Genetic analysis, of an influenza B virus isolated from a patient with encephalopathy in Japan

Citation
K. Shiraishi et al., Genetic analysis, of an influenza B virus isolated from a patient with encephalopathy in Japan, J MED VIROL, 65(3), 2001, pp. 590-597
Citations number
31
Categorie Soggetti
Clinical Immunolgy & Infectious Disease",Microbiology
Journal title
JOURNAL OF MEDICAL VIROLOGY
ISSN journal
01466615 → ACNP
Volume
65
Issue
3
Year of publication
2001
Pages
590 - 597
Database
ISI
SICI code
0146-6615(200111)65:3<590:GAOAIB>2.0.ZU;2-C
Abstract
An influenza B virus, B/Saga/S172/99 (SAG99), was isolated from the nasopha rynx of a patient with encephalopathy/encephalitis in Japan in 1999. To cla rify the molecular characteristics of this virus, detailed analysis of the gene segments coding for the hemagglutinin (HA), neuraminidase (NA), nucleo protein (NP), matrix protein (M) and non-structural protein (NS) was undert aken. All five genes of SAG99 showed high nucleotide and predicted amino ac id similarities with those of recent non-encephalopathic strains isolated i n the same epidemic season. Subsequent phylogenetic analysis revealed that all five gene segments of SAG99 analyzed in the present study were most sim ilar to those of the recent Yamagata/16/88-like viruses. The hemagglutinin and neuraminidase proteins of SAG99 were each distinguished from those of r ecent epidemic strains by one characteristic amino acid substitution. These substitutions were not found in the previously reported encephalopathy/enc ephalitis-derived influenza B viruses, and we could not find any common cha racteristic amino acid, changes in SAG99, and these viruses. Similarly, amo ng the internal proteins studied, only the M2 protein of SAG99 was found to contain a single novel amino acid change when compared with other recent i solates. Thus, it was apparent that SAG99 contained very few amino acid dif ferences when compared: with other epidemic viruses. The association of rec ent B/Yamagatal 16/88....like viruses with encephalitis/encephalopathy obse rved in the present study and, previously suggest that these viruses may ha ve a, higher potential for causing neurological complications in certain in dividuals. (C) 2001 Wiley-Liss,inc.