title: Differences in lineage replacement dynamics of G1 and G2 rotavirus strains versus G9 strain over a period of 22 years in Bangladesh.
abstract: Group A rotaviruses (RVAs) have been a major cause of severe gastroenteritis in Bangladesh, mainly in children below the age of five. At the icddr,b, RVA strains collection and characterization dates back for more than 20 years. This sample collection was used to study the molecular evolution of the VP7 gene of G1, G2 and G9 RVA strains, which have been circulating in Bangladesh for most of this study period. The evolutionary rates (95% HPD) for G1, G2 and G9 were calculated to be 0.93×10(-3) (0.68-1.18), 1.45×10(-3) (1.12-1.78) and 1.07×10(-3) (0.78-1.39), respectively, which is in line with previous data for the RVA VP7 outer capsid protein, which is under strong negative selective pressure. Bayesian analyses revealed that for the G1 and G2 genotypes, one or multiple lineages co-circulated for one or a few seasons, frequently followed by replacement with genetically different lineages. This can be explained by the existence of a large variety of G1 and G2 RVA lineages and the rapid dissemination of different lineages across the globe. In contrast, circulating G9 lineages were rather closely related to each other across the study period and they were usually derived from variants circulating in the previous season(s). This is consistent with the fact that G9 RVAs have circulated in the human population for less than 20 years, and therefore their genetic diversity is much smaller, not resulting in the replacement of circulating G9 strains by highly divergent G9 lineages from abroad. Such different evolutionary dynamics for different RVA genotypes may alter their response to the selective pressure that might be exerted by the introduction of RVA vaccines and therefore a continued close monitoring is warranted.
authors.affiliation: Virology Laboratory, International Centre for Diarrhoeal Disease and Research, Bangladesh (icddr,b), Bangladesh. Electronic address: afradhassan@gmail.com.
authors.forename: Mokibul Hassan
authors.initials: MH
authors.lastname: Afrad
authors.affiliation: Laboratory of Clinical & Epidemiological Virology, Department of Microbiology & Immunology, Rega Institute for Medical Research, University of Leuven, Belgium.
authors.forename: Jelle
authors.initials: J
authors.lastname: Matthijnssens
authors.affiliation: Virology Laboratory, International Centre for Diarrhoeal Disease and Research, Bangladesh (icddr,b), Bangladesh.
authors.forename: Syeda Farhana
authors.initials: SF
authors.lastname: Afroz
authors.affiliation: Department of Biochemistry and Microbiology, North South University, Dhaka, Bangladesh.
authors.forename: Pranab
authors.initials: P
authors.lastname: Rudra
authors.affiliation: Virology Laboratory, International Centre for Diarrhoeal Disease and Research, Bangladesh (icddr,b), Bangladesh.
authors.forename: Lutfun
authors.initials: L
authors.lastname: Nahar
authors.affiliation: Virology Laboratory, International Centre for Diarrhoeal Disease and Research, Bangladesh (icddr,b), Bangladesh.
authors.forename: Rajibur
authors.initials: R
authors.lastname: Rahman
authors.affiliation: Virology Laboratory, International Centre for Diarrhoeal Disease and Research, Bangladesh (icddr,b), Bangladesh.
authors.forename: Mohammad Enayet
authors.initials: ME
authors.lastname: Hossain
authors.affiliation: Department of Microbiology, University of Dhaka, Bangladesh.
authors.forename: Sabita Rezwana
authors.initials: SR
authors.lastname: Rahman
authors.affiliation: Virology Laboratory, International Centre for Diarrhoeal Disease and Research, Bangladesh (icddr,b), Bangladesh.
authors.forename: Tasnim
authors.initials: T
authors.lastname: Azim
authors.affiliation: Virology Laboratory, International Centre for Diarrhoeal Disease and Research, Bangladesh (icddr,b), Bangladesh.
authors.forename: Mustafizur
authors.initials: M
authors.lastname: Rahman
mesh_terms: D000956:Antigens, Viral / Q000235:genetics*; D001459:Bangladesh; D001499:Bayes Theorem; D036022:Capsid Proteins / Q000235:genetics*; D002675:Child, Preschool; D019143:Evolution, Molecular; D005759:Gastroenteritis / Q000821:virology*; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007223:Infant; D010802:Phylogeny; D012401:Rotavirus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D012400:Rotavirus Infections / Q000821:virology*; D012641:Selection, Genetic
chemical_list: D000956:Antigens, Viral; D036022:Capsid Proteins; C050779:VP7 protein, Rotavirus
keywords: Evolutionary substitution rate; G1; G2; G9; Rotavirus; VP7