Browsing by Author "Timurkan, Mehmet Ozkan"

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Characterisation of Env and Gag Gene Fragments of Bovine Leukemia Viruses (Blvs) From Cattle in Turkey
(Springer Wien, 2011) Alkan, Feray; Oguzoglu, Tuba Cigdem; Timurkan, Mehmet Ozkan; Karapinar, Zeynep
The aim of this work was to investigate the molecular characteristics of bovine leukemia viruses (BLVs) in Turkey. The variability of env and gag fragments of BLVs was examined using DNA from blood samples obtained for sequence analysis of BLVs in four cattle herds from three different geographical areas in Turkey. The env gene sequences were highly similar to those of Brasilian, Argentine, and Japanese BLV strains, while gag genes from Turkish BLV isolates showed greatest similarity to those of Iranian isolates. This paper is the first report on the partial characterisation of env and gag genetic fragments of BLVs from Turkey.
Several Tick-Borne Pathogenic Viruses in Circulation in Anatolia, Turkey
(Mary Ann Liebert, inc, 2022) Dincer, Ender; Timurkan, Mehmet Ozkan; Oguz, Bekir; Sahindokuyucu, Ismail; Sahan, Adem; Ekinci, Mustafa; Ergunay, Koray
Introduction: We screened host-collected ticks for tick-borne viruses, including those recently documented as human pathogens.Methods: During 2020-2021, ticks removed form cattle, sheep, dogs, and cats in 11 provinces in 5 geographically distinct regions of Anatolia were identified, pooled, and screened using pan-nairovirus, pan-flavivirus and individual assays for Jingmen tick virus (JMTV), and Tacheng tick virus 1 and 2 (TcTV-1 and TcTV-2).Results: A total of 901 tick specimens, comprising 6 species were included. Rhipicephalus sanguineus complex was the most abundant species (44.1%), followed by Rhipicephalus bursa (38.3%), Haemaphysalis parva (7.2%), and others. The specimens were screened in 158 pools with 12 pools (7.6%) being positive. Crimean-Congo hemorrhagic fever virus (CCHFV) lineage Europe 2 (genotype VI) sequences were detected in R. bursa in five (3.2%) of the pools, with similar prevalences in central and Mediterranean Anatolian provinces. JMTV was identified in four R. bursa and one Rhipicephalus turanicus pools, collected from Mediterranean and southeastern Anatolia, with a CCHFV and JMTV coinfected R. bursa pool. The JMTV segment 1 sequences formed a separate cluster with those from Turkey and the Balkan peninsula in the maximum likelihood analysis. TcTV-2 was detected in two Dermacentor marginatus specimens (1.3%) collected in central Anatolia, with nucleocapsid sequences forming a phylogenetically segregated group among viruses from humans and ticks from China and Kazakhstan.Discussion: CCHFV Europe 2 was initially documented in ticks from central Anatolian locations, where related orthonairoviruses had been previously recorded. Ongoing activity and a wider distribution of JMTV and TcTV-2 were observed. These viruses should be screened as potential etiological agents in human infections associated with tick bites.
Striking Tick-Borne Virus Diversity and Potential Reservoirs Documented During One-Health Cross-Sectional Screening in Anatolia
(BMC, 2025) Dincer, Ender; Timurkan, Mehmet Ozkan; Oguz, Bekir; Ozan, Emre; Coskun, Nuvit; Kiziltepe, Semistan; Ergunay, Koray
An expansion of recently described human pathogenic tick-borne viruses from Central Asia toward Europe has been documented. Located on important bird migration routes, Anatolia is an intercontinental crossing hub with various climactic zones and with an abundance of endemic tick species. We sought to investigate tick-borne viruses utilizing a One Health approach encompassing host-removed ticks and host samples.MethodsWe collected host-attached ticks and accompanying plasma in 2023-2024 at locations in 20 provinces representing the 7 distinct geographical regions in Anatolia. The hosts comprised cattle, sheep, dogs, goats, and tortoises. The ticks were morphologically identified, processed in pools, and these pools, along with plasma from cattle, sheep and goats, were subjected to nucleic acid purification and complementary DNA synthesis. Viruses were screened by generic (nairovirus) and specific (Jingmen tick virus, JMTV; Tacheng tick virus 1, TcTV-1; Tacheng tick virus 2, TcTV-2; and Tamdy virus, TAMV) amplification assays and characterized by sequencing.ResultsA total of 93 animal plasma samples and 1265 samples from 11 tick species were screened in 192 pools. Crimean-Congo hemorrhagic fever virus (CCHFV) was detected in five tick species in ten pools (5.2%). Three distinct virus lineages, including Europe 1 and 2, as well as Africa 1, were noted. TcTV-1 was identified in 6 tick species in 12 pools (6.3%) and in a cattle plasma sample. Analysis of the nucleoprotein-encoding sequences revealed two separate virus clades, distinct from those reported from Asia and Europe. TAMV was identified in two tick species (1%). We further detected JMTV in 7 pools (3.6%), with sequences forming a new clade phylogenetically closer to viruses of Asian origin than local strains. Finally, highly divergent sequences of a novel nairovirus, forming a distinct group sharing ancestors with TcTV-1, TAMV, and pangolin/tick-associated nairoviruses, was observed in four pools (2%), comprising Haemaphysalis parva ticks.ConclusionsWe described a previously undocumented diversity of tick-borne viral pathogens, CCHFV, TcTV-1, and JMTV, in Anatolia. Possible animal reservoirs of TcTV-1 were identified. These pathogens and TAMV should be considered in the diagnostic workup of cases with symptoms associated with tick bites and in future surveillance efforts.