A porcine G9 rotavirus strain shares neutralization and VP7 phylogenetic sequence lineage 3 characteristics with contemporary human G9 rotavirus strains.
Of five globally important VP7 (G) serotypes (G1-4 and 9) of group A rotaviruses (the single most important etiologic agents of infantile diarrhea worldwide), G9 continues to attract considerable attention because of its unique natural history. Serotype G9 rotavirus was isolated from a child with diarrhea first in the United States in 1983 and subsequently in Japan in 1985. Curiously, soon after their detection, G9 rotaviruses were not detected for about a decade in both countries and then reemerged in both countries in the mid-1990s. Unexpectedly, however, such reemerged G9 strains were distinct genetically and molecularly from those isolated in the 1980s. Thus, the origin of the reemerged G9 viruses remains an enigma. Sequence analysis has demonstrated that the G9 rotavirus VP7 gene belongs to one of at least three phylogenetic lineages: lineage 1 (strains isolated in the 1980s in the United States and Japan), lineage 2 (strains first isolated in 1986 and exclusively in India thus far), and lineage 3 (strains that emerged/reemerged in the mid-1990s). Currently, lineage 3 G9 viruses are the most frequently detected G9 strains globally. We characterized a porcine rotavirus (A2 strain) isolated in the United States that was known to belong to the P[7] genotype but had not been serotyped by neutralization. The A2 strain was found to bear serotype G9 and P9 specificities as well as NSP4 [B] and subgroup I characteristics. By VP7-specific neutralization, the porcine G9 strain was more closely related to lineage 3 viruses than to lineage 1 or 2 viruses. Furthermore, by sequence analysis, the A2 VP7 was shown to belong to lineage 3 G9. These findings raise intriguing questions regarding possible explanations for the emergence of variations among the G9 strains.
Hoshino
Yasutaka
Y
Epidemiology Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Building 50, Room 6308, 50 South Drive MSC 8026, Bethesda, MD 20892-8026, USA. thoshino@niaid.nih.gov
Honma
Shinjiro
S
Jones
Ronald W
RW
Ross
Jerri
J
Santos
Norma
N
Gentsch
Jon R
JR
Kapikian
Albert Z
AZ
Hesse
Richard A
RA
D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology*; D000956:Antigens, Viral / Q000145:classification* / Q000235:genetics / Q000276:immunology*; D036022:Capsid Proteins / Q000145:classification* / Q000235:genetics; D002478:Cells, Cultured; D006801:Humans; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D010802:Phylogeny; D016865:Reassortant Viruses / Q000235:genetics; D012401:Rotavirus / Q000145:classification* / Q000235:genetics / Q000276:immunology; D012400:Rotavirus Infections / Q000453:epidemiology / Q000821:virology*; D012703:Serotyping; D013045:Species Specificity
D000914:Antibodies, Viral; D000956:Antigens, Viral; D036022:Capsid Proteins; C050779:VP7 protein, Rotavirus