Emel Bozkaya

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

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. One hundred sixty‐three (31%) samples were positive for influenza viruses of which 111 (68%) were influenza A, 52 (31%) influenza B using an immuno‐capture ELISA. Forty isolates were selected at random from influenza A positive samples and grown in MDCK cell cultures. The supernatant of the cell cultures was used for RNA extraction followed by RT‐PCR to detect the sub‐types. Sub‐typing revealed all samples as A/H1N1. The N1 gene segment of 30 A/H1N1 samples was sequenced in part, from the 201st to 365th residue, which included the critical region for oseltamivir resistance. Then resulting sequences were analyzed with oseltamivir sensitive and resistant strains obtained from National Center for Biotechnology Information (NCBI) GenBank by CLC Main Workbench Software. H275Y (H274Y according to N2 numbering) mutation, which is known to confer resistance to oseltamivir, was detected in 6 out of 30 (20%) H1N1 isolates from four cities (Istanbul, Bursa, Ankara, and Izmir). The D354G mutation was observed in all oseltamivir resistant H1N1 isolates but not in the oseltamivir sensitive isolates. Assay of neuraminidase activity revealed that these isolates were resistant to oseltamivir, but sensitive to zanamivir. J. Med. Virol. 81:1645–1651, 2009.

Sensitivity of rapid influenza antigen tests in the diagnosis of pandemic (H1N1)2009 compared with the standard rRT-PCR technique during the 2009 pandemic in Turkey.

Abstract The real-time reverse transcription polymerase chain reaction (rRT-PCR) technique has been used as the reference technique for the diagnosis of pandemic (H1N1)2009 virus infections. However, rapid influenza diagnostics tests (RIDTs) have been considered in the diagnosis of pandemic (H1N1)2009 by some healthcare institutions in Turkey due to their ease of use and generation of fast results. Nevertheless, their low sensitivity has caused concern during the control of the pandemic. This study aimed to determine the sensitivity of 4 different rapid tests available on the market in Turkey in the diagnosis of pandemic (H1N1)2009 infections compared to the reference rRT-PCR technique. One hundred and four patient samples that tested positive and 88 samples that tested negative for pandemic (H1N1)2009 by rRT-PCR were tested with RIDTs available on the market. The sensitivity of the rapid tests ranged from 31.7% to 50% depending on the brand of RIDT. Specificity ranged from 97.7% to 100%. Currently available RIDTs are not sensitive enough and could lead physicians to delay the treatment of patients, adversely affecting control efforts to mitigate the pandemic. Therefore, these tests should only be used for screening, and negative results should not rule out influenza. More sensitive and rapid point-of-care techniques are needed to meet the demands of point-of-care testing.

Role of the line probe assay INNO-LiPA HBV DR and ultradeep pyrosequencing in detecting resistance mutations to nucleoside/nucleotide analogues in viral samples isolated from chronic hepatitis B patients.

Despite the effectiveness of nucleoside/nucleotide analogues in the treatment of chronic hepatitis B (CHB), their long-term administration is associated with the emergence of resistant hepatitis B virus (HBV) mutants. In this study, mutations resulting in antiviral resistance in HBV DNA samples isolated from 23 CHB patients (nine treatment naïve and 14 treated previously) were studied using a line probe assay (INNO-LiPA HBV DR; Innogenetics) and ultradeep pyrosequencing (UDPS) methods. Whilst the INNO-LiPA HBV DR showed no resistance mutations in HBV DNA samples from treatment-naive patients, mutations mediating lamivudine resistance were detected in three samples by UDPS. Among patients who were treated previously, 19 mutations were detected in eight samples using the INNO-LiPA HBV DR and 29 mutations were detected in 12 samples using UDPS. All mutations detected by the INNO-LiPA HBV DR were also detected by UDPS. There were no mutations that could be detected by INNO-LiPA HBV DR but not by UDPS. A total of ten mutations were detected by UDPS but not by INNO-LiPA HBV DR, and the mean frequency of these mutations was 14.7 %. It was concluded that, although INNO-LiPA HBV DR is a sensitive and practical method commonly used for the detection of resistance mutations in HBV infection, UDPS may significantly increase the detection rate of genotypic resistance in HBV at an early stage.

Mutations in influenza A virus (H5N1) and possible limited spread, Turkey, 2006.

We report mutations in influenza A virus (H5N1) strains associated with 2 outbreaks in Turkey. Four novel amino acid changes (Q447L, N556K, and R46K in RNA polymerase and S133A in hemagglutinin) were detected in virus isolates from 2 siblings who died.