Navegando por Palavras-chave "Cattle"

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    High occurrence of Shiga toxin-producing Escherichia coli (STEC) in healthy cattle in Rio de janeiro State, Brazil
    (Elsevier B.V., 1999-10-01) Cerqueira, Aloysio de Mello Figueiredo [UNIFESP]; Guth, Beatriz Ernestina Cabilio [UNIFESP]; Joaquim, Rogério Marques; Andrade, João Ramos da Costa; Universidade Federal Fluminense (UFF); Universidade Federal de São Paulo (UNIFESP); Universidade do Estado do Rio de Janeiro (UERJ)
    In order to evaluate the prevalence of Shiga toxin-producing Escherichia coli (STEC) strains, 197 fecal samples of healthy cattle from 10 dairy farms, four beef farms and one slaughterhouse at Rio de Janeiro State, Brazil, were examined for Shiga toxin (Stx) gene sequences by polymerase chain reaction (PCR). for presumptive isolation of O157:H7 E. coli, the Cefixime-potassium tellurite-sorbitol MacConkey Agar (CT-SMAC) was used. A high occurrence (71%) of Stx was detected, and was more frequently found among dairy cattle (82% vs. 53% in beef cattle), in which no differences were observed regarding the age of the animals. Dot blot hybridization with stx1 and stx2 probes revealed that the predominant STEC type was one that had the genes for both stx1 and stx2 in dairy cattle and one that had only the stx1 gene for beef cattle. Three (1.5%) O157:H7 E. coli strains were isolated from one beef and two dairy animals by the use of CT-SMAC. To our knowledge, this is the first report of O157:H7 isolation in Brazil. A PCR-based STEC detection protocol led to the isolation of STEC in 12 of 16 randomly selected PCR-positive stool samples. A total of 15 STEC strains belonging to 11 serotypes were isolated, and most of them (60%) had both stx1 and stx2 gene sequences. Cytotoxicity assays with HeLa and Vero cells revealed that all strains except two of serotype O157:H7 expressed Stx. the data point to the high prevalence of STEC in our environment and suggest the need for good control strategies for the prevention of contamination of animal products. (C) 1999 Elsevier Science B.V. All rights reserved.
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    Ocorrência da diarréia bovina a vírus - doença das mucosas no Brasil: sua demonstração pelo encontro de anticorpos neutralizantes
    (Universidade Federal de São Paulo (UNIFESP), 1973) Soares, Laurinda Aparecida [UNIFESP]; Pereira, Octavio Augusto de Carvalho [UNIFESP]
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    Pre-treatment of cattle semen or oocytes with purified milk osteopontin affects in vitro fertilization and embryo development
    (Elsevier B.V., 2008-11-01) Goncalves, R. F.; Chapman, D. A.; Bertolla, R. P. [UNIFESP]; Eder, I.; Killian, G. J.; Universidade de São Paulo (USP); Penn State Univ; Universidade Federal de São Paulo (UNIFESP)
    This study was designed to investigate the effects of pre-incubating cattle spermatozoa or matured oocytes with purified osteopontin (OPN) from cattle milk on fertilization in cattle and embryonic development in vitro. There were two different experiments, semen from six mature Holstein bulls (Bos Taurus) was frozen with different concentrations of OPN (0, 1, 10, 100 mu g/mL). Matured cattle oocytes were also pre-treated with OPN (0, 10, 100 mu g/mL). in both experiments, pre-treated oocytes or frozen semen, was processed for in vitro fertilization and embryo development. Significantly more oocytes were fertilized when using frozen semen with 10 mu g/mL OPN (bull 2 = 85 +/- 4% and bull 5 = 78 +/- 4%) than without OPN (bull 2 = 75 +/- 4% and bull 5 = 69 +/- 4%). Those bulls also had increase in cleavage and embryo development (bull 2 = 85 +/- 3%, 41 +/- 1.9%; bull 5 = 76 +/- 2%, 37 +/- 1.8%) compared with control (bull 2 = 75 +/- 3%, 30 +/- 2%; bull 5 = 68 +/- 2%, 29 +/- 2%). Incubating matured oocytes in 10 mu g/mL OPN (87 +/- 3%) and 100 mu g/mL OPN (88 +/- 3%) significantly increased fertilization than control (73 +/- 3%). OPN also improve cleavage, and embryo development in treatments with 10 mu g/mL OPN (82.7 +/- 1.3%; 31.7 +/- 1.4%) and 100 mu g/mL OPN (85.8 +/- 1.3%; 33.8 +/- 1.5%) when compared with control (74.1 +/- 1.3%; 24.2 +/- 1.2%). These data suggest that both, spermatozoa from some bulls and oocytes may associate with OPN, suggesting a facilitory role on in vitro fertilization and embryo development. (C) 2007 Elsevier B.V. All rights reserved.
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    Serotypes, virulence markers and cell invasion ability of Shiga toxin-producing Escherichia coli strains isolated from healthy dairy cattle
    (Wiley-Blackwell, 2016) Gonzalez, Alice Gonçalves Martins; Cerqueira, Aloysio de Mello Figueiredo; Guth, Beatriz Ernestina Cabilio [UNIFESP]; Coutinho, Cesar Augusto de Souza; Liberal, Maira Halfen Teixeira; Souza, Rossiane de Moura; Andrade, João Ramos da Costa; Universidade Federal de São Paulo (UNIFESP)
    AimThe occurrence of virulence markers, serotypes and invasive ability were investigated in Shiga toxin-producing Escherichia coli (STEC) isolated from faecal samples of healthy dairy cattle at Rio de Janeiro State, Brazil. Methods and ResultsFrom 1562 stx-positive faecal samples, 105 STEC strains were isolated by immuno-magnetic separation (IMS) or plating onto MacConkey agar (MC) followed by colony hybridisation. Fifty (476%) strains belonged to nine serotypes (O8:H19, O22:H8, O22:H16, O74:H42, O113:H21, O141:H21, O157:H7, O171:H2 and ONT:H21). The prevalent serotypes were O157:H7 (124%), O113:H21 (67%) and O8:H19 (57%). Virulence genes were identified by polymerase chain reaction (PCR). E-hlyA (771%) was the more prevalent virulence marker, followed by espP (648%), saa (39%), eae (248%) and astA (219%). All O157:H7 strains carried the (gamma) variant of the locus of enterocyte effacement (LEE) genes and the stx2c gene, while the stx1/stx2 genotype prevailed among the eae-negative strains. None of the eae-positive STEC produced the localized adherence (LA) phenotype in HEp-2 or Caco-2 cells. However, intimate attachment (judged by the fluorescent actin staining test) was detected in some eae-positive strains, both in HEp-2 (231%) and in Caco-2 cells (115%). Most strains (875%) showed peripheral association' (PA) adherence phenotype to undifferentiated Caco-2 cells. Twenty-five (926%) of 27 strains invaded Caco-2 cells. The highest average value of invasion (96%) was observed among the eae-negative bovine strains from serotypes described in human disease. ConclusionHealthy dairy cattle is a reservoir of STEC carrying virulence genes and properties associated with human disease. Significance and Impact of the StudyAlthough reports of human disease associated with STEC are scarce in Brazil, the colonization of the animal reservoir by potentially pathogenic strains offers a significant risk to our population.