Pathological and molecular investigation of canine distemper virus: Phylogenetic analysis of co-circulating genetic lineages in Türkiye.

Canine distemper virus (CDV) is a highly contagious virus that infects a wide variety of animals of carnivore species and may cause manifestations from subclinical infection to fatal disease. In this study, dogs clinically suspected having distemper were examined by reverse transcriptase-polymerase chain reaction (RT-PCR), histopathology and immuno-histochemistry. By histopathological examination, characteristic intracytoplasmic and/or intranuclear inclusion bodies were observed in the lung, stomach, small intestine, liver, kidney, spleen and central nervous system. Interstitial and broncho-interstitial pneumonia, gastroenteritis and encephalitis were revealed. CDV antigens were detected in all tissues with characteristic histopathological findings. The antigens were more abundant in the bronchial and bronchiolar epithelium and in the syntitial cells. Phylogenetic analyses were performed using the PCR-amplified partial sequences of the genes encoding the viral heamagglutinin and fusion proteins. The phylogenetic trees showed that the newly determined sequences were diverse and clustered within different lineages of the European or the Arctic strains.

A Snapshot Avian Surveillance Reveals West Nile Virus and Evidence of Wild Birds Participating in Toscana Virus Circulation.

INTRODUCTION: Birds are involved in the epidemiology of several vector-borne viruses, as amplification hosts for viruses, dissemination vehicles for the vectors, and sources of emerging strains in cross-species transmission. Turkey provides diverse habitats for a variety of wild birds and is located along major bird migration routes. This study was undertaken to provide a cross-sectional screening of avian specimens for a spectrum of vector-borne viruses. MATERIALS AND METHODS: The specimens were collected in Hatay province, in the Mediterranean coast of the Anatolian peninsula, located in the convergence zone of the known migration routes. Generic PCR assays were used for the detection of members of Nairovirus, Flavivirus, and Phlebovirus genera of Flaviviridae and Bunyaviridae families. The circulating viruses were characterized via sequencing and selected specimens were inoculated onto Vero cell lines for virus isolation. RESULTS AND DISCUSSION: Specimens from 72 wild birds belonging in 8 orders and 14 species were collected. A total of 158 specimens that comprise 32 sera (20.3%) from 7 species and 126 tissues (79.7%) from 14 species were screened. Eight specimens (8/158, 5%), obtained from 4 individuals (4/72, 5.5%), were positive. West Nile virus (WNV) lineage 1 sequences were characterized in the spleen, heart, and kidney tissues from a lesser spotted eagle (Clanga pomarina), which distinctly clustered from sequences previously identified in Turkey. Toscana virus (TOSV) genotype A and B sequences were identified in brain and kidney tissues from a greater flamingo (Phoenicopterus roseus), a great white pelican (Pelecanus onocrotalus), and a black stork (Ciconia nigra), without successful virus isolation. Partial amino acid sequences of the viral nucleocapsid protein revealed previously unreported substitutions. This study documents the involvement of avians in WNV dispersion in Anatolia as well in TOSV life cycle.

Generic amplification and next generation sequencing reveal Crimean-Congo hemorrhagic fever virus AP92-like strain and distinct tick phleboviruses in Anatolia, Turkey.

BACKGROUND: Ticks are involved with the transmission of several viruses with significant health impact. As incidences of tick-borne viral infections are rising, several novel and divergent tick- associated viruses have recently been documented to exist and circulate worldwide. This study was performed as a cross-sectional screening for all major tick-borne viruses in several regions in Turkey. Next generation sequencing (NGS) was employed for virus genome characterization. Ticks were collected at 43 locations in 14 provinces across the Aegean, Thrace, Mediterranean, Black Sea, central, southern and eastern regions of Anatolia during 2014-2016. Following morphological identification, ticks were pooled and analysed via generic nucleic acid amplification of the viruses belonging to the genera Flavivirus, Nairovirus and Phlebovirus of the families Flaviviridae and Bunyaviridae, followed by sequencing and NGS in selected specimens. RESULTS: A total of 814 specimens, comprising 13 tick species, were collected and evaluated in 187 pools. Nairovirus and phlebovirus assays were positive in 6 (3.2%) and 48 (25.6%) pools. All nairovirus sequences were closely-related to the Crimean-Congo hemorrhagic fever virus (CCHFV) strain AP92 and formed a phylogenetically distinct cluster among related strains. Major portions of the CCHFV genomic segments were obtained via NGS. Phlebovirus sequencing revealed several tick-associated virus clades, including previously-characterized Antigone, Lesvos, KarMa and Bole tick viruses, as well as a novel clade. A wider host range for tick-associated virus strains has been observed. NGS provided near-complete sequences of the L genomic segments of Antigone and KarMa clades, as well as Antigone partial S segment. Co- infections of CCHFV and KarMa or novel phlebovirus clades were detected in 2.1% of the specimens. CONCLUSIONS: Widespread circulation of various tick-associated phlebovirus clades were documented for the first time in Anatolia. Genomes of CCHFV AP92 strains were identified in previously unexplored locations. NGS provided the most detailed genomic characterization of the Antigone and KarMa viruses to date. The epidemiological and health-related consequences must be elucidated.

Canine Infections and Partial S Segment Sequence Analysis of Toscana Virus in Turkey.

INTRODUCTION: Toscana virus (TOSV) is a sandfly-borne bunyavirus with a significant public health impact. Preliminary studies have revealed TOSV exposure in dogs and they were suggested as potential reservoirs. This study was performed to characterize canine TOSV infections in an endemic region. Sequencing of TOSV small (S) segment in several previously identified specimens was also undertaken to reveal viral genealogy. MATERIALS AND METHODS: Canine and feline plasma were collected in several districts of Mersin province, Mediterranean Anatolia, Turkey, during May-September, 2015. Phlebovirus RNA was screened through two nested polymerase chain reaction (PCR) assays, targeting S and large (L) segments of the viral genome. A kinetoplast minicircle nested PCR was employed for Leishmania DNA detection and typing. Previously collected TOSV-positive specimens from humans, dogs, cats, and sandflies from various regions in Turkey and Cyprus were further evaluated through the S segment PCR. All amplicons were characterized through sequencing. RESULTS: A total of 210 specimens that comprise canine (76.2%) and feline (23.8%) plasma were screened. In three (1.9%) and two (1.3%) canine specimens, TOSV and Leishmania nucleic acids were detected, respectively. The TOSV strains were characterized as genotype B, and Leishmania infantum was identified in positive specimens. Twenty-four partial S segment sequences were amplified, which demonstrated a maximum intramural diversity of 3.88% in the nucleotide level. Sequence comparisons revealed significant similarities to particular genotype B strains characterized in Spain and France, whereas a notable divergence was observed among several TOSV strains. Single or recurrent amino acid substitutions were noted in eight residues of the viral nucleocapsid. DISCUSSION: Canine infections of TOSV genotype B, with temporal and spatial association with L. infantum, were detected. Divergent TOSV S segment sequences with amino acid substitutions, presumably associated with host adaptation, were observed.

First genetic characterization of equine adenovirus type 1 (EAdV-1) in Turkey.

Equine adenovirus type 1 (EAdV-1) is a cause of repiratory tract infection in equids. In present study for the first time in Turkey, the prevalence of EAdV-1 in nasal swab samples obtained from horses showing respiratory symptoms was investigated by polymerase chain reaction (PCR), and molecular characterization of the hexon gene detected in the Turkish (TR) strain was performed. Overall, the prevalence of EAdV-1 was found low (1.4%) as indicated by a positive PCR reaction from the nasal swab extracts tested. Phylogenetic analysis based on the partial sequences of the hexon gene of a TR-EAdV-1 strain with those of previously isolated AdVs from different mammals and an EAdV-1 M1 strain showed that the EAdV-1 strains were placed into a unique cluster. Although the TR-EAdV-1 strain was closely related to CAV-1, CAV-2 and bat adenovirus reference strains, larger-scale studies are necessary to better understand the molecular epidemiology and population structure of EAdV-1 in Turkey.

Characterisation of env and gag gene fragments of bovine leukemia viruses (BLVs) from cattle in Turkey.

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.