Comparable fitness and transmissibility between oseltamivir-resistant pandemic 2009 and seasonal H1N1 influenza viruses with the H275Y neuraminidase mutation

Limited antiviral compounds are available for the control of influenza, and the emergence of resistant variants would further narrow the options for defense. The H275Y neuraminidase (NA) mutation, which confers resistance to oseltamivir carboxylate, has been identified among the seasonal H1N1 and 2009 pandemic influenza viruses; however, those H275Y resistant variants demonstrated distinct epidemiological outcomes in humans. Specifically, dominance of the H275Y variant over the oseltamivir-sensitive viruses was only reported for a seasonal H1N1 variant during 2008-2009. Here, we systematically analyze the effect of the H275Y NA mutation on viral fitness and transmissibility of A(H1N1)pdm09 and seasonal H1N1 influenza viruses. The NA genes from A(H1N1)pdm09 A/California/04/09 (CA04), seasonal H1N1 A/New Caledonia/20/1999 (NewCal), and A/Brisbane/59/2007 (Brisbane) were individually introduced into the genetic background of CA04. The H275Y mutation led to reduced NA enzyme activity, an increased K(m) for 3'-sialylactose or 6'-sialylactose, and decreased infectivity in mucin-secreting human airway epithelial cells compared to the oseltamivir-sensitive wild-type counterparts. Attenuated pathogenicity in both RG-CA04(NA-H275Y) and RG-CA04 x Brisbane(NA-H275Y) viruses was observed in ferrets compared to RG-CA04 virus, although the transmissibility was minimally affected. In parallel experiments using recombinant Brisbane viruses differing by hemagglutinin and NA, comparable direct contact and respiratory droplet transmissibilities were observed among RG-NewCal(HA,NA), RG-NewCal(HA,NA-H275Y), RG-Brisbane(HA,NA-H275Y), and RG-NewCal(HA) x Brisbane(NA-H275Y) viruses. Our results demonstrate that, despite the H275Y mutation leading to a minor reduction in viral fitness, the transmission potentials of three different antigenic strains carrying this mutation were comparable in the naive ferret model.published_or_final_versio

Hemagglutinin-neuraminidase balance confers respiratory droplet transmissibility of the pandemic H1N1 influenza virus in ferrets

Conference Theme: Pathogenesis of Influenza: Host-Virus Interaction

Examining the acceptance and use of online social networks by preservice teachers within the context of unified theory of acceptance and use of technology model

Social network sites (SNSs) has a big potential to improve teaching and learning experience. It has become a necessity for teachers to transfer this technologies to learning environments has become a requirement. For this reason, the use of SNSs in the education process of preservice teachers who are the teachers of the future and examination of variables that have an impact on the acceptance of these technologies are found important. The use of SNSs in teacher education will enable preservice teachers to be more willing to use information technologies and will improve their skills in using these technologies. For the reasons given, in this study, it is aimed to examine the acceptance and use of SNSs by preservice teachers for educational purposes on the basis of unified theory of acceptance and use of technology model. The study was designed according to relational screening model. Study group of the study consists of 274 preservice teachers at a university in 2017. Data were collected via various scales and personal information form at the end of an application process of 14weeks+14weeks. Descriptive statistics, linear multiple hierarchical regression analysis and structural equation model were used in analysing the data. As a result of the study, it was determined that the acceptance of SNSs for educational purposes was affected respectively by social effect, performance expectation and effort expectation, and behavioral intention of using these technologies affected the actual use. Besides, variables of moderators that were effective on acceptance and use were also determined