Identification of pathogens and virulence profile of Rhodococcus equi and Escherichia coli strains obtained from sand of parks

The identification of pathogens of viral (Rotavirus, Coronavirus), parasitic (Toxocara spp.) and bacterial (Escherichia coli, Salmonella spp., Rhodococcus equi) origin shed in feces, and the virulence profile of R. equi and E. coli isolates were investigated in 200 samples of sand obtained from 40 parks, located in central region of state of Sao Paulo, Brazil, using different diagnostic methods. From 200 samples analyzed, 23 (11.5%) strains of R. equi were isolated. None of the R. equi isolates showed a virulent (vapA gene) or intermediately virulent (vapB gene) profiles. Sixty-three (31.5%) strains of E. coli were identified. The following genes encoding virulence factors were identified in E. coli: eae, bfp, saa, iucD, papGI, sfa and hly. Phylogenetic classification showed that 63 E. coli isolates belonged to groups B1 (52.4%), A (25.4%) and B2 (22.2%). No E. coli serotype O157:H7 was identified. Eggs of Toxocara sp. were found in three parks and genetic material of bovine Coronavirus was identified in one sample of one park. No Salmonella spp. and Rotavirus isolates were identified in the samples of sand. The presence of R. equi, Toxocara sp, bovine Coronavirus and virulent E. coli isolates in the environment of parks indicates that the sanitary conditions of the sand should be improved in order to reduce the risks of fecal transmission of pathogens of zoonotic potential to humans in these places.

Cell-mediated immune response to Leishmania chagasi experimental infection of BALB/c immunosuppressed mice

Leishmaniasis, a zoonosis of worldwide distribution, presents a significant impact on immunosupressed patients. This study aimed to evaluate Leishmania chagasi infection in BALB/c mice immunosuppressed with dexamethasone. Spleen cells stimulated or not with L. chagasi were cultured for cytokine quantification (IFN-gama, IL-2, IL-4 and IL-10) by sandwich ELISA. Parasite loads in the spleen and liver were determined by means of culture microtitration. Immunosuppressed groups showed statistically lower spleen weight and CD4-cell percentage in blood on the day of infection and produced Th1 and Th2 cytokines on other days of the study. The other infected groups, weather immunosupressed or not, also produced Th1 and Th2 cytokines. Parasite loads in the spleen and liver were not statistically different among the groups. It was concluded that L. chagasi infection was not affected by dexamethasone-induced immunosuppression, probably due the reversible effect of the treatment.

Prevalence and risk factors for human toxoplasmosis in a rural community

Toxoplasma gondii infection may lead to important pathological questions, especially in rural areas, where several sources of infection exist. Therefore, it is important to determine risk factors in order to establish adequate prophylactic measures. The present study aimed to assess the prevalence and risk factors involved in human toxoplasmosis infection in a rural community, in Eldorado, Mato Grosso do Sul State, Brazil. This community was composed of 185 farms - with 671 inhabitants - from which 20 were randomly chosen. In these farms, blood samples were collected from rural workers, who also answered a risk factor questionnaire. Serum samples were analyzed by means of direct agglutination test for the detection of anti-Toxoplasma gondii antibodies. From 73 samples collected, 79.45% were positive. None of the studied variables was significantly associated with the prevalence of the infection. However, among the individuals who reported eyesight impairments, 94.4% had anti-T. gondii antibodies, compared with 74.0% who did not report eyesight changes (p = 0.0594). Moreover, most individuals in the study (68.20%) were older than 18 years and presented 84.44% positivity, compared with 66.67% of positive individuals younger than 18 years old. We were able to conclude that a high prevalence of antibodies did not imply significant associations with the risk factors studied.(AU)

Serological profile of anti-Toxoplasma gondii antibodies in apparently healthy dogs of the city of Botucatu, São Paulo State, Brazil

Toxoplasmosis is a zoonosis caused by Toxoplasma gondii, a coccidian protozoan of worldwide distribution. The seroprevalence in canine population can be an alternative for measuring T. gondii urban spreading. A total of 780 blood samples from dogs were collected, during the yearly anti-rabies campaign, carried out by the Department of Veterinary Hygiene and Public Health, School of Veterinary Medicine and Animal Husbandry (FMVZ), São Paulo State University, UNESP, together with the county health authorities, in August 1999. Using Indirect Fluorescent Antibody Test (IFAT) for detecting antibodies anti-T. gondii in the sera samples, we observed that 258 dogs (33.1 percent) were positive. The associations between the serological results and the epidemiological variables were studied. Statistically significant differences were not found regarding sex (32.2 percent male and 34.3 percent female reactors). Dogs without a defined breed showed seropositivity statistically higher than the pedigreed group. The occurrence of infection was considered higher with age.

Corynebacterium bovis e os padrões de contagem de células somáticas no Brasil / The corynebacterium bovis and the somatic cell counting standards in Brazil / El Corynebacterium bovis y los paradrones celulares somáticos en brasil

Foram estudadas 60 amostras de leite de glândulas mamárias bovinas naturalmente infectadas pelo Corynebacterium bovis em estado puro, exuberante e que apresentavam pelo menos uma glândula contralateral com cultivo microbiológico negativo, provenientes de cinco propriedades leiteiras localizadas no interior do estado de São Paulo. Essas foram cultivadas em ágar sangue ovino e em agar MacConkey e submetidas à contagem eletrônica de células somáticas. Obtiveram-se medianas de contagens de células somáticas (CCS), 262 x 10³ céls/mL e 806 x 10³ céls/mL de leite, para as amostras negativas e positivas ao Corynebacterium bovis respectivamente, sendo que, em alguns casos positivos, a CCS superou 10.000.000 céls/mL de leite. Os dados obtidos no presente estudo sugerem que o Corynebacterium bovis é responsável por alterações celulares significativas no leite, podendo acarretar prejuízos aos produtores e à indústria de laticínios, na medida que se observam os padrões celulares stabelecidos pelo Ministério da Agricultura, Pecuária e Abastecimento em vigor desde setembro de 2002.

ABSTRACT: Sixty milk samples from bovine mammary glands naturally infected by Corynebacterium bovis in pure state, which presented at least one contralateral gland with negative microbiological culture from fi ve dairy farms in the State of Sao Paulo were studied. These samples were cultivated in MacConkey agar and submitted to an electronic Somatic Cell Counting (SCC). The medians of SCC results were 262 x 103 cells/mL and 806 x 103 cells/mL from negative and positive milk samples to C. bovis respectively. In some positive samples to the agent, it was observed SCC over 10.000.000 cells/mL of milk suggesting that C. bovis may be responsible for signifi cant cell alterations in the milk, which might cause serious economic damages to the producers and to the milk industry, according to the cell standards established by Agriculture Ministry, Brazilian law from September of 2002

RESUMEN: Fueron estudiadas sesenta muestras de leche de glándulas mamarias bovinas naturalmente infectadas por el Corynebacterium bovis en cultivo puro, provenientes de cinco haciendas lecheras localizadas en el interior del estado de São Paulo. Las muestras fueron cultivadas en agar sangre ovino y en agar MacConkey, y sometidas a cómputo electrónico de células somáticas. Se obtuvo medianas de los cómputos de células somáticas, 262 x 103 céls/mL y 806 x 103 céls/mL en la leche, para las muestras negativas y positivas al Corynebacterium bovis respectivamente, siendo que en algunos casos positivos, la CCS superó 10.000.000 céls/mL de leche. Los datos obtenidos en el presente estudio sugieren que el Corynebacterium bovis es responsable por alteraciones celulares signifi cativas en la leche, pudiendo acarrear perjuicios a los productores y a la manufactura de lácteos, en la medida que se observan los moldes celulares establecidos por el Ministerio de la Agricultura, Pecuaria y Abastecimiento en vigor desde setiembre de 2002

Modified E-test by the addition of EDTA-Tris and dimethyl sulfoxide on the potentiation of the effects of some antimicrobials in Pseudomonas aeruginosa strains isolated from bovine mastitis

A concentração inibitória mínima-MIC em 30 estirpes de Pseudomonas aeruginosa isoladas de mastite bovina foi avaliada utilizando o E-test padrão e o método modificado, pela adição de Tris-EDTA e DMSO. Os métodos modificados apresentaram redução significativa da MIC das estirpes utilizando a gentamicina, a ciprofloxacina e a norfloxacina.