Abed Y, etc.,al. Comparison of early and recent influenza A(H1N1)pdm09 isolates harboring or not the H275Y neuraminidase mutation, in vitro and in animal models. Antiviral Res. 2018 Sep 13.
After 6 years of circulation in humans, a novel antigenic variant of influenza A(H1N1)pdm09 (i.e., A/Michigan/45/2015) emerged in 2015-16 and has predominated thereafter worldwide. Herein, we compared in vitro and in vivo properties of 2016 wild-type (WT) A/Michigan/45/15-like isolate and its H275Y neuraminidase (NA) variant to the original A/California/07/09-like counterparts. The H275Y mutation induced comparable levels of resistance to oseltamivir and peramivir without altering zanamivir susceptibility in both 2009 and 2016 isolates. In vitro, the two WT isolates had comparable replicative properties. The 2016-H275Y isolate had lower titers at 36?h post-inoculation (PI) (P?0.05) while the 2009-H275Y titers were lower at both 24?h (P?0.01) and 36?h PI (P?0.001) vs the respective WTs. In mice, the 2016-WT isolate caused less weight losses (P?0.001) and lower lung viral titers (LVTs) (P?0.01) vs the 2009-WT. The LVTs of 2016-WT and 2016-H275Y groups were comparable whereas the 2009-H275Y LVTs were lower vs the respective WT (P?0.01). Ferrets infected with the 2016-WT isolate and their contacts had higher nasal viral titers (NVTs) at early time points vs the 2009-WT group (P?0.01). Also, NVTs of 2016-H275Y animals were lower vs the 2016-WT group at early time points in both infected (P?0.01) and contact animals (P?0.001). In conclusion, while the H275Y mutation similarly impacts the A/California/07/2009- and A/Michigan/45/2015-like A(H1N1)pdm09 NAs, the fitness of these isolates differs according to animal models with the 2016 virus being less virulent in mice but slightly more virulent in ferrets, potentially reflecting a period of cumulative changes in surface and internal genes.
See Also:
Latest articles in those days:
- The evolution, complexity, and diversity of swine influenza viruses in China: A hidden public health threat 2 days ago
- MHC class II proteins mediate sialic acid independent entry of human and avian H2N2 influenza A viruses 2 days ago
- Histopathologic Features and Viral Antigen Distribution of H5N1 Highly Pathogenic Avian Influenza Virus Clade 2.3.4.4b from the 2022–2023 Outbreak in Iowa Wild Birds 2 days ago
- Detection and characterization of H5N1 HPAIV in environmental samples from a dairy farm 2 days ago
- Genomic Characterization of Highly Pathogenic Avian Influenza A H5N1 Virus Newly Emerged in Dairy Cattle 2 days ago
[Go Top] [Close Window]