RESUMO
Rotaviruses were detected by enzyme immunoassay (EIA) in 53 (13.3%) of 397 fecal samples from children with acute gastroenteritis in the city of Maceió, Alagoas, Brazil. Polyacrylamide gel electrophoretic (PAGE) patterns characteristic of rotavirus double-stranded RNA were detected in 51 (96.2%) of the 53 EIA-positive samples. Of the RNA-positive samples, 1 (2%) was classified as subgroup 1 (short profile), 49 (96%) as subgroup 2 (long profile) and 1 (2%) could not be classified because of the absence of bands 10 and 11. The strains of subgroup 2 showed a great degree of electrophoretic heterogeneity and could be divided into several subcategories. Two samples showed splitting of one of the genome segments. PAGE, a very sensitive method capable of identifying rotavirus RNA genomes, has demonstrated that human rotaviruses detected in Maceió present many differences in RNA electrophoretic patterns.
Assuntos
Genes Virais , RNA Viral/análise , Rotavirus/genética , Doença Aguda , Brasil , Pré-Escolar , Eletroforese em Gel de Poliacrilamida , Fezes/microbiologia , Gastroenterite/microbiologia , Humanos , LactenteRESUMO
Monoclonal antibodies were prepared against serotype 3 simian rotavirus SA11. Antigenic analysis of 18 hybridoma cell lines secreting monoclonal antibodies by radioimmunoprecipitation and Western blot revealed that seven monoclonals were directed against the major inner capsid protein VP6, four against VP3, an outer capsid protein with hemagglutinating activity, and one against VP7, the main outer capsid protein of the virus. The specificity of six monoclonals could not be determined. One monoclonal (1P14E2) directed against VP3 showed serotype 3-specific neutralizing activity. This monoclonal, which recognized only serotype 3 viruses in an enzyme-linked immunosorbent assay, could be useful in assays for serotyping rotavirus directly in stool samples.
Assuntos
Anticorpos Monoclonais/isolamento & purificação , Anticorpos Antivirais/isolamento & purificação , Antígenos Virais/imunologia , Rotavirus/imunologia , Animais , Anticorpos Monoclonais/imunologia , Especificidade de Anticorpos , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Testes de Inibição da Hemaglutinação , Humanos , Hibridomas , Camundongos , Camundongos Endogâmicos BALB C , Testes de Neutralização , Rotavirus/classificação , SorotipagemRESUMO
Rotaviruses were detected by enzyme-linked immunosorbent assay (ELISA) in stool samples from 504 infants admitted with gastroenteritis to the children's hospital of the University Bochum in the period from 1979 to 1984. In most infants rotaviruses persisted in the stools for 6-8 days. Rotavirus RNA was extracted from stool samples from 203 infants. By acrylamide gel electrophoresis, bands characteristic of rotavirus double-stranded RNA were detected in 172 (85%) of these 203 samples in which the presence of rotavirus had been demonstrated by ELISA. Of the RNA-positive samples 87% had a "long" RNA pattern. Six different electropherotypes co-circulated and one electropherotype predominated for more than 4 years. In stool samples of one infant 12 genome segments were found, suggesting the possibility of simultaneous infection by more than one electropherotype or the occurrence of modification in the length of RNA segments during infection. In another infant the sequential infection by two different electropherotypes was observed.