Molecular epidemiology of respiratory syncytial virus in children with acute respiratory tract infections and sequence analysis of G gene in Chongqing area / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the epidemiological features of respiratory syncytial virus (RSV) A and B in hospitalized children with acute respiratory tract infections(ARTIs) and to analyze the genetic characteristics of G protein gene of RSV in Chongqing area, especially for BA strains. Methods Nasopharyngeal secretions collected from 508 hospitalized children with ARTls from April, 2008 to March, 2009 were screened for RSV using RT-PCR. Full length G protein gene was amplified by RT-PCR from 10 RSV subtype A and 29 RSV subtype B strains. Results Out of the total 508 specimens, 126 (24.8%) were revealed positive for RSV. RSV subtype A and B viruses accounted for 34.1% and 63.5% of the total positive specimens, respectively. The remaining 2.4% of the specimens were positive for both subtype A and B. At the nucleotide level, identities between the 10 subtype A virus G genes and that of the prototype strain A2 were 91.4% -92.0%, indicating genotype GA2. Identities of the 29 subtype B virus G genes and that of the CH18537 strain were 92.0%-93.0%. Nineteen out of 29 RSV subtype B isolates contained highly repeated 60 nucleotides insertion in G protein gene, namely BA strain. As compared to the prototypes, the RSV G protein gene included nucleotide deletion, insertion, substitutions, especially in the carboxy-terminal third of the G gene. Condnsion RSV has been the major cause of acute respiratory tract infections in children in Chongqing area. Subtype B strains, especially BA strains, were predominant during the study peried. Whether the predominated circulation of BA strain is resulted from enhanced attachment function of G protein remains unknown.