14th ICID - Poster Abstracts - International Society for Infectious ...

When citing these abstracts please use the following reference:
Author(s) of abstract. Title of abstract [abstract]. Int J Infect Dis 2010;14S1: Abstract number.
Please note that the official publication of the International Journal of Infectious Diseases 2010, Volume 14, Supplement 1
is available electronically on http://www.sciencedirect.com
Final Abstract Number: 84.034
Session: Virology and Viral Infections (Non-HIV)
Date: Friday, March 12, 2010
Time: 12:30-13:30
Room: Poster & Exhibition Area/Ground Level
Type: Poster Presentation
Introduction of a new lineage VP7 of rotavirus G1 in the Venezuelan population
E. Vizzi 1 , O. Piñeros 1 , A. C. Alcala 1 , L. Naranjo 2 , J. A. Suarez 2 , F. Liprandi 1
1 Instituto Venezolano de Investigaciones Cientificas, Caracas, Miranda, Venezuela, 2 Instituto de
Medicina Tropical , Caracas, Venezuela
Background: G1 is the most widespread rotavirus type associated to acute gastroenteritis in
children from many countries. Genetic and antigenic heterogeneity seem to be the reason for this
consistent predominance of G1 serotype rotaviruses throughout the world over the years.
Although studies previously conducted in Venezuela indicated a broad diversity in circulating
rotavirus types, more recent data show that G1P[8] rotaviruses is the most widely circulating type
since November 2007 in Caracas. In an attempt to investigate the impact of currently available
vaccines, human rotavirus isolates obtained from clinical samples in Venezuelan cities over time
and identified as G1P[8], were studied to acquire information about the pattern of genetic
evolution of this type, and to understand the mechanisms of distribution and selection of rotavirus
strains and lineages.
Methods: Sequences of amplicons of 850 bp from VP7 rotavirus genes of one G1 strain isolated
in Valencia during year 2003, and 3 strains obtained during the 2008 in Caracas were compared
with the homologous regions of 43 reference G1 strains obtained from GenBank. Phylogenetic
analysis was made using the neighbor-joining method.
Results: VP7 gene analysis demonstrated that Venezuelan G1 rotavirus strains segregated in
two different genetic lineages, with the three most recent isolates of 2008 clustering into lineage I
and the strain of the 2003 into lineage II, the latter closely related to the recently introduced
monovalent G1 Rotarix® vaccine. Analysis of deduced amino acid VP7 sequences of the three
G1 rotavirus strains isolated during the 2008 revealed amino acid changes located on B (94SN)
and E (217TM) regions.
Conclusion: The increase in circulation of G1 rotaviruses observed in Caracas since November
2007 may be associated with the introduction of novel G1 strains that exhibited amino acid
changes in antigenic regions involved in rotavirus neutralization. It is important to continue the
surveillance to understand how these changes might affect the effectiveness of the vaccine.