tetano
Editor, Senior Moderator
J Infect Chemother. 2016 Jun 23. pii: S1341-321X(16)30086-1. doi: 10.1016/j.jiac.2016.06.002. [Epub ahead of print]
[h=1]In vitro neuraminidase inhibitory concentration (IC50) of four neuraminidase inhibitors against clinical isolates of the influenza viruses circulating in the 2010-2011 to 2014-2015 Japanese influenza seasons.[/h] Ikematsu H[SUP]1[/SUP], Kawai N[SUP]2[/SUP], Iwaki N[SUP]2[/SUP], Kashiwagi S[SUP]2[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] To assess the extent of viral resistance to the four neuraminidase inhibitors (NAIs), we measured their 50% inhibitory concentration (IC[SUB]50[/SUB]) for influenza virus isolates from the 2014-2015 influenza season for comparison with those circulating in the 2010-2011 to 2013-2014 influenza seasons. Viral isolation was done with specimens obtained prior to treatment, and the type and subtype of influenza was determined by RT-PCR using type- and subtype-specific primers. The IC[SUB]50[/SUB] was determined by a neuraminidase inhibition assay using a fluorescent substrate. IC[SUB]50[/SUB] was measured for 200 influenza A(H3N2) and 19 influenza B in the 2014-2015 season, and no virus with highly reduced sensitivity to the four NAIs was detected. The ratios of the geometric means of the A(H3N2) IC[SUB]50[/SUB]s of 2014-2015 to those of the 2010-2011, 2011-2012, 2012-2013, and 2013-2014 seasons ranged from 0.72 to 1.05, 0.82 to 1.22, 0.69 to 1.00, and 0.70 to 1.03, respectively. The ratios of the geometric mean of the B IC[SUB]50[/SUB]s to the previous four seasons ranged from 0.59 to 1.28, 0.66 to 1.34, 0.84 to 1.21, and 1.06 to 1.47, respectively. There was no trend in the change of the IC[SUB]50[/SUB]s for A(H3N2) or B. Significant differences were found in some seasons, but the differences in the IC[SUB]50[/SUB]s were all less than two fold. These results show change in the geometric mean IC[SUB]50[/SUB] by season but with no trend, which indicates that the influence of viral mutation on the effectiveness of these NAIs was minute for A(H3N2) and B over the past five seasons.
Copyright ? 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
[h=4]KEYWORDS:[/h] A(H3N2); B; IC(50); Influenza; Neuraminidase inhibitor; Resistance
PMID: 27346379 DOI: 10.1016/j.jiac.2016.06.002
[PubMed - as supplied by publisher]
[h=1]In vitro neuraminidase inhibitory concentration (IC50) of four neuraminidase inhibitors against clinical isolates of the influenza viruses circulating in the 2010-2011 to 2014-2015 Japanese influenza seasons.[/h] Ikematsu H[SUP]1[/SUP], Kawai N[SUP]2[/SUP], Iwaki N[SUP]2[/SUP], Kashiwagi S[SUP]2[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] To assess the extent of viral resistance to the four neuraminidase inhibitors (NAIs), we measured their 50% inhibitory concentration (IC[SUB]50[/SUB]) for influenza virus isolates from the 2014-2015 influenza season for comparison with those circulating in the 2010-2011 to 2013-2014 influenza seasons. Viral isolation was done with specimens obtained prior to treatment, and the type and subtype of influenza was determined by RT-PCR using type- and subtype-specific primers. The IC[SUB]50[/SUB] was determined by a neuraminidase inhibition assay using a fluorescent substrate. IC[SUB]50[/SUB] was measured for 200 influenza A(H3N2) and 19 influenza B in the 2014-2015 season, and no virus with highly reduced sensitivity to the four NAIs was detected. The ratios of the geometric means of the A(H3N2) IC[SUB]50[/SUB]s of 2014-2015 to those of the 2010-2011, 2011-2012, 2012-2013, and 2013-2014 seasons ranged from 0.72 to 1.05, 0.82 to 1.22, 0.69 to 1.00, and 0.70 to 1.03, respectively. The ratios of the geometric mean of the B IC[SUB]50[/SUB]s to the previous four seasons ranged from 0.59 to 1.28, 0.66 to 1.34, 0.84 to 1.21, and 1.06 to 1.47, respectively. There was no trend in the change of the IC[SUB]50[/SUB]s for A(H3N2) or B. Significant differences were found in some seasons, but the differences in the IC[SUB]50[/SUB]s were all less than two fold. These results show change in the geometric mean IC[SUB]50[/SUB] by season but with no trend, which indicates that the influence of viral mutation on the effectiveness of these NAIs was minute for A(H3N2) and B over the past five seasons.
Copyright ? 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
[h=4]KEYWORDS:[/h] A(H3N2); B; IC(50); Influenza; Neuraminidase inhibitor; Resistance
PMID: 27346379 DOI: 10.1016/j.jiac.2016.06.002
[PubMed - as supplied by publisher]