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Article Citation - WoS: 18Citation - Scopus: 20Quartz Crystal Microbalance-Based Aptasensor Integrated With Magnetic Pre-Concentration System for Detection of listeria Monocytogenes in Food Samples(Springer Wien, 2024) Beyazit, Fatma; Arica, Mehmet Yakup; Acikgoz-Erkaya, Ilkay; Ozalp, Veli Cengiz; Bayramoglu, GulayA fast and accurate identification of Listeria monocytogenes. A new quartz crystal microbalance (QCM) aptasensor was designed for the specific and rapid detection of L. monocytogenes. Before detection of the target bacterium from samples in the QCM aptasensor, a magnetic pre-enrichment system was used to eliminate any contaminant in the samples. The prepared magnetic system was characterized using ATR-FTIR, SEM, VSM, BET, and analytical methods. The saturation magnetization values of the Fe3O4, Fe3O4@PDA, and Fe3O4@PDA@DAPEG particles were 57.2, 40.8, and 36.4 emu/g, respectively. The same aptamer was also immobilized on the QCM crystal integrated into QCM flow cell and utilized to quantitatively detect L. monocytogenes cells from the samples. It was found that a specific aptamer-magnetic pre-concentration system efficiently captured L. monocytogenes cells in a short time (approximately 10 min). The Fe3O4@PDA@DA-PEG-Apt particles provided selective isolation of L. monocytogenes from the bacteria-spiked media up to 91.8%. The immobilized aptamer content of the magnetic particles was 5834 mu g/g using 500 ng Apt/mL. The QCM aptasensor showed a very high range of analytical performance to the target bacterium from 1.0 x 10(2) and 1.0 x 10(7) CFU/mL. The limit of detection (LOD) and limit of quantitation (LOQ) were 148 and 448 CFU/mL, respectively, from the feeding of the QCM aptasensor flow cell with the eluent of the magnetic pre-concentration system. The reproducibility of the aptasensor was more than 95%. The aptasensor was very specific to L. monocytogenes compared to the other Listeria species (i.e., L. ivanovii, L. innocua, and L. seeligeri) or other tested bacteria such as Staphylococcus aureus, Escherichia coli, and Bacillus subtilis. The QCM aptasensor was regenerated with NaOH solution, and the system was reused many times.Article Citation - WoS: 9Citation - Scopus: 12Exosomes as Biomarkers and Therapeutic Agents in Neurodegenerative Diseases: Current Insights and Future Directions(Springer, 2025) Dehghani, Sam; Ocakci, Ozgecan; Hatipoglu, Pars Tan; Ozalp, Veli Cengiz; Tevlek, AtakanNeurodegenerative diseases (NDs) like Alzheimer's, Parkinson's, and ALS rank among the most challenging global health issues, marked by substantial obstacles in early diagnosis and effective treatment. Current diagnostic techniques frequently demonstrate inadequate sensitivity and specificity, whilst conventional treatment strategies encounter challenges related to restricted bioavailability and insufficient blood-brain barrier (BBB) permeability. Recently, exosomes-nanoscale vesicles packed with proteins, RNAs, and lipids-have emerged as promising agents with the potential to reshape diagnostic and therapeutic approaches to these diseases. Unlike conventional drug carriers, they naturally traverse the BBB and can deliver bioactive molecules to affected neural cells. Their molecular cargo can influence cell signaling, reduce neuroinflammation, and potentially slow neurodegenerative progression. Moreover, exosomes serve as non-invasive biomarkers, enabling early and precise diagnosis while allowing real-time disease monitoring. Additionally, engineered exosomes, loaded with therapeutic molecules, enhance this capability by targeting diseased neurons and overcoming conventional treatment barriers. By offering enhanced specificity, reduced immunogenicity, and an ability to bypass physiological limitations, exosome-based strategies present a transformative advantage over existing diagnostic and therapeutic approaches. This review examines the multifaceted role of exosomes in NDDs, emphasizing their diagnostic capabilities, intrinsic therapeutic functions, and transformative potential as advanced treatment vehicles.Article Citation - WoS: 2Citation - Scopus: 1Direct 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 GuvencPoint-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.imageArticle Citation - WoS: 4Citation - Scopus: 6Bacterial 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, MertBacterial 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.Article Citation - WoS: 2Citation - Scopus: 2Global Insights Into Food Fraud From Location-Based Analysis: Food Adulteration in Turkey(Wiley, 2025) Kavruk, Murat; Balci, Tugce Nur; Ozel, Irem Cagla; Ozalp, Veli Cengiz; Aydin, AliBackgroundFood fraud and adulteration pose critical global challenges impacting economic stability and public health. This study examines the prevalence and characteristics of food fraud incidents in Turkey, an international player in the food supply chain. Controls carried out from production to consumption reveal many fraudulent events worldwide.ResultsData collected by the Ministry of Agriculture and Forestry of T & uuml;rkiye from 2012 to 2022, covering 4007 incidents and 7180 specific cases of adulteration, form the basis of this analysis. The study categorizes food fraud by region, product group and type of fraud, revealing trends and patterns. Key findings indicate a higher incidence of fraud in milk, meat and vegetable oil products, including the detection of drug-based adulteration having potential for serious health consequences.ConclusionAt most importance, we demonstrated the importance of risk-based food inspections and the development of new detection technologies to enhance food safety. The results are fundamental for more effective food inspections in terms of risk-based conformity assessment approaches or developing new methods, devices and analysis kits in terms of scientific and technological approaches. Still, they can also significantly improve future food safety measures. These insights are aimed at informing global food safety strategies and policymaking, contributing to a safer and more transparent food supply chain. (c) 2025 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.Article Citation - WoS: 8Citation - Scopus: 8Bacterial 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, EdgarFarming 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.