Extensive antigenic and genetic variation among foot-and-mouth disease type A viruses isolated from the 1994 and 1995 foci in São Paulo, Brazil

Nine foot-and-mouth disease virus (FMDV) type A isolates recovered from the field FMD foci in São Paulo State, Brazil, during 1994 and 1995 (a period preceding the last reported focus of FMD in 1996 in this state) were compared among themselves and with the reference vaccine strain A(24)Cruzeiro. The techniques used were sandwich ELISA, virus neutralization (VN), polyacrylamide gel electrophoresis (PAGE) of the structural polypeptides and direct sequencing of the VP1-coding region (1D gene). Results of VN were recorded as serological relationships R and those from ELISA were expressed as percentage of the homologous reaction r. ELISA and VN gave comparable results (correlation coefficient, 0.936) allowing assignment of these field viruses to four groups which were distinct from the A(24)Cruzeiro strain. PAGE and ID nucleotide sequencing were also able to distinguish between these viruses. The high level:of genetic and antigenic variation found when comparing the A(24)Cruzeiro vaccine strain and type A strains recovered, from the last identified foci of FMD came from a formerly endemic area where vaccination with polyvalent vaccines (O(1)Campos, A(24)Cruzciro and C(3)Indaial) had been extensively applied. The similarity between the results of the serological and genetic analyses suggest that the antigenic differences found are mainly located in the 1D protein. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Carcinoma de células de Merckel humano e sua potencial associação com o recémdescrito poliomavírus MCPyV: avaliação preliminar de biopsias e análise de casualidade

Neoplasias malignas da pele são os cênceres mais comuns da espécie humana. No entanto há tipos raros como o Carcinoma de células de Merkel (CCM), cuja incidência tem aumentado em todo mundo. O CCM possui curso agressivo, com freqüente envolvimento de nódulos linfáticos regionais e metástases à distância. Adicionalmente, afeta predominantemente idosos e imunocomprometidos, fato que levou-se a suspeita de uma possível etiologia infecciosa para essa neoplasia. Nesse foi-se isolado e descrito o MCPyV, um novo poliomavirus humano, diretamente de células tumorais do CCM. O objetivo do presente trabalho é dar continuidade à pesquisa desse novo vírus apresentando dados iniciais da pesquisa do MCPyV em número significativo de casos de CCM de pacientes brasileiros. Para tanto, foram analisadas 24 biópsias de CCM fixadas e incluídas em parafina, das quais foram extraído o material genômico e o produto submetido à PCR convencional com três pares de iniciadores descritos pela literatura (LT1, LT3 e VP1), com a finalidade de se detectar segmentos do vírus. No presente estudo o genoma viral foi detectado em 11/24 (45,8%) das amostras avaliadas, sendo que a positividade para cada par de iniciadores foi de 4/24 (16,7%) para LT1, 11/24 (45,8%) para LT3 e 4/24 (16.7%) para VP1. Essas freqüências são menores do que a relatada pela literatura e essa diferença pode ser devida a diferença nas amostras analisadas e nas técnicas empregadas. Outros estudos são necessários para comprovar a relação de causalidade, assim como desvendar o ciclo do MCPyV

Prevalência da excreção e caracterização molecular do poliomavírus humano JC em amostras de urina de pacientes com aids sem leucoencefalopatia multifocal pro-gressiva

The human poliomavirus is the etiologic agente of Progressive multifocal leukoencephalopathy (PML), a disease characterized by focal lesions not expansives of the central nervous system that develops in imunocompromissed patients, specially people with aids. The main aim of the study was to evalute the prevalence of the JCV excretion in urine samples of patients with aids, without PML, to compare two JCV DNA detection techniques through of two diferents genomic regions and to evaluate the genotypic characterization of the positive samples. A total of 75 samples were colected in the Instituto de Infectologia Emílio Ribas, in Sao Paulo, Brazil, between may and november, 2009. To detect the JC virus it was made the DNA extraction and then the polimerase chain reaction (PCR). Firstly a fragment of 215 bp was amplified, which corresponds to the codifying gene of the strutural protein of de JC vírus capsid VP1. All the samples were later submitted to another PCR that uses a pair of primers complementaries to the early region of the JCV (T antigen) amplifying a fragment of 173 bp. Followed by the digestion of the amplified product with the restriction enzime BamH1, resulting in two smaller fragments (120 bp and 53 bp). The JC vírus was detected in 53 samples, for both techniques (70,7% for VP1 PCR, and the restriction enzime BamH1), 34/46 were men (73,9%) and 19/29 were women (65,5%). The JCV excretion was higher in individuals that were over 46 years old. Regarding the seven genotypes described in the literature, the ones that were more prevalent among the JC positive patients were 3B and 3A with 10 samples each (21,0%), the 2B with 9 samples (19,0%) and genotype 6, with six samples (13,0%). As in the brown patients as the white ones, the most prevalent genotype was 3B. In the present study it was observed a high prevalence of JCV DNA (70,7%) and the genotype 3 (43,0%)... (Complete abstract click electronic access below)