Emrah Güler

Human parasites negatively impact health and reduce the quality of life worldwide. Therefore, preventing the spread of parasites and treating infections are essential for public health. Pinworm parasites are among the most common human parasites and directly affect sleep quality. It has a worldwide distribution and is the leading cause of helminthiasis in the United States, Western Europe, and Oceania. Enterobiasis, caused by pinworm parasites, significantly impairs sleep quality and restfulness, particularly in children. This study aimed to semantically segment pinworm parasite eggs in microscopic images using deep learning techniques. The proposed approach assists clinical experts by enabling more accurate and consistent detection of parasite eggs, thereby overcoming the limitations of visual inspection under a microscope. Improved identification supports timely treatment and enhances patients' overall well-being.We investigated a baseline U-Net model and several transfer-learning variants in which the encoder was replaced with pretrained convolutional networks, including VGG19, EfficientNetV2M, MobileNetV2, ResNet50V2, and DenseNet201. In addition, a stacked ensemble framework is proposed, in which the predictions of multiple base models are combined using a meta U-Net. The experimental results showed that DenseNet201+U-Net achieved the strongest standalone performance, with a Dice coefficient of 0.9135. Based on this, the proposed stacking ensemble further improves the segmentation accuracy. In particular, the ensemble combining DenseNet201, EfficientNetV2M, and MobileNetV2 with a U-Net meta-learner achieved the best overall performance, with a Dice coefficient of 0.9257. These findings confirm that the selective stacking of complementary architectures provides a robust and effective solution for pinworm-egg segmentation in microscopic images.

Currently, the treatment of Trichomonas vaginalis (T. vaginalis) typically involves the use of 5-nitroimidazoles (such as metronidazole and tinidazole). However, an increasing failure in treatment is observed due to resistance developed to these drugs. For this reason, alternative drugs have been investigated, especially by using natural products. In our study, the anti-T. vaginalis activity of the Origanum majorana essential oil (OMEO), which is a Cyprus endemic plant, and its synergistic effect with metronidazole were investigated. The essential oil was extracted through hydrodistillation of the dried flowering tops of the plant. Gas chromatography and mass spectrometry (GC-MS) analyses were performed using the Agilent 5975 GC-MSD system. L929 mouse fibroblast cell line was used to determine cytotoxic activity. Two clinical strains and one metronidazole-resistant T. vaginalis standard strain were used. LC50, and MLC (minimum lethal concentration) values of OMEO and metronidazole were determined by the broth microdilution method in vitro in aerobic and anaerobic conditions. The combination of OMEO with metronidazole was investigated against all strains by the checkerboard method. The major compounds in the OMEO content were determined as cis-sabinene hydrate (29.1%) and terpinen-4-ol (19.6%). In cytotoxic analyses, it was observed that the cell viability remained stable at low doses. OMEO is effective against all three T. vaginalis strains. There is a significant difference between the IC50 averages at the 24th and 48th hours (333.03 µg/mL and 226.43 µg/mL, respectively) in aerobic conditions (p=0.003). In addition, there is a statistically significant relationship between the results of the 24th and 48th hours (348.77 µg/mL and 238.80 µg/mL, respectively) in the anaerobic conditions (p=<0.0001). In general, OMEO has been shown to have a synergistic effect with metronidazole. In conclusion, we believe that OMEO is a potential natural agent that can be particularly used in the treatment of protozoan infections, including T. vaginalis.

Antileishmanial activity guided studies on the methanolic extract of the tubers of Cyclamen rohlfsianum Asch. resulted in the isolation and characterization of six saponins. All saponins were established as tri-, tetra-, and pentaglycosidic derivatives of 13β-28- epoxy-oleanane-type triterpenic sapogenols. Two of them were found to be newly described saponins, rohlfsianosides A and B. Their structures were identified as 3-O-β-{[β-Dxylopyranosyl-( 1→2)-β-D-lucopyranosyl-(1→4)]-[β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranosyl}- 13β,28-epoxy-16α-hydroxy-30-acetoxy-oleanane (rohlfsianoside A), and 3-O- β-{{[β-D-xylopyranosyl-(1→2)]-[β-D-glucopyranosyl-(1→4)]-[β-D-glucopyranosyl-(1→4) ]}-[β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranosyl}-protoprimulagenin A (rohlfsianoside B), respectively. Additionally, three known compounds, cyclamiretin A (3β,16α- dihydroxy-13β-28-epoxy-oleanan-30-al) glycosides; cyclaminorin, deglucocyclamin and cyclamen, and protoprimulagenin A (13β-28-epoxy-3β,16α-dihydroxy-oleanane) derivative, lysikoianoside I, were identified. The structure elucidation of the saponins was established by means of spectroscopic methods (1D and 2D NMR, HR-MS). All the saponins showed notable growth inhibitory activity against Leishmania ropica, with IC50 values ranging from 17.5 to 21.9/mL.

This study focused on synthesizing and characterizing novel thiosemicarbazide derivatives containing a 1,2,4-triazole moiety and evaluating their antimicrobial activity against several bacterial strains. The research aimed to identify key structural features that enhance antimicrobial efficacy through structure-activity relationship analysis and identify the minimum inhibitory concentration (MIC) of the most potent compounds to assess their potential for further development as antimicrobial agents. Nine novel thiosemicarbazide derivatives containing a 1,2,4-triazole moiety were synthesized by reacting 1,2,4-triazole derivatives with thiosemicarbazide precursors, and the products were characterized using infrared spectroscopy, proton nuclear magnetic resonance (¹H-NMR), carbon-13 nuclear magnetic resonance (¹³C-NMR) spectroscopy, and elemental analysis. The antimicrobial activity of these compounds (5a-i) was tested against Klebsiella pneumoniae (K. pneumoniae),Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, and Pseudomonas aeruginosa (P. aeruginosa), using microdilution, disk diffusion, and broth microdilution methods. Dimethyl sulfoxide was used as a negative control, and Vancomycin and Meropenem were used as positive controls, with all results converted to µM for consistent analysis. The synthesized thiosemicarbazide derivatives (5a-i) were confirmed to be structurally correct through Fourier-transform infrared spectroscopy, ¹H-NMR, and ¹³C-NMR spectroscopy. Among the tested compounds, 5e (4-bromophenyl) and 5g (n-propyl) showed significant antimicrobial activity, with 5g exhibiting the strongest effects against S. aureus and P. aeruginosa. Other derivatives, such as 5b (4-NO₂Ph), 5c (4-FPh), and 5d (4-ClPh), showed moderate activity, while no significant activity was observed against K. pneumoniae or E. faecalis. The study successfully synthesized a series of novel thiosemicarbazide derivatives with a 1,2,4-triazole moiety and evaluated their antimicrobial potential. Compounds 5e and 5g exhibited significant antibacterial activity, particularly against S. aureus and P. aeruginosa, with MIC values in the low micromolar range. These findings suggest that the compounds hold promise as potential antimicrobial agents, and further studies should focus on optimizing their efficacy and exploring their mechanism of action.

Layşmanyazis, tropikal ve subtropikal bölgelerde Leishmania türlerinin neden olduğu parazitik bir enfeksiyondur. Doğu Akdeniz havzasında yer alan Kıbrıs, layşmanyazis için endemik kabul edilmektedir. Bu çalışmada, Kuzey Kıbrıs Türk Cumhuriyeti'nde izole edilen iki Leishmania suşunun sekanslanarak kökenlerinin araştırılması ayrıca bu suşların farelerdeki klinik yansımaları incelenerek in vivo hayvan modellerinin oluşturulması amaçlanmıştır. Alnında lupoid lezyonu olan yedi yaşındaki bir kız hastadan biyopsi örneği alınmış ve yayma preparatlarında amastigotlar tespit edilmiştir. Örneğin zenginleştirilmiş NNN besiyerinde yapılan kültürü sonucu promastigotların saptanmasını takiben hastaya kutanöz layşmanyazis (KL) tanısı koyulmuştur (no: 504). Dört yaşında boxer cinsi bir bekçi köpeği, kilo kaybı, halsizlik, tüy dökülmesi ve lenfadenopati şikayetleriyle bir veteriner kliniğine götürülmüştür. Kanin layşmanyazis (KanL) semptomları bulunan köpekten kan örneği alınmıştır. Kan örneğinin zenginleştirilmiş NNN besiyerinde kültürü yapılmış ve promastigotların üremesiyle KanL teşhisi konulmuştur (no: 753). KL ve KanL olgularından elde edilen Leishmania promastigotları kriyoprezerve edilmiş ve Manisa Celal Bayar Üniversitesi, Tıbbi Parazitoloji Laboratuvarı Parazit Bankasında saklanmıştır. İzolatlar kullanılacakları zaman RPMI-1640 besiyerine aktarılmış, çalışma için gerekli olan 107 promastigot/mL konsantrasyonuna kadar çoğaltılmıştır. Üreyen izolatlardan, Leishmania'nın ITS-1 ve cpb E/F bölgelerine özgü primerler kullanılarak tür tayinleri yapılmıştır. Tür tanımlaması yapılan Kuzey Kıbrıs izolatlarının dizi analizlerinden elde edilen verilere göre bir filogenetik ağaç oluşturulmuştur. In vivo çalışmalar için Kuzey Kıbrıs Leishmania izolatlarına ek olarak, karşılaştırma yapılması amacıyla, Manisa'dan izole edilen birer tane Leishmania donovani (MLd) ve Leishmania tropica (MLt) izolatı çalışmaya dahil edilmiştir. Her grupta beş adet Mus musculus (Balb/c) fare olacak şekilde sekiz çalışma grubu ve iki kontrol grubu (enfekte olmamış) (toplam 10 grup ve 50 Balb/c fare) oluşturulmuştur. KL hayvan modeli için MLt, 753, MLd ve 504 suşlarıyla ayrı ayrı dört fare çalışma grubu kullanılmıştır. Diğer dört fare grubu ise aynı suşlarla VL hayvan modeli için ayrılmıştır. Ayrıca, KL ve VL modelleri için birer grup negatif kontrol grubu olarak belirlenmiştir. KL gruplarındaki fareler, hazırlanan promastigot süspansiyonundan 100 µL ile sağ ayak tabanına intradermal yolla enfekte edilmiş ve farelerin ayak tabanı genişliği ve yüksekliği altı hafta boyunca her hafta olacak şekilde ölçülmüştür. VL gruplarındaki farelere ise 100 µL promastigot süspansiyonu intraperitoneal yolla peritondan verilmiş ve farelerdeki VL semptomları takip edilmiştir. Enjeksiyondan 30 gün sonra otopsi yapılarak dalak ve karaciğerleri çıkartılıp boyutları ölçülmüştür. Çalışmada, moleküler olarak karakterize edilen iki Leishmania izolatından biri L.donovani (insan suşu, no: 504), diğeri ise L.tropica (köpek suşu, no: 753) idi. KL ve VL gruplarında bulunan farelerde sırasıyla KL ve VL semptomlarının geliştiği ve hem Manisa hem de Kuzey Kıbrıs izolatlarının hayvan modellerindeki yansımalarının benzer olduğu tepit edilmiştir. Literatürde, Kuzey Kıbrıs'taki KanL olgularına Leishmania infantum'un neden olduğu belirtilmektedir. Fakat çalışmadan elde edilen veriler doğrultusunda, farklı olarak, L.tropica'nın da adadaki KanL enfeksiyonlarının kaynağı olabileceği düşünülmektedir. Ayrıca, Kuzey Kıbrıs izolatlarının, farelerde hem KL hem de VL enfeksiyonlarına neden olduğu görülmüş ve ileride yapılacak olan in vivo çalışmalarda kullanılabileceği kanısına varılmıştır.

(1) Background: Helminth infections are a widespread global health concern, with Ascaris and taeniasis representing two of the most prevalent infestations. Traditional diagnostic methods, such as egg-based microscopy, are fraught with challenges, including subjectivity and low throughput, often leading to misdiagnosis. This study evaluates the efficacy of advanced deep learning models in accurately classifying Ascaris lumbricoides and Taenia saginata eggs from microscopic images, proposing a technologically enhanced approach for diagnostics in clinical settings. (2) Methods: Three state-of-the-art deep learning models, ConvNeXt Tiny, EfficientNet V2 S, and MobileNet V3 S, are considered. A diverse dataset comprising images of Ascaris, Taenia, and uninfected eggs was utilized for training and validating these models by performing multiclass experiments. (3) Results: All models demonstrated high classificatory accuracy, with ConvNeXt Tiny achieving an F1-score of 98.6%, followed by EfficientNet V2 S at 97.5% and MobileNet V3 S at 98.2% in the experiments. These results prove the potential of deep learning in streamlining and improving the diagnostic process for helminthic infections. The application of deep learning models such as ConvNeXt Tiny, EfficientNet V2 S, and MobileNet V3 S shows promise for efficient and accurate helminth egg classification, potentially significantly enhancing the diagnostic workflow. (4) Conclusion: The study demonstrates the feasibility of leveraging advanced computational techniques in parasitology and points towards a future where rapid, objective, and reliable diagnostics are standard.

Background: Infection caused by the hepatitis delta virus (HDV), a defective virus, is among the important viral infections. This virus can only cause infection in the presence of the hepatitis B virus (HBV). Determining the prevalence of HDV in the general population, including risk groups, and estimating the relative contribution of HDV to liver disease development is critical to guide clinical care and strategies. Objectives: The aim of this study was to determine the seroprevalence of HDV in HBsAg (hepatitis B surface antigen)-positive patients diagnosed in a university hospital in Northern Cyprus. Methods: Four hundred serum samples with only HBsAg positivity from patients admitted to our hospital between 2016 and 2022 were analyzed in our study. Samples were removed from -80°C retrospectively, and HDV-Ag and HDV-Ab tests were performed by the manual enzyme-linked immunosorbent assay (ELISA) method following the manufacturer's recommendations. Hepatitis delta virus RNA levels in HDV-Ag and/or HDV-Ab positive serum samples were quantitated by the in-house real-time polymerase chain reaction (RT-PCR) method. Results: The HDV-Ab positivity rate was determined to be 1.3% (5/400). All patients were negative for HDV-Ag, and HDV RNA was not detected in any of the HDV-Ab positive patients. Conclusions: Based on the data obtained from our study, it was concluded that HDV seropositivity in HBsAg-positive patients is low in our country.

Background: The inappropriate use of antibiotics may cause antibiotic resistance, cause side effects, and eventually cause an increase in healthcare costs. This study aimed to determine a flow cytometry-based test to detect ESBL E. coli and MDR p. aeruginosa in a short time. Methods: The study included 25 E.coli isolates and 25 P.aeruginosa isolates identified by Phoenix TM 100 automated system [Becton Dickinson, USA]. In the flow cytometric method, the percentages of death cells exposed to cephalosporin including ceftazidime [CAZ] or cefotaxime [CTX] and clavulanic acid [CLA] combination, were compared with death cells exposed only to a cephalosporin [CAZ or CTX]. CLA index values [CAZ-CLA and CTX-CLA indices] were obtained for CTX and CAZ. Index values that were higher than 1.5 just for one cephalosporin were accepted as positive. Results: Cell viability was performed after 1-hour exposure to the drugs. When PI staining was applied to ESBL-treated and MDR-treated bacteria, 65% and 85% had nonviable membranes, indicating the method efficiently identified only cells with damaged membranes. Conclusion: Flow cytometry is a rapid and reliable method for the detection of ESBL and MDR in clinical microbiology laboratories Keywords: Antibiotic resistance; ESBL; flow cytometry; MDR.

Background: Tularemia is a zoonotic disease (reservoir is usually rodents) caused by Francisella tularensis, especially seen in the northern hemisphere. Hunters are in the risk group for this disease. In this study, it was aimed to determine the seroprevalence of tularemia among hunters and determine the risk factors of tularemia in our country. Methods: The Turkish Republic of Northern Cyprus (TRNC) is divided into four regions (Nicosia, Kyrenia, Famagu­sta/Trikomo, and Morphou/Lefka) and 100 volunteer hunters randomly selected from these regions were included in our study. Tube agglutination test (TAT) and F. tularensis IgG and IgM (ELISA method) were applied in all sera. All hunt­ers were filled with a pre-prepared questionnaire to determine risk factors for tularemia. Results: TAT positivity was found in 11%. While F. tularensis ELISA IgG positivity was 17%, IgM positivity was not found in any hunters. Hunters with positive F. tularensis ELISA IgG test (17%) were accepted as seropositive in terms of tularemia. There was no statistically significant difference between the mean age of IgG-positive and negative hunt­ers (p= 0.915). Of the 86 hunters who kept at least one hunting dog in their garden, 15 (17.4%) were IgG-positive. There was no significant relationship between feeding hunting dogs and tularemia (p= 0.561). Conclusion: Our study showed that the seroprevalence of tularemia was high (17%) among hunters, who are consid­ered a risk group, in our country. We think that more epidemiological research should be done on tularemia infection and it should not be overlooked in the clinic.

The distribution of human immunodeficiency virus-1 (HIV-1) subtypes indicates difference from region to region and in risk groups acquiring the disease worldwide. Although subtype C is more in terms of total cases, subtype B is dominant in certain regions, especially in Western and Central Europe. Molecular epidemiological studies are essential for the control, effective treatment, and understanding in transmission routes of HIV-1 infection. This study aims to determine the molecular epidemiology and antiretroviral drug resistance profiles of HIV-1 in Northern Cyprus. The study involved 71 naive HIV-positive patients diagnosed in Northern Cyprus between 2016-2022. HIV-1 subtypes and CRFs were identified by phylogenetic analysis (Neighbor-Joining method) of pol gene sequences. Drug resistance mutations were analyzed using the WHO lists of mutations for surveillance. The Stanford University HIVdb program was used to interpret drug resistance mutations. In our study, 40 of 71 samples were successfully sequenced. The subtype B of HIV-1 was dominant with a rate of 52.5%, followed by CRF02_AG (20%) and G (7.5%) subtypes. The rate of subtype B (71.4%) in Northern Cyprus was significantly higher than in the other country of origin (p=0.028). Antiretroviral drug resistance was found in 15% of the sequenced serum samples. NRTI, NNRTI, and PI resistance rates were 10% (4/40), 7.5% (3/40), and 2.5% (1/40), respectively. According to the results, it is noteworthy that the dominant subtype circulating in Northern Cyprus is the B subtype, and CRFs were detected at a higher rate than expected.