Fatih Şaban Beriş

Aims: Aedes albopictus (Skuse, 1895) (Diptera: Culicidae) is a highly invasive vector responsible for the transmission of several arboviruses worldwide. This study aimed to evaluate the chemical composition, larvicidal activity, and oviposition deterrent effects of EOs extracted from Laurus nobilis L. (Lauraceae), Cupressus macrocarpa Hartw. (Cupressaceae), and Eucalyptus globulus Labill. (Myrtaceae) harvested from the Eastern Black Sea region of Türkiye against Ae. albopictus.Materials and Methods: Essential oils were obtained by hydrodistillation and their chemical constituents were identified using GC-MS. Larvicidal bioassays were conducted to determine the median lethal concentrations LC50, and oviposition preference was evaluated across multiple concentrations to calculate the Oviposition Deterrence Index (ODI).Results: GC-MS analysis revealed that the major constituents were p-cymene (%31.81) and eucalyptol (%15.88) for L. nobilis, sabinene (%27.25) and terpinen-4-ol (%25.01) for C. macrocarpa, and eucalyptol (%39.09) for E. globulus. In larvicidal assays, L. nobilis exhibited the highest toxicity with an LC50 of 53.19 ppm, followed by C. macrocarpa (58.42 ppm) and E. globulus (62.15 ppm). Furthermore, all EOs demonstrated exceptional oviposition deterrence at the highest surface concentration (1.2738 µL/cm²), with ODI values ranging from -0.95 to -1.00. While L. nobilis maintained consistent deterrence at lower doses, C. macrocarpa showed a biphasic response, acting as a slight attractant at 14.9 ppm before becoming a potent deterrent at higher concentrations.Discussion: Our findings suggest that EOs from the Eastern Black Sea flora, particularly L. nobilis, possess significant potential as eco-friendly larvicides and behavioral modifiers for the management of Ae. albopictus populations.

In this study, the cloning, expression, and biochemical characterization of GTP cyclohydrolase I, the first enzyme involved in phenylketonuria metabolism, from the thermophilic bacterium Anoxybacteroides amylolyticum was investigated. The gchI gene, identified by PCR from A. amylolyticum, is a single open reading frame encoding a total of 186 amino acids with a size of 555 bp. The expression of the enzyme, which catalyzes the conversion of GTP to dihydroneopterin triphosphate, was induced in E. coli BL21(DE3) cells using 1 mM IPTG cloned into pET28a(+). A Ni-NTA affinity column was used for purification of the enzyme. The characterization studies revealed that the enzyme's Vmax was 6.9x10-5 ± 2.3x10-4 μM/min/mg protein and its Km was 7.0 ± 1.4 mM. The enzyme showed the best activity at a temperature of 70°C and an optimal pH of 7.0. It was demonstrated that thermophilic A. amylolyticum GCHI could be used in the first step of the conversion of GTP under in vitro conditions as an alternative to the chemical synthesis of BH4, which is used in the treatment of phenylketonuria.

Understanding the host-feeding patterns of Culex pipiens is essential to elucidate its role in zoonotic transmission cycles. In this study, blood-fed Culex pipiens females were collected from 14 localities across the northeastern provinces of Türkiye between June and September 2022. A total of 42 blood-fed specimens were subjected to DNA extraction, and vertebrate host identification was performed through PCR amplification of the mitochondrial cytochrome c oxidase subunit I (COI) gene, followed by sequence analysis. The results revealed that Culex pipiens predominantly fed on avian hosts, particularly on both local and migratory bird species such as Fringilla coelebs, Turdus pilaris, Corvus corax, and Cyanistes caeruleus. Mammalian hosts were also detected, including Rattus norvegicus, Canis lupus, and Homo sapiens, suggesting opportunistic feeding behavior. Phylogenetic analysis of COI sequences confirmed accurate host identification and demonstrated clear clustering patterns among avian and mammalian taxa. This study provides the first molecular insights into the host preferences of Culex pipiens in northeastern Türkiye. The findings highlight the species’ predominant ornithophilic tendency while emphasizing its potential bridge-vector capacity between avian and mammalian hosts. Despite limitations due to the small number of blood-fed specimens and the narrow time window for DNA retrieval, this study contributes valuable regional data and supports future ecological and epidemiological assessments of vector–host interactions in Türkiye and beyond.

Aedes aegypti (Linnaeus 1762) is a significant public health concern in both its native and invaded regions because of the transmission of arboviruses. Target-site mutations in the voltage-gated sodium channel (vgsc) gene, commonly referred to as knockdown resistance (kdr), represent the most extensively studied mechanism underlying pyrethroid resistance. Therefore, we aimed to assess possible pyrethroid and organochlorine resistance levels, knockdown resistance, and mutation types known to contribute to the resistance profile in the Black Sea region of Türkiye in 2020. Bioassay results showed that all field populations, as well as the Bora Bora laboratory strain, were susceptible and predominantly carried wild-type genotypes. For kdr, all samples were wild type for the V410L, L982W, S989P, I1011V/M, L1014F, V1016I/G, and T1520I mutations. The mutant allele was detected in only one specimen in the Pazar population, where it was found in a homozygous state at position F1534C from ten specimens. Novel mutations in the vgsc gene region, with unknown implications for resistance, were determined at positions A1498T, R1599C, P1611L, and P1615S in the studied populations. Two different intron types were detected in the kdr gene (in domain 2) between nucleotide positions 3111 and 3228 and within an intron region (coded as type-1 and type-2). These findings indicate that, Ae. aegypti populations in the Eastern Black Sea region remain susceptible to pyrethroid and organochlorine insecticides. Genetic analyses indicate that these populations likely originated from Asia, with evidence of two distinct lineages. Notably, this study represents the first molecular and phenotypic assessment of insecticide resistance in Ae. aegypti populations conducted in Türkiye.

Genotype and cultivar identification is essential for conserving tea genetic diversity within plantation ecosystems and ensuring the sustainability of high-quality tea production. This study represents the first large-scale genetic characterization of 200 elite varietal candidate tea (Camellia sinensis) clones, which were pre-selected from 2,034 genotypes originating from the Eastern and Western Black Sea regions of Türkiye. Eight polymorphic simple sequence repeat (SSR) markers located near loci associated with catechin content, including epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC), and epigallocatechin gallate (EGCG), were employed. SSR profiles were generated for all 200 tea clones cultivated in control plots at the National Tea Gene Bank, and the resulting data were additionally used for DNA barcoding of 12 varietal candidate tea clones currently under registration. Among the evaluated markers, TM412 (EGC) exhibited the highest polymorphism information content (PIC = 0.8816), whereas TM376 (EC) showed the lowest (0.4321). Notably, TM412 (EGC) and TM399 (ECG) displayed high PIC values, indicating their strong discriminatory potential for Turkish tea genotypes. The findings indicate that Turkish tea germplasm possesses substantial genetic diversity, and some markers may be effectively utilized in variety registration and breeding efforts. This study presents the first comprehensive molecular characterization of tea genetic resources in Türkiye. It contributes to the long-term conservation of selected clones and supports the variety registration process through DNA barcoding and a QR code-based traceability system. The genetic dataset generated in this work contributed directly to the establishment of Türkiye’s first and the world’s fifth-largest tea gene pool in Rize Province, providing a valuable reference for strengthening tea genetic resource conservation and breeding programs at both national and global scales.

The establishment of tea gardens and tea production in Turkey began to spread after 1938 and became an important economic sector. The first tea gardens in Ordu province were established in 1960 in Perşembe district due to the expansion of the tea production area with a law enacted in 1951. Since this date, the production area and the number of producers began to develop rapidly. The tea production area in this district is between 250-800 m altitude, which is expressed as the middle and high region, and has a topographic area with variable slopes. Since the gardens established in Perşembe, as in other gardens in our country, are established with seeds, the plants differ from each other. This difference in the genetic structure of the plant is reflected in the product, namely the quality of the tea. Therefore, determining this difference is important. This study was conducted to determine the genetic diversity of the teas grown in Perşembe and the genetic relationship between intra-population and inter-cultivar. The plant materials used in the study were taken from different elevations and different gardens. 20 plant materials were collected to represent the study area. There are three standard varieties as control: Derepazarı7, Fener3 and Tuğlalı10. ISSR method was used in the study. Genetic diversity and related relationships were revealed in the study using 10 ISSR markers. According to the cluster analysis performed using UPGMA, significant differences were detected among individuals.

Objective: In our study, K. pneumoniae strains (non-susceptible to carbapenem) (n = 60) were obtained from various clinical samples from Rize State Hospital between 2015 and 2017 and it is aimed to identify antibiotic resistance genes and replicon typing. Methods: Antibiotic susceptibility tests of the strains were performed with Kirby-Bauer disk diffusion test and the Vitek-2 automated system (BioMerieux, France). Antibiotic resistance genes and replicon typing was characterized by PCR method. Results: It was determined that K. pneumaniae isolates were mostly isolated from the samples of the intensive care unit. All of the K. pneumoniae strains examined in this study were found to be ampicillin/sulbactam and ertapenem resistant but colistin susceptible. Amoxacillin/clavulonic acid resistance was detected at 98.14% of strains. The bla_OXA-48 gene was mostly detected in isolates. The most common type of plasmid was I1 and 3 different plasmid types were found in five different strains together. Conclusion: This study also shows that the distribution of NDM-1 and OXA-48 carbapenemases has increased since the first co-display in Türkiye and that IncHI1 is the first record in our country. This study provides an overview of the major plasmid families occurring in multiple antibiotic-resistant strains of K. pneumoniae. To our knowledge, this study represents the first report of IncHI1 record in Türkiye.

Bu çalışmanın amacı Acinetobacter baumannii ve Pseudomonas aeruginosa izolatlarının antibiyotik duyarlılık profilini araştırmak ve bu izolatlarda direnç genlerinin varlığını belirlemektir. Direnç genlerinin tespiti PCR yöntemi ile değerlendirildi. Acinetobacter baumannii izolatlarında imipenem ve meropenem direnci sırasıyla %93,2 ve %91 olduğu görüldü. P. aeruginosa izolatlarında imipenem direnç oranı %53,9 ve meropenem direnç oranı %38,5 olarak belirlendi. Pseudomonas aeruginosa izolatları arasında aranan genlerden bir izolatta sadece OXA-23 tespit edildi. Acinetobacter baumannii izolatlarından bir izolatta OXA-24, 40 izolatta OXA-23 saptandı. Bu çalışma, CRPA (Karbapenem dirençli Pseudomonas aeruginosa) ve CRAB (Karbapenem dirençli Acinetobacter baumannii) izolatlarında karbapenem direncinden OXA-23'ün sorumlu olduğunu göstermektedir.

Phenylketonuria (PKU) is a disease caused by phenylalanine hydroxylase enzyme deficiency in newborn infants and is the most important cause of treatable mental retardation. One of the causes of the disease comes from the defects of the PTPS in the metabolic pathway of phenilalanine metabolisms. Treatment of the disease is not feasible, and life-time tetrahydrobiopterin loading is performed in chronic patients. Today, tetrahydrobiopterin is chemically synthesized. Biological production is a different point of view due to the long duration of chemical synthesis, costs, and exposure to chemical pollutants. For this reason, the gch-I gene from the thermophilic A. flavithermus DSM 2641T was identified by PCR method. We cloned the gchI gene that was 603 bp and its open reading frame has 200 amino acids. The gene was cloned into pET28a(+) expression vector with 6xHis tags and transform in E. coli BL21(DE3)pLys host cells to express with 1 mM IPTG induction. After purification with Ni-NTA resin, we determined that GCH-I is 24 kDa, its optimum pH is 8.0 and temperature is 65C.Under optimal conditions, GCH-I exhibited enzymatic activity with Km- and Vmax- values of 243 ± 23,25 μM and 100,93 ± 3,5 nM/min/mg protein, respectively.

Bu çalışma ile Rize İlinde yayılım gösteren 8 Rubus taksonu morfolojik, mikromorfolojik ve moleküler sistematik yönden araştırıldı. Bitki materyalleri 2019 yılında yapılan arazi çalışmaları ile toplandı. Araştırma bölgesinden toplanan örnekler teşhis edildi ve herbaryum haline getirildi. Bu taksonların gövde, yaprak ve çiçek gibi bitki kısımları stereomikroskopta morfolojik, SEM’de ise mikromorfolojik olarak incelendi. Sonrasında örneklere ait ITS bölgeleri PCR ile çoğaltılarak dizi analizi yapıldı. Analiz sonucu 8 takson arasındaki benzerlik ilişkisini ortaya koyan filogenetik ağaç oluşturuldu. Mikromorfolojik görüntülere bakıldığında 8 takson arasında gövde, yaprak tüylenmesi, tüy tipleri ve diken yapısının ayırıcı özellikte olduğu tespit edildi. Morfolojik bulgular sonucunda 8 Rubus taksonunun yaprak, meyve, diken, petal, yaprak ve yaprakçık ölçüsü, meyve tanelerinin yapısı, sayısı ve şekli, yaprak alt ve üst yüzey, petal yüzeyi tüylenme durumu, meyve ve sepallerin rengi, yaprak kenarı yapısı bakımından birbirinden ayrıldığı, bu özelliklerin karakteristik olduğu belirlendi. Moleküler bulgular sonucu Rubus taksonlarının dizi analizi sonucunda ortalama baz uzunluğunun 709 ile 731 bp arasında değiştiği belirlendi. Oluşturulan filogenetik ağaç sonucunun Rosacea familyasına en yakın taksonun Rubus hirtus ve Rubus tereticaulis, en uzak takson ise Rubus sanctus olduğu belirlendi.