29 results match your criteria detect oseltamivir-resistant

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Detection of variants with reduced baloxavir marboxil and oseltamivir susceptibility in children with influenza A during the 2019-2020 influenza season.

J Infect Dis 2021 Apr 10. Epub 2021 Apr 10.

Department of Pediatrics, Fukushima Medical University, Fukushima, Japan.

Background: We aimed to detect influenza variants with reduced susceptibility to baloxavir marboxil (baloxavir) and oseltamivir and identify differences in the clinical course between children with and without these variants after anti-viral treatment.

Methods: During the 2019-2020 influenza season, we enrolled children with confirmed influenza A (20 treated with baloxavir and 16 with oseltamivir). We analyzed patients' sequential viral RNA loads and infectious virus titers, the drug susceptibilities of clinical isolates, and amino acid substitutions in the viral polymerase acidic protein subunits or neuraminidase. Read More

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Genetic sequencing of influenza A (H1N1) pdm09 isolates from South India, collected between 2011 and 2015 to detect mutations affecting virulence and resistance to oseltamivir.

Indian J Med Microbiol 2020 Jul-Dec;38(3 & 4):324-337

Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India.

Background: Influenza A viruses evolve continuously and the two surface antigens, hemagglutinin (HA) and neuraminidase (NA) have been the target proteins for research as they are vital components in determining the virulence, immune effectiveness, pathogenicity, transmission and resistance.

Methods: Both HA and NA (partial genes) of 45 pandemic influenza A(H1N1)pdm09 isolates were sequenced. Phylogenetic analysis was performed with reference to representative global isolates retrieved from Influenza Virus Resource (IVR), GISAID EpiFluTM and GenBank and evolutionary analyses. Read More

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November 2020

Diagnosis of Tamiflu-Resistant Influenza Virus in Human Nasal Fluid and Saliva Using Surface-Enhanced Raman Scattering.

ACS Sens 2019 09 23;4(9):2282-2287. Epub 2019 Aug 23.

Department of Nanobiotechnology , KRIBB School of Biotechnology, UST , Daejeon 34113 , Republic of Korea.

Influenza viruses cause respiratory infection, spread through respiratory secretions, and are shed into the nasal secretion and saliva specimens. Therefore, nasal fluid and saliva are effective clinical samples for the diagnosis of influenza virus-infected patients. Although several methods have been developed to detect various types of influenza viruses, approaches for detecting mutant influenza viruses in clinical samples are rarely reported. Read More

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September 2019

Characterization of viral genomic mutations in novel influenza A (H7N9)-infected patients: the association between oseltamivir-resistant variants and viral shedding duration.

Virus Genes 2019 Oct 13;55(5):592-599. Epub 2019 Jul 13.

Center of Clinical Laboratory, First Affiliated Hospital, School of Medicine, Zhejiang University, 79 Qingchun Road, Hangzhou, 310003, People's Republic of China.

Since February 2013, human infections with the novel influenza A H7N9 virus have occurred in eastern China. It is important to detect mutations in viral genes and analyze the clinical features of patients and viral shedding duration related to neuraminidase inhibitor (NAI) resistance. We collected clinical specimens from 31 hospitalized H7N9 patients and sequenced NA, PB2, HA, and M gene fragments. Read More

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October 2019

Community spread and late season increased incidence of oseltamivir-resistant influenza A(H1N1) viruses in Norway 2016.

Influenza Other Respir Viruses 2019 07 4;13(4):372-381. Epub 2019 Mar 4.

Department of Influenza, Norwegian Institute of Public Health, Oslo, Norway.

Background: Antiviral resistance in Norwegian influenza viruses is rare. Only one A(H1N1)pdm09 virus from May 2015 had been found resistant to oseltamivir since the introduction of these viruses in 2009.

Objectives: Surveillance of antiviral resistance is part of the Norwegian surveillance system, to rapidly detect the development of antiviral-resistant viruses and spread in the community. Read More

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Surveillance for antiviral resistance among influenza viruses circulating in Algeria during five consecutive influenza seasons (2009-2014).

J Med Virol 2018 05 30;90(5):844-853. Epub 2018 Jan 30.

Faculty of Sciences, Department of Biology, EcoSTAq Research Laboratory, University Badji Mokhtar, Annaba, Algeria.

Influenza season 2007/2008 was marked by a worldwide emergence of oseltamivir-resistant A(H1N1) viruses possessing a mutation in the neuraminidase gene causing His-to-Tyr substitution at amino acid position 275 (H275Y). These strains were isolated in Algeria where 30% of seasonal A(H1N1) viruses harbored the H275Y mutation. Emergence of resistant viruses to currently approved antiviral drug determined the need for antiviral susceptibility monitoring in Algeria especially that oseltamivir is currently used in hospitals of some provinces of the country for treatment of influenza in populations at risk. Read More

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Characterization of oseltamivir-resistant influenza virus populations in immunosuppressed patients using digital-droplet PCR: Comparison with qPCR and next generation sequencing analysis.

Antiviral Res 2017 Sep 3;145:160-167. Epub 2017 Aug 3.

Hospices Civils de Lyon, Centre National de Référence des virus Influenzae France Sud, Laboratoire de Virologie, Institut des Agents Infectieux, Groupement Hospitalier Nord, F-69317, Lyon Cedex 04, France; Univ Lyon, Université Lyon 1, Faculté de Médecine Lyon Est, CIRI, Inserm U1111, CNRS UMR5308, équipe Virpath, F-69372, Lyon Cedex 08, France. Electronic address:

Introduction: The H275Y substitution in neuraminidase (NA) confers oseltamivir-resistance in A(H1N1) influenza viruses (IV). Droplet digital PCR (ddPCR) is a new technique to explore single nucleotide polymorphisms. The aim of this study was to compare the performances of reverse transcriptase (RT)-ddPCR, RT-qPCR and next generation sequencing (NGS). Read More

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September 2017

Prevalence of Influenza A(H1N1)pdm09 Virus Resistant to Oseltamivir in Shiraz, Iran, During 2012 - 2013.

Jundishapur J Microbiol 2015 Aug 29;8(8):e23690. Epub 2015 Aug 29.

Department of Bacteriology and Virology, Shiraz University of Medical Sciences, Shiraz, IR Iran.

Background: Oseltamivir has been used as a drug of choice for the prophylaxis and treatment of human influenza A(H1N1)pdm09 infection across the world. However, the most frequently identified oseltamivir resistant virus, influenza A(H1N1)pdm09, exhibit the H275Y substitution in NA gene.

Objectives: This study aimed to determine the prevalence and phylogenetic relationships of oseltamivir resistance in influenza A(H1N1)pdm09 viruses isolated in Shiraz, Iran. Read More

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Characteristics of oseltamivir-resistant influenza A (H1N1) pdm09 virus during the 2013-2014 influenza season in Mainland China.

Virol J 2015 Jun 24;12:96. Epub 2015 Jun 24.

National Institute for Viral Disease Control and Prevention, China CDC, Key Laboratory for Medical Virology, National Health and Family Planning Commission, 155 Changbai Road, Changping District, Beijing, 102206, PR China.

Background: In this study, we analyzed the characteristics of oseltamivir-resistant influenza A (H1N1) pdm09 virus isolated from patients in mainland China during the influenza season from September 2013 through March 2014, and provide guidance on which antiviral to be used for clinical treatment.

Methods: The all viruses collected from September 1, 2013 through March 31, 2014 were obtained from the Chinese National Influenza Surveillance Network. A fluorescence-based assay was used to detect virus sensitivity to neuraminidase inhibitors (NAIs). Read More

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Oseltamivir-resistant seasonal A(H1N1) and A(H1N1)pdm09 influenza viruses from the 2007/2008 to 2012/2013 season in Nara Prefecture, Japan.

Jpn J Infect Dis 2014 ;67(5):385-8

Virology and Epidemiology Division, Nara Prefecture Institute of Health.

We examined the incidence of oseltamivir-resistant seasonal A(H1N1) and A(H1N1)pdm09 influenza viruses from the 2007/2008 to 2012/2013 season in Nara Prefecture, Japan. To detect the oseltamivir resistance marker in neuraminidase (NA), 365 influenza viruses (60 seasonal A(H1N1) and 305 A(H1N1)pdm09) were sequenced. The H275Y mutation in the NA gene, which confers resistance to oseltamivir, was identified in 93. Read More

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Mass spectrometry-based comparative sequence analysis for the genetic monitoring of influenza A(H1N1)pdm09 virus.

PLoS One 2014 3;9(4):e92970. Epub 2014 Apr 3.

Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands.

The pandemic influenza A (H1N1) 2009 virus (pH1N1) contains novel gene segments of zoonotic origin that lack virulence and antiviral resistance markers. We aimed to evaluate the applicability and accuracy of mass spectrometry-based comparative sequence analysis (MSCSA) to detect genetic mutations associated with increased virulence or antiviral resistance in pH1N1. During the 2009 H1N1 pandemic, routine surveillance specimens and clinical antiviral resistance monitoring specimens were analyzed. Read More

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January 2015

Oseltamivir resistance among influenza viruses: surveillance in northern Viet Nam, 2009-2012.

Western Pac Surveill Response J 2013 Apr-Jun;4(2):25-9. Epub 2013 Jun 26.

National Influenza Center, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.

Introduction: Antiviral resistance has been reported in seasonal influenza A viruses and avian influenza A(H5N1) viruses in Viet Nam, raising concerns about the efficacy of treatment.

Methods: We analysed specimens from two sources during the period 2009-2012: influenza-positive samples from influenza-like illness patients at sentinel clinics in northern Viet Nam and isolates from patients with confirmed A(H5N1) infections. Pyrosequencing was used to detect mutations: H275Y [for A(H1N1) and A(H5N1)], E119V [for A(H3N2)] and I117V [for A(H5N1)]. Read More

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September 2015

[Clinical characteristics and molecular epidemiology of the novel influenza A (H1N1) infection in children in Shanghai].

Zhonghua Er Ke Za Zhi 2013 May;51(5):356-61

Department of Infectious Diseases, Children's Hospital of Fudan University, Shanghai 201102, China.

Objective: To investigate the epidemiological features, genetic drift in the epitopes of hemagglutinin (HA) of the novel influenza A (H1N1) virus and oseltamivir-resistant variants characterized by H275Y and N295S mutations in children in Shanghai since the outbreak.

Method: Between June 2009 and May 2012, a prospective surveillance study was carried out in Shanghainese children who attended the outpatient clinic of Children's Hospital of Fudan University for influenza-like illness. One-step real-time fluorescence quantitative RT-PCR was performed to detect seasonal influenza A and influenza B virus and the novel influenza A (H1N1) virus in the respiratory samples. Read More

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Bioluminescence-based neuraminidase inhibition assay for monitoring influenza virus drug susceptibility in clinical specimens.

Antimicrob Agents Chemother 2013 Nov 5;57(11):5209-15. Epub 2013 Aug 5.

Virus Surveillance and Diagnosis Branch, Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.

The QFlu prototype bioluminescence-based neuraminidase (NA) inhibition (NI) assay kit was designed to detect NA inhibitor (NAI)-resistant influenza viruses at point of care. Here, we evaluated its suitability for drug susceptibility assessment at a surveillance laboratory. A comprehensive panel of reference viruses (n = 14) and a set of 90 seasonal influenza virus A and B isolates were included for testing with oseltamivir and/or zanamivir in the QFlu assay using the manufacturer-recommended protocol and a modified version attuned to surveillance requirements. Read More

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November 2013

Virological self-sampling to monitor influenza antiviral susceptibility in a community cohort.

J Antimicrob Chemother 2013 Oct 12;68(10):2324-31. Epub 2013 Jun 12.

Microbiology Services Colindale, Public Health England, London, UK.

Objective: To perform antiviral susceptibility monitoring of treated individuals in the community during the 2009 influenza A(H1N1) pandemic in England.

Patients And Methods: Between 200 and 400 patients were enrolled daily through the National Pandemic Flu Service (NPFS) and issued with a self-sampling kit. Initially, only persons aged 16 and over were eligible, but from 12 November (week 45), self-sampling was extended to include school-age children (5 years and older). Read More

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October 2013

Oseltamivir-zanamivir bitherapy compared to oseltamivir monotherapy in the treatment of pandemic 2009 influenza A(H1N1) virus infections.

Antiviral Res 2012 Nov 14;96(2):130-7. Epub 2012 Aug 14.

Hospices Civils de Lyon, Centre National de Référence virus influenzae France Sud, Laboratoire de Virologie Est, F-69677 Bron, France.

Background: The emergence of oseltamivir resistance in 2007 highlighted the need for alternative strategies against influenza. To limit the putative emergence of resistant viruses this clinical trial aimed to evaluate the antiviral efficacy and tolerability of oseltamivir-zanamivir (O+Z) bitherapy compared to oseltamivir monotherapy (O). This clinical trial was designed in 2008-2009 and was conducted during the A(H1N1) influenza virus pandemic in 2009-2010. Read More

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November 2012

Analysis of influenza viruses from patients clinically suspected of infection with an oseltamivir resistant virus during the 2009 pandemic in the United States.

Antiviral Res 2012 Mar 7;93(3):381-6. Epub 2012 Feb 7.

Influenza Division, Centers for Disease Control and Prevention, Mail Stop G-16, 1600 Clifton Road, Atlanta, GA 30333, USA.

During the 2009 influenza pandemic, the Centers for Disease Control and Prevention provided antiviral susceptibility testing for patients infected with suspected drug-resistant viruses. Specimens from 72 patients admitted to an intensive care unit or with a severe immunocompromising condition, who failed to clinically improve after oseltamivir treatment, were accepted for testing. Respiratory specimens were tested for the presence of the oseltamivir resistance-conferring H275Y substitution in the neuraminidase (NA) by pyrosequencing. Read More

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High-resolution melting approach to efficient identification and quantification of H275Y mutant influenza H1N1/2009 virus in mixed-virus-population samples.

J Clin Microbiol 2011 Oct 24;49(10):3555-9. Epub 2011 Aug 24.

Molecular Diagnosis Center, National University of Singapore, Singapore, Republic of Singapore.

The single-nucleotide variation 823C to T (His275Tyr), responsible for oseltamivir drug resistance has been detected in some isolates of the influenza A/H1N1/2009 virus. Early detection of the presence of this oseltamivir-resistant strain allows prompt consideration of alternative treatment options. An isolated-probe-asymmetric amplification PCR (Roche LightCycler v2. Read More

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October 2011

Adamantane- and oseltamivir-resistant seasonal A (H1N1) and pandemic A (H1N1) 2009 influenza viruses in Guangdong, China, during 2008 and 2009.

J Clin Microbiol 2011 Jul 18;49(7):2651-5. Epub 2011 May 18.

Guangdong Center for Disease Control and Prevention, Guangzhou, Guangdong, People’s Republic of China.

Adamantane and oseltamivir resistance among influenza viruses is a major concern to public health officials. To determine the prevalence of antiviral-resistant influenza viruses in Guangdong, China, 244 seasonal A (H1N1) and 222 pandemic A (H1N1) 2009 viruses were screened for oseltamivir resistance by a fluorescence-based neuraminidase (NA) inhibition assay along with NA gene sequencing. Also, 147 seasonal A (H1N1) viruses were sequenced to detect adamantane resistance markers in M2. Read More

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Oseltamivir-resistant pandemic influenza a (H1N1) 2009 viruses in Spain.

J Clin Virol 2011 Jul 17;51(3):205-8. Epub 2011 May 17.

Centro Nacional de Gripe, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.

Background: Pandemic influenza A (H1N1) 2009 virus appeared in Spain on April 25, 2009 for the first time. This new virus was adamantane-resistant but it was sensitive to neuraminidase (NA) inhibitors oseltamivir and zanamivir.

Objectives: To detect oseltamivir-resistant pandemic influenza A (H1N1) 2009 viruses by the Spanish Influenza Surveillance System (SISS) and a possible spread of oseltamivir-resistant viruses in Spain since starting of the pandemic situation. Read More

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Rapid discrimination of oseltamivir-resistant 275Y and -susceptible 275H substitutions in the neuraminidase gene of pandemic influenza A/H1N1 2009 virus by duplex one-step RT-PCR assay.

J Med Virol 2011 Jul;83(7):1121-7

Influenza Virus Research Center, National Institute of Infectious Diseases, Musashimurayama, Tokyo, Japan.

Pandemic influenza A/H1N1 2009 (A/H1N1pdm) virus caused significant outbreaks worldwide last year (2009). A number of oseltamivir-resistant A/H1N1pdm viruses possessing an H275Y substitution in the neuraminidase (NA) protein were reported sporadically in several countries, including Japan, but they were sensitive to zanamivir and did not spread in the community. In this study, to monitor rapidly and simply oseltamivir-resistant A/H1N1pdm viruses possessing H275Y, a duplex one-step RT-PCR assay (H275Y RT-PCR assay) was developed based on an endpoint genotyping analysis method. Read More

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A comparison of pyrosequencing and neuraminidase inhibition assays for the detection of oseltamivir-resistant pandemic influenza A(H1N1) 2009 viruses.

Antiviral Res 2011 Apr 2;90(1):87-91. Epub 2011 Mar 2.

WHO Collaborating Centre for Reference and Research on Influenza, 10 Wreckyn Street, North Melbourne, VIC 3051, Australia.

Currently most pandemic influenza A(H1N1) 2009 (H1N1pdm) viruses are sensitive to oseltamivir, but a single point mutation (H275Y) in the neuraminidase (NA) gene of H1N1pdm can lead to resistance and such viruses have been reported from several countries. In this study we compare the performance of a pyrosequencing-based method for the detection of the H275Y mutation in H1N1pdm viruses with a conventional NA inhibition assay. Pyrosequencing could detect as little as 5% H275Y mutants in a mixed viral population, while mixtures with 25% or greater mutant virus were required before a significant increase in IC50 value could be detected. Read More

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Comprehensive assessment of 2009 pandemic influenza A (H1N1) virus drug susceptibility in vitro.

Antivir Ther 2010 ;15(8):1151-9

Virus Surveillance and Diagnosis Branch, Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.

Background: Antiviral drugs are an important option for managing infections caused by influenza viruses. This study assessed the drug susceptibility of 2009 pandemic influenza A (H1N1) viruses collected globally between April 2009 and January 2010.

Methods: Virus isolates were tested for adamantane susceptibility, using pyrosequencing to detect the S31N marker of adamantane resistance in the M2 protein and biological assays to assess viral replication in cell culture. Read More

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The validation of a real-time RT-PCR assay which detects influenza A and types simultaneously for influenza A H1N1 (2009) and oseltamivir-resistant (H275Y) influenza A H1N1 (2009).

J Virol Methods 2011 Jan 14;171(1):86-90. Epub 2010 Oct 14.

West of Scotland Specialist Virology Centre, Gartnavel General Hospital, Glasgow, United Kingdom.

Influenza A H1N1 (2009) was declared by the World Health Organisation (WHO) as the first influenza pandemic of the 21st century. Rapid detection of influenza A and differentiation of influenza A H1N1 (2009) and seasonal influenza A is beneficial. In addition the rapid detection of antiviral resistant strains of influenza A H1N1 (2009) would be useful for clinicians to allow for change to an effective treatment at a much earlier stage if resistance is found. Read More

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January 2011

Emergence of intratreatment resistance to oseltamivir in pandemic influenza A H1N1 2009 virus.

Antivir Ther 2010 ;15(6):923-7

Hospital de Niños R Gutiérrez, Buenos Aires, Argentina.

Background: Pandemic influenza A H1N1 2009 virus presents a new challenge to health authorities and communities worldwide. In Argentina, the outbreak was at its peak by the end of June 2009, during the southern winter. A systematic analysis of samples from patients with pandemic H1N1 2009 studied in our laboratory (Virology Laboratory, Hospital de Niños R Gutiérrez, Buenos Aires, Argentina) detected two patients presenting intratreatment emergence of the H275Y neuraminidase mutation, which confers resistance to oseltamivir. Read More

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December 2010

Simplified screening method for detecting oseltamivir resistant pandemic influenza A (H1N1) 2009 virus by a RT-PCR/restriction fragment length polymorphism assay.

J Virol Methods 2010 Dec 15;170(1-2):165-8. Epub 2010 Sep 15.

Department of Virology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.

The sudden emergence of the pandemic influenza A (H1N1) 2009 virus in early 2009 has resulted in a rapid transmission of this virus worldwide. Within a short time span, sporadic cases infected with this virus that shows oseltamivir resistance have also been reported. These resistant viruses have an amino acid change from histidine to tyrosine at position 275 (H275Y) of the neuraminidase gene. Read More

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December 2010

The detection of oseltamivir-resistant pandemic influenza A/H1N1 2009 viruses using a real-time RT-PCR assay.

J Virol Methods 2010 Oct 30;169(1):47-51. Epub 2010 Jun 30.

Department of Microbiology, PathWest Laboratory Medicine WA, Nedlands, Australia.

A real-time reverse transcription PCR (rRT-PCR) assay was designed and evaluated for the detection of the point mutation in the influenza A N1 neuraminidase gene that results in a tyrosine to histidine substitution at amino acid position 275 (H275Y) causing resistance to oseltamivir, an antiviral neuraminidase inhibitor. The rRT-PCR assays detected the presence or absence of the H275Y mutation in 387/388 (99.7%) of clinical samples containing the pandemic influenza A/H1N1 2009 virus. Read More

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October 2010

Surveillance and oseltamivir resistance of human influenza a virus in Turkey during the 2007-2008 season.

J Med Virol 2009 Sep;81(9):1645-51

Istanbul Faculty of Medicine, Department of Microbiology and Clinical Microbiology, Istanbul University, Istanbul, Turkey.

Monitoring the activity of influenza viruses is important for establishing the circulating types and for detection of the emergence of novel sub-types and antiviral resistant strains. This is the first report from Turkey on the surveillance and oseltamivir resistance of influenza viruses in 2007-2008. Five hundred twenty-four nasal swabs were tested from different geographical regions in Turkey during November 2007-April 2008. Read More

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September 2009

Rapid identification of oseltamivir-resistant influenza A(H1N1) viruses with H274Y mutation by RT-PCR/restriction fragment length polymorphism assay.

Antiviral Res 2009 Apr 31;82(1):29-33. Epub 2009 Jan 31.

Virus Surveillance and Diagnosis Branch, Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd, MS:G-16, Atlanta, GA 30333, USA.

In the beginning of 2007-2008 Northern Hemisphere influenza season, the frequency of influenza A(H1N1) viruses bearing a previously defined oseltamivir resistance conferring amino acid change of Histidine to Tyrosine at position 274 (H274Y) of the neuraminidase (NA) increased dramatically. In order to rapidly detect such resistant viruses, an RT-PCR/restriction fragment length polymorphism (RT-PCR/RFLP) assay targeting amino acid 274 of the N1 NA molecule was developed to investigate the presence or absence of the H274Y mutation. The reverse primer was engineered to produce a BspHI site in the amplicon for oseltamivir-sensitive viruses with Histidine at position 274 (274H). Read More

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