In the genome of SARS-CoV-2, the 5′-terminus encodes a polyprotein, which is further cleaved into 15 non-structural proteins whereas the 3′ terminus encodes four structural proteins and eight accessory proteins. Among these 27 proteins, the present study aimed to discover likely antigenic proteins and epitopes to be used for the development of a vaccine or serodiagnostic assay using an in silico approach. For this purpose, after the full genome analysis of SARS-CoV-2 Wuhan isolate and variant proteins that are detected frequently, surface proteins including spike, envelope, and membrane proteins as well as proteins with signal peptide were determined as probable vaccine candidates whereas the remaining were considered as possible antigens to be used during the development of serodiagnostic assays. According to results obtained, among 27 proteins, 26 of them were predicted as probable antigen. In 26 proteins, spike protein was selected as the best vaccine candidate because of having a signal peptide, negative GRAVY value, one transmembrane helix, moderate aliphatic index, a big molecular weight, a long-estimated half-life, beta wrap motifs as well as having stable, soluble and non-allergic features. In addition, orf7a, orf8, and nsp-10 proteins with signal peptide were considered as potential vaccine candidates. Nucleocapsid protein and a highly antigenic GGDGKMKD epitope were identified as ideal antigens to be used in the development of serodiagnostic assays. Moreover, considering MHC-I alleles, highly antigenic KLNDLCFTNV and ITLCFTLKRK epitopes can be used to develop an epitope-based peptide vaccine.

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Background The emergence of tick-borne disease is increasing because of the effects of the temperature rise driven by global warming. In Turkey, 19 pathogens transmitted by ticks to humans and animals have been reported. Based on this, this study aimed to investigate tick-borne pathogens including Hepatozoon spp., Theileria spp., Babesia spp., Anaplasma spp., Borrelia spp., and Bartonella spp. in tick samples (n = 110) collected from different hosts (dogs, cats, cattle, goats, sheep, and turtles) by molecular methods. Methods To meet this objective, ticks were identified morphologically at the genus level by microscopy; after DNA isolation, each tick sample was identified at the species level using the molecular method. Involved pathogens were then investigated by PCR method. Results Seven different tick species were identified including Rhipicephalus sanguineus, R. turanicus, R. bursa, Hyalomma marginatum, H. anatolicum, H. aegyptium, and Haemaphysalis erinacei. Among the analyzed ticks, Hepatozoon spp., Theileria spp., Babesia spp., and Anaplasma spp. were detected at rates of 6.36%, 16.3%, 1.81%, and 6.36%, respectively while Borrelia spp. and Bartonella spp. were not detected. Hepatozoon spp. was detected in R. sanguineus ticks while Theileria spp., Babesia spp., and Anaplasma spp. were detected in R. turanicus and H. marginatum. According to the results of sequence analyses applied for pathogen positive samples, Hepatozoon canis, Theileria ovis, Babesia caballi, and Anaplasma ovis were identified. Conclusion Theileria ovis and Anaplasma ovis were detected for the first time to our knowledge in H. marginatum and R. turanicus collected from Turkey, respectively. Also, B. caballi was detected for the first time to our knowledge in ticks in Turkey.

Background Bartonella spp. are vector-borne pathogens that cause zoonotic infections in humans. One of the most well-known of these is cat-scratch disease caused by Bartonella henselae and Bartonella clarridgeiae, with cats being the major reservoir for these two bacteria. Izmir, Turkey is home to many stray cats, but their potential role as a reservoir for the transmission of Bartonella to humans has not been investigated yet. Therefore, the aim of this study was to investigate the prevalence of Bartonella species and their genetic diversity in stray cats living in Izmir. Methods Molecular prevalence of Bartonella spp. in stray cats (n = 1012) was investigated using a PCR method targeting the 16S-23S internal transcribed spacer gene (ITS), species identification was performed by sequencing and genetic diversity was evaluated by haplotype analysis. Results Analysis of the DNA extracted from 1012 blood samples collected from stray cats revealed that 122 samples were Bartonella-positive, which is a molecular prevalence of 12.05% (122/1012; 95% confidence interval [CI] 10.1–14.2%). Among the Bartonella-positive specimens, 100 (100/122; 81.96%) were successfully sequenced, and B. henselae (45/100; 45%), B. clarridgeiae (29/100; 29%) and Bartonella koehlerae (26/100; 26%) were identified by BLAST and phylogenetic analyses. High genetic diversity was detected in B. clarridgeiae with 19 haplotypes, followed by B. henselae (14 haplotypes) and B. koehlerae (8 haplotypes). Conclusions This comprehensive study analyzing a large number of samples collected from stray cats showed that Bartonella species are an important source of infection to humans living in Izmir. In addition, high genetic diversity was detected within each Bartonella species.

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Background Discovery of new Toxoplasma gondii serotyping epitopes is important due to reports showing the influence of genotype on the severity of toxoplasmosis. In Turkey, genotypes belonging to type II, type III and Africa 1 lineages were mainly detected. The present study focused on to find out epitopes with high discriminative capacity to serotype these genotypes using well characterized strains isolated from Turkey. Methods To meet this objective, GRA6 and GRA7 genes were sequenced from strains belonging to the type II, III and Africa 1 lineages, and B cell epitopes inside these sequences were predicted by Bcepred and additional docking analysis was performed with B cell receptor. Based on these analyses, 22 peptides harboring lineage specific epitopes were synthesized. Then, the serotyping potency of these peptides was tested using peptide ELISA and well categorized serum samples collected from stray cats infected with genotypes of the different lineages type II (n:9), III (n:1) and Africa 1 (n:1). As a result of peptide-ELISA, a serotyping schema was constructed with peptides that show high discriminative capacity and this assay was validated by sera collected from humans after an outbreak (n:30) and mother/newborn pair sera (n:3). Later, the validated serotyping schema was used to serotype a larger group of human (n:38) and cat (n:24) sera. Results Among 22 peptides, GRA6II/c, GRA7III/d, and GRA6 Africa 1/b epitopes have shown discriminative capacity. During the validation of peptide-ELISA, the serotype of toxoplasmosis outbreak and mother/newborn cases were detected to be serotype II. Moreover, the analyses in a larger group showed that serotype II was prevalent in humans and stray cats. Conclusions Overall, the results showed that the serotyping schema could be successfully used to serotype T. gondii infections caused by type II, III and Africa 1 genotype.

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