Table 1

Characterization of the A/Mississippi/05/2011(H3N2) virus passaged on MDCK cells

A(H3N2) virus nameMean IC50 ± SDa [nM (foldb)]NA residue (%)c
ZanamivirOseltamivirPeramivirLaninamivir119 (E/V)148 (T/I)
A/Mississippi/05/2011 (P0)dNAeNANANA28/72100/0
A/Mississippi/05/2011 (P2)1.19 ± 0.01 (5)65.36 ± 13.07 (726)0.20 ± 0.01 (2)0.79 ± 0.08 (3)0/10035/65
A/Mississippi/05/2011 (P3)195.00 ± 7.47 (813)720.45 ± 57.71 (8,005)10.42 ± 1.34 (116)71.85 ± 3.63 (257)0/1000/100
Reference viruses
    A/Washington/01/20070.24 ± 0.010.09 ± 0.010.09 ± 0.010.28 ± 0.03100/057/43
    A/Texas/12/2007 (E119V), oseltamivir resistant0.40 ± 0.0245.48 ± 9.70 (505)0.11 ± 0.010.34 ± 0.030/100100/0
  • a Based on at least three independent experiments.

  • b Fold increase based on comparison to the respective IC50s of the reference virus, A/Washington/01/2007.

  • c Proportion of NA variants determined using SNP pyrosequencing analysis.

  • d P0, clinical specimen; P2 and P3, virus isolates passaged two and three times, respectively, on MDCK cells using the standard procedure. The GISAID accession numbers for the NA genes are EPI408578, EPI366355, and EPI408583.

  • e NA, not applicable; neuraminidase inhibition testing was not performed on the clinical specimen.