Journal
ANTIVIRAL RESEARCH
Volume 101, Issue -, Pages 93-96Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/j.antiviral.2013.11.001
Keywords
Neuraminidase inhibition assay; Pyrosequencing; Recombinant protein; NA-Star (R) kit; NA-Fluor (TM) kit
Categories
Ask authors/readers for more resources
Propagation of influenza A(H3N2) viruses in MDCK cells has been associated with the emergence of neuraminidase (NA) variants carrying a change at residue 151. In this study, the pyrosequencing assay revealed that similar to 90% of A(H3N2) virus isolates analyzed (n = 150) contained more than one amino acid variant (D/G/N) at position 151. Susceptibilities of the virus isolates to zanamivir and oseltamivir were assessed using the chemiluminescent and fluorescent NA inhibition (NI) assays. In the chemiluminescent assay, which utilizes NA-Star (R) substrate, up to 13-fold increase in zanamivir-IC50 was detected for isolates containing a high proportion (>50%) of the G151 NA variant. However, an increase in zanamivir-IC(50)s was not seen in the fluorescent assay, which uses MUNANA as substrate. To investigate this discrepancy, recombinant NAs (rNAs) were prepared and tested in both NI assays. Regardless of the assay used, the zanamivir-IC50 for the rNA G151 was much greater (>1500-fold) than that for rNA D151 wildtype. However, zanamivir resistance conferred by the G151 substitution was masked in preparations containing the D151 NA which had much greater activity, especially against MUNANA. In conclusion, the presence of NA D151G variants in cell culture-grown viruses interferes with drug susceptibility assessment and therefore measures need to be implemented to prevent their emergence. Published by Elsevier B.V.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available