Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: A two-year survey of the oseltamivir-resistant influenza A(H1N1) virus in Yamagata, Japan and the clinical effectiveness of oseltamivir and zanamivir | Matsuzaki et al. Virology Journal 2010 7 53 http content 7 1 53 VIROLOGY JOURNAL RESEARCH Open Access A two-year survey of the oseltamivir-resistant influenza A H1N1 virus in Yamagata Japan and the clinical effectiveness of oseltamivir and zanamivir Yoko Matsuzaki1 Katsumi Mizuta2 Yoko Aoki2 Asuka Suto2 Chieko Abiko2 Kanako Sanjoh3 Kanetsu Sugawara4 Fmi T2l 2chii 7i4 5 Tci itnmi I S1H6 Vi iril fci ichimsỉ7 k i l r 11-r i I liil o5 ini I OKi Iftai5 f H niri5 Emi Takashita Tsutomu Itagaki Yuriko Katsushima Makoto Ujike Masatsugu Obuchi Takato Odagiri Masato Tashiro5 Abstract Background Oseltamivir is the preferred antiviral drug for influenza but oseltamivir-resistant A H1N1 viruses have circulated worldwide since the 2007-2008 influenza season. We aimed to determine the rate of oseltamivir resistance among A H1N1 isolates from Yamagata Japan to compare the virological characteristics between isolates from the 2007-2008 and 2008-2009 seasons and to evaluate the clinical effectiveness of oseltamivir. Results Oseltamivir resistance determined by detecting the H275Y mutation in the neuraminidase NA gene was observed in 2 of 79 and 100 77 of 77 of isolates from the 2007-2008 and 2008-2009 seasons respectively. Antigenic analysis suggested that antigenically different variants of A H1N1 viruses circulated in the 2008-2009 season. Growth testing demonstrated that the ability of the 2008-2009 isolates to replicate in MDCK cells was similar to those of the oseltamivir-susceptible isolates from the 2007-2008 season. A phylogenetic analysis revealed that two oseltamivir-resistant viruses isolated in the 2007-2008 season were closely related to other oseltamivir-susceptible viruses in Yamagata but were different from oseltamivir-resistant viruses isolated in Europe and North America in the 2007-2008 season. The oseltamivir-resistant viruses isolated in Japan in the 2008-2009 season were phylogenetically similar to oseltamivir-resistant isolates from Europe
