Browsing by Author "Özalp, Veli Cengiz"

Now showing 1 - 20 of 28

Citation Count: 6
Antibiotic administration in targeted nanoparticles protects the faecal microbiota of mice
(Royal Soc Chemistry, 2021) Borsa, Baris A.; Sudagidan, Mert; Aldag, Mehmet E.; Baris, Isik I.; Acar, Elif E.; Acuner, Cagatay; Ozalp, Veli C.; Basic Sciences
Antibiotic therapy comes with disturbances on human microbiota, resulting in changes of bacterial communities and thus leading to well-established health problems. In this study, we demonstrated that targeted teicoplanin administration maintains the faecal microbiota composition undisturbed in a mouse model while reaching therapeutic improvements for S. aureus infection.
Citation Count: 0
Aptamer decorated PDA@magnetic silica microparticles for bacteria purification
(Springer Wien, 2024) Kavruk, Murat; Babaie, Zahra; Kibar, Gunes; Cetin, Barbaros; Yesilkaya, Hasan; Amrani, Yassine; Ozalp, V. Cengiz; Basic Sciences; Nutrition and Dietetics
One significant constraint in the advancement of biosensors is the signal-to-noise ratio, which is adversely affected by the presence of interfering factors such as blood in the sample matrix. In the present investigation, a specific aptamer binding was chosen for its affinity, while exhibiting no binding affinity towards non-target bacterial cells. This selective binding property was leveraged to facilitate the production of magnetic microparticles decorated with aptamers. A novel assay was developed to effectively isolate S. pneumoniae from PBS or directly from blood samples using an aptamer with an affinity constant of 72.8 nM. The capture experiments demonstrated efficiencies up to 87% and 66% are achievable for isolating spiked S. pneumoniae in 1 mL PBS and blood samples, respectively.
Citation Count: 0
Aptamer-based magnetic isolation and specific detection system for Listeria monocytogenes from food samples
(Elsevier, 2024) Bayramoglu, Gulay; Ozalp, Veli Cengiz; Arica, Mehmet Yakup; Basic Sciences
In this work, an aptamer-based magnetic system was designed for specific and rapid detection of Listeria monocytogenes in food samples. To prepare the selective magnetic system against the target bacterium, firstly, magnetic particles (Fe3O4) were coated with two hydrophilic polymer layers. The specific aptamer immobilized magnetic system efficiently captured L. monocytogenes cells in a competitive response time of approximately 10 min. The magnetic aptamer detection system was very specific to L. monocytogenes and had high selective, up to 97.6 % compared to the Listeria species (Listeria ivanovii, Listeria innocua, and Listeria seeligeri) and other bacteria species Escherichia coli, Staphylococcus aureus, and Basillus subtilus. The isolation and detection of L. monocytogenes from food samples using the presented method are fast and reliable. Moreover, another significant factor to be contemplated is the use of a few chemicals for detection, reducing the cost of analysis, and the results can be obtained within 18 h.
Citation Count: 2
Bacterial and fungal microbiota of mould-ripened cheese produced in Konya
(Wiley, 2023) Yurt, Mediha Nur Zafer; Omeroglu, Esra Ersoy; Tasbasi, Behiye Busra; Acar, Elif Esma; Altunbas, Osman; Ozalp, Veli Cengiz; Sudagidan, Mert; Basic Sciences
Bacterial and fungal diversities of 24 mould-ripened cheeses originating from Konya-Turkiye were examined by metagenomic analysis. Firmicutes phylum, Enterococcus, Clostridium sensu stricto and Lactobacillus (Levilactobacillus) genera were the dominant bacteria. Ascomycota phylum and Penicillium and Pichia genera and Penicillium roqueforti and Pichia membranifaciens species were dominant fungi. Enterococcus faecium (n = 30) and Enterococcus faecalis (n = 6) were identified, and all strains were susceptible to penicillin, ampicillin, vancomycin, teicoplanin, chloramphenicol and linezolid. The highest resistance (n = 14) was against rifampin. Tetracycline resistance was determined in two strains. Biofilm-forming ability was found in nine E. faecium and 1 E. faecalis. E. faecium strains revealed 40-88.9%, and E. faecalis showed 59.2-100% homology by pulsed field gel electrophoresis.
Citation Count: 3
Bacterial Skin Microbiota of Seabass from Aegean Fish Farms and Antibiotic Susceptibility of Psychrotrophic Pseudomonas
(Mdpi, 2023) Aydin, Ali; Sudagidan, Mert; Mamatova, Zhanylbubu; Yurt, Mediha Nur Zafer; Ozalp, Veli Cengiz; Zornu, Jacob; Brun, Edgar; Basic Sciences
Farming seabass (Dicentrarchus labrax) is an essential activity in the Mediterranean basin including the Aegean Sea. The main seabass producer is Turkey accounting for 155,151 tons of production in 2021. In this study, skin swabs of seabass farmed in the Aegean Sea were analysed with regard to the isolation and identification of Pseudomonas. Bacterial microbiota of skin samples (n = 96) from 12 fish farms were investigated using next-generation sequencing (NGS) and metabarcoding analysis. The results demonstrated that Proteobacteria was the dominant bacterial phylum in all samples. At the species level, Pseudomonas lundensis was identified in all samples. Pseudomonas, Shewanella, and Flavobacterium were identified using conventional methods and a total of 46 viable (48% of all NGS+) Pseudomonas were isolated in seabass swab samples. Additionally, antibiotic susceptibility was determined according to standards of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and Clinical and Laboratory Standards Institute (CLSI) in psychrotrophic Pseudomonas. Pseudomonas strains were tested for susceptibility to 11 antibiotics (piperacillin-tazobactam, gentamicin, tobramycin, amikacin, doripenem, meropenem, imipenem, levofloxacin, ciprofloxacin, norfloxacin, and tetracycline) from five different groups of antibiotics (penicillins, aminoglycosides, carbapenems, fluoroquinolones, and tetracyclines). The antibiotics chosen were not specifically linked to usage by the aquaculture industry. According to the EUCAST and CLSI, three and two Pseudomonas strains were found to be resistant to doripenem and imipenem (E-test), respectively. All strains were susceptible to piperacillin-tazobactam, amikacin, levofloxacin, and tetracycline. Our data provide insight into different bacteria that are prevalent in the skin microbiota of seabass sampled from the Aegean Sea in Turkey, and into the antibiotic resistance of psychrotrophic Pseudomonas spp.
Citation Count: 12
Bacterial surface, biofilm and virulence properties of Listeriamonocytogenes strains isolated from smoked salmon and fish food contact surfaces
(Elsevier, 2021) Sudagidan, Mert; Ozalp, Veli Cengiz; Ozturk, Orhan; Yurt, Mediha Nur Zafer; Yavuz, Orhan; Tasbasi, Behiye Busra; Aydin, Ali; Basic Sciences
Biofilm formation is one of the defense mechanisms of bacteria against disinfectants and antimicrobials. The aim of this study was to determine biofilm-forming L.monocytogenes from fish processing and salmon surfaces. Biofilm formation at 15, 25, 37, and 40 degrees C from 1 to 6-days period, adhesion to glass, polypropylene and stainless-steel surfaces, bacterial surface charge and hydrophobicity was determined. Adhesion behavior of the strains was evaluated using Surface Plasmon Resonance (SPR) technique. Totally 32 L.monocytogenes strains belonging to serogroups IIa (n:17), IIc(n:14) and IVb(n:1) were detected from 1320 swabs and 16 smoked salmons. Biofilm formation tests revealed that 21 strains form biofilm on microplate by increasing time and temperature. Although all strains strongly formed biofilm on glass surfaces, two strains slightly adhered polypropylene surfaces. High surface roughness of stainless-steel FeCrNi alloy (Ra = 4.15 nm) and CoCrMo alloy (Ra = 10.75 nm) increased biofilm formation of L.monocytogenes on stainless-steel surfaces. Zeta potential results showed that non-biofilm formers were more negatively charged after 6-days and hydrophobicity couldn't give a distinct distribution among biofilm formers and non-formers. SPR analysis method was evaluated to distinguish biofilm formers to adhere SPR gold chip surfaces. PCR results revealed that all strains were positive for hylA, iap, actA, plcA, plcB, fri, flaA, inlA, inlB, inlC, inlJ, and lmo1386 genes. Additionally, all strains were susceptible to penicillin, ampicillin, meropenem, erythromycin and trimethoprim-sulfamethoxazole. Biofilm-forming, virulence properties of L. monocytogenes strains isolated from fish processing surfaces and smoked salmons were evaluated and SPR was used to differentiate biofilm formers as a sensitive technique for biofilm studies.
Citation Count: 1
Biosensor for ATP detection via aptamer-modified PDA@POSS nanoparticles synthesized in a microfluidic reactor
(Springer Wien, 2024) Kibar, Gunes; Sahinoglu, O. Berkay; Kilincli, Betul; Erdem, E. Yegan; Cetin, Barbaros; Ozalp, V. Cengiz; Basic Sciences
This study introduces aptamer-functionalized polyhedral oligomeric silsesquioxane (POSS) nanoparticles for adenosine triphosphate (ATP) detection where the POSS nanoparticles were synthesized in a one-step, continuous flow microfluidic reactor utilizing thermal polymerization. A microemulsion containing POSS monomers was generated in the microfluidic reactor which was designed to prevent clogging by using a continuous oil flow around the emulsion during thermal polymerization. Surfaces of POSS nanoparticles were biomimetically modified by polydopamine. The aptamer sequence for ATP was successfully attached to POSS nanoparticles. The aptamer-modified POSS nanoparticles were tested for affinity-based biosensor applications using ATP as a model molecule. The nanoparticles were able to capture ATP molecules successfully with an affinity constant of 46.5 mu\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upmu $$\end{document}M. Based on this result, it was shown, for the first time, that microfluidic synthesis of POSS nanoparticles can be utilized in designing aptamer-functionalized nanosystems for biosensor applications. The integration of POSS in biosensing technologies not only exemplifies the versatility and efficacy of these nanoparticles but also marks a significant contribution to the field of biorecognition and sample preparation.
Citation Count: 6
Detection of viruses by probe-gated silica nanoparticles directly from swab samples
(Elsevier, 2022) Tuna, Bilge Guvenc; Durdabak, Dilara Buse; Ercan, Meltem Kazak; Dogan, Soner; Kavruk, Murat; Dursun, Ali Dogan; Ozalp, Veli Cengiz; Basic Sciences; Nutrition and Dietetics
Viral infection has been one of the major health issues for human life. The real-time reverse transcription polymerase chain reaction (RT-PCR)-based detection has primarily been used for virus detection as a highly reliable procedure. However, it is a relatively long and multi-stage process. In addition, required skilled personnel and complex instrumentation presents difficulties in large scale monitoring efforts. Therefore, we report here a direct and fast detection method for CoV-2 genome as applied in the nose-throat swab samples without any further processing. The detection principle is based on fluorescein-loaded mesoporous silica nanoparticles capped by specific gene sequences probes immobilized on the surface of the nanoparticles. Upon hybridization with the target viral genome, the fluorescein molecules were released from the mesopores. Testing with synthetic oligonucleotides, the NSP12 gene-based detection resulted in a strong signal. Target detection time could be optimized to 15 min and the limit of detection was 1.4 RFU with 84% sensitivity with clinical samples (n = 43).
Citation Count: 16
Development of electrochemical aptasensors detecting phosphate ions on TMB substrate with epoxy-based mesoporous silica nanoparticles
(Pergamon-elsevier Science Ltd, 2022) Altuner, Elif Esra; Ozalp, Veli Cengiz; Yilmaz, M. Deniz; Sudagidan, Mert; Aygun, Aysenur; Acar, Elif Esma; Sen, Fatih; Basic Sciences
This study, it is aimed to develop an electrochemical aptasensor that can detect phosphate ions using 3.3 & PRIME;5.5 & PRIME; tetramethylbenzidine (TMB). It is based on the principle of converting the binding affinity of the target molecule phosphate ion (PO43-) into an electrochemical signal with specific aptamer sequences for the aptasensor to be developed. The aptamer structure served as a gate for the TMB to be released and was used to trap the TMB molecule in mesoporous silica nanoparticles (MSNPs). The samples for this study were characterized by transmission electron spectroscopy (TEM), Brunner-Emmet-Teller, dynamic light scattering & electrophoretic light scattering, and induction coupled plasma atomic emission spectroscopy. According to TEM analysis, MSNPs have a morphologically hexagonal structure and an average size of 208 nm. In this study, palladium-carbon nano particles (Pd/C NPs) with catalytic reaction were used as an alternative to the biologically used horseradish peroxidase (HRP) enzyme for the release of TMB in the presence of phosphate ions. The limit of detection (LOD) was calculated as 0.983 mu M, the limit of determination (LOQ) was calculated as 3.276 mu M, and the dynamic linear phosphate range was found to be 50-1000 mu M. The most important advantage of this bio-based aptasensor assembly is that it does not contain molecules such as a protein that cannot be stored for a long time at room temperature, so its shelf life is very long compared to similar systems developed with antibodies. The proposed sensor shows good recovery in phosphate ion detection and is considered to have great potential among electrochemical sensors.
Citation Count: 0
Direct Detection of Viral Infections from Swab Samples by Probe-Gated Silica Nanoparticle-Based Lateral Flow Assay
(Wiley-v C H verlag Gmbh, 2024) Durdabak, Dilara Buse; Dogan, Soner; Tekol, Serap Demir; Celik, Caner; Ozalp, Veli Cengiz; Tuna, Bilge Guvenc; Basic Sciences
Point-of-care diagnosis is crucial to control the spreading of viral infections. Here, universal-modifiable probe-gated silica nanoparticles (SNPs) based lateral flow assay (LFA) is developed in the interest of the rapid and early detection of viral infections. The most superior advantage of the rapid assay is its utility in detecting various sides of the virus directly from the human swab samples and its adaptability to detect various types of viruses. For this purpose, a high concentration of fluorescein and rhodamine B as a reporting material was loaded into SNPs with excellent loading capacity and measured using standard curve, 4.19 mu mol & sdot; g-1 and 1.23 mu mol & sdot; g-1, respectively. As a model organism, severe acute respiratory syndrome coronavirus-2 (CoV-2) infections were selected by targeting its nonstructural (NSP9, NSP12) and envelope (E) genes as target sites of the virus. We showed that NSP12-gated SNPs-based LFA significantly outperformed detection of viral infection in 15 minutes from 0.73 pg & sdot; mL-1 synthetic viral solution and with a dilution of 1 : 103 of unprocessed human samples with an increasing test line intensity compared to steady state (n=12). Compared to the RT-qPCR method, the sensitivity, specificity, and accuracy of NSP12-gated SNPs were calculated as 100 %, 83 %, and 92 %, respectively. Finally, this modifiable nanoparticle system is a high-performance sensing technique that could take advantage of upcoming point-of-care testing markets for viral infection detections. Here, universal-modifiable probe-gated silica nanoparticles (SNPs) based lateral flow assay (LFA) is developed in the interest of the rapid and early detection of viral infections. The most superior advantage of the rapid assay is its utility in detecting various sides of the virus directly from the human swab samples and its adaptability to detect various types of viruses. The NSP12, NSP9, and E gene targets of CoV-2 were used as detection targets.image
Citation Count: 0
The Effects of Paddy Cultivation and Microbiota Members on Arsenic Accumulation in Rice Grain
(Mdpi, 2023) Ersoy Omeroglu, Esra; Bayer, Asli; Sudagidan, Mert; Ozalp, Veli Cengiz; Yasa, Ihsan; Basic Sciences
Access to safe food is one of the most important issues. In this context, rice plays a prominent role. Because high levels of arsenic in rice grain are a potential concern for human health, in this study, we determined the amounts of arsenic in water and soil used in the rice development stage, changes in the arsC and mcrA genes using qRT-PCR, and the abundance and diversity (with metabarcoding) of the dominant microbiota. When the rice grain and husk samples were evaluated in terms of arsenic accumulation, the highest values (1.62 ppm) were obtained from areas where groundwater was used as irrigation water, whereas the lowest values (0.21 ppm) occurred in samples from the stream. It was observed that the abundance of the Comamonadaceae family and Limnohabitans genus members was at the highest level in groundwater during grain formation. As rice development progressed, arsenic accumulated in the roots, shoots, and rice grain. Although the highest arsC values were reached in the field where groundwater was used, methane production increased in areas where surface water sources were used. In order to provide arsenic-free rice consumption, the preferred soil, water source, microbiota members, rice type, and anthropogenic inputs for use on agricultural land should be evaluated rigorously.
Citation Count: 0
Enhanced SELEX Platforms for Aptamer Selection with Improved Characteristics: A Review
(Springernature, 2024) Didarian, Reza; Ozbek, Hatice K.; Ozalp, Veli C.; Erel, Ozcan; Yildirim-Tirgil, Nimet; Basic Sciences
This review delves into the advancements in molecular recognition through enhanced SELEX (Systematic Evolution of Ligands by Exponential Enrichment) platforms and post-aptamer modifications. Aptamers, with their superior specificity and affinity compared to antibodies, are central to this discussion. Despite the advantages of the SELEX process-encompassing stages like ssDNA library preparation, incubation, separation, and PCR amplification-it faces challenges, such as nuclease susceptibility. To address these issues and propel aptamer technology forward, we examine next-generation SELEX platforms, including microfluidic-based SELEX, capillary electrophoresis SELEX, cell-based aptamer selection, counter-SELEX, in vivo SELEX, and high-throughput sequencing SELEX, highlighting their respective merits and innovations. Furthermore, this article underscores the significance of post-aptamer modifications, particularly chemical strategies that enhance aptamer stability, reduce renal filtration, and expand their target range, thereby broadening their utility in diagnostics, therapeutics, and nanotechnology. By synthesizing these advanced SELEX platforms and modifications, this review illuminates the dynamic progress in aptamer research and outlines the ongoing efforts to surmount existing challenges and enhance their clinical applicability, charting a path for future breakthroughs in this evolving field.
Citation Count: 0
Enhancement of Paclitaxel Therapeutic Effect by Aptamer Targeted Delivery in PLGA Nanoparticles
(2021) Dursun, Ali; Ucak, Samet; Poyraz, Fatma Sayan; Yilmaz, Elif; Mansuroglu, Banu; Ozalp, Veli Cengiz; Basic Sciences
Objectives: Paclitaxel is a drug molecule used in the therapy of various cancer types, including breast cancer. It is one of the preferred chemotherapy agent due to its high efficacy. However, many side effects have been observed associ- ated with paclitaxel use such as allergy, hair loss, diarrhea and pain. Methods: We evaluated therapeutic efficacy of paclitaxel when it is actively targeted to breast cancer tumours inside a polymeric nanoparticle. Targeted delivery of paclitaxel to tumour sites has been reported as an improved cytotoxicity strategy with a variety of nanoparticles. In this study, poly Lactic-co-Glycolic Acid (PLGA) nanoparticles were used as drug carrier and nucleolin aptamers as affinity targeting agents. Results: Paclitaxel molecules were entrapped during the synthesis of PLGA nanoparticles of 238 nm in diameter. The encapsulation and loading efficiencies of paclitaxel was 97% and 21% respectively. The paclitaxel loaded PLGA nanoparticles were functionalized with nucleolin aptamers and their targeting ability to cultured mouse cancer cells was determined for two cell lines (E0771 and 4T1). E0771 cell line was chosen for the preparation of allograph breast cancer mouse models. Evaluations of the targeted paclitaxel in PLGA nanoparticles showed 38% better performance in inhibiting tumour growth compared to free paclitaxel treatment groups of mouse models. Conclusion: The chemotherapeutic effect of cancer drugs like paclitaxel can be increased by loading inside tumour targeted polymeric nanoparticles
Fluorescent and electrochemical detection of nuclease activity associated with Streptococcus pneumoniae using specific oligonucleotide probes
(Analyst, 2024) Goikoetxea, Garazi; Akhtar, Khadija-tul Kubra; Prysiazhniuk, Alona; Borsa, Barış A.; Aldağ, Mehmet Ersoy; Kavruk, Murat; Özalp, Veli Cengiz; Hernandez, Frank J.; Basic Sciences; Nutrition and Dietetics
Streptococcus pneumoniae (S. pneumoniae) represents a significant pathogenic threat, often responsible for community-acquired pneumonia with potentially life-threatening consequences if left untreated. This underscores the pressing clinical need for rapid and accurate detection of this harmful bacteria. In this study, we report the screening and discovery of a novel biomarker for S. pneumoniae detection. We used S. pneumoniae nucleases as biomarker and we have identified a specific oligonucleotide that works as substrate. This biomarker relies on a specific nuclease activity found on the bacterial membrane, forming the basis for the development of both fluorescence and electrochemical biosensors. We observed an exceptionally high sensitivity in the performance of the electrochemical biosensor, detecting as low as 102 CFU mL−1, whereas the fluorescence sensor demonstrated comparatively lower efficiency, with a detection limit of 106 CFU mL−1. Moreover, the specificity studies have demonstrated the biosensors’ remarkable capacity to identify S. pneumoniae from other pathogenic bacteria. Significantly, both biosensors have demonstrated the ability to identify S. pneumoniae cultured from clinical samples, providing compelling evidence of the potential clinical utility of this innovative detection system.
Citation Count: 15
High-efficiency application of CTS-Co NPs mimicking peroxidase enzyme on TMB(ox)
(Pergamon-elsevier Science Ltd, 2022) Altuner, Elif Esra; Ozalp, Veli Cengiz; Yilmaz, M. Deniz; Bekmezci, Muhammed; Sen, Fatih; Basic Sciences
In this study, analytical studies of Chitosan-Cobalt(II) (CTS-Co(II)) nanoparticles (CTS - Co NPs) by mimicking horseradish peroxidase (HRP) were evaluated. In the applications, it was observed that CTS-Co NPs 3,3 ' 5,5 ' tetramethylbenzidine (TMB) oxidized in the presence of hydrogen peroxide (H2O2). The required CTS-Co NPs were synthesized at 50 degrees C in 30 min and characterized using Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), inductively coupled plasma-optical emission spectroscopy (ICP-OES), and Xray photon spectroscopy (XPS) was done. CTS-Co NPs were studied to develop a selective TMB biosensor on TMB (ox) substrate. The synthesized CTS-Co NPs formed a catalytic reaction with 30% 0.2 mM H2O2 on 0.2 M TMB substrate. After the catalytic reaction, sensitive signals were obtained from the desired biosensor. Electrochemical measurements were taken as low limit of 10 mg and a high limit of 20 mg for the determination of CTSCo NPs to TMB(ox). In the microplate study; The sensors were applied on 1.5 mu g and 3 mu g CTS-Co NPs TMB(ox) substrate, respectively. CTS- Co NPs; for TMB(ox) determination, optical density (OD) measurement was taken as a low limit of 1.5 mu g and a high limit of 3 mu g. Electrochemical applications of particles and microplate reader results were compared with horseradish peroxidase (HRP) enzyme for sensor properties. According to the data obtained, it was observed that it behaved similarly to the CTS-Co NPs peroxidase enzyme. This work presents innovations for nanoparticle extraction and sensor study from chitosan and other naturally sourced polymers.
Citation Count: 0
Horse Meat Microbiota: Determination of Biofilm Formation and Antibiotic Resistance of Isolated Staphylococcus Spp.
(Mary Ann Liebert Inc., 2024) Aydin,A.; Sudagidan,M.; Abdramanov,A.; Yurt,M.N.Z.; Mamatova,Z.; Ozalp,V.C.; Basic Sciences; Mathematics
Domestic horses could be bred for leisure activities and meat production, as is already the case in many countries. Horse meat is consumed in various countries, including Kazakhstan and Kyrgyzstan, and with the increase in this consumption, horses are registered as livestock by the Food and Agricultural Organization. In this study, horse meat microbiota of horse samples (n = 56; 32 samples from Kazakhstan and 24 samples from Kyrgyzstan) from two countries, Kazakhstan (n = 3) and Kyrgyzstan (n = 1), were investigated for the first time by next-generation sequencing and metabarcoding analysis. The results demonstrated that Firmicutes, Proteobacteria, and Actinobacteria were the dominant bacterial phyla in all samples. In addition, three (5.4%) Staphylococcus strains were isolated from the Uzynagash region, Kazakhstan. Staphylococcus strains were identified as Staphylococcus warneri, S. epidermidis, and S. pasteuri by partial 16S rRNA DNA gene Sanger sequencing. All three Staphylococcus isolates were nonbiofilm formers; only the S. pasteuri was detected as multidrug-resistant (resistant to penicillin, cefoxitin, and oxacillin). In addition, S. pasteuri was found to carry mecA, mecC, and tetK genes. This is the first study to detect potentially pathogenic Staphylococcus spp. in horse meat samples originating from Kazakhstan. In conclusion, it should be carefully considered that undercooked horse meat may pose a risk to consumers in terms of pathogens such as antibiotic-resistant Staphylococcus isolates. © Mary Ann Liebert, Inc.
Citation Count: 0
Identification of Bacterial Diversity of Bee Collected Pollen and Bee Bread Microbiota by Metagenomic Analysis
(Aves, 2022) Arserim Ucar, Dilhun Keriman; Yurt, Mediha Nur Zafer; Tasbasi, Behiye Busra; Acar, Elif Esma; Yegin, Zeynep; Ozalp, Veli Cengiz; Sudagidan, Mert; Basic Sciences
This study investigated the bacterial diversities of bee-collected pollen and bee bread of Apis mellifera in Turkey. The bacterial community structure of 14 bee pollen from Bingol, Konya, and Hakkari and 11 bee bread samples from Bingol were studied using 16 S rRNA amplicon sequencing and metagenomic analysis. The dominant bacterial phylum in pollen and bee bread samples was Firmicutes, followed by Proteobacteria. In pollen and bee bread samples, Bacillaceae, Clostridiaceae, Enterococcaceae, and Enterobacteriaceae were identified as dominant bacterial families. At the genus level, Bacillus, Clostridium sensu stricto, and Enterococcus were dominant bacteria in both pollen and bee bread samples. The most abundant species was Clostridium perfringens in both pollen and bee bread samples. Escherichia vulneris, Enterococcus faecalis, Bacillus cereus, Enterococcus casseliflavus, and Cronobacter malonaticus were identified with high reads in pollen samples. In bee bread samples, E. faecalis, Clostridium bifermentans, and Pantoea calida were abundant bacterial species. Alpha diversity showed that pol-3 sample had the highest diversity. Beta-diversity plots separated the pollen samples into four main groups and bee bread samples into three main groups. Our results indicated that the culture-independent metagenomic analysis will be a valuable tool for determining the microbial diversity of bee products produced in Bingol-Turkey one of the important centers of apiculture.
Citation Count: 0
Identification of Bacterial Vaginal Microbiota via Metagenomic Approach
(Galenos Publ House, 2022) Ucak, Samet; Sudagidan, Mert; Yurt, Mediha Nur Zafer; Tasbasi, Behiye Busra; Acar, Elif Esma; Tuna, Bilge Guvenc; Ozalp, Veli Cengiz; Basic Sciences
Aim: The aim of the current study was to identify vaginal bacterial microbiota of 38 Turkish women using the high -throughput next -generation sequencing and metagenomic approach at different taxonomic levels from the kingdom to the species level. Materials and Methods: Vaginal swab samples (n=38) were collected in the DNA/RNA shield collection tubes at Yeditepe University Hospital, Department of Obstetrics and Gynecology in June 2021 and DNA extraction was performed by ZymoBIOMICS DNA miniprep kit. The information related to age, marital status, preliminary diagnosis and anamnesis status of patients were collected. To determine the vaginal microbiota, a metagenomic approach was applied using 16S rRNA amplicon sequencing. Results: The dominant phylum Firmicutes was followed by Proteobacteria, Actinobacteria, Tenericutes, Fusobacteria, and Synergistetes in the vaginal samples. Lactobacillus was the most abundant genus followed by Prevotella, Enterobacter, Gardnerella, and Dialister. Lactobacillus iners was dominant at the species level in vaginal swab samples, followed by Gardnerella vaginalis, Enterobacter tabaci, Prevotella timonensis, Prevotella bivia, and Lactobacillus jensenii. Canonical correspondence analysis (CCA) showed that Proteobacteria and Fusobacteria were mainly related to married/single variable with the highest percentages, whereas Actinobacteria and Tenericutes were related to age variable at the phylum level. Campylobacter , Atopobium , Enterobacter , and Lactococcus were mainly found in married/single variable with the highest percentages, whereas Anaerococcus, Streptococcus, Sutterella , and Veillonella were related to age. Moreover, CCA showed that Campylobacter ureolyticus, Lb. jensenii , and Atopobium vaginae were associated with married/single variable, whereas Lactobacillus johnsonii and G. vaginalis were found in age variable with the highest percentages at the species level. Conclusion: Vaginal diseases are still a major public health concern. The vaginal microbiota, which has been studied in more depth in recent years, has been discovered to be more complicated than previously imagined thanks to technological developments. More patient investigations are needed to confirm and develop these findings.
Citation Count: 33
Inhibitory effects of aptamer targeted teicoplanin encapsulated PLGA nanoparticles for Staphylococcus aureus strains
(Springer, 2020) Ucak, Samet; Sudagidan, Mert; Borsa, Baris A.; Mansuroglu, Banu; Ozalp, Veli C.; Basic Sciences
Emergence of resistance to traditional antibiotic treatments necessitates alternative delivery systems. Teicoplanin is a glycopeptide antibiotic used in the treatments of serious infections caused by Gram-positive bacteria, including Methicillin Resistant Staphylococcus aureus (MRSA). One strategy to keep up with antibiotic resistance development is to limit dose and amount during treatments. Targeted delivery systems of antibiotics have been suggested as a mechanism to slow-down the evolution of resistance and to increase efficiency of the antimicrobials on already resistant pathogens. In this study, we report teicoplanin delivery nanoparticles of Poly Lactic-co-Glycolic Acid (PLGA), which are functionalized with S. aureus specific aptamers. A 32-fold decrease in minimum inhibitory concentration (MIC) values of teicoplanin for S. aureus was demonstrated for susceptible strains and about 64-fold decline in MIC value was achieved for moderately resistant clinical isolates of MRSA upon teicoplanin treatment with aptamer-PLGA nanoparticles. Although teicoplanin delivery in PLGA nanoparticles without targeting demonstrated eightfold decrease in MIC of susceptible strains of S. aureus and S. epidermidis and twofold in MIC of resistant strains, the aptamer targeting specifically decreased MIC for S. aureus, but not for S. epidermidis. Therefore, aptamer-targeted PLGA delivery of antibiotic can be an attractive alternative to combat with some of the multi-drug resistant bacterial pathogens.
Citation Count: 0
AN INVESTIGATION ON THE DNA BINDING ACTIVITIES OF MELAMINE, CYANURIC ACID AND URIC ACID
(Editura Acad Romane, 2021) Senol, Ali; Devrim, Alparslan Kadir; Sudagidan, Mert; Ozalp, Veli Cengiz; Basic Sciences
Melamine can be added to various foods such as milk, milk powder, baby food, pet, and livestock feed for cheating purposes due to its high nitrogen content. Regarding its usage in food products, there is a need to investigate its possible interactions with DNA. Thus, this study aimed to investigate the interactions of melamine and its metabolized products, cyanuric acid and uric acid with genomic DNA, isolated from eukaryotic (calf thymus) and prokaryotic (Staphylococcus aureus) sources. UV-absorbance spectrophotometry, fluorescence spectrophotometry, and agarose gel electrophoresis techniques were used to evaluate these interactions. The five different concentrations of melamine, cyanuric acid, and uric acid were incubated with fixed DNA concentration and it was determined that the test compounds interacted with the DNA molecules. The data obtained by UV-absorbance and fluorescence spectrophotometry techniques revealed an increase in wave peaks observed with the increasing substance concentration. After the obtained data of the aforementioned techniques were evaluated together, it was concluded that melamine, cyanuric acid, and uric acid bonded to the eukaryotic and prokaryotic genomic DNA materials via groove binding.