Neuraminidase gene profiling of influenza B virus in Shangrao / 中国感染与化疗杂志

ABSTRACT

Objective To characterize the neuraminidase (NA) genes of influenza B virus in Shangrao.Methods The specimens of nasopharyngeal swabs were collected from patients with influenza-like symptoms in influenza sentinel hospital.Seven strains of influenza B virus were randomly selected for culture and isolation in Madin-Darby Canine Kidney Epithelial Cells (MDCK Line).Viral RNA was extracted.Fragments of NA genes were amplified by one-step RT-PCR and then were sequenced.The data obtained were analyzed with software DNAStar 6.0 and Mage 5.0.The deduced amino acid sequences were examined to explore the features ofNA gene.Results The NA gene showed high homology ofnucleotides between the 7 strains of influenza B virus.No amino acid substitution was found in catalytic or framework residues of the deduced amino acid sequences of NA gene.Conclusions All the 7 strains of influenza B virus were sensitive to neuraminidase inhibitors.However,ongoing resistance surveillance is necessary for control and prevention of influenza.