Browsing by Author "Unlu, Ahmet Hakan"

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Comparison of Protectiveness of Recombinant Babesia Ovis Apical Membrane Antigen 1 and B. Ovis-Infected Cell Line as Vaccines Against Ovine Babesiosis
(Elsevier Gmbh, 2020) Bilgic, Huseyin Bilgin; Hacilarlioglu, Selin; Bakirci, Serkan; Kose, Onur; Unlu, Ahmet Hakan; Aksulu, Ayca; Karagenc, Tulin
Babesiosis is a disease complex caused by unicellular Babesia parasites and among them, malignant ovine babesiosis caused by B. ovis has a devastating economical impact on the small ruminant industry. The control of disease is mainly based on chemotherapy and preventing animals from tick infestation and to date no vaccine is available against ovine babesiosis. The requirement for vaccination against B. ovis infection in endemically unstable regions is necessary for implementation of effective disease control measures. The aim of the present study was to evaluate the effectiveness of different immunisation protocols against disease in sheep experimentally vaccinated with recombinant B. ovis apical membrane antigen-1 (rBoAMA-1) and/or live, a B. ovis-infected cell line. Sheep were divided into four experimental groups, plus a control group. Animals were immunised either with the B. ovis stabilate, or with rBoAMA-1, or with both rBoAMA-1 and the B. ovis stabilate. Western blots and ELISAs indicated that immunisation with rBoAMA-1 resulted in generation of a specific response against the recombinant protein, but the degree of antibody response did not correlate with the level of induced protection against challenge. The strongest immune response was induced in animals co-immunised with the live B. ovis stabilate plus rBoAMA-1. Both the hematological and parasitological findings indicated that this co-immunisation regimen has vaccine potential to limit losses incurred by ovine babesiosis in endemic countries.
Evaluation of Seroprevalence and Clinical and Laboratory Findings of Patients Admitted To Health Institutions in Gumushane With Suspicion of Crimean-Congo Hemorrhagic Fever
(Tubitak Scientific & Technological Research Council Turkey, 2021) Gurbuz, Esra; EkIcI, Abdurrahman; Unlu, Ahmet Hakan; Yilmaz, Hasan
Background/aim: To determine the seroprevalence and evaluate clinical findings and laboratory results of patients prediagnosed with Crimean-Congo hemorrhagic fever (CCHF) in Gumushane. Materials and methods: Included in the cross-sectional study were 362 patients (162 female, 200 male) between 0 and 94 years of age, who were followed up after receiving a preliminary diagnosis of CCHF between January 2011 and December 2019. Anamnesis, age, sex, clinical findings, laboratory results, epidemiological and clinical evaluations, severity criteria, risk factor reviews, and a comparison of the suspected negative cases with positive cases were analyzed retrospectively. Patients included in the study were evaluated as RNA positive by polymerase chain reaction (PCR) or IgM-positive by ELISA. Results: Of the 362 patients admitted to health institutions with a preliminary diagnosis of CCHF, 242 were diagnosed as CCHFpositive (66.9%). Moreover, 196 of those CCHF-positive patients (81%) were admitted to health institutions during the summer months. Statistical analyses revealed a significant relationship between the incidence of CCHF and patients who had been in contact with animals, lived in rural areas, and had engaged in farming and animal husbandry. In addition, fever, headache, diffuse bodily pain, nausea and vomiting, diarrhea, fever of 38 degrees C or higher, tachycardia, elevated ALT/AST, creatine kinase (CK), and lactate dehydrogenase (LDH) levels, leukopenia, and thrombocytopenia were detected in the CCHF-positive patients. Significant relations were found between this disease and these symptoms. However, there was no significant relationship between the statistical evaluation of the disease and bloody diarrhea, bodily bruises, rash, unconsciousness, gingival bleeding, hypotension, epistaxis, petechiae, splenomegaly, ecchymosis, hematuria, maculopapular rash, gastrointestinal system complaints, anemia, or elevation of the international normalized ratio and activated partial thromboplastin time duration, separately. Conclusion: Of the 362 patients, 66.9% (242) of those who received a preliminary diagnosis of CCHF were indeed CCHF-positive in Gumushane. It was concluded that CCHF remains an important endemic disease in Gumushane. In addition, elevated ALT/AST, CK, and LDH levels, leukopenia, and thrombocytopenia in patients presenting with headache, fever, fever of 38 degrees C or higher, generalized body pain, nausea/vomiting, diarrhea, and tachycardia will play a pivotal role in the preliminary diagnosis of CCHF.
High Genetic Diversity and Differentiation of Thebabesia Ovispopulation in Turkey
(Wiley, 2020) Mira, Anabela; Unlu, Ahmet Hakan; Bilgic, Huseyin Bilgin; Bakirci, Serkan; Hacilarlioglu, Selin; Karagenc, Tulin; Schnittger, Leonhard
Babesia ovisis a tick-transmitted protozoan haemoparasite causing ovine babesiosis in sheep and goats leading to considerable economic loss in Turkey and neighbouring countries. There are no vaccines available, therapeutic drugs leave toxic residues in meat and milk, and tick vector control entails environmental risks. A panel of eight mini- and micro-satellite marker loci was developed and applied to study genetic diversity and substructuring ofB. ovisfrom western, central and eastern Turkey. A high genetic diversity (H-e = 0.799) was found for the sample of overallB. ovispopulation (n = 107) analyzed. Principle component analysis (PCoA) revealed the existence of three parasite subpopulations: (a) a small subpopulation of isolates from Aydin, western Turkey; (b) a second cluster predominantly generated by isolates from western Turkey; and (c) a third cluster predominantly formed by isolates from central and eastern Turkey. TwoB. ovisisolates from Israel included in the analysis clustered with isolates from central and eastern Turkey. This finding strongly suggests substructuring of a major Turkish population into western versus central-eastern subpopulations, while the additional smallerB. ovispopulation found in Aydin could have been introduced, more recently, to Turkey. STRUCTURE analysis suggests a limited exchange of parasite strains between the western and the central-eastern regions andvice versa, possibly due to limited trading of sheep. Importantly, evidence for recombinant genotypes was obtained in regionally interchanged parasite isolates. Important climatic differences between the western and the central/eastern region, with average yearly temperatures of 21 degrees C versus 15 degrees C, correspond with the identified geographical substructuring. We hypothesize that the different climatic conditions may result in variation in the activity of subpopulations ofRhipicephalusspp. tick vectors, which, in turn, could selectively maintain and transmit different parasite populations. These findings may have important implications for vaccine development and the spread of drug resistance.
Infection Dynamics of Theileria Annulata Over a Disease Season Following Cell Line Vaccination
(Elsevier Science Bv, 2019) Bilgic, Huseyin Bilgin; Aksulu, Ayca; Bakirci, Serkan; Unlu, Ahmet Hakan; Kose, Onur; Hacilarhoglu, Selin; Karagenc, Tulin
Tropical theileriosis is a tick-borne haemoparasitic disease of cattle caused by the protozoan parasite Theileria annulata. Globally, the economic impact of the disease is immense and enhanced control measures would improve livestock production in endemic regions. Immunisation with a live attenuated vaccine is an effective and widely used control method, however, the repeated use of live vaccines may have an impact on the field parasite population at a genetic level. Additionally, there has been an increasing number of reports of vaccine break-through cases in recent years. Thus, the present study was designed to evaluate the genetic composition of a parasite population over a disease season in a locality where live cell line vaccination is practised. A diverse range of parasite genotypes was identified and every T. annulata positive cattle blood sample harboured multiple parasite genotypes. An alteration in the major genotype and an increasing multiplicity of infection in individual animals was observed over the course of the disease season. Vaccination status was found not to effect within-host multiplicity of infection, while a significantly higher number of genotypes was detected in grazed cattle compared to non-grazed ones. A degree of genetic isolation was evident between parasite populations on a micro-geographic scale, which has not been reported previously for T. annulata. Analysis of parasite genotypes in vaccinated animals suggested only a transient effect of the vaccine genotype on the genetic diversity of the T. annulata population. The vaccine genotype was not detected among clones of two vaccine 'breakthrough' isolates and there is no suggestion that it was responsible for disease. The obtained data indicated that in the system studied there is no apparent risk of introducing the vaccine genotype into the population with only a transient effect on the genetic diversity of the parasite population during the disease season.
Investigation of Mitochondrial Cytb Gene Region of Both Echinococcus Granulosus Eggs From Dogs and Cystic Echinococcosis Isolates Obtained From Sheep and Cattle by Molecular Methods
(Iranian Scientific Society Medical Entomology, 2024) Yildiz, Rahmi; Aydemir, Selahattin; Halidi, Ahmet Galip; Unlu, Ahmet Hakan; Yilmaz, Hasan
Background:We aimed to determine the common Echinococcus granulosus genotypes in A & gbreve;r & imath;, T & uuml;rkiye and to obtain information on the transmission of this parasite. Methods:Cystic echinococcosissamples from 100 slaughtered cattle and 100 slaughtered sheep and faecal samples from 200 stray dogs were included in 2021. Collected cyst fluid samples and faces were examined microscopically. DNA was isolated from the germinal membrane of the cysts and from the parasite eggs in the stool samples. The mitochondrial cytbgene region of the parasite was amplified by PCR. Genotypes were determined using the Basic Local Alignment Search Tool (BLAST) after sequence analysis of PCR amplicons. Results:The highest percentage of cysts was found in the lungs of sheep and the liver of cattle. In addition, 75% of sheep cysts and 25.6% of cattle cysts were fertile. Taenia spp./Echinococcus spp. eggs werefound in 6% of the faeces of 200 dogs ex-amined microscopically. E. granulosuseggs were detected in 4 out of 50 stool sam-ples analysed by PCR. All samples analysed by sequence analysis were identified as E. granulosuss.s. G1 genotype. Sequence comparisonrevealed revealed one or more-pointmutations in different regions of the five samples. Conclusion:E. granulosuss.s. G1 genotype, known as sheep strain, is common in the A & gbreve;r & imath;, T & uuml;rkiye. The controlled slaughter of livestock, especially sheep, and the avoidance of feeding hydatid cyst organs to dogs, together with public education, were necessary to prevent the spread of the disease.
Phenoloxidase Is Involved in the Immune Reaction of Helix Lucorum To Parasitic Infestation by Dicrocoeliid Trematode
(inst Rural Health Lublin, Poland, 2021) Unlu, Ahmet Hakan; Ekici, Abdurrahman
Introduction. Phenoloxidases are known to play a role in the immune defences of arthropods and molluscs. In the invertebrates, phenoloxidases mediate three major physiologically important processes: sclerotization, wound healing, and defence reactions. Helix lucorum serve as the first intermediate host for the larval stages of dicrocoeliid trematodes which infects animals as well as human beings. Objective. The aim of the study is to investigate the effect of larval forms of dicrocoeliid trematodes to phenoloxidase acitivity in H. lucorum, Linneaus, 1758, in Bitlis, Turkey. The effect of the snail's shell colour to phenoloxidase activity was also investigated. Materials and method. Land snails (n=200) were collected by hand from their natural habitats during the period May - June 2019 in Bitlis, Turkey. Evaluation of the process was performed by measuring immune reaction of the snails against larval forms of dicrocoeliid trematodes. Phenoloxidase activity assay was carried out using a spectrophotometer device based on 3,4-Dihydroxy-L-phenylalanine (L-dopa) hydrolysis. Results. The natural infection rate of the land snails with the developmental stages of dicrocoeliid trematodes was 20%. Phenoloxidase activity was found to be significantly higher (*p<0.05) in larval forms of dicrocoeliid trematodes infected snails when compared with non-infected snails. No effect of shell colours to phenoloxidase activity was observed. Conclusions. To the best of the authors' knowledge, this study is the first to report that the phenoloxidase system is involved in the immune reaction of Helix lucorum to parasitic infestation by larval forms of dicrocoeliid trematodes.
Prevalence of Blastocystis Infection in Humans in Turkiye: a Systematic Review and Meta-Analysis
(Academic Press Ltd- Elsevier Science Ltd, 2024) Aydemir, Selahattin; Barlik, Fethi; Yurekturk, Sehriban; Saygin, Murat; Unlu, Ahmet Hakan; Ekici, Abdurrahman; Yilmaz, Hasan
Although Blastocystis, a protozoan, is commonly found in all species of animals and in humans, there remains a lack of clear information about its epidemiology and routes of transmission. The aim of this meta-analysis study was to determine the changes in Blastocystis prevalence and subtype distribution in humans in T & uuml;rkiye according to geographical regions. Databases were searched using the Web of Science, PubMed, Scopus, EBSCO, and TRDizin to identify studies on the prevalence of Blastocystis in humans in T & uuml;rkiye published from 2009 to 2023. As a result of this systematic search, 117 of 730 articles were included in the meta-analysis. The pooled prevalence of human Blastocystis infection in T & uuml;rkiye was 13.08 %. The prevalence of the pool was higher in the Black Sea region, which is the most humid region in T & uuml;rkiye, than in other regions. Blastocystis subtypes were identified in a total of 885 positive samples. The most common subtypes (ST) in T & uuml;rkiye were ST3, ST1 and ST2, respectively. In addition to these ST4, ST5, ST6 and ST7 were also detected in humans in T & uuml;rkiye. In conclusion, the prevalence of Blastocystis in humans is high in T & uuml;rkiye, especially in the Black Sea region.
Prevalence of Tick-Borne Haemoparasites in Small Ruminants in Turkey and Diagnostic Sensitivity of Single-Pcr and Rlb
(Biomed Central Ltd, 2017) Bilgic, Huseyin Bilgin; Bakirci, Serkan; Kose, Onur; Unlu, Ahmet Hakan; Hacilarlioglu, Selin; Eren, Hasan; Karagenc, Tulin
Background: Tick-borne haemoparasitic diseases (TBHDs), caused by Theileria, Babesia, Anaplasma and Ehrlichia, are common in regions of the world where the distributions of host, pathogen and vector overlap. Many of these diseases threaten livestock production and some also represent a concern to human public health. The primary aim of this study was to determine the prevalence of the above-mentioned pathogens in a large number of blood samples (n = 1979) collected from sheep (n = 1727) and goats (n = 252) in Turkey. A secondary aim was to assess the diagnostic sensitivity of a number of species-specific polymerase chain reaction (PCR) tests and the reverse line blotting (RLB) assay. DNA samples were screened using species-specific PCR for the presence of Theileria ovis, Theileria sp. MK, T. lestoquardi, T. uilenbergi, T. luwenshuni, Babesia ovis, Anaplasma ovis and A. phagocytophilum while RLB was undertaken to test for the presence of all known Theileria, Babesia, Anaplasma and Ehrlichia species. The diagnostic sensitivity of these two approaches was then compared in terms of their ability to detect single species and mixed infections. Results: Overall, 84 and 74.43% of the small ruminants sampled were identified as hosting one or more pathogen(s) by species-specific PCR and RLB respectively. The presence of Theileria sp. OT1, T. luwenshuni and T. uilenbergi in Turkey was revealed for the first time while the presence of Babesia motasi, B. crassa and T. separata in Turkish small ruminants was confirmed using molecular methods. A high prevalence of mixed infection was evident, with PCR and RLB approaches indicating that 52.24 and 35.42% of animals were co-infected with multiple species, respectively. More than 80% of the mixed infections contained T. ovis and/or A. ovis. The RLB approach was found to be capable of detecting mixed infections with species such as Theileria sp. OT1, Theileria sp. OT3, T. separata, B. crassa and Babesia spp. Conclusion: The results indicated that pathogens causing TBHDs are highly prevalent in sheep and goats in Turkey. The diagnostic sensitivity of species-specific single PCR was generally higher than that of RLB. However, the latter approach was still capable of identifying a high proportion of individuals containing mixed-species infections. The use of species-specific single PCR is recommended to accurately estimate pathogen prevalence and to identify co-infected hosts.
The Secreted Theileria Annulata Ta9 Protein Contributes To Activation of the Ap-1 Transcription Factor
(Public Library Science, 2018) Unlu, Ahmet Hakan; Tajeri, Shahin; Bilgic, Huseyin Bilgin; Eren, Hasan; Karagenc, Tulin; Langsley, Gordon
Theileria annulata is an obligate intracellular protozoan parasite of the phylum Apicomplexa. Theileria sporozoites invade bovine leukocytes and develop into a multinucleate syncytial macroschizont that causes uncontrolled proliferation and dissemination of infected and transformed leukocytes. Activator protein 1 (AP-1) is a transcription factor driving expression of genes involved in proliferation and dissemination and is therefore a key player in Theileria-induced leukocytes transformation. Ta9 possesses a signal peptide allowing it to be secreted into the infected leukocyte cytosol and be presented to CD8 T cells in the context of MHC class I. First, we confirmed that Ta9 is secreted into the infected leukocyte cytosol, and then we generated truncated versions of GFP-tagged Ta9 and tested their ability to activate AP-1 in non-infected HEK293T human kidney embryo cells. The ability to activate AP-1-driven transcription was found to reside in the C-terminal 100 amino acids of Ta9 distant to the N-terminally located epitopes recognised by CD8+ T cells. Secreted Ta9 has therefore, not only the ability to stimulate CD8+ T cells, but also the potential to activate AP-1-driven transcription and contribute to T. annulata-induced leukocyte transformation.
Subtyping of Cryptosporidiumparvum Obtained From Humans and Calves in Van, Turkey
(Iranian Scientific Society Medical Entomology, 2022) Ekici, Abdurrahman; Unlu, Ahmet Hakan; Aydemir, Selahattin; Barlik, Fethi; Yilmaz, Hasan
Background: We aimed to investigate the prevalence of Cryptosporidium species detected in humans and calves in the Van region of Turkey.Methods: A total of 150 patients, comprising 60 who were immunosuppressed, 50 who were immunosuppressed and had diarrhea, and 40 who had only diarrhea, were enrolled in this study in the Department of Medical Parasitology, Van Yuzuncu Yil University Faculty of Medicine, Turkey. Stool samples were taken from the rectums of a total of 50 calves that had 30 diarrhea and 20 that did not have diarrhea, from the stables and farms of 10 central villages of Van, Turkey. All samples were analyzed using modified acid-fast staining, immunochromatographic test, and PCR. Cryptosporidium positive samples were also subtyped.Results: Only C. parvum subtypes were detected in all positive samples. C. parvum was detected in 30 (20%) of the 150 human stool samples, while it was detected in 5 (10%) of the 50 samples from the calves. The GP60 gene region was amplified and sent for sequence analysis to identify the C. parvum subtypes.Conclusion: As a result, C. parvum is found to be an active species that caused cryptosporidiosis is in the Van region. IIdA24G1 subtype of C. parvum were found in both human and calf. Therefore, due to the zoonotic feature of the C. parvum IIdA24G1 subtype, it has been shown that the calves in the region are a significant risk for humans.
Trends in Naegleria Fowleri Global Research: a Bibliometric Analysis Study
(Elsevier, 2022) Ekici, Abdurrahman; Alkan, Sevil; Aydemir, Selahattin; Gurbuz, Esra; Unlu, Ahmet Hakan
Naegleria fowleri is one of the most dangerous protozoan agents. This article describes a bibliometric review of the literature on N. fowleri research indexed in WoS during a 51-year period. The VOSviewer visualization meth-odology was used to conduct a bibliometric study. The data included articles from the Web of Science database, nations, institutions, journals, keywords, co-authorship, co-citations, international collaborations, and citation rates. A total of 1106 articles were retrieved from the Web of Science database. The articles were cited 21,904 times in total (cited 12,138 times without self-citations). The average citation per article was 19.82. The Hirsch index was 63. The leading country according to the number of published articles was the United States of America (USA) (n = 447; 40.416%), followed by Mexico (n = 80; 7.233%), and Australia (n = 63; 5.696%). Other than these top three countries, the publications were from 74 countries globally. Especially after the 2000s, both the number of citations and the number of publications exhibited an increasing trend. The Virginia Common-wealth University (USA) (9.584%), Centers for Disease Control Prevention (USA) (8.770%), and Instituto Poli-tecnico Nacional Mexico (4.069%) were the leading affiliations. Most of the leading affiliations were from the USA and Mexico. In conclusion, a bibliometric evaluation of N. fowleri was performed for the first time. Authors affiliated with institutions in the USA and Mexico have led scientific production on PAM. Efforts should be made to help developing countries with the highest prevalence of N. fowleri to develop scientific research networks with the USA and/or Mexico in order to increase research with interdisciplinary teams.