Comparison of the complete nucleotide sequences of echovirus 7 strain UMMC and the prototype (Wallace) strain demonstrates significant genetic drift over time.
The complete nucleotide sequences are reported of two strains of echovirus 7, the prototype Wallace strain (Eo7-Wallace) and a recent Malaysian strain isolated from the cerebrospinal fluid of a child with fatal encephalomyelitis (Eo7-UMMC strain). The molecular findings corroborate the serological placement of the UMMC strain as echovirus 7. Both Eo7-Wallace and Eo7-UMMC belong to the species human enterovirus B and are most closely related to echovirus 11. Eo7-UMMC has undergone significant genetic drift from the prototype strain in the 47 years that separate the isolation of the two viruses. Phylogenetic analysis revealed that Eo7-UMMC did not arise from recombination with another enterovirus serotype. The molecular basis for the severely neurovirulent phenotype of Eo7-UMMC remains unknown. However, it is shown that mutations in the nucleotide sequence of the 5' untranslated region (UTR) of Eo7-UMMC result in changes to the putative structure of the 5' UTR. It is possible that these changes contribute to the neurovirulence of Eo7-UMMC.
Chua
B H
BH
Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia1.
McMinn
P C
PC
Division of Virology, TVW Telethon Institute for Child Health Research, Perth, WA, Australia2.
Lam
S K
SK
Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia1.
Chua
K B
KB
Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia1.
D020413:3' Untranslated Regions / Q000737:chemistry; D020121:5' Untranslated Regions / Q000737:chemistry; D000595:Amino Acid Sequence; D001483:Base Sequence; D002555:Cerebrospinal Fluid / Q000821:virology; D002675:Child, Preschool; D018792:Encephalitis, Viral / Q000821:virology*; D029822:Enterovirus B, Human / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D004769:Enterovirus Infections / Q000821:virology*; D005787:Gene Frequency; D016679:Genome, Viral; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D017422:Sequence Analysis, DNA
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions