High prevalence of amantadine‐resistance influenza a (H3N2) in six prefectures, Japan, in the 2005–2006 Season

Saito, Reiko; Li, Danjuan; Suzuki, Yasushi; Sato, Ichiro; Masaki, Hironori; Nishimura, Hidekazu; Kawashima, Takashi; Shirahige, Yutaka; Shimomura, Chieko; Asoh, Norichika; Degawa, Satoshi; Ishikawa, Hidefumi; Sato, Maki; Shobugawa, Yugo; Sano, Hiroshi

doi:10.1002/jmv.20946

Cited by 50 publications

(52 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…None of the patients in our study were known to have received amantadine. However, we detected amantadine-resis- (29,30,32). The source of the international spread of amantadine-resistant strains is speculated to be Southeast and East Asia (6).…”

Section: Discussionmentioning

confidence: 68%

“…The molecular basis of resistance has been identified as single nucleotide changes that lead to corresponding amino acid substitutions at one of four critical amino acid residues (residues 26, 27, 30, and 31) in the transmembrane region of the M2 ion channel protein (19,26,27). Recent studies suggest that the rates of influenza virus A/H3N2 resistance to amantadine and rimantadine have been high globally since 2005 (2,6,7,9,29,30), while the rates of resistance among A/H1N1 viruses varied from country to country but increased sharply from 2006 onwards (1,9,32). It should be noted that resistance in both subtypes was almost exclusively associated with one amino acid substitution at residue 31 (Ser to Asn) of the M2 ion channel protein after 2005 (1,2,6,7,9,29,30,32).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Rapid and Specific Detection of Amantadine-Resistant Influenza A Viruses with a Ser31Asn Mutation by the Cycling Probe Method

et al. 2010

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Discussionmentioning

confidence: 68%

mentioning

confidence: 99%

Rapid and Specific Detection of Amantadine-Resistant Influenza A Viruses with a Ser31Asn Mutation by the Cycling Probe Method

et al. 2010

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, resistance to these drugs has been reported. [5][6][7][8] Furthermore, the high price and lack of a sufficient supply prevent oseltamivir (Tamiflu) from being widely used in developing countries. Traditional Chinese medicine, which is widespread in nature with good efficacy, is beginning to play a more important role in this area.…”

mentioning

confidence: 99%

Inhibitory Effects of Baicalein on the Influenza Virus in Vivo Is Determined by Baicalin in the Serum

Dou

Zhang

et al. 2010

Biological & Pharmaceutical Bulletin

View full text Add to dashboard Cite

Baicalein (5,6,7-trihydroxyflavone) is a flavonoid derived from the root of Scutellaria baicalensis, a traditional Chinese medicine used for hundreds of years. This flavonoid demonstrates a variety of biological activities, such as antibacterial, antiinflammatory, antioxidant, antitumor, antiproliferative, anticoagulant, and vascular-protective effects. 1,2) Baicalein is also an inhibitor of reverse transcriptase of the human immunodeficiency virus (HIV), interferes with the RNA replication of HIV, and induces apoptosis in infected cells in vitro.3) Baicalein is the most potent inhibitor of the human cytomegalovirus (HCMV), displaying an IC 50 value of 0.4Ϯ0.04 mM in the colorimetric assay and 1.2Ϯ0.8 mM in the titer reduction assay. It also significantly reduces the levels of early and late proteins of HCMV, as well as viral DNA synthesis. 4)Influenza, one of the major pandemic diseases worldwide, represents a grave threat to human health. At present, only two types of chemical drug are used clinically in the treatment of influenza. One type is the M2 proton channel blockers (amantadine and rimantadine), and the other is neuraminidase inhibitors (zanamivir and oseltamivir). However, resistance to these drugs has been reported. [5][6][7][8] Furthermore, the high price and lack of a sufficient supply prevent oseltamivir (Tamiflu) from being widely used in developing countries. Traditional Chinese medicine, which is widespread in nature with good efficacy, is beginning to play a more important role in this area.It has been reported that baicalein demonstrates inhibitory effects on viruses and that more than 90% of baicalein is rapidly metabolized into baicalin, which is transported to the mesenteric blood when perfused through the rat jejunum. 9,10) However, the mechanism of its antiviral effect is unknown. Here, we report for the first time that baicalein has an inhibitory effect on the influenza virus A/FM1/1/47(H1N1) in vivo and that this effect is mainly due to its metabolite baicalin in serum. MATERIALS AND METHODSReagents Baicalein was a gift from Prof. Qinglong Guo of the Deptartment of Physiology, China Pharmaceutical University. It was dissolved in 0.5% sodium carboxymethyl cellulose (CMC) for in vivo experiments and in dimethyl sulfoxide (DMSO) for in vitro tests. Ribavirin injection was obtained from the China Pharmaceutical University Pharmaceutical Co., Ltd., Nanjing, China. Reference samples of baicalein and baicalin used in HPLC analysis were obtained from the National Institution for the Control of Pharmaceutical and Biological Products, China. Methanol, acetonitrile, and phosphoric acid (HPLC grade) were purchased from Sinopharm Chemical Reagent Co., Ltd., Shanghai, China. Virus and CellsThe influenza A/FM1/1/47(H1N1) virus used in this study was preserved in the Department of Microbiology, School of Life Science and Technology, China Pharmaceutical University. The virus was grown in the allantoic cavity of 10-d-old embryonated hen eggs at 37°C for 2 d.11) The allantoic fluid was harvested and fil...

show abstract

“…The widespread use of antiviral drugs, however, has the potential to promote the emergence of drug-resistant viruses (4,6,14). In fact, the majority of H3N2 and H1N1 viruses in humans are now amantadine and rimantadine resistant (11,12).…”

mentioning

confidence: 99%

Oseltamivir-Resistant Influenza A Viruses Circulating in Japan

Tamura

Mitamura

Yamazaki³

et al. 2009

J Clin Microbiol

View full text Add to dashboard Cite

Surveillance studies of the influenza viruses circulating in Europe and other countries in 2007 and 2008 have revealed rates of resistance to oseltamivir of up to 67% among H1N1 viruses. In the present study, we examined 202 clinical samples obtained from patients infected with H1N1 virus in Japan in 2007 and 2008 for oseltamivir resistance and found that three were oseltamivir resistant (1.5%). The 50% inhibitory concentrations (IC 50 s), as measured by a sialidase inhibition assay with these drug-resistant viruses, were >100-fold higher than those of the nonresistant viruses (median IC 50 , 12.6 nmol/liter). The His274Tyr (strain N2 numbering) mutation of the neuraminidase protein, which is known to confer oseltamivir resistance, was detected in these three isolates. Phylogenetic analysis showed that one virus belonged to a lineage that is composed of drug-resistant viruses isolated in Europe and North America and that the other two viruses independently emerged in Japan. Continued surveillance studies are necessary to observe whether these viruses will persist.

show abstract

High prevalence of amantadine‐resistance influenza a (H3N2) in six prefectures, Japan, in the 2005–2006 Season

Cited by 50 publications

References 32 publications

Rapid and Specific Detection of Amantadine-Resistant Influenza A Viruses with a Ser31Asn Mutation by the Cycling Probe Method

Rapid and Specific Detection of Amantadine-Resistant Influenza A Viruses with a Ser31Asn Mutation by the Cycling Probe Method

Inhibitory Effects of Baicalein on the Influenza Virus in Vivo Is Determined by Baicalin in the Serum

Oseltamivir-Resistant Influenza A Viruses Circulating in Japan

Contact Info

Product

Resources

About