Monitoring Genetic Diversity of Influenza A(H1N1)pdm09 Virus Circulating during the Post-Pandemic Period in Turkey

WOS: 000322850800007PubMed: 23883840The aimes of the present study were to monitor genetic alterations in the hemagglutin (HA) gene and oseltamivir resistance-related alterations in the neuraminidase (NA) gene of influenza A(H1N1)pdm09 viral isolates detected during the post-pandemic period in Turkey. A total of 2601 clinical specimens obtained from suspected cases of influenza A(H1N1)pdm09 viral infections were analyzed by real-time reverse transcription polymerase chain reaction. Viral RNA was detected in 233 (9%) clinical specimens. Sequence analysis of the HA gene in 16 random isolates showed >98.7% homology among each other and with the A/California/07/2009 vaccine strain. These 16 isolates had common (75%-100%) amino acid substitiutions at positions P83S, D97N, S203T, R205K, I216V, V249L, I321V, and E374K in the HA gene. In addition, two additional rare mutations were also observed at positions S162N (addition of a glycosylation site, 6.25%) and A186T (receptor binding region, 6.25%). On the basis of amino acid substitutions in the HA1 domain, majority of the Turkish isolates were classified in the genetic group v and others in the genetic groups ii, iii, and vi. In the present study, we observed an increase in the variety and ratio of mutations detected in the HA1. and HA2 domains of the HA gene; however, these alterations have not yet resulted in vaccine escape mutants in Turkey. In addition, analysis of the NA regions of the isolates revealed that oseltamivir resistance was not an issue in Turkey

Lack of genetic diversity in Crimean-Congo hemorrhagic fever viruses in Turkey: Assessment of present and future patterns of disease

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne zoonosis which is common in Africa, Asia, Eastern Europe, and the Balkan Peninsula. CCHF has been reported in Turkey with high frequency since 2002. The aim of the present study was to investigate the genetic diversity and genetic relationship between CCHF virus (CCHFV) isolates derived from infected patients over a 2-year period (2009 and 2010) in several provinces of Turkey. Serum samples (n=48) were selected from CCHFV RNA positive patients and subjected to sequence analysis of the gene regions encoding the S (48 samples) and M (14 samples) segments. The nucleotide sequence alignments showed that the nucleic acid relatedness of CCHFV isolates ranged from 95.7% to 100% and from 93.7% to 100% for S and M segments, respectively. Phylogenetic analysis of both segment sequences revealed that CCHFV isolates circulating in Turkey belonged to the European lineage I and were closely related to the viruses found in the Eastern European-Russian and Balkan Peninsula. The M gene segment-based phylogenetic analysis suggested that 2/14 CCHFV isolates (KYSR3159/09 and YZGT714/10) had additional genetic variations. The results of the present study confirmed that the CCHFV isolates present in Turkey associated with human disease had high genetic homology in S segment, but some variability in the M segment of the RNA. J. Med. Virol. 84:471478, 2012. (C) 2012 Wiley Periodicals, Inc

Molecular Characterization of Measles Viruses in Turkey (2010-2011): First Report of Genotype D9 Involved in an Outbreak in 2011

Bakkaloglu, Zekiye/0000-0001-9137-016XWOS: 000325153400010PubMed: 23959542Genetic characterization of measles viruses (MVs) combined with acquisition of epidemiologic information is essential for measles surveillance programs used in determining transmission pathways. This study describes the molecular characterization of 26 MV strains (3 from 2010, 23 from 2011) obtained from urine or throat swabs harvested from patients in Turkey. MV RNA samples (n=26) were subjected to sequence analysis of 450 nucleotides comprising the most variable C-terminal region of the nucleoprotein (N) gene. Phylogenetic analysis revealed 20 strains from 2011 belonged to genotype D9, 3 to D4, 2 strains from 2010 to genotype D4 and 1 to genotype B3. This study represents the first report describing the involvement of MV genotype D9 in an outbreak in Turkey. The sequence of the majority of genotype D9 strains was identical to those identified in Russia, Malaysia, Japan, and the UK. Despite lack of sufficient epidemiologic information, the presence of variants observed following phylogenetic analysis suggested that exposure to genotype D9 might have occurred due to importation more than once. Phylogenetic analysis of five genotype D4 strains revealed the presence of four variants. Epidemiological information and phylogenetic analysis suggested that three genotype D4 strains and one genotype B3 strain were associated with importation. This study suggests the presence of pockets of unimmunized individuals making Turkey susceptible to outbreaks. Continuing molecular surveillance of measles strains in Turkey is essential as a means of acquiring epidemiologic information to define viral transmission patterns and determine the effectiveness of measles vaccination programs designed to eliminate this virus. J. Med. Virol. 85:2128-2135, 2013. (c) 2013 Wiley Periodicals, Inc.Ministry of Health, Turkish National Public Health Agency, Adnan Saygun cad Ankara, TurkeyMinistry of Health - Turkey [55, 06100]Grant sponsor: Ministry of Health, Turkish National Public Health Agency, Adnan Saygun cad. No. 55, 06100 Ankara, Turke