This Regional Research Communication describes the characterisation of ampicillin, penicillin and tetracycline resistance in Staphylococcus aureus isolated from bovine subclinical mastitis in Minas Gerais State, Brazil. Ninety S. aureus isolates from bovine mastitis exhibiting phenotypic resistance to ampicillin, penicillin and/or tetracycline were selected for this study. The minimum inhibitory concentration (MIC) of each antibiotic was determined using the E-Test® and the production of beta-lactamase was determined by cefinase disks. The resistance genes blaZ, tet(K), tet(L), tet(M), and tet(O) were investigated by PCR in all of the isolates. The MIC results classified 77, 83 and 71% of the isolates as resistant to ampicillin, penicillin and tetracycline, respectively. The MIC50 and MIC90 were, respectively, 1 and 2 µg/ml for ampicillin, 0·5 and 1 µg/ml for penicillin and 32 and 64 µg/ml for tetracycline. Eighty-six per cent of beta-lactamase producing isolates were detected. Of the 90 isolates investigated, 97% amplified blaZ, 84% amplified tet(K), 9% amplified tet(L), 2% amplified tet(M) and 1% amplified tet(O). Seventy-nine isolates (88%) showed blaZ together with at least one tet gene. S. aureus isolates showed high MIC50 and MIC90 values for the three antimicrobials. The blaZ and tet(K) genes were widespread in the herds studied, and most of the isolates harboured blaZ and tet(K) concomitantly.

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The serrano artisan cheese produced from raw milk of dairy cattle is a typical product of high-altitude farms in the states of Santa Catarina and Rio Grande do Sul. However, marketing of the cheeses occurs illegally because they lack the minimum maturation period required for cheese produced from raw milk. The production of artisan cheeses is required to follow strict hygiene standards. This study aimed to test the quality and safety of cheeses that were produced in 31 farms of the Serrana region in Santa Catarina after 14 and 28 days of maturation. Coliform count was measured at 35 °C, and presence of other microorganisms such as Escherichia coli, Staphylococcus, Listeria spp., and Salmonella spp. were also tested. Fat and protein percentages, acidity, salt content, and humidity were also evaluated. Data were subjected to statistical analyses using the SAS ® software. After 14 and 28 days of maturation, 74.19% (23/31) and 64.52% (20/31) of samples, respectively, showed higher numbers of coliforms at 35 °C than those permissible by law. Higher than permissible numbers of E. coli were observed in 45.16% (14/31) and 48.39% (15/31) of the samples analyzed after 14 and 28 days of maturation, respectively. Coagulasepositive staphylococci values above 10 3 CFU/g were observed in 54.84% (17/31) and 51.61% (16/31) of cheese samples after 14 and 28 days of maturation, respectively. Contamination with Salmonella spp. was not detected. However, Listeria monocytogenes serovar 4b was isolated in 3.23% (1/31) and 6.45% (2/31) of samples after 14 and 28 days of maturation, respectively. The results of humidity tests classified the cheese samples into three categories: low, medium, and high humidity. Semi fat cheeses were predominant in both maturation periods, although the samples were classified in thin, semi fat, and fat cheeses. The main variations in the compositions of analyzed samples occurred for salt and acidity levels. The maturation process has not proven to be effective in reducing microbiological contamination to compliance levels. Considering the heterogeneity of the analyzed cheese samples, the frequency of non-conformities with respect to microorganisms and pathogens present in the samples, this study indicates the necessity to improve the Serrano artisan cheese production system through adoption of good manufacturing practice measures. 3 UFC/g. Nenhuma das amostras avaliadas estava contaminada com Salmonella spp., porém Listeria monocytogenes sorovar 4b foi isolada em 3,23% (1/31) e em 6,45% (2/31) das amostras aos 14 e 28 dias de maturação, respectivamente. Em relação à umidade, os queijos foram classificados como de baixa, média e alta umidade. Em relação aos teores de gordura houve a predominância de queijos semigordos nos dois períodos de maturação, embora as amostras tenham sido enquadradas como queijos magros, semigordos e gordos. As principais variações na composição entre as amostras avaliadas ocorreram nos teores de sal e acidez. O processo de maturação não demonstrou ser efetivo na redução de ...

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A competition ELISA utilizing a mAb directed towards a peplomer protein epitope common to TGEV, PRCV and related feline and canine coronaviruses is described.

The neonatal diarrhea in swine caused by enterotoxigenic Escherichia coli (ETEC) is responsible for high mortality and low growth rate in pigs and it is mainly dependent on the capacity of E. coli to attach to the surface of the small intestine, a property mediated by fimbria. In this study the faeC gene, which codes for the minor fimbrial subunit of E. coli K88ab, was cloned in the eukaryotic expression vector pcDNA3, associated or not to the Kozak sequence. Plasmid DNA of the two versions of the vaccine candidate was inoculated in mice by the intramuscular route, in two doses, at 0 and 21 days. The animals that received the DNA vaccine containing faeC associated to the Kozak sequence presented seroconversion significantly higher (P<0.05) than the one vaccinated with pcDNA3/faeC without the Kozak sequence.

Os distúrbios gastrintestinais e toxi-infeciosos causadas por Escherichia coli são uma importante causa de mortalidade, atrasos no crescimento e decréscimo na taxa de conversão alimentar em leitões no período pós-desmame, gerando perdas econômicas severas. Dentre as estratégias de combate a estas formas de apresentação estão à utilização de antimicrobianos, probióticos e aditivos na dieta, como o óxido de zinco. O zinco tem efeito promotor de crescimento, diminui a incidência de diarréia e mortalidade de leitões desmamados. O objetivo da realização desse trabalho foi verificar, in vitro, o papel de diferentes concentrações de zinco na adesão da E. coli aos enterócitos de suínos. O ensaio avaliou a eficácia de quatro suspensões: zero (controle negativo), 1200, 2400 e 3000 ppm de óxido de zinco. O teste de adesão fundamentou-se na exposição de enterócitos suínos, a uma cepa patogênica de E. coli e ao zinco, simulando o que ocorreria in vivo. Nas condições in vitro em que foi desenvolvido o experimento, o zinco não foi capaz de inibir a adesão de E.coli aos enterócitos em nenhuma das concentrações utilizadas.

O presente estudo foi realizado em sete propriedades no Planalto Catarinense, os quais apresentavam algum histórico de transtorno reprodutivo. Foram coletadas 101 amostras de urinas de matrizes em produção. Foi colhida uma amostra da primeira urina espontânea da manhã e foi feito imunofluorescência indireta a partir de esfregaços do sedimento urinário. As lâminas foram avaliadas e classificadas como negativas (ausência de bastonete ou raros bastonetes com fluorescência leve) e positiva (presença de bastonetes com fluorescência celular ou nas bordas evidente e brilhante). Dos 101 esfregaços examinados, 17 (16,8%) foram positivos para a presença do Actinomyces suis (A. suis), observando-se uma variaçãno de 14 a 80%, sendo os mesmos procedentes de quatro propriedades. Estes resultados encontrados mostram que em granjas com problemas reprodutivos o A. suis pode ser um dos agentes etiológicos envolvidos no desencadeamento do problema.