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: 84.012
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
Full genome sequence analysis of Group B human rotaviruses
D. Yamamoto 1 , N. Kobayashi 1 , S. Ghosh 1 , S. nagashima 2 , T. Krishnan 3 , M. Chawla-Sarkar 3 , S.
K. Paul 4 , T. S. Aung 5
1 Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan, 2 Jichi Medical
University School of Medicine, Tochigi, Japan, 3 National Institute of Cholera and Enteric
Diseases, Kolkata, India, 4 Mymensingh Medical College, Mymensingh, Bangladesh, 5 National
Health Laboratory, Yangon, Myanmar
Background: Rotavirus is a major causative pathogen of severe diarrhea in humans and
animals. On the basis of VP6 antigen, Rotaviruses are classified into seven groups (A-G), among
which only groups A-C rotaviruses cause infection in humans. Group B rotavirus (GBR) was first
detected in China in 1982 as a cause of adult diarrheal outbreaks. Although the detection of GBR
had been limited in China, GBR has been found in India since 1998, in Bangladesh since 2000,
and in Myanmar in 2007. Because of limited data, genetic characteristics of GBR have not been
well known so far.
Methods: GBRs detected recently in India (IDH-084 in 2007, IC-008 in 2008), Bangladesh
(Bang117 in 2003), and Myanmar (MMR-B1 in 2007) were analyzed genetically. Full genome
sequences of these strains were determined by RT-PCR and direct sequencing methods.
Sequence data was analyzed phylogenetically by MEGA4 program with those of GBRs reported
previously.
Results: Sequences of all genes of GBRs, including those of animals, were classified into three
clusters, i.e., Chinese lineage, India-Bangladeshi-Myanmar lineage, and animal (bovine and
murine) lineages. Each strain showed high sequence identity among the same lineage (e.g.,95.6-
100% among India-Bangladeshi-Myanmar lineage). The evolutionary rate of all segment genes of
GBRs was estimated to be 1.89-2.0510-3 nucleotide substitutions per site per year, using the
synonymous substitutions between CAL-1(1998 in India) and IDH-084, CAL-1 and IC-008, and
Bang373(2000 in Bangladesh) and Bang117 .
Conclusion: Full genome sequences of recent group B human rotaviruses were determined and
revealed the presence of two major lineages in human GBRs by phylogenetic analysis.
Compared to the strains detected in different years, the substitution rate was estimated for the
first time for all the gene segments. It was similar to those from partial sequence data reported
previously and was comparable to the rate of other rapidly evolving RNA viruses. Further
accumulation of genetic data is needed for resolution of ecological features of group B
rotaviruses.