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J Clin Microbiol. 2014 Mar 12. [Epub ahead of print]
Detection of non-hemagglutinating influenza A(H3) viruses by ELISA in quantitative influenza virus culture.
Van Baalen CA1, Els C, Sprong L, van Beek R, van der Vries E, Osterhaus AD, Rimmelzwaan GF.
Author information
Abstract
To assess the efficacy of novel antiviral drugs against influenza in clinical trials it is necessary to quantify infectious virus titers in patients' respiratory tract samples. Typically, this is achieved by inoculating virus-susceptible cells with serial dilutions of clinical specimens, and detecting the production of progeny virus by hemagglutination since influenza viruses generally have the capacity to bind and agglutinate erythrocytes of various species through their hemagglutinin (HA). This readout method is no longer adequate, since an increasing number of currently circulating A(H3) influenza viruses display reduced capacity to agglutinate erythrocytes.Here, we report the magnitude of this problem by analyzing the frequency of HA deficient A(H3) viruses detected in the Netherlands from 1999-2012. Furthermore, we report development and validation of an alternative method to monitor the production of progeny influenza virus in quantitative virus cultures, which is independent of the capacity to agglutinate erythrocytes. This method is based on detection of viral nucleoprotein (NP) in virus culture plates by ELISA, and it produced similar results compared to the hemagglutination assay using strains with good HA activity, including A/Brisbane/059/07 (H1N1), A/Victoria/210/09 (H3N2) and other seasonal A(H1N1), A(H1N1)pdm09 and the majority of A(H3) virus strains isolated in 2009. In contrast, many A(H3) viruses that circulate since 2010 failed to display HA activity and infectious virus titers could only be determined by detecting NP. The virus culture ELISA described here will enable efficacy testing of new antiviral compounds in clinical trials during seasons in which non-hemagglutinating influenza A viruses circulate.
PMID:
24622097
[PubMed - as supplied by publisher]
Detection of non-hemagglutinating influenza A(H3) viruses by ELISA in quantitative influenza virus culture.
Van Baalen CA1, Els C, Sprong L, van Beek R, van der Vries E, Osterhaus AD, Rimmelzwaan GF.
Author information
Abstract
To assess the efficacy of novel antiviral drugs against influenza in clinical trials it is necessary to quantify infectious virus titers in patients' respiratory tract samples. Typically, this is achieved by inoculating virus-susceptible cells with serial dilutions of clinical specimens, and detecting the production of progeny virus by hemagglutination since influenza viruses generally have the capacity to bind and agglutinate erythrocytes of various species through their hemagglutinin (HA). This readout method is no longer adequate, since an increasing number of currently circulating A(H3) influenza viruses display reduced capacity to agglutinate erythrocytes.Here, we report the magnitude of this problem by analyzing the frequency of HA deficient A(H3) viruses detected in the Netherlands from 1999-2012. Furthermore, we report development and validation of an alternative method to monitor the production of progeny influenza virus in quantitative virus cultures, which is independent of the capacity to agglutinate erythrocytes. This method is based on detection of viral nucleoprotein (NP) in virus culture plates by ELISA, and it produced similar results compared to the hemagglutination assay using strains with good HA activity, including A/Brisbane/059/07 (H1N1), A/Victoria/210/09 (H3N2) and other seasonal A(H1N1), A(H1N1)pdm09 and the majority of A(H3) virus strains isolated in 2009. In contrast, many A(H3) viruses that circulate since 2010 failed to display HA activity and infectious virus titers could only be determined by detecting NP. The virus culture ELISA described here will enable efficacy testing of new antiviral compounds in clinical trials during seasons in which non-hemagglutinating influenza A viruses circulate.
PMID:
24622097
[PubMed - as supplied by publisher]
