The objective of the present study was to evaluate the occurrence of Staphylococcus aureus in milk produced in 37 farms located in the regions of Ribeirão Preto and São Carlos, state of São Paulo, Brazil.Two-hundred and eight samples of milk from individual cows showing subclinical mastitis, and 37 samples of bulk tank milk were analyzed. S. aureus strains were detected in 18 (7.3%) milk samples: 14 (6.7%) from samples of individual cows, and 4 (10.8%) from bulk tank milk. Two individual milk samples (14.3%) and two bulk milk samples contained enterotoxigenic S. aureus. PFGE analysis revealed the genetic heterogeneity of the strains isolated from raw milk, which presented to 13 S. aureus patterns.Results confirmed the potential transmission of staphylococcal food poisoning to consumers via milk of cows affected by subclinical mastitis, mainly when raw milk is ingested.
Biofilm formation is considered to be a selective advantage for Staphylococcus aureus mastitis isolates by facilitating bacterial persistence in the udder. It requires attachment to mammary epithelium, proliferation and accumulation of cells in multilayers. The objective of this study was to determine the sensitivity and specificity of three techniques for the detection of S. aureus biofilm-positive strains. Two phenotypic tests, including growth on microtitre plates and Congo red agar, were compared with a PCR technique using 94 S. aureus strains obtained from cows with subclinical mastitis from two farms in the state of São Paulo. These strains were characterised by in vitro slime production on Congo red agar, biofilm formation on microtitre plates and the presence of the icaA and icaD genes. The results revealed that 85% of the isolates tested produced slime on the Congo red agar, 98.9% of the isolates produced biofilms in vitro by adhering to sterile 96-well “U” bottom polystyrene tissue culture plates, and 95.7% of the isolates carried the icaA and icaD genes. The results of the phenotypic tests for biofilm formation were compared with those of the molecular analysis, and the sensitivity and specificity of the Congo red agar test were 88.9% and 100%, respectively, while those of the microtitre plate test were 100% and 25%, respectively. When the phenotypic methods for the detection of biofilm producers, namely growth on microtitre plates and Congo red agar, were compared, the sensitivity and specificity were 86% and 100%, respectively. Therefore, growth on Congo red agar and the microtitre plate test are methods that could be used to determine whether an isolate has the potential for biofilm production.
RESUMO Foram submetidas a PCR-Ribotipagem e aos testes de sensibilidade in vitro frente a 12 antimicrobianos 77 estirpes de Staphylococcus aureus isoladas em amostras de leite procedentes de 40 vacas da raça holandesa que apresentaram mastite subclínica, em uma propriedade rural localizada no
Doxorubicin (DXR) is a potent antitumor drug used worldwide against many forms of human cancer. However, in addition to intercalating into the DNA molecule, this drug generates free radicals that induces chromosome aberrations. Fruits of Salanum melongena are rich in flavonoids. Since several flavonoids have been reported to be efficient antioxidants by scavenging oxygen radicals, the objective of the present study was to investigate the possible protective effect of a standardized extract of Solanum melongena on Wistar rat cells treated with DXR in vivo. The animals were treated by gavage with the extract at 50% of the LD 50 (3 g/kg determined for mice) for 10 consecutive days (group 1) and during 1 day (a single dose, group 2), and submitted to euthanasia 24 h after DXR injection (10 mg/kg body weight) for micronucleus assay (MN) and chromosome preparations. Control groups received a single dose of DXR or S. melongena extract. In both treatments where the animals were treated with the extract and with the DXR simultaneously, rat bone marrow cells developed significantly fewer MN and chromosomal aberrations than those treated with DXR alone.
O leite bovino é um importante alimento e produto do Agronegócio brasileiro, porém, para agradar às exigências do consumidor o mercado necessita se reinventar constantemente. Com isso, produtos como o leite com o selo A2 ganham destaque por ser considerado de mais fácil digestão, visto que não possui, em sua composição, peptídeos bioativos, relacionados ao desenvolvimento de alergias e outras doenças humanas. O objetivo deste trabalho foi demonstrar a possibilidade da produção exclusiva do leite A2 em fazendas no Brasil, abordando seu processo produtivo, suas características e vantagens. Diante disso, observou-se que, para a obtenção de um leite com essas características, é necessário o investimento em biotecnologias, como a seleção dos animais e a associação da inseminação artificial com a fertilização in vitro e transferência de embriões, possibilitando, assim altos índices de produção de bezerros/vaca/ano com o gene A2A2 e ainda provar a confiabilidade do sistema de produção utilizando métodos de rastreabilidade eficientes, o que proporcionou a obtenção do selo A2. No entanto, devido aos benefícios do leite A2 apresentados nesse trabalho, acredita-se que o investimento realizado trará um excelente retorno financeiro, pois esse projeto visa fazer com que pessoas que deixaram de beber leite devido ao desconforto voltassem a consumi-lo. Abstract: Bovine milk is an important food and product of the Brazilian Agribusiness, however, to please consumer demands, the market needs to constantly reinvent itself. As a result, products such as milk with the A2 seal gain prominence for being considered easier to digest, since it does not have bioactive peptides in its composition, related to the development of allergies and other human diseases. The objective of this project was to demonstrate the possibility of exclusive production of A2 milk on farms in Brazil, addressing it is production process, it is characteristics and advantages. Therefore, it was observed that to obtain milk with these characteristics, it is necessary to invest in biotechnologies, such as animal selection and the association of artificial insemination with in vitro fertilization and embryo transfer, enabling high production rates of calves/cow/year with the A2A2 gene and still prove the reliability of the production system using efficient traceability methods, which provided for obtaining the A2 seal. However, due to the benefits of A2 milk presented in this work, it is believed that the investment made will bring an excellent financial return, as this project aims to make people who stopped drinking milk due to discomfort to consume it again. Keywords: Bovine milk. Production of A2 milk. Genetic selection. Agribusiness.
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