Diversity of group A rotavirus genes detected in the Triângulo Mineiro region, Minas Gerais, Brazil

ABSTRACT Group A rotaviruses are the main causative agent of infantile gastroenteritis. The segmented nature of the viral genome allows reassortment of genome segments, which can generate genetic variants. In this study, we characterized the diversity of the VP7, VP4 (VP8*), VP6, NSP4, and NSP5 genes of the rotaviruses that circulated from 2005 to 2011 in the Triângulo Mineiro (TM) region of Brazil. Samples with genotypes G2 (sublineages IVa-1 and IVa-3), G1 (sublineage I-A), G9 (lineage III), G12 (lineages II and III), G8 (lineage II), G3 (lineage III), P[4] (sublineages IVa and IVb), P[8] (sublineages P[8]-3.6, P[8]-3.3, and P[8]-3.1), I2 (lineage VII), E2 (lineages VI, XII, and X), and H2 (lineage III) were identified. The associations found in the samples were G1, G9, or G12 with P[8]-I1-E1-H1; G2 or G8 with P[4]-I2-E2-H2; G12 with I3-E3-H6; and G3 with P[4]-I2-E3-H3 (previously unreported combination). Reassortment events in G2P[4] strains and an apparent pattern of temporal segregation within the lineages were observed. Five TM samples contained genes that exhibited high nucleotide and amino acid identities with strains of animal origin. The present study includes a period of pre- and post-introduction of rotavirus vaccination in all Brazilian territories, thereby serving as a basis for monitoring changes in the genetic constitution of rotaviruses. The results also contribute to the understanding of the diversity and evolution of rotaviruses in a global context.

Molecular epidemiology of group A rotavirus causing acute diarrhea in infants and young children in Rio de Janeiro, Brazil, 1997-1998

During April, 1997, to February, 1998, an epidemiological survey of group A rotavirus strains causing acute diarrhea in infants and young children was conducted in Hospital Municipal Jesus (Rio de Janeiro, D.C.). Rotaviruses were detected in 18.6 percent of examined specimens. Among the rotavirus strains tested for RNA by PAGE, 70 percent belonged to the long pattern and 30 percent the short pattern. A long pattern classified as LD was the most common electropherotype among all of the types. This same pattern had been identified in the city 15 years ago. The most common short pattern was SA type and a few were SB types. The SB types were more common than SA types 15 years ago. Rotavirus infection was observed throughout the period studied, but peaks of infection occurred in May, June, and September. The long pattern was recorded continuously and in all ages studied (0-8 years old), but the short pattern ocurred only in young children (age range 0-11 months) and only in May and June, 1997. This data show epidemiologic differences in infection associated with long and short electropherotypes; the long electropherotypes appear to circulate continuously in the community, whereas the sort electropherotype strains appear only in young children in an episodic fashion.