The first serological detection of West Nile virus infection among residents living in northern Turkey.

BACKGROUND & OBJECTIVES: West Nile virus (WNV) is transmitted by a mosquito-borne virus whose natural reservoir is birds. Humans and horses are considered accidental hosts. Even if the vast majority of WNV infections in humans have asymptomatic or mild disease settings, serious neurological disorders with lethal outcomes can also be observed in around 1% of the cases. We aimed to serologically investigate the presence of WNV in humans living in Black sea of Turkey, and to obtain epidemiological data that will contribute to the implementation of public health policies to control and prevent potentially other life-threatening arboviral infections. METHODS: In the current study, a total of 416 human sera were collected from native patients of Samsun and its boroughs attending Samsun Training and Research Hospital; these sera were tested for WNV with pooling method, using anti-IgM and IgG ELISA commercial kits. All pools that were found positive for both IgM and IgG were individually retested for the detection of positive WNV sera. After that, all positive samples were tested using real-time PCR to detect the presence of WNV-RNA particles. RESULTS: Total seropositivity rates of WNV in terms of IgM and IgG were found as 0.96% and 0.72%, respectively. No presence of WNV-RNA could be detected in positive samples. INTERPRETATION & CONCLUSION: According to the data, further studies should be conducted to better understand the epidemiological dynamics of WNV in Turkey. It is recommended that other antigenically related flaviviruses which can give cross-reaction with WNV should also be investigated.

First isolation and molecular characterization of canine parvovirus-type 2b (CPV-2b) from red foxes (Vulpes vulpes) living in the wild habitat of Turkey.

BACKGROUND: The canine parvovirus, with its many variants, is responsible for a pivotal and common viral infection affecting millions of dogs and other carnivore species worldwide, particularly the wild ones, which are considered as the main reservoir hosts. To that end, this study investigated the presence of canine parvovirus (CPV) in red foxes (Vulpes vulpes) living in wild habitats of several regions of Turkey. METHODS: We randomly collected 630 archival fox stool specimens from rural areas of 22 provinces and used real-time PCR to detect CPV. RESULTS: Two of the 630 (0.3%) stool samples were positive for CPV-DNA, named Tr-Fox/128(Aydin) and Tr-Fox/159(Manisa). We attempted to isolate the virus in a MDCK cell line, and cytopathic effects were observed four days post-inoculation. Three regions corresponding to the CPV capsid protein VP2 gene from extracted DNA of positive samples were amplified by conventional PCR, and the products were visualised, purified, and Sanger sequenced. Three overlapping DNA raw sequence fragments, were read, assembled, and aligned to obtain approximately 1.5 kb-long regions that cover most of the VP2 gene, then deposited in GenBank. After comparing the isolates with parvovirus sequences data of domestic and wild carnivores by BLAST processing, our isolates' similarity rate with each other was 99.40%, with base differences in 9 nucleotide positions. They were classified as 2b variant closely related to isolates from dogs in Turkey, Egypt, Iraq, Italy, Thailand, and China. CONCLUSION: This study presents evidence of interspecies transmission of CPV, of which there are no reports on prevalence in wildlife carnivores of our country. Identification of CPV in red foxes threatens local and hunting dogs, which may contract the infection or disseminate it to other wild animal species or vice-versa.

A one-year extensive molecular survey on SARS-CoV-2 in companion animals of Turkey shows a lack of evidence for viral circulation in pet dogs and cats.

Current evidence have now demonstrated that SARS-CoV-2 infects a wide array of mammalian animals; however, the full range of hosts and the viral circulation in companion animals remains to be clarified. In this context, as no such evidenced cases have been reported from Turkey, we aimed to screen for SARS-CoV-2 nucleic acid in housed dogs and cats clinically evaluated for respiratory symptoms and reared in different locations of Samsun province in the black sea region of Turkey from July 2020 to July 2021. Nasal swabs were collected from a total of 415 pets (65 cats and 350 dogs) aged between 1 and 9 years old. All the specimens were tested for SARS-CoV-2 RNA presence by real-time RT-PCR targeting two genomic regions of SARS-CoV-2, but none showed positive results. Our findings suggest that SARS-CoV-2 does not circulate in local pets and is not responsible for respiratory symptoms. However, further comprehensive molecular and serological surveys are required to have a better picture of the zoonotic, reverse zoonotic and pathogenic consequences of the ongoing COVID-19 pandemic in Turkey.

First detection and molecular characterisation of a pigeon aviadenovirus A and pigeon circovirus co-infection associated with Young Pigeon Disease Syndrome (YPDS) in Turkish pigeons (Columba livia domestica).

Pigeon aviadenovirus A and Pigeon circovirus are both DNA viruses, infect and cause severe clinical diseases in pigeons. These viruses are associated with an immunosuppression syndrome similar to 'Young Pigeon Disease Syndrome' (YPDS). This study reports the identification of a natural co-infection, with severe clinical signs (crop vomiting, watery diarrhoea, anorexia and sudden death) of Pigeon aviadenovirus A and Pigeon circovirus in a breeding pigeon flock in Central Anatolia, Turkey. Both viruses were isolated from pigeons pooled internal organs using primary chicken embryo kidney cell cultures (CEKC) and specific pathogen-free (SPF) embryonated chicken eggs. Also, both viruses were identified by PCR amplification followed by Sanger sequencing whereas histopathological examination showed degenerated hepatocytes with basophilic intranuclear viral inclusions. As known, both viruses typically have similar transmission characteristics and common clinical manifestations; however, co-infection may exacerbate the disease with devastating outcomes. This is the first report of its kind in Turkey for those viruses and is essential for the protection against these kinds of infections in pigeons.

Serological study on the presence of some alpha-herpesviruses in goats of northern Anatolia, Turkey.

The aim of this study was to investigate the presence of caprine herpes virus-1 (CpHV-1) and bovine herpes virus-1 (BoHV-1) in 269 goat sera collected from small-scale family farms located in six provinces within the Black Sea region of northern Turkey. The overall seropositivity for alpha-herpesvirus in the native goats was found as 19.33% using BoHV-1 glycoprotein B (gB)-blocking enzyme-linked immunosorbent assay (ELISA). Additionally, the seroprevalence of BoHV-1 was determined in 5.20% of the goats using virus neutralization test. To distinguish between CpHV-1 and BoHV-1, the combinations of gB/gE-blocking ELISA tests were performed. Of tested samples, 15.24% were CpHV-1 seropositive; whereas, 4.09% were BoHV-1 seropositive. The results indicated that CpHV-1 is in circulation among local goats of northern Turkey. Considering the close relationship between BoHV-1 and CpHV-1, the transmission of BoHV-1 via goats may also be one of the predisposing factors involving in the spread of virus among the surrounding cattle.

Sentinel serosurveillance of backyard hens proved West Nile virus circulation in the western provinces of Turkey.

West Nile virus (WNV) is a mosquito-borne virus of a re-emergence importance with a wide range of vertebrate hosts. Granted, it causes asymptomatic infection, but fatal cases and neurologic disorders were also recorded, especially in humans, horses and some exposed birds. The virus is globally spread and birds are considered an amplifying and reservoir host of WNV, helping to spread the disease due to their close contact with main hosts. In this study, we aimed to detect the presence of antibodies against WNV in backyard hens that were reared in the western Anatolian part of Turkey. A total of 480 chicken sera were randomly collected from six provinces in the west of Turkey (Mugla, Izmir, Aydin, Afyonkarahisar, Kutahya and Manisa) with 80 samples from each province (40 in spring and 40 in fall seasons). They were tested by using a competitive ELISA method to identify the specific avian antibodies of IgG that produced against the WNV envelope proteins (pr-E). Twelve of 480 (2.5%) sera were found seropositive, three of these positive sera were detected from the Izmir province (3.75%) collected in the spring session and the other nine positive sera were detected from the Mugla province (11.25%) collected in the fall session. Both of these provinces are located seaside and have suitable climate conditions for vectors of infection. The results indicated that WNV infection is in circulation in these provinces, and that may put the other susceptible vertebrates under risk of infection.

A serosurvey for bovine respirovirus 3 in Turkish domestic ruminants: The first comparison study of A and C genotypes.

Bovine parainfluenza virus-3 (BPIV-3), also known as bovine respirovirus 3, causes serious respiratory infection in ungulates, often involving other pathogens, such as viruses, bacteria and mycoplasmas. In this study, we evaluated antibody titers against virus genotypes A (BPIV-3a) and C (BPIV-3c). We conducted a serological survey and comparison analysis of archived serum samples from small and large ruminants reared in four Turkish provinces. A total of 1,307 samples, consisting of sheep (n = 444), cattle (n = 402), water buffalo (n = 261) and goat (n = 200) sera, were randomly selected from stock samples collected between 2015 and 2019 and screened by standard virus neutralisation assay. We found that 49.9% (653/1307) of all samples were positive for neutralising antibody titers. Goats had the highest titer, with total seropositivity of 63% (126/200), followed in descending order by cattle, sheep and water buffalo at 56.2% (226/402), 32.2% (143/444) and 26% (68/261) total seropositivity, respectively. BPIV-3c had the highest neutralising antibody rate at 34.3% (448/1307), whereas BPIV-3a had a 24.3% (317/1307) seropositivity rate. Neutralising antibody titers for positive samples ranged between 1/4 and 1/512 per the SN50 test. Seropositivity rates ranged from a low of 8.9% to a high of 18.3%. Our study was the first to compare antibody seroprevalence for two BPIV-3 genotypes in small and large domestic ruminants, which were shown to be more commonly exposed to BPIV-3c than BPIV-3a. This finding could have significant implications as current vaccines mainly use the BPIV-3a genotype. Further research can determine if current vaccines protect against different BPIV-3 virus genotypes.

Marek's disease virus in vaccinated poultry flocks in Turkey: its first isolation with molecular characterization.

Marek's disease (MD) is an important disease of avian species and a potential threat to the poultry industry worldwide. In this study, 16 dead commercial chickens from flocks with suspected MD were necropsied immediately after death. Pathological findings were compatible with MD, and gallid alphaherpesvirus 2 was identified in PCR of spleen samples. Virus isolation was performed in primary cell culture, and partial sequencing of the meq gene of the isolate revealed >99% nucleotide sequence identity to virulent and very virulent plus strains from a number of European countries, placing it in the same subclade of clade III as two virulent Italian strains and a very virulent plus Polish strain as well as virulent strains of geese and ducks. The data reported here indicate that a virulent strain of Marek's disease virus is circulating in Turkey and has not been stopped by the current national vaccination programme.

Circulation of Indigenous Bovine Respiratory Syncytial Virus Strains in Turkish Cattle: The First Isolation and Molecular Characterization.

Bovine respiratory disease (BRD) is a huge economic burden on the livestock industries of countries worldwide. Bovine respiratory syncytial virus (BRSV) is one of the most important pathogens that contributes to BRD. In this study, we report the identification and first isolation, with molecular characterization, of a new BRSV strain from lung specimens of three beef cows in Turkey that died from respiratory distress. After the screening of lung tissues for BRD-associated viruses using a multiscreen antigen-ELISA, a BRSV antigen was detected. This was then confirmed by real-time RT-PCR specific for BRSV. Following confirmation, virus isolation was conducted in MDBK cell cultures and clear CPE, including syncytia compatible with BRSV, were detected. RT-nested PCR, using F gene-specific primers, was performed on the cultured isolates, and the products were sequenced and deposited to Genbank with accession numbers MT179304, MT024766, and MT0244767. Phylogenetic analysis of these sequences indicated that the cattle were infected with BRSV from subgroup III and were closely related to previously identified American and Turkish strains, but contained some amino acid and nucleotide differences. This research paves the way for further studies on the molecular characteristics of natural BRSV isolates, including full genome analysis and disease pathogenesis, and also contributes to the development of robust national strategies against this virus.

Field investigation and phylogenetic characterization of orf virus (ORFV) circulating in small ruminants and Pseudocowpoxvirus (PCPV) in dromedary camels of eastern Sudan.

In this study, livestock herders in eastern Sudan were interviewed through structured questionnaire involved 14046 animals in 151 herds (87 camel herds, 51 sheep and 13 goats) from June to September of 2016 in Showak area of Gadarif State to get some epidemiological information on contagious ecthyma (CE) infection. 102 suspected cases of CE were investigated (38 sheep, 22 goats and 42 camels) by a second questionnaire focusing on age and sex of affected animals beside number and localization of the lesions. Representative tissue samples of scab lesion scrapings were collected from a total of 36 suspected sheep, goats and camels for DNA extraction to identify PPV by quantitative real-time PCR and gel-based PCR, then a PCR protocol was used to obtain DNA fragment of B2L gene from six DNAs (2 from each animal species) for sequencing. Phylogenetic tree based on nucleotide sequences was constructed and all data were analyzed statistically. Obtained result has shown morbidity rate of 23.8% and a case fatality rate of 4.7 % in overall investigated animals resulting in a significant economic loss. Within individual herd, the morbidity rate varied from 5.6 to 42.8%, while the case fatality rate ranged between 0 and 33.3%. Camels accounted for the highest case fatality rate with 6.5% compared to sheep and goats which their rates were 2.8% and 1.3%, respectively. 93% of the affected animals were young less than one-year-old. The prevalence of CE was high in the rainy season compared to winter and summer. Out of 36 scab materials collected from sheep, goats, and camels, 24 gave positive specific amplification in real-time PCR and 21 in the gel-based PCR. DNA sequencing confirmed the PCR results. All sequences had a high G + C content of 62.6-63.9%. A BLAST search also revealed that the studied sheep PPV (SPPV) isolates shared 99.08% nucleotide sequence intragroup identity, 96.88-97.27% identity with the goat PPV (GPPV) isolates and together they belong to the Orf virus (ORFV) species, while the camel PPV (CPPV) isolates are close to the Pseudocowpoxvirus (PCPV) species of the PPV genus and share 92.51-93.62 % identity with the GPPV isolates. In conclusion the present study demonstrated that the gross lesion produced by PPV in sheep, goats and camels is generally similar, yet the PPVs circulating in eastern Sudan in camels (PCPV) are genetically distinct from those affecting sheep and goats (ORFV). Contagious ecthyma in eastern Sudan causes significant morbidities and mortalities and control measures, guided by the results of this investigation ought to be implemented.