4 resultados para Rotavirus - Thesis

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo


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This study investigated the occurrence of rotavirus infections in ostriches (Struthio camelus) reared in Northern Parana, Brazil. Fecal (n = 66) and serum (n = 182) samples from nine farms located in four different cities were analyzed by silver stained-polyacrylamide gel electrophoresis (ss-PAGE), RT-PCR assay, virus isolation, and counterimmunoelectroosmophoresis (CIE). Rotavirus group A seropositivity occurred in 5.49% (10/182) of serum samples of ostriches originated from two farms. Only 9.09% (6/66) of fecal samples from ostriches with diarrhea maintained in one farm were positive by ss-PAGE, RT-PCR, and virus isolation. The G (VP7) and P (VP4) genotypes of rotavirus wild strains isolated in cell culture were determined by multiplex-nested PCR. The genotyping identified two rotavirus strains: G6P[1] and G10P[1]. In three rotavirus strains it was only possible to identify the P type; one strain being P[1] and two strains that presented the combination of P[1] + P[7]. These findings might represent the first characterization of rotavirus in ostriches, and the finding of porcine and bovine-like rotavirus genotypes in ostriches might suggest virus reassortment and possible interspecies transmission. (C) 2011 Elsevier Ltd. All rights reserved.

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Rotavirus is an important cause of neonatal diarrhea in humans and several animal species, including calves. A study was conducted to examine 792 fecal samples collected from calves among 65 dairy and beef herds distributed in two of Brazil's major livestock producing regions, aiming to detect the occurrence of rotavirus and perform a molecular characterization of the rotavirus according to G and P genotypes in these regions. A total of 40 (5.05%) samples tested positive for rotavirus by the polyacrylamide gel electrophoresis (PAGE) technique. The molecular characterization was performed by multiplex semi-nested RT-PCR reactions, which indicated that the associations of genotypes circulating in herds in Brazil's southeastern region were G6P[11], G10P[11], G[-]P[5] + [11], G[-]P[6] in the state of Sao Paulo and G6P[11], G8P[5], G11P[11], G10P[11] in the state of Minas Gerais. In the central-western region, the genotypes G6P[5] + [11], G6P[5], G8P[-], G6P[11], G [-] P[1], G[-] P[11], and G[-] P[5] were detected in the state of Goias, while the genotypes G6P[5], G8[P11], G6[P11], G8[P1], G8[P5], G6[P1] were circulating in herds in the state of Mato Grosso do Sul. The genotypic diversity of bovine rotavirus found in each region under study underlines the importance of characterizing the circulating samples in order to devise the most effective prophylactic measures.

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We conducted a phase I, double-blind, placebo-controlled trial to evaluate a new 5-valent oral rotavirus vaccine’s safety and immunogenicity profiles. Subjects were randomly assigned to receive 3 orally administered doses of a live-attenuated human-bovine (UK) reassortant rotavirus vaccine, containing five viral antigens (G1, G2, G3, G4 and G9), or a placebo. The frequency and severity of adverse events were assessed. Immunogenicity was evaluated by the titers of anti-rotavirus IgA and the presence of neutralizing antibodies anti-rotavirus. No severe adverse events were observed. There was no difference in the frequency of mild adverse events between experimental and control groups. The proportion of seroconversion was consistently higher in the vaccine group, for all serotypes, after each one of the doses. The 5-valent vaccine has shown a good profile of safety and immunogenicity in this small sample of adult volunteers.

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Rotaviruses are a major cause of diarrhea in humans and animals, including several mammalian and avian species. Using different PCR protocols, we report the occurrence of rotavirus A in 21 (53.84%; 21/39) from 39 fecal pool samples of broilers, layers, and broiler breeders from Brazilian avian farms. We typed the G5, G8, G11, G19, and P[31] genotypes