RESUMEN
Global rotavirus surveillance has led to the detection of many unusual human rotavirus (HRV) genotypes. The aim of this study was to elucidate the genetic and evolutionary relationships of short fragments of all 11 gene segments of G10 HRV strains identified in West Africa through the African Rotavirus Network (ARN) system. During 1998-2004 surveillance within the ARN, we identified 5 G10 P[8] HRV strains. Fragments of all 11 gene segments of these G10 strains were sequenced. Phylogenetic and sequence analyses of each gene segment revealed high nucleotide similarities amongst the ARN strains (97-100%) except in the case of the VP1(85-96%) and NSP2 genes (87.8-99.7%) where some strains were divergent. All genes of the ARN strains were classified as Wa-like (genotype 1) with the exception of their VP7 gene of all strains (genotype G10) and the VP6 gene of a single strain, 6755/2002/ARN (DS-1 like, genotype 2). While classified as Wa-like, the NSP2 genes of four of the ARN strains occupied a distinct sub-lineage related to simian strain Tuch, while the NSP2 of strain 6755/2002/ARN and NSP5 genes of all strains were closely related to the cognate genes of both human and animal strains belonging to the Wa-like genogroup. Although these findings help to elucidate the evolution of ARN G10 strains, additional sequence studies of cognate animal rotavirus genes are needed to determine irrefutably the specific origin of those genes relative to both human and animal rotavirus strains.
Asunto(s)
Genoma Viral , Rotavirus/genética , Animales , Humanos , Filogenia , Rotavirus/clasificación , Especificidad de la EspecieRESUMEN
Global rotavirus surveillance has led to the detection of many unusual human rotavirus (HRV) genotypes. During 1996-2004 surveillance within the African Rotavirus Network (ARN), six P[8],G8 and two P[6],G8 human rotavirus strains were identified. Gene fragments (RT-PCR amplicons) of all 11-gene segments of these G8 strains were sequenced in order to elucidate their genetic and evolutionary relationships. Phylogenetic and sequence analyses of each gene segment revealed high similarities (88-100% nt and 91-100% aa) for all segments except for gene 4 encoding VP4 proteins P[8] and P[6]. For most strains, almost all of the genes of the ARN strains other than neutralizing antigens are related to typical human strains of Wa genogroup. The VP7, NSP2, and NSP5 genes were closely related to cognate genes of animal strains (83-99% and 97-99% aa identity). This study suggests that the ARN G8 strains might have arisen through VP7 or VP4 gene reassortment events since most of the other gene segments resemble those of common human rotaviruses. However, VP7, NSP2 (likely), and NSP5 (likely) genes are derived potentially from animals consistent with a zoonotic introduction. Although these findings help elucidate rotavirus evolution, sequence studies of cognate animal rotavirus genes are needed to conclusively determine the specific origin of those genes relative to both human and animal rotavirus strains.
Asunto(s)
Evolución Molecular , Genoma Viral , Recombinación Genética , Infecciones por Rotavirus/epidemiología , Rotavirus/clasificación , Rotavirus/genética , África/epidemiología , Animales , Proteínas de la Cápside/química , Proteínas de la Cápside/genética , ADN Viral/análisis , Humanos , Filogenia , Vigilancia de la Población/métodos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Infecciones por Rotavirus/virología , Análisis de Secuencia de ADN , Proteínas no Estructurales Virales/química , Proteínas no Estructurales Virales/genéticaRESUMEN
Rotavirus serotype G12 was initially identified in the Philippines in 1987 and was not described again until it reemerged more than 13 years later. G12 strains were first detected in the United States in 2002 and have recently assumed a worldwide distribution. The high similarity between the sequence of the major outer capsid VP7 gene of human G12 strains and the single porcine G12 isolate raised the prospect that human strains may have arisen through reassortment with porcine strains or, alternatively, that the porcine strain originally came from humans. We sequenced portions of the remaining 10 segments of two human G12 strains (G12P[8] and G12P[6]) and a currently circulating common strain (G1P[8]) identified during the 2005-2006 surveillance season and compared the sequences with those of strains available through GenBank. By comparison, the three strains were all Wa-like and not porcine-like. A newly outlined classification system proposed genotypes for each gene segment based on nucleotide similarity. Using this approach, gene segments VP1-3, VP6 and NSP1-5 grouped within the same genotype, indicating that the three strains analyzed were closely related. These results suggest that the novel G12P[8] strain could have been formed by the solitary introduction of a VP7 gene into a globally common rotavirus strain, G1P[8]. Classifying rotavirus strains based only on VP7 (G) and VP4 (P) genotype potentially underestimates diversity and sequence analysis of the other segments is required to assess the complete genetic relationships between strains.
Asunto(s)
Evolución Molecular , Filogenia , Infecciones por Rotavirus/epidemiología , Rotavirus/clasificación , Rotavirus/genética , Animales , Antígenos Virales/genética , Proteínas de la Cápside/genética , Heces/virología , Genotipo , Humanos , Datos de Secuencia Molecular , Virus Reordenados/genética , Rotavirus/aislamiento & purificación , Infecciones por Rotavirus/virología , Análisis de Secuencia de ADN , Porcinos/virología , Estados Unidos/epidemiologíaRESUMEN
The risk of neck injury in football is high, and the consequences can be tragic. The authors present a simple, inexpensive method for preventing these injuries.