tetano
Editor, Senior Moderator
J Infect Chemother. 2015 May 30. pii: S1341-321X(15)00124-5. doi: 10.1016/j.jiac.2015.05.004. [Epub ahead of print]
[h=1]In vitro neuraminidase inhibitory activity of four neuraminidase inhibitors against clinical isolates of the influenza virus circulating in the Japanese 2013-2014 season.[/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, we measured the 50% inhibitory concentration (IC[SUB]50[/SUB]) of neuraminidase inhibitors (NAIs) for the influenza virus isolates in the 2013-2014 influenza season and compared the results to those of the 2010-2011 to 2012-2013 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. A total of 327 influenza viruses were isolated: 172 influenza A(H1N1)pdm09 (52.6%), 49 A(H3N2) (15.0%), and 106 B (32.4%). Numbers of Victoria and Yamagata lineage isolates were 36 and 70, respectively. Two A(H1N1)pdm09 isolates showed a high IC[SUB]50[/SUB] for oseltamivir (130 and 150 nM) exceeding by 100 times the geometric mean of the IC[SUB]50[/SUB] of oseltamivir for A(H1N1)pdm09 isolates (0.76 nM). No isolate showed a very high IC[SUB]50[/SUB] for A(H3N2) or B. The IC[SUB]50[/SUB] of the NAIs except for oseltamivir for A(H1N1) pdm09 were significantly higher than those of the 2010-2011 season (P < 0.05). The IC[SUB]50[/SUB] of all four NAIs for A(H3N2) were significantly lower than those of the 2012-2013 season (P < 0.001). The IC[SUB]50[/SUB] of the NAIs for B except for oseltamivir were significantly lower than those of the 2012-2013 season (P < 0.001). Although there are some isolates that show highly reduced sensitivity to oseltamivir among A(H1N1)pdm09 isolates, the currently epidemic influenza A(H1N1)pdm09, A(H3N2) and B viruses are susceptible to all four NAIs with no trend toward decreased sensitivity.
Copyright ? 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
[h=4]KEYWORDS:[/h] 50% Inhibitory concentration; Influenza; Laninamivir; Oseltamivir; Peramivir; Zanamivir
PMID: 26096495 [PubMed - as supplied by publisher]
[h=1]In vitro neuraminidase inhibitory activity of four neuraminidase inhibitors against clinical isolates of the influenza virus circulating in the Japanese 2013-2014 season.[/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, we measured the 50% inhibitory concentration (IC[SUB]50[/SUB]) of neuraminidase inhibitors (NAIs) for the influenza virus isolates in the 2013-2014 influenza season and compared the results to those of the 2010-2011 to 2012-2013 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. A total of 327 influenza viruses were isolated: 172 influenza A(H1N1)pdm09 (52.6%), 49 A(H3N2) (15.0%), and 106 B (32.4%). Numbers of Victoria and Yamagata lineage isolates were 36 and 70, respectively. Two A(H1N1)pdm09 isolates showed a high IC[SUB]50[/SUB] for oseltamivir (130 and 150 nM) exceeding by 100 times the geometric mean of the IC[SUB]50[/SUB] of oseltamivir for A(H1N1)pdm09 isolates (0.76 nM). No isolate showed a very high IC[SUB]50[/SUB] for A(H3N2) or B. The IC[SUB]50[/SUB] of the NAIs except for oseltamivir for A(H1N1) pdm09 were significantly higher than those of the 2010-2011 season (P < 0.05). The IC[SUB]50[/SUB] of all four NAIs for A(H3N2) were significantly lower than those of the 2012-2013 season (P < 0.001). The IC[SUB]50[/SUB] of the NAIs for B except for oseltamivir were significantly lower than those of the 2012-2013 season (P < 0.001). Although there are some isolates that show highly reduced sensitivity to oseltamivir among A(H1N1)pdm09 isolates, the currently epidemic influenza A(H1N1)pdm09, A(H3N2) and B viruses are susceptible to all four NAIs with no trend toward decreased sensitivity.
Copyright ? 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
[h=4]KEYWORDS:[/h] 50% Inhibitory concentration; Influenza; Laninamivir; Oseltamivir; Peramivir; Zanamivir
PMID: 26096495 [PubMed - as supplied by publisher]