Characterization of Staphylococcus species isolated in production stages of brazilian colonial cheese

Colonial cheese is a culturally and economically important product from the south of Brazil. As most of its production is artisanal, the technology employed is mostly knowledge passed down from one generation to the next according to family tradition and may be produced with raw or pasteurized milk. It is noted for its spicy flavour and variable composition and is often classified as a medium to high-moisture cheese. This intrinsic feature increases the risk of microbial spoilage and food poisoning. One of the main bio-indicators of contamination in colonial cheese is coagulase positive Staphylococcus. The purpose of this study was the phenotypic identification of Staphylococcus species isolated from the products and surfaces in the main production stages of colonial cheese. Staphylococcus sp. isolates from the food and the production environment were obtained from two colonial cheese-production agro-industries in Rio Grande do Sul. Samples of fresh milk, curd, ripening and final colonial cheese were collected. In addition, surface sampling was performed on the coagulation tanks, production tables, molds, cheese ripening shelves and on the hands of the handlers. Staphylococcus sp. isolates in the cheese and the production environments tested in this study were identified by phenotypic techniques through biochemical and MALDI-TOF MS analyses. These isolates were subjected to gene expression analysis for enterotoxins A, B, C, D, and E. All isolates (72) were identified as Staphylococcus sp., and 43% of the total isolates tested were coagulase positive. Staphylococcus aureus was the predominant species in the raw milk and production tanks. Regarding coagulase negative staphylococci isolates, S. warneri and S. sciuri were most abundant. The sea and seb genes were detected in 4% of the Staphylococcus isolates. The results indicate eleven different species of Staphylococcus present in the colonial cheese production environments studied. The predominant presence of S. aureus in the different samples of milk, curd, ripened cheese, ready-to-eat cheese and hands of the handlers indicates that there are issues with the selection of milk-producing animals, pasteurization process and/or hygiene control of handlers. The sea and seb genes were detected in samples of raw milk and colonial cheese. No enterotoxin genes were detected in coagulase negative staphylococci.

Microbial contamination in industrial tofu / Contaminação microbiana em tofu industrial

ABSTRACT: This study aimed to evaluate the microbiological quality of tofu sold in supermarkets in Porto Alegre/Brazil. Bacteria counts were performed for Bacillus cereus , mesophilic, coliforms and Staphylococcus coagulase positive and negative. The presence of Listeria sp. was also evaluated. Two different brands of tofu (A and B) were collected, one lot per month, for six months. Five samples from each lot were analyzed. All lots presented mesophilic aerobic counts above 4.3x105CFU g-1. Four of the six lots from brand A and all lots from brand B showed E. coli and/or Staphylococcus coagulase positive counts above the Brazilian law accepted limits. The Staphylococcus coagulase negative counts were higher than those of coagulase positive in all lots. In all lots where Staphylococcus coagulase positive counts were above the legal limit, there were counts of coagulase negative above 104CFU g-1. B. cereus and Listeria sp. were not found in either brand. The majority of lots of brand A and all lots of brand B were unsuitable for human consumption. Our results showed that there are problems in tofu manufacturing in both industries analyzed. There is a need of improvement on its microbial quality to avoid problems of food-borne illness, and finally the need of a better control by the Brazilian inspection services.

RESUMO: Este estudo teve como objetivo avaliar a qualidade microbiológica de queijo tofu comercializados em um supermercado da cidade de Porto Alegre, RS. Foram realizadas contagens de Bacillus cereus , bactérias mesófilas, coliformes, Staphylococcus coagulase positive e negativo e, a pesquisa de Listeria sp. Foi realizada a coleta de duas diferentes marcas (A e B), com um lote por mês, durante seis meses; sendo analisadas cinco amostras de cada lote. Todos os lotes apresentaram contagens de mesófilos aeróbios acima de 4,3x105UFC g-1. Quatro dos seis lotes da marca A e todos os lotes da marca B apresentaram contagens de E. coli e/ou Staphylococcus coagulase positive acima do permitido pela legislação vigente. As contagens de Staphylococcus coagulase negativos foram superiores às contagens dos coagulase positivos em todos os lotes. Nos lotes em que foram encontradas contagens fora do padrão estabelecido para os Staphylococcus coagulase positivos, havia contagens dos coagulase negativos acima de 104UFC g-1. Não foram isolados B. cereus e Listeria sp. Ambas as marcas apresentaram sérios problemas sanitários, pois a maioria dos lotes da marca A e todos os lotes da marca B estavam impróprios para o consumo mesmo na ausência dos outros patógenos pesquisados. Nossos resultados mostram que há problemas sérios na produção de tofu em ambas as indústrias analisadas. Existe a necessidade de melhorias no sistema de produção para evitar a ocorrência de doenças causadas por este alimento e, também, que deve haver um maior controle da qualidade deste alimento pelos serviços de fiscalização.

Sanitary quality, occurrence and identification of Staphylococcus sp: in food services

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.

Antimicrobial susceptibility profile of brucella spp. isolated in Brazil

The intention of this work was to investigate the susceptibility profile of 27 Brucella strains isolated from animals in Brazil, using the E-test method with antimicrobials recommended for the treatment of human brucellosis, to monitor the activities of these antimicrobials and their potential efficacy for human brucellosis treatment. Efficiency of SE-AFLP in determining the genetic diversity of the species of Brucella and its correlation with their susceptibility profile was also evaluated. All 27 strains were susceptible to doxycycline. With the exception of one strain of B. canis and of B. abortus, all strains were susceptible to gentamicin and streptomycin. Of the wild Brucella strains tested, ten, nine and five showed reduced susceptibility to rifampicin, ceftriaxone and trimetoprim/sulfamethoxazole, respectively. One B. abortus and three B. canis strains showed multi-resistance profiles. The strain of B. abortus was resistant to streptomycin, rifampicin and ceftriaxone. Two strains of B. canis were resistant to rifampicin, ceftriaxone and trimetoprim/sulfamethoxazole, and one strain was resistant to rifampicin, ceftriaxone, streptomycin and gentamicin. Rifampicin, in combination with doxycycline, is one of the principal antibiotics prescribed to treat human brucellosis. The occurrence of strains resistant to rifampicin and other antimicrobials must be monitored before initiating this treatment, since the resistance of these strains could be one of the causes of the failure of some brucellosis treatment. No relationship was observed between SE-AFLP profiles and regional origin of the strains; neither between SE-AFLP profiles and antimicrobial profiles...

O objetivo deste trabalho foi investigar o perfil de susceptibilidade de 27 cepas de Brucella isoladas de animais no Brasil, utilizando-se o método E-test com os antimicrobianos recomendados para o tratamento da brucelose humana. Com este método, pretendeu-se monitorar a atividade destes antimicrobianos e seu potencial de eficacidade no tratamento desta enfermidade no homem. Também foi avaliada a eficiência da técnica SE-AFLP para discriminar as diferentes cepas de Brucella sp. e para analisar se os perfis gerados mostram alguma relação com os resultados de susceptibilidade. Todas as 27 cepas testadas foram sensíveis à doxiciclina, com exceção de uma cepa de B. canis e outra de B. abortus; as demais cepas foram sensíveis à gentamicina e à estreptomicina. Do total de cepas de campo testadas, respectivamente, dez, nove e cinco apresentaram susceptibilidade reduzida à rifampicina, ceftriaxona e trimetoprim/sulfametoxazol. Uma cepa de B. abortus e três de B. canis apresentaram perfil de multirresistência. A cepa de B. abortus mostrou-se resistente à estreptomicina, rifampicina e ceftriaxona. Duas cepas de B. canis foram resistentes à rifampicina, ceftriaxona e trimetoprim/sulfametoxazol e uma cepa foi resistente à rifampicina, ceftriaxona, streptomicina e gentamicina. Rifampicina e doxiciclina, associadas, são os principais antibióticos recomendados para o tratamento da brucelose humana. A ocorrência de cepas resistentes à rifampicina e outros antimicrobianos deve ser monitorada antes do início do tratamento, pois a resistência a esses antimicrobianos pode ser uma das causas do insucesso de alguns tratamentos de brucelose. Não foi observada nenhuma correlação entre os perfis SE- AFLP gerados e a origem das cepas, nem com os perfis de susceptibilidade destas cepas...

Molecular analysis of the iap gene of Listeria monocytogenes isolated from cheeses in Rio Grande do Sul, Brazil

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).

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).

Qualidade bacteriológica de queijos artesanais comercializados em estradas do litoral norte do Rio Grande do Sul, Brasil / Bacteriological quality of homemade cheeses commercialised in roads of the northern coast of Rio Grande do Sul, Brazil

O consumo de queijo artesanal, vendido em estabelecimentos de beira de estrada, é comum no Estado do Rio Grande do Sul. Geralmente estes produtos não são fabricados em acordo com as boas normas de fabricação e podem constituir perigo à saúde do consumidor. Objetivou-se, com o presente trabalho, verificar a qualidade bacteriológica de queijos artesanais comercializados em estradas litorâneas por meio da contagem de coliformes e pesquisa de Listeria spp. e Brucella spp. Foram analisados 80 queijos, sendo 62 do tipo Colonial, dez do tipo Provolone, seis do tipo Ricota e dois do tipo Caccio Cavallo. No momento da coleta, 71 por cento das amostras não estavam sob refrigeração. Todas as amostras apresentaram contagens de coliformes totais e, destas, 62 foram testadas para a presença de coliformes fecais. Um total de 84 por cento das amostras apresentou contagens de coliformes fecais acima de 2,73- 3,7 log.UFC g- 1 (de 500 a 5000UFC mL-1), previsto como limite máximo a ser encontrado em queijos. Dos 29 estabelecimentos, 27 tinham produtos fora destes limites. Das 80 amostras, 16 por cento continham Listeria spp., sendo 3,7 por cento identificadas como Listeria monocytogenes. As estações do ano influenciaram no isolamento de Listeria spp., sendo a primavera considerada a estação do ano com maior número de isolados. Brucella spp. não foram isoladas nas 80 amostras de queijos analisadas. A alta freqüência de coliformes fecais e a presença de L. monocytogenes revelam que o consumo destes queijos constitui perigo de infecção à população em geral e especialmente àquelas pessoas imunocomprometidas.

The consumption of homemade cheese, which is sold in little shops along the road, is very common in the state of Rio Grande do Sul, Brazil. Generally, these products are not manufactured according to the good hygiene guidelines; and may be a risk to the consumersÆ health. The aim of this research was the assessment of the bacteriological quality of homemade cheese sold in the region along the northern coast of Rio Grande do Sul. Cheese samples were taken and total and faecal coliform counting per gram sample were established. The samples were also examined for the presence of Listeria spp. and Brucella spp. In total, 80 samples, from 29 commercial establishments were analysed, of which 62 of Colonial type; 10, of Provolone; 6 of Ricotta and 2, of Cacciocavallo type. At the moment of sampling, 71 percent of them were not stored under refrigeration conditions. In all the samples the presence of total coliform could be demonstrated and 62 of these were tested for the presence of faecal coliforms. In 84 percent of the samples more then 2.73 - 3.7log.UFC g- 1 (from 500 to 5000UFC mL-1) of faecal coliform could be demonstrated, with is considered the maximum limit still allowed to be present in cheese samples. Of the 29 establishments analysed, 27 had products with coliforms counts above these limits. Of the 80 samples, 16 percent had Listeria sp., of which 3.7 percent were identified as Listeria monocytogenes. A correlation was found between the season and the isolation of Listeria spp.: in the spring the highest number was detected. Brucella spp. could not be detected in the 80 samples analysed. The high frequency of faecal coliforms and the presence of L. monocytogenes revealed that the consumption of these homemade cheeses can become a risk of infection to the population, especially for immunocompromised persons.

Prevalência de Salmonella sp em suínos abatidos em frígoríficos do Rio Grande do Sul / Prevalence of Salmonella sp. carrier pigs in slaughterhouses of Rio Grande do Sul, Brazil

Este estudo foi realizado com o objetivo de determinar a prevalência de Salmonella sp em suínos abatidos em frigoríficos sob inspeção federal no Rio Grande do Sul. Amostras de fezes e linfonodos foram coletadas em três diferentes frigoríficos no Estado. A partir da análise microbiológica das amostras de 300 animais, encontrou-se uma prevalência de Salmonella sp de 55,66 por cento, com 17,6 por cento de isolamentos a partir dos linfonodos, 18,3 por cento das fezes e 19,6 por cento em ambos os materiais. Foram identificados 26 sorovares diferentes em 226 isolados de Salmonella sp. Os sorovares mais prevalentes foram: Typhimurium (24,3 por cento), Agona (19,9 por cento), Derby (13,2 por cento) e Bredeney (12 por cento). Estes resultados indicam a necessidade de implementar programas de controle com o objetivo de diminuir a prevalência de animais portadores ao abate.

Comparison of different selective enrichment steps to isolate Salmonella sp. from feces of finishing swine

A two-phase study was conducted to compare the efficacy of several enrichment selective-broth steps associated to different plating media for recovery of Salmonella sp. from finishing swine feces. In a first phase, Rappaport-Vassiliadis broth (RV) incubated at 42liC, Tetrathionate Mseller-Kauffmann broth at 37liC (TMK37) and 42liC (TMK42), and Selenite Cystine broth (SC) at 37liC, in combination with three selective plating media Rambach agar (RA), Xylose-Lysine-Tergitol 4 agar (XLT4), and Brilliant-Green Phenol-Red Lactose Sucrose agar (VB) were compared for recovery of Salmonella from artificially contaminated swine feces. In a second phase, RV, TMK37, and TMK42, associated with XLT4 and VB , were tested with naturally contaminated swine feces. In this study RV, TMK42 and TMK37 were superior to SC for isolating Salmonella sp. from artificially contaminated feces. TMK42 and RV were more productive than TMK37 for recovery of Salmonella from naturally contaminated feces samples. Selectivity and indication capability of the plating media were remarkably affected by the selective enrichment step effectiveness. The TMK42/XLT4 association was the most sensitive and RV/XLT4 the most specific. The use of VB agar is also recommended to increase the likelihood of isolating atypical H2S-late producing/ non-producing Salmonella. In this study RV and TMK42 were the most efficient selective enrichment for recovery of Salmonella sp. from swine feces.

Ocorrência de Salmonella sp em suínos de terminaçäo no Rio Grande do Sul / Occurrence of Salmonella sp in finishing pigs in Rio Grande do Sul, Brazil

Foram colhidas amostras de fezes de lote de suínos em 10 granjas terminadoras do Estado do Rio Grande do Sul para pesquisa de Salmonella sp. Duas granjas consideradas negativas (N1 e N2) e uma positiva (P1) nesta primeira etapa foram escolhidas para colheita de amostras de fezes individuais de 25 animais escolhidos aleatoriamente. No abatedouro foram coletados swab retal, conteúdo intestinal e linfonodos mesentéricos dos mesmos animais amostrados na granja. Após a introduçäo de novos animais nas granjas N1 e P1, outros 25 animais foram amostrados em cada granja, da mesma forma descrita acima. Três granjas tiveram amostras de fezes de lote positivas, sendo que em duas foi constatado um alto nível de contaminaçäo. Foram encontrados 8 sorotipos de Salmonella (Agona, Bredeney, Lexington, London, Mbandaka, Panama, Schwartzengrund, Salmonella sp), sendo os sorotipos Agona e Bredeney os mais encontrados. Na colheita individual realizada, todas as granjas amostradas foram positivas. Em 6,4 por cento das amostras de fezes colhidas na granja, 5,3 por cento das amostras de conteúdo intestinal e 5,6 por cento dos linfonodos mesentéricos foi possível isolar Salmonella. O antibiograma das linhagens de Salmonella isoladas demonstrou 97,8 por cento de resistência à sulfonamida, 82,6 por cento à estreptomicina, 36,9 por cento à tetraciclina e 15,2 por cento à sulfazotrim

Sorotipos de Salmonella isolados em uma propriedade de suínos de terminação no Sul do Brasil / Salmonella serotypes isolated from a finishing swine farm in the South of Brazil

Em uma granja de suínos, foram isolados quinze sorotipos diferentes de Salmonella. Dois dos sorotipos isolados, Mbandaka e Tennessee, foram também encontrados na raçäo fornecida aos animais. Este estudo demonstrou a diversidade de sorotipos que podem estar presentes em uma granja e a necessidade de um melhor entendimento da epidemiologia da infecçäo por Salmonella