The aim of the present study was to detect the genomic DNA of Toxoplasma gondii in milk samples from naturally infected goats in the state of Pernambuco, (Brazil). In total, 248 blood serum samples were collected and processed from lactating goats and then submitted to a search for antibodies to T. gondii through the indirect immunofluorescence reaction. Samples with a score of 64 or more were considered positive. In total, 248 milk samples were collected and processed from the same group of goats in order to study the DNA of T. gondii using the polymerase chain reaction (PCR) technique. In the serum samples, 56/248 (22.58%) of the animals were positive, whereas the DNA of the parasite was detected in 15/248 (6.05%) of the milk samples. Five of these 15 samples were animals who were also positive in the serology. This study reports the first occurrence of the elimination of T. gondii from the milk of naturally infected goats in the north-east of Brazil. It is suggested that the consumption of in natura goat milk may constitute a potential risk to the health of milk consumers in this region.

The microbiota of lactic acid bacteria (LAB) from Minas artisanal cheese was evaluated. Samples of Minas artisanal cheese were collected at the farms in the region of Araxá, Brazil, over two seasons. Molecular approaches were used to assess the biodiversity of the isolates. The median value of the counts of LAB ranged from 6.4 to 9.5 log units in cheeses throughout the ripening period, in both seasons. The genera of Lactobacillus, Enterococcus, Pediococcus, and Lactococcus were found. L. plantarum and L. rhamnosus were the prevailing species during both seasons, suggesting they may play a role in the development of the cheese attributes. Enterococcus rivorum was identified in one sample and it was probably the first description in cheeses. This is an important report describing the varieties of LAB in this cheese and the identification of its lactic communities could be a source of strains with specific properties.Aislamiento e identificación de las baterias ácido-lácticas del queso brasileño Minas artesanal RESUMEN Se evaluó la microbiota de la bacteria ácido-láctica (BAL) del queso Minas artesanal. Se recogieron muestras del queso Minas artesanal en granjas de la región de Araxá, Brasil, durante dos estaciones. Se utilizaron enfoques moleculares para examinar la biodiversidad de los aislados. El valor medio de los recuentos de BAL fue de entre 6,4 y 9,5 unidades log en los quesos durante el periodo de maduración, en las dos estaciones. Se encontraron los géneros Lactobacillus, Enterococcus, Pediococcus, y Lactococcus. L. plantarum y L. rhamnosus fueron las especies predominantes durante las dos estaciones, sugiriendo que podrían jugar un papel importante en el desarrollo de los atributos del queso. Se identificó Enterococcus rivorum en una muestra y probablemente fue la primera descripción en los quesos. Este es un importante estudio que describe las variedades de BAL en este tipo de queso y la identificación de sus comunidades lácticas podría ser una fuente de cepas con propiedades específicas. ARTICLE HISTORY

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Reports of β-lactam-resistant Staphylococcus aureus in artisanal goat cheese are increasing, and this phenomenon is relevant to public health. The objective of the present study was to determine the prevalence of S. aureus strains carrying the blaZ and mecA resistance genes, as well as the genes encoding the staphylococcal enterotoxins SEA, SEB, SEC, SED, SEE, and TSST-1 in artisanal coalho cheese made from goat milk produced in northeastern Brazil. We used biochemical and molecular tests to characterize 54 S. aureus isolates found in artisanal coalho cheese collected from commercial establishments producing animal products in 11 municipalities of Pernambuco State, Brazil. A PCR analysis revealed that 42.6% (23/54) of the isolates were positive for the blaZ gene, and 7.4% (4/54) were resistant to methicillin by phenotypic testing. We did not detect mecA or any genes encoding enterotoxins. The presence of S. aureus carriers of the blaZ gene and the identification of methicillin-resistant S. aureus strains are of concern for the health of consumers of this type of cheese.

The construction of a hexahistidine-tagged version of the B fragment of diphtheria toxin (DTB) represents an important step in the study of the biological properties of DTB because it will permit the production of pure recombinant DTB (rDTB) in less time and with higher yields than currently available. In the present study, the genomic DNA of the Corynebacterium diphtheriae Park Williams 8 (PW8) vaccine strain was used as a template for PCR amplification of the dtb gene. After amplification, the dtb gene was cloned and expressed in competent Escherichia coli M15™ cells using the expression vector pQE-30™. The lysate obtained from transformed E. coli cells containing the rDTB PW8 was clarified by centrifugation and purified by affinity chromatography. The homogeneity of the purified rDTB PW8 was confirmed by immunoblotting using mouse polyclonal anti-diphtheria toxoid antibodies and the immune response induced in animals with rDTB PW8 was evaluated by ELISA and dermonecrotic neutralization assays. The main result of the present study was an alternative and accessible method for the expression and purification of immunogenically reactive rDTB PW8 using commercially available systems. Data also provided preliminary evidence that rabbits immunized with rDTB PW8 are able to mount a neutralizing response against the challenge with toxigenic C. diphtheriae.

RESUMO.-Staphylococcus spp. são os micro-organismos mais relacionados a casos de mastite bovina. Algumas cepas destes micro-organismos têm apresentado fatores de virulência como genes de resistência a antimicrobianos com destaque para a resistência à meticilina que é um problema de saúde pública. Esta revisão de literatura tem o objetivo de compilar dados sobre a mastite bovina causada por Staphylococcus spp. resistente à meticilina (MRS). Apesar desse antimicrobiano não ser comumente utilizado no tratamento das mastites, a frequência de casos de infecção da glândula mamária causada por MRS tem variado entre 1,34 a 47,6%. Acredita-se que o contato dos humanos com animais positivos para MRS e vice-versa favoreça a transmissão deste patógeno entre as espécies, contribuindo para a variação nas taxas de infecção. A detecção de MRS pode ser realizada por meio de provas fenotípicas, moleculares ou sorológicas e as medidas de controle devem contemplar a identificação dos casos, segregação dos animais, estudo epidemiológico da fonte de infecção do rebanho, além da constante limpeza e higienização do ambiente de confinamento, equipamentos e utensílios de ordenha. Casos de mastite ocasionados por esse patógeno assumem relevância para a saúde pública, pois a ingestão de leite e/ou derivados contaminados podem desencadear a transferência de MRS para seres humanos. Com isso, é necessário um alerta constante quanto à vigilância epidemiológica em fazendas leiteiras. The most related microorganism in cases of bovine mastitis are Staphylococcus spp. Some strains of these microorganisms have shown virulence factors like antibiotic resistance genes, such as the resistance to methicillin, which represents a public health problem. This literature review aims to compile data related to bovine mastitis caused by Staphylococcus spp. Methicillin-resistant (MRS). Despite this antimicrobial not be commonly used in the treatment of mastitis, the frequency of cases of infection of the mammary gland caused by MRS has ranged from 1.34 to 47.6%. It is believed that the contact of humans with animals positive for MRS and vice versa favors the transmission of this pathogen among species, contributing to the variation in infection rates. MRS detection can be performed by phenotypic tests, molecular tests or serological tests and control measures must be taken such as the identification of cases, animal segregation, epidemiological study of the infection source of herd and the constant cleanliness and hygiene of the confined environment, equipment and milking utensils. Mastitis cases caused by this pathogen are of great relevance to public health because the ingestion of contaminated and/or derived from milk may trigger the transfer of MRS for human. Thus, a constant warning is required on the epidemiological surveillance in dairy farms.

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