3.69 and 1.87 (log CFU/g), respectively. Levels of protein, total lipids, moisture, ashes and carbohydrates were 27.50; 7.83; 63.88%; 0.24%; and 0.55%, respectively, and energy content was 182.63 kcal/100g. Discussion: Results of microbiological analyses demonstrated that, although low, the final product showed to be contaminated. Contamination that occurred during the second grinding procedure may be an explanation for these bacterial counts. Also, the temperature used for fat fusion was not enough to eliminate thermoduric microorganisms. However, even with the presence of indicator microorganisms in the samples, none was contaminated by E. coli, sulfite-reducing Clostridium, S. aureus, Salmonella or L. monocytogenes. Physical-chemical analyses showed that the product had adequate nutritional quality. Based on these results, it was possible to conclude that protein material obtained in fat rendering showed characteristics that enable the use of this product as raw material for processed meat products. Besides, the present study was the first one to present scientific results in relation to edible by-products obtained in fat rendering, supplying important information for slaughterhouses and meat-processing plants. The study also produced relevant data on the innocuousness of the product, which may be used to guide decision-making of health inspectors.

Testes de redutase para a avaliação da qualidade de leite cru refrigerado / Reductase tests in for quality assessment evaluation of refrigerated raw milk

Os testes qualitativos de redutase são largamente utilizados pela indústria de laticínios para avaliar de forma indireta a qualidade microbiológica do leite. No entanto, para o leite refrigerado, apresentam a desvantagem de subestimar a contaminação, pois a refrigeração reduz a atividade redutora dos micro-organismos. O objetivo deste trabalho foi correlacionar as contagens de micro-organismos mesófilos com os testes de redução do azul de metileno (TRAM) e o teste de redução da resazurina (TRR). Foram coletadas 284 amostras de leite cru estocadas em propriedades rurais por sistemas de tanques de expansão e imersão bem como amostras coletadas na plataforma de recepção do laticínio. De acordo com os resultados, pode-se concluir que os métodos qualitativos não devem ser substitutos definitivos para a contagem em placas, devendo ser usado apenas como forma de triagem. De qualquer maneira o TRR se mostrou mais confiável, por não ter apresentado resultados falso-negativos, além de ser um método mais rápido que o TRAM.

Qualitative reductase tests to evaluate the microbiological quality of milk are largely used by the dairy industry. However, these tests may underestimate contamination of, refrigerated milk, once refrigeration decreases the reducing activity of microorganisms. The objective of this study was to correlate the total count of mesophilic microorganisms with the methylene blue reduction test (MBRT) and the resazurin reduction test (RRT). A total of 284 raw milk samples were collected either from farms where milk was stored in cooling and immersion tanks, and in reception platforms in dairy factories. Results showed that qualitative methods should not replace plate counts, and should only be used as screening tools. RRT showed to be faster and more reliable than MBRT because it did not present false-negative results.

Ocorrência de Bacillus cereus em leite comercializado nos estados do Paraná, Santa Catarina e São Paulo / Occurrence of Bacillus cereus in milks traded in Paraná, Santa Catarina and São Paulo States

Bacillus cereus é uma bactéria que desperta grande preocupação do setor laticinista. A combinação das características termodúrica e psicrotrófica denota seu grande potencial deteriorante, além do perigo que representa à saúde pública por ser bactéria patogênica. A presença de B. cereus foi avaliada em 260 amostras, sendo 100 de leite pasteurizado, 110 de leite ultra high temperature (UHT) e 50 de leite em pó, pelo método quantitativo (plaqueamento direto) e pelo método qualitativo (enriquecimento seletivo). Das amostras de leite pasteurizado avaliadas pelo método quantitativo, 19% foram positivas para B. cereus, com média de 1,25 (±0,27) log unidades formadoras de colônias (UFC)/ml. Para o leite em pó, 16% das amostras foram positivas, com média de 2,00 (±0,36) log UFC/g. O leite UHT não apresentou resultados dentro do limite de detecção do método de plaqueamento direto (>10 UFC/ml) para nenhuma das amostras avaliadas. Pelo método qualitativo 24% das amostras de leite pasteurizado, 34% de leite em pó e 16,4% de leite UHT foi positiva para B. cereus. Para as amostras de leite pasteurizado e leite em pó não houve diferença significativa (P>0,05) na positividade entre os métodos quantitativo e qualitativo. Os resultados do presente trabalho ressaltam que, mesmo em pequenas quantidades, B. cereus está presente não apenas em leite pasteurizado, mas também em produtos lácteos processados a altas temperaturas (leite UHT) e desidratados (leite em pó).

Bacillus cereus is a bacterium that arouses great concern on dairy sector. Its psychrotrophic and thermoduric behavior confers great spoiling potential and its pathogenicity is extremely worrynig to public health. This study evaluated the presence of B. cereus in 260 samples, from which 100 was pasteurized milk, 110 was UHT milk and 50 was milk powder. The techiques used were both quantitative (direct plating) and qualitative (selective enrichment) methods. 19% of pasteurized milk samples evaluated by the quantitative method were positive for B. cereus, with an average contamination of 1.25 (± 0.27) log CFU/ml. For milk powder, 16% of the samples was positive for this microorganism, with an average of 2.00 (± 0.36) log CFU/g. UHT milk samples did not show results within the detection limit of the direct plating method (> 1 log CFU/ml). Regarding the qualitative method, 24% of the pasteurized milk samples, 34% of milk powder and 16.4% of UHT milk was positive for B. cereus. There was no significant difference (P <0.05) by quantitative and qualitative methods for pasteurized milk and milk powder samples. The results concludes that, even in small amounts, B. cereus is present in processed dairy products, either in high temperature processes (UHT) and dried (powder milk) and pasteurized milk.