Abstract
Acute respiratory illness (ARI) is one of the major health problems in tropical countries of Asia, like India where approximately 0.5. million children in the age group of <5. years die annually. Previously we have reported the genetic characterization of influenza A (Inf-A) strains circulating in Kolkata, eastern India. This study was initiated to characterize the genetic diversity of the circulating influenza B (Inf-B) viruses. Of 3035 nasal/throat swabs, 494 (16.3%) samples were identified as influenza A/B positive by real time RT-PCR, of which 244 samples were confirmed having Inf-B infection. Comparison of nucleotide (nt) and amino acid (aa) sequences of HA and NA gene of Inf-B viruses revealed co-circulation of B/Yamagata and B/Victoria lineages. Of the 32 randomly selected Inf-B strains from Kolkata, seventeen strains possessed reassorted NA gene. There was a single Histidine to Asparagine substitution in the 131st position which is a part of 120 loop on HA1 region along with a deletion at position 178 in the Kolkata strains belonging to the Yamagata lineage. Amino acid substitution was observed at position 198 on NA gene in the strains B/Kol/542/2006, B/Kol/1373/2008, B/Kol/1880/2008, B/Kol/2044/2008 and in all the representative strains isolated during 2009 with respect to the circulating vaccine strains. This substitution is responsible for reduced sensitivity of neuraminidase inhibitors. The results highlight the importance of monitoring Inf-B viruses for development of antiviral resistance among circulating strains.
Original language | English (US) |
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Pages (from-to) | 1595-1601 |
Number of pages | 7 |
Journal | Infection, Genetics and Evolution |
Volume | 11 |
Issue number | 7 |
DOIs | |
State | Published - Oct 2011 |
Externally published | Yes |
Keywords
- Co-circulation of different lineages
- Influenza B
- Molecular characterization of Inf-B
- Reassortant strain
- Surveillance
ASJC Scopus subject areas
- Microbiology
- Ecology, Evolution, Behavior and Systematics
- Molecular Biology
- Genetics
- Microbiology (medical)
- Infectious Diseases