Kursat Altay

Crimean-Congo hemorrhagic fever virus: genetic analysis and tick survey in Turkey.

ABSTRACT Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne virus in the family Bunyaviridae, genus Nairovirus. The virus is transmitted to humans through infected tick bites or from direct contact with viremic animals or humans. In the present study, a total of 1,015 adult ticks were collected from cattle (603 specimens), sheep (17 specimens), and goats (395 specimens) in the Kelkit Valley in Turkey. Four tick species were recognized on the animals in the surveyed region. The most abundant species were Rhipicephalus bursa and Hyalomma marginatum marginatum, at 47.68% (484/1,015) and 46.40% (471/1,015), respectively. Reverse transcriptase PCR was used to recover partial sequences of the CCHFV small (S) genome segment. The presence of CCHFV was determined in 3 of 33 (9.09%) R. bursa pools and in 1 of 31 (3.22%) H. m. marginatum pools. Virus sequences from R. bursa were extremely different from those of the Greek CCHFV strain (U04958) isolated from an R. bursa tick. Phylogenetic analysis indicated that the CCHFV isolates obtained in this study clustered in group 5, whose range encompasses southwestern Russian and Kosovo. This is the first evidence of CCHFV in ticks from Turkey. Even though Hyalomma is the main vector for CCHFV, R. bursa may play a role in CCHFV transmission.

Molecular detection of Theileria and Babesia infections in cattle

This study was carried out to determine the presence and distribution of tick-borne haemoprotozoan parasites (Theileria and Babesia) in apparently healthy cattle in the East Black Sea Region of Turkey. A total of 389 blood samples were collected from the animals of various ages in six provinces in the region. Prevalence of infection was determined by reverse line blot (RLB) assay. The hypervariable V4 region of the 18S ribosomal RNA (rRNA) gene was amplified with a set of primers for members of the genera Theileria and Babesia. Amplified PCR products were hybridized onto a membrane to which generic- and species-specific oligonucleotide probes were covalently linked. RLB hybridization identified infection in 16.19% of the samples. Blood smears were also examined microscopically for Theileria and/or Babesia spp. and 5.14% were positive. All samples shown to be positive by microscopy also tested positive with RLB assay. Two Theileria (T. annulata and T. buffeli/orientalis) and three Babesia (B. bigemina, B. major and Babesia sp.) species or genotypes were identified in the region. Babesia sp. genotype shared 99% similarity with the previously reported sequences of Babesia sp. Kashi 1, Babesia sp. Kashi 2 and Babesia sp. Kayseri 1. The most frequently found species was T. buffeli/orientalis, present in 11.56% of the samples. T. annulata was identified in five samples (1.28%). Babesia infections were less frequently detected: B. bigemina was found in three samples (0.77%), B. major in two samples (0.51%) and Babesia sp. in five samples (1.28%). A single animal infected with T. buffeli/orientalis was also infected with B. bigemina.

Determination of prevalence and risk factors for infection with Babesia ovis in small ruminants from Turkey by polymerase chain reaction

In this study, PCR and thin blood smear-based diagnostic methods were used to assess the frequency of Babesia infection in small ruminants. A total of 300 sheep and 100 goats from 37 randomly selected herds located in eight locations of eastern Turkey were examined for the presence of Babesia infection and any tick species on the body of the animals. Of 400 blood samples examined, 6 (1.5%) were positive for Babesia spp. piroplasms upon microscopic examination, whereas 33 (8.25%) were positive for the presence of B. ovis by PCR. The prevalence of babesiosis in small ruminants detected by PCR was significantly higher than obtained in microscopic examination of thin blood smears (P < 0.05). Thirty-three animals produced the DNA fragment specific for Babesia ovis of which 32 (10.66%) were sheep and 1 (1%) was goat. The difference between the prevalence of Babesia infection in sheep and goats were statistically significant (P < 0.05). The prevalence of Babesia infection in different age groups of sheep were statistically non-significant (P > 0.05). The frequency of B. ovis infection was higher in herds with tick burden than no tick burden (P < 0.05). Seven amplicons (six from sheep and one from goat) were sequenced. The resulting sequences were identical to the recently reported nucleotide sequence of B. ovis. A total of 510 ticks belonging to the Rhipicephalus spp. were collected from sheep. Ticks were identified to be R. bursa and R. turanicus on the basis of morphological features.

Molecular detection and identification of Ehrlichia and Anaplasma species in ixodid ticks

A polymerase chain reaction (PCR) assay followed by partial sequencing of the 16S ribosomal RNA gene was performed for the presence of Ehrlichia and/or Anaplasma. A total of 242 ixodid ticks were collected from domestic ruminants and their shelters, as well as humans, and their individual salivary glands were dissected out for DNA. From the 242 ticks analyzed, six (2.47%), comprising three Hyalomma anatolicum anatolicum, one Rhipicephalus bursa, and two Rhipicephalus sanguineus, were positive. Of these sequenced samples directly obtained from the PCR products, three sequences from H. a. anatolicum were identical to that of the gene of Ehrlichia spp. strains. One sequence identified in R. bursa was closely related to Anaplasma platys. The remaining two sequences detected in R. sanguineus were similar to that of the gene of Anaplasma ovis. The study presented here provides preliminary data regarding the presence of rickettsial pathogens in ticks in Turkey.

Molecular detection and identification of Anaplasma and Ehrlichia species in cattle from Turkey

Bovine anaplasmosis is a tick-borne rickettsial disease widespread in tropical and subtropical areas. We investigated the presence and distribution of Anaplasma spp. in cattle from 6 provinces in Turkey. For amplification of the segment spanning the V1 region of the 16S ribosomal RNA (rRNA) gene of Anaplasma species, a reverse line blot (RLB) hybridization assay was performed on 389 blood samples. RLB identified Anaplasma infections in 9.0% (35/389) of the samples. The most frequently found species was A. marginale (11/389, 2.8%), followed by A. centrale (4/389, 1.0%) and A. phagocytophilum (4/389, 1.0%). Eighteen of 35 PCR-positive samples gave positive signals to the catch-all probes, but did not show any response to the species-specific probes tested. Sequencing results of 5 representative amplicons randomly selected from these specimens indicated that 3 were 100% identical to the sequence of A. ovis, and the other 2 sequences were 99.5% identical to the sequence of Ehrlichia sp. Omatjenne strain. The results further confirmed that A. ovis and Ehrlichia sp. Omatjenne infection occurs in cattle populations in Turkey.

Molecular evidence for Anaplasma phagocytophilum in Ixodes ricinus from Turkey

This study investigated the presence of the pathogen Anaplasma phagocytophilum in ixodid ticks removed from humans living in three provinces (Giresun, Trabzon, Rize) in the east of the Black Sea Region of Turkey. A total of 1097 ixodid ticks were examined for the presence of A. phagocytophilum DNA. From the 95 pooled tick samples tested, species-specific fragments of A. phagocytophilum (11/95 samples, 11.6%) were amplified by nested PCR. Adult Ixodes ricinus (9/53 samples, 17.0%) and Ixodes spp. nymphs (2/9 samples, 22.2%) were infected with A. phagocytophilum. None of the remaining tick species gave a positive result for the presence of the pathogen. All nested PCR-positive samples were directly sequenced. The partial sequences (457bp) of the amplicons obtained from the infected tick pools were 100% identical to one another and to previously isolated sequences from human patients. To obtain a longer 16S rRNA gene sequence, one representative sample was reamplified with the universal primer set. The longer representative sequence (1306bp) also shared 99.92% similarity (a single adenine deletion) with the recently reported complete sequence of A. phagocytophilum.

Molecular detection of tick-borne rickettsial and protozoan pathogens in domestic dogs from Turkey

BackgroundCanine tick-borne parasites have emerged in recent years, showing a wider geographic distribution and increased global prevalence. In addition to their veterinary importance, domestic dogs play an important role in the transmission cycles of some agents by acting as reservoirs and sentinels. This study investigated Babesia, Theileria, Anaplasma, and Ehrlichia species in asymptomatic dogs in ten provinces of Turkey.MethodsDNA obtained from blood samples collected from 757 domestic dogs (243 stray, 351 shelter, 163 pet) of both sexes and various ages were evaluated using PCR and reverse line blotting (RLB) assays.ResultsOf the 757 dogs tested, 41 (5.4%) were found to be infected with one or more parasites. Ehrlichia canis (37/757, 4.9%) was the most common canine tick-borne pathogen, followed by Anaplasma platys (4/757, 0.5%). Babesia canis and Theileria annulata were each detected in 1 (0.13%) sample. Combined infection of E. canis and A. platys was detected in 2 (0.3%) samples. The prevalence of tick-borne pathogens was higher in adult dogs (6.8%) than in those under one year old (3.1%). Difference in infection rate of male and female dogs was not significant. Pet dogs had a lower prevalence of infection (1.2%) compared to stray (7.4%) and shelter dogs (6%) although the difference between stray and shelter dogs was not significant.ConclusionsBabesia canis, T. annulata, A. platys, and E. canis species were identified at the molecular level in dogs in several provinces of Turkey, with E. canis being the most common species among tick-borne pathogens. Detailed studies should be conducted regarding the existence and prevalence of B. canis and Dermacentor reticulatus in eastern Turkey.

Evaluation of a PCR and comparison with RLB for detection and differentiation of Theileria sp. MK and other Theileria and Babesia species of small ruminants

Theileria sp. MK in sheep and goats were detected first time by polymerase chain reaction (PCR) and detection limit of PCR and reverse line blotting (RLB) were compared. A part of 18S ssu rRNA gene was amplified from blood samples that were taken from sheep and goats naturally infected with Theileria sp. MK by PCR. Detection limit of both PCR and RLB methods was one infected cell in 107 sheep erythrocytes. Nine hundred twenty field samples that had been tested previously by RLB were evaluated by the PCR assay. As found by RLB previously, 12 of 920 (1.30%) samples were detected as positive by PCR. Two positive PCR products, one of which was from sheep and the other from goat, were sequenced. These sequences were identical to the reported nucleotide sequence of Theileria sp. MK. It is concluded that the PCR described in this study will be useful for epidemiological studies and for discrimination between Theileria sp. MK and other Theileria species. In addition, PCR has superiority over RLB because of its ease of use and time period required.

A survey of ixodid ticks feeding on cattle and prevalence of tick-borne pathogens in the Black Sea region of Turkey

The study reports the frequency of infestation and the prevalence of tick-borne pathogens in feeding adult ticks detached from cattle in two climatic zones of the Black Sea region of Turkey. A total of 2160 adult ticks were collected during 2007-2008. Of these, 1062 were randomly selected, divided into 224 pools, and tested for the presence of bovine Theileria, Babesia, and Anaplasma species. Eleven tick species were recognized on cattle in the study. Hyalomma marginatum was widely disrubuted in the semi-arid bioclimatic zone, but few specimens were collected in the humid bioclimatic zone. The most prevalent tick species in the humid climatic zone was Ixodes ricinus. Infection rates were calculated as the maximum likelihood estimation with 95% confidence intervals (CI). Overall, 4% (CI 2.87-5.44) of 224 tick pools were found to be positive for the pathoges by Reverse line blot. Maximum likelihood estimation of the infection rate varied among tick species, ranging from 2.68% (CI 0.16-12.68) in Haemaphysalis sulcata to 10.49% (CI 4.07-23.66) in Rhipicephalus bursa. The most prevalent tick-borne pathogen was Anaplasma phagocytophilum at 6.78% (CI 3.41-12.18) followed by A. centrale (6.56%, CI 0.42-31.47), Anaplasma/Ehrlichia spp. (3.61%, CI 1.99-6.06), Babesia spp. (3.33%, CI 1.65-6.03), and T. buffeli/orientalis (2.71%, CI 0.73-7.18). Sequencing results indicated that Babesia spp. shared 99% to 100% similarity with the unnamed Babesia sp. Kashi 1 and 2, Babesia sp. Kayseri 1 and Babesia sp.CS58. Anaplasma/Ehrlichia spp. were 98% and 100% identical to Ehrlichia canis and Ehrlichia sp. Omatjenne strain, respectively.

A study on ovine tick-borne hemoprotozoan parasites (Theileria and Babesia) in the East Black Sea Region of Turkey

In this study, the frequency of Theileria and Babesia species was assessed via reverse line blotting and blood smear-based diagnostic methods in small ruminants. A total of 201 apparently healthy animals from 26 randomly selected herds located in 4 locations (Artvin, Giresun, Gumushane, and Tokat) of East Black Sea Region of Turkey were investigated for the blood protozoans. In a polymerase chain reaction (PCR), the hypervariable V4 region of the 18S ribosomal RNA gene was amplified with a set of general primers specific for all Theileria and Babesia species. The PCR products were hybridized against catchall and species-specific (Theileria spp., Theileria lestoquardi, Theileria ovis, Theileria sp. OT1, Theileria sp., OT3, Theileria sp., MK, Theileria luwenshuni, Theileria uilenbergi, Babesia spp., Babesia ovis, Babesia motasi, and Babesia crassa) probes. Theileria piroplasms were identified in nine (4.47%) samples by microscopic examination. Reverse line blotting (RLB) detected the infection in 19.90% of the samples. The infection rate of sheep (28.90%) was higher than goats (4.10%). T. ovis, Theileria sp., MK, and Theileria sp. OT3 were detected by RLB. The most prevalent Theileria species was T. ovis (18.90%) followed by Theileria sp. MK (0.99%). Theileria sp. OT3 was detected in one sample (0.43%). A single animal was infected as mix with T. ovis and Theileria sp. MK. The other Theileria (T. lestoquardi, Theileria sp. OT1, T. luwenshuni, and T. uilenbergi) and Babesia (B. ovis, B. motasi, and B. crassa) species were not detected. This study is the first molecular survey on ovine tick-borne protozoans in East Black Sea Region of Turkey.