Distribution of two distinct rotavirus B (RVB) strains in the north-central Bangladesh and evidence for reassortment event among human RVB revealed by whole genomic analysis.
Human rotavirus B (RVB), a rare cause of diarrhea in several Asian countries, has been reported to be genetically highly conserved. However, 14 RVB strains with two distinct RNA electropherotypes E1 and E2 (11 and 3 strains, respectively) were detected in adult patients with diarrhea, in Mymensingh in the north-central Bangladesh in 2014. In this study, VP7 gene sequences of all the 14 strains and nearly full-length sequences of all the 11 RNA segments of four RVB (two strains each representing E1 and E2 types) were determined and analyzed phylogenetically. For all the gene segments, sequence identities among strains with the same RNA pattern were higher (99%-100%) than those between strains with different RNA patterns (94-98%). Although all the gene segments of RVB strains were grouped into Indian-Bangladeshi lineage, VP1-3, VP6, VP7, NSP1, NSP2 and NSP5 genes of strains with E1 and E2 types were assigned to distinct sublineages S1 and S2, respectively. E1-strains clustered with Bangladeshi RVB strains reported previously (e.g., Bang117), while E2-strains with those from India (e.g., NIV-1048101), Myanmar, and Nepal. In contrast, VP4, NSP3 and NSP4 genes of both E1 and E2 RVB strains were classified into sublineage S2. These findings indicated that two genetically distinct RVB strains were simultaneously circulating in Mymensingh, Bangladesh. RVB strains with E1 electropherotype were suggested to be reassortants acquiring three gene segments (VP4, NSP3 and NSP4 genes) from the foreign RVB in the genetic background of indigenous Bangladeshi RVB represented by the strain Bang117.
Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan.
Meiji Soe
MS
Aung
Department of Microbiology, Mymensingh Medical College, Mymensingh, Bangladesh.
Samsoon
S
Nahar
Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan.
Satoru
S
Aida
Department of Microbiology, Mymensingh Medical College, Mymensingh, Bangladesh.
Shyamal Kumar
SK
Paul
Department of Microbiology, Mymensingh Medical College, Mymensingh, Bangladesh.
Muhammad Akram
MA
Hossain
Department of Microbiology, Mymensingh Medical College, Mymensingh, Bangladesh.
Salma
S
Ahmed
Department of Microbiology, Mymensingh Medical College, Mymensingh, Bangladesh.
Nazia
N
Haque
Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan; Department of Biomedical Sciences, Ross University School of Veterinary Medicine, Saint Kitts and Nevis.
Souvik
S
Ghosh
Division of Biological Standardisation, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India.
Yashpal Singh
YS
Malik
Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan.
Noriko
N
Urushibara
Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan.
Mitsuyo
M
Kawaguchiya
Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan.
Ayako
A
Sumi
Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan. Electronic address: nkobayas@sapmed.ac.jp.
Nobumichi
N
Kobayashi
D000328:Adult; D000368:Aged; D001459:Bangladesh; D014644:Genetic Variation / Q000235:genetics; D016679:Genome, Viral / Q000235:genetics*; D006801:Humans; D008875:Middle Aged; D016865:Reassortant Viruses / Q000235:genetics*; D012401:Rotavirus / Q000145:classification* / Q000235:genetics*; D012400:Rotavirus Infections / Q000821:virology*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014764:Viral Proteins / Q000235:genetics; D055815:Young Adult
D014764:Viral Proteins
Bangladesh; Diversity; Human; Reassortment; Rotavirus B; Whole genome