Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
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Article Citation - WoS: 3Citation - Scopus: 2Targeted Multidrug Delivery Systems To Kill Antibiotic-Resistant Staphylococcus Aureus(Editions de Sante, 2023) Özalp, Veli Cengiz; Ucak, Samet; Dursun, Ali D.; Sudağıdan, Mert; İçin, Öykü; Ahmetoğlu, Çekdar Vakıf; Henning, Laura M.; Simon, Ulla; Gurlo, AleksanderDifferent ordered mesoporous silica (OMS) nanoparticles, ranging from regular COK-12 to COK-12 modified in terms of pore shape and size, have been employed as standard drug carriers for the controlled adsorption and release of drug molecules in comparison to well-known OMS SBA-15 and MCM-41. The cytotoxicity analysis demonstrated that regular COK-12 particles were less harmful to mammalian cultured cells, causing lower apoptosis induction than modified COK-12, MCM-41, and SBA-15 particles. Thus, regular COK-12 was further used to prepare a dual antibiotic-loaded drug delivery material, followed by surface functionalization with Staphylococcus aureus-specific aptamers for targeting. The results demonstrated that the joint loading of lysozyme and vancomycin in regular COK-12 improved the ability of the antibiotic treatments to kill methicillin-resistant Staphylococcus strains via aptamer targeting. The minimum inhibitory concentration (MIC) values decreased 4.1-fold and 12-fold compared to the non-targeted use of the antimicrobial agents in homogeneous solutions for vancomycin and lysozyme, respectively, clearly demonstrating the high potential of COK-12 to be used as a carrier in multidrug therapy. © 2023 Elsevier B.V.Article Citation - WoS: 8Citation - Scopus: 8Surface Microbiota and Associated Staphylococci of Houseflies (musca Domestica) Collected From Different Environmental Sources(Elsevier, 2022) Sudağıdan, Mert; Özalp, Veli Cengiz; Can, Özge; Eligül, Hakan; Yurt, Mediha Nur Zafer; Tasbasi, Behiye Busra; Acar, Elif Esma; Kavruk, Murat; Koçak, OnerHouseflies (Musca domestica) are important mechanical vectors for the transmission of pathogenic microorganisms. In this study, 129 houseflies (69 males and 60 females) were collected from 10 different environmental sources and a laboratory population was used. The surface microbiota of houseflies was identified by Next-Generation Sequencing. Staphylococci from the surfaces of houseflies were selectively isolated and their virulence genes, antibiotic susceptibilities, biofilm formation, and clonal relatedness were determined. Metagenomic analysis results demonstrated that Staphylococcus, Bacillus, and Enterococcus were mostly present on the surface of houseflies at the genus level. Additionally, the isolated 32 staphylococcal strains were identified as Staphylococcus sciuri (n = 11), S. saprophyticus (n = 9), S. arlettae (n = 6), S. xylosus (n = 4), S. epidermidis (n = 1) and S. gallinarum (n = 1). tetK, tetM, tetL, ermC, msrAB, and aad6 genes were found to carry by some of the staphylococcal strains. The strains were mostly resistant to oxacillin, penicillin, and erythromycin and three strains were multi-drug resistant. There was a statistical difference between housefly collection places and antibiotic resistance of isolated staphylococci to penicillin G, gentamicin, and erythromycin (p < 0.05). Biofilm test showed that 17 strains were strong biofilm formers, and it plays important role in the transmission of these bacteria on the surface of houseflies. Staphylococcal strains showed extracellular proteolytic and lipolytic activity in 31 and 12 strains, respectively. Closely related species were found in PFGE analysis from different environmental sources. By this study, surface microbiota and carriage of pathogenic staphylococci on the surfaces of houseflies and their virulence properties were elucidated.Article Citation - WoS: 17Citation - Scopus: 19Bacterial Surface, Biofilm and Virulence Properties of Listeriamonocytogenes Strains Isolated From Smoked Salmon and Fish Food Contact Surfaces(Elsevier, 2021) Sudağıdan, Mert; Özalp, Veli Cengiz; Öztürk, Orhan; Yurt, Mediha Nur Zafer; Yavuz, Orhan; Taşbaşı, Behiye Busra; Uçak, Samet; Mavili, Zehra Seda; Çoban, AyşenBiofilm 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.Article Citation - WoS: 10Citation - Scopus: 9Bi̇yomalzemelerden İ̇zole Edi̇len Staphylococcus Epidermidis Suşlarinin Yüzey Özelli̇kleri̇ni̇n Beli̇rlenmesi̇(Ankara Mikrobiyoloji Derneği, 2010) Sudağıdan, Mert; Erdem, İlker; Çavuşoğlu, Cengiz; Çiftçioğlu, MuhsinThe surface properties of bacteria play an important role on adhesion to the biomaterial surface. In this study, the surface properties of Staphylococcus epidermidis strains isolated from clinically used polymeric biomaterial surfaces were investigated on the basis of zeta potential, hydrophobicity and surface topography. A total of 10 S.epidermidis strains isolated from intravenous catheters (n= 5), endotracheal tubes (n= 3) and central venous catheters (n= 2) which were used in the patients of pulmonary Intensive Care Unit, Ege University Medical Faculty Hospital, were included to the study. Seven of those isolates were biofilm producers, inhabiting biofilm genes, 2 were non-biofilm producers, however, inhabiting biofilm genes, and 1 was non-biofilm producer, inhabiting no biofilm genes. Zeta potential analysis have been performed in 3 different buffers (phosphate-buffered saline, 1 mM potassium chloride and 1 mM potassium phosphate buffer) and at different pH values (pH 4.1-8.2), in order to simulate in vivo environment of the biomaterials. Hydrophobicities of the strains were examined by bacterial adhesion to hydrocarbon (BATH) test and the surface topography of biofilms and slime layers were visualized by atomic force microscopy (AFM) and scanning electron microscopy (SEM) methods. It was found that all strains have negative zeta potential values (surface charge) in all buffers and pH values. In hydrophobicity analysis, the highest value (86%) was determined for non-biofilm forming S.epidermidis strain YT-169b (endotracheal tube isolate) and the lowest hydrophobicity (2.5%) was determined for biofilm forming S.epidermidis strain YT-212 (central venous catheter isolate). Biofilm and slime layers of the strains were imaginated by AFM and SEM analysis in ?m scale. SEM analysis showed that bacteria highly adhered to rough surfaces on biomaterial surfaces and the produced slime layers covered the surface of bacteria. In conclusion, elucidating the surface properties of opportunistic pathogens in different physiologic buffers will give important clues for the production of non-adhesive materials and antibacterial surfaces for those bacteria. It was also estimated that designing the surface of the biomaterial to have negative surface charge in the body and to be as smooth as possible will hamper biofilm formation.Article Citation - WoS: 19Citation - Scopus: 18Biyomalzeme Yüzeylerinden İzole Edilen Metisiline Dirençli Staphylococcus Aureus Suşlarında Virülans Genlerinin Araştırılması(Ankara Microbiology Society, 2008) Sudağıdan, Mert; Çavuşoğlu, Cengiz; Bacakoğlu, FezaStafilokoklar, biyomalzeme kaynaklı nozokomiyal enfeksiyonların en önemli etkenlerindendir. Bu çalışmada, Göğüs Hastalıkları Yoğun Bakım Ünitesi (YBÜ)'nde yatan 48 hastada kullanılan polimerik biyomalzeme yüzeylerinden izole edilen metisiline dirençli 11 Staphylococcus aureus suşunda virülans genlerinin varlığının saptanması ve bunların bazılarının fenotipik ifadelerinin araştırılması amaçlanmıştır. Çalışmamızda polimeraz zincir reaksiyonu (PCR) ile özgül primerler kullanılarak, bağlanma ve biyofilm oluşumundan sorumlu genler (icaA, icaC, bap), metisilin direnç geni (mecA), enterotoksin A-E üretiminden sorumlu genler (sea, seb, sec, sed, see), toksik şok sendromu toksini geni [tst), eksfoliatif toksin A ve B genleri (eta ve etb), alfa ve beta-hemolizin genleri (hla ve hlb), stafilokokal ekzotoksin benzeri protein-1 geni (sef1), proteaz genleri (sspA, sspB, aur, serine proteaz geni), lipaz geni (geh) ve regülatör genler (sarA ve agrCA) araştırılmıştır. Ayrıca suşların fenotipik olarak biyofilm oluşturma, antibiyotik duyarlılık, proteaz ve lipaz üretimi gibi özellikleri de değerlendirilmiştir. Biyofilm testlerinde, biyofilm yapan ve "slime" üreten suşlara rastlanmamış, ancak tüm suşların biyofilm yapımında rol oynayan icaA genine sahip olduğu bulunmuştur. Bununla birlikte biyofilm yapımında rol oynayan icaC ve bap genleri tespit edilememiştir. Tüm suşlarda mecA geninin varlığı saptanmış ve suşların hepsinin oksasilin, penisilin G ve gentamisine; 10'unun eritromisine ve dokuzunun da ofloksasine dirençli olduğu bulunmuştur. İzolatların tümü vankomisin, teikoplanin ve ko-trimoksazole duyarlı olarak saptanmıştır. Ekzotoksin ve regülatör genlerinin taranması sonucunda, suşların sea, seti, hla, hlb ve sarA genlerini taşıdığı belirlenmiştir. PCR ile tüm suşların, çalışılan bütün proteaz genlerine (sspA, sspB, aur ve serin proteaz geni) sahip olduğu görülmüş, ancak sütlü (skim milk ve milk agar) ve kazein ağarlarda yapılan proteaz üretimi testlerinde negatif sonuç alınmıştır. Lipaz üretiminin belirlenmesi için Tween 20, Tween 80 ve tributyrin içeren besiyerleri kullanılmış ve tüm suşlarda geç dönemde (inkübasyonun üçüncü günü) pozitif sonuç alınmasına karşın, izolatların hiçbirisinde lipaz üretiminden sorumlu geh geni bulunmamıştır. Sonuç olarak, biyomalzeme yüzeylerinden izole edilen S.aureus suşlarında, araştırılan virülans genlerinden bazılarının varlığı saptanmış, ancak bunların tam olarak fenotipe yansımadığı izlenmiştir. İzolat sayısının azlığına ve tüm genlerin ekspresyonlarının fenotipik olarak çalışılamamış olmasına rağmen, bu genlerin varlığının yoğun bakım hastalan için potansiyel bir risk teşkil edebileceği düşünülmüştür.Article Citation - WoS: 12Citation - Scopus: 14Prevalence, Virulence Characterization, and Genetic Relatedness of Listeria Monocytogenes Isolated From Chicken Retail Points and Poultry Slaughterhouses in Turkey(Springer, 2019) Çoban, Ayşen; Pennone, Vincenzo; Sudağıdan, Mert; Molva, Çelenk; Jordan, Kieran; Aydın, AliListeria monocytogenes is one of the most important foodborne pathogens and is a causal agent of listeriosis in humans and animals. The aim of this study was to determine the prevalence, serogroups, antibiotic susceptibility, virulence factor genes, and genetic relatedness of L. monocytogenes strains isolated from 500 poultry samples in Turkey. The isolation sources of 103 L. monocytogenes strains were retail markets (n = 100) and slaughterhouses (n = 3). L. monocytogenes strains were identified as serogroups 1/2a-3a (75.7%, lineage I), 1/2c-3c (14.56%, lineage I), 1/2b-3b-7 (5.82%, lineage II), 4a-4c (2.91%, lineage III), and 4b-4d-4e (0.97%, lineage III). Most of the L. monocytogenes strains (93.2%) were susceptible to the antibiotics tested. PCR analysis indicated that the majority of the strains (95% to 100%) contained most of the virulence genes (hylA, plcA, plcB, prfA, mpl, actA, dltA, fri, flaA inlA, inlC, and inlJ). Pulsed-field gel electrophoresis (PFGE) demonstrated that there were 18 pulsotypes grouped at a similarity of >90% among the strains. These results indicate that it is necessary to prevent the presence of L. monocytogenes in the poultry-processing environments to help prevent outbreaks of listeriosis and protect public health.Article Citation - WoS: 2Citation - Scopus: 2Staphylococcus Epidermidis Adhesion on Surface-Treated Open-Cell Ti6al4v Foams(Walter de Gruyter GmbH, 2016) Türkan, Uğur; Güden, Mustafa; Sudağıdan, MertThe effect of alkali and nitric acid surface treatments on the adhesion of Staphylococcus epidermidis to the surface of 60% porous open-cell Ti6Al4V foam was investigated. The resultant surface roughness of foam particles was determined from the ground flat surfaces of thin foam specimens. Alkali treatment formed a porous, rough Na2Ti5O11 surface layer on Ti6Al4V particles, while nitric acid treatment increased the number of undulations on foam flat and particle surfaces, leading to the development of finer surface topographical features. Both surface treatments increased the nanometric-scale surface roughness of particles and the number of bacteria adhering to the surface, while the adhesion was found to be significantly higher in alkali-treated foam sample. The significant increase in the number of bacterial attachment on the alkali-treated sample was attributed to the formation of a highly porous and nanorough Na2Ti5O11 surface layer.Article Citation - WoS: 49Citation - Scopus: 55Effects of Nisin and Lysozyme on Growth Inhibition and Biofilm Formation Capacity of Staphylococcus Aureus Strains Isolated From Raw Milk and Cheese Samples(International Association for Food Protection, 2012) Sudağıdan, Mert; Yemenicioğlu, AhmetEffects of nisin and lysozyme on growth inhibition and biofilm formation capacity of 25 Staphylococcus aureus strains isolated from raw milk (13 strains) and cheese (12 strains) were studied. Nisin was tested at concentrations between 0.5 and 25 μg/ ml; the growth of all strains was inhibited at 25 μg/ml, but the resistances of strains showed a great variation at lower nisin concentrations. In contrast, lysozyme tested at concentrations up to 5.0 mg/ml showed no inhibition on the growth of strains. Nisin used at the growth inhibitory concentration prevented the biofilm formation of strains, but strains continued biofilm formation at subinhibitory nisin concentrations. Lysozyme did not affect the biofilm formation of 19 of the strains, but it caused a considerable activation in the biofilm formation capacity of six strains. Twelve of the strains contained both biofilm-related protease genes (sspA, sspB, and aur) and active proteases; eight of these strains were nisin resistant. These results suggest a potential risk of S. aureus growth and biofilm formation when lysozyme is used in the biopreservation of dairy products. Nisin can be used to control growth and biofilm formation of foodborne S. aureus, unless resistance against this biopreservative develops. Copyright ©, International Association for Food Protection.Article Citation - WoS: 6Citation - Scopus: 7Assessment of Tnf-Alpha and Leptin Gene Expression by Rt-Pcr in Blood of Cows With Left Abomasal Displacement(Ecole Nationale Veterinaire, 2012) Devrim, A. K.; Sözmen, M.; Yiğitarslan, K.; Sudağıdan, Mert; Kankavi, O.; Atabay, Halil İbrahimThe aims of this study are to evaluate the TNF-α and leptin gene expression in blood from Holstein cows with left abomasal displacement and to correlate it with induced liver injury. The TNF-α and leptin expression in blood samples was determined by RT-PCR after normalisation using the constant expression of the housekeeping GAPDH gene in cows with left abomasal displacement (LAD) (n = 20) before surgery and 7 days after as well as in healthy controls (n = 10). Plasma hepatic enzyme (AST: aspartate aminotransferase, ALT: alanine aminotransferase and ALP: alkaline phosphatase) activities were measured in parallel. Plasma AST and ALP activities dramatically increased in diseased cows during the preoperative period and then declined. Although not significantly, the leptin expression tended to decrease in LAD affected cows while the TNF-α expression tended to increase during the postoperative period. These results suggest that TNF-α may be associated with liver damage during abomasal displacement and that leptin was inversely correlated.Article Citation - WoS: 105Citation - Scopus: 125Prevalence of Staphylococcal Enterotoxins, Toxin Genes and Genetic-Relatedness of Foodborne Staphylococcus Aureus Strains Isolated in the Marmara Region of Turkey(Elsevier Ltd., 2011) Aydın, Ali; Sudağıdan, Mert; Muratoğlu, KarloStaphylococcus aureus is a major foodborne pathogen and it has the ability to produce a number of extracellular toxins. We analyzed 1070 food samples obtained from retail markets and dairy farms in the Marmara Region of Turkey for the presence of S. aureus. Out of 147 isolates, 92 (62.6%) were enterotoxigenic. PCR was used to investigate the presence of staphylococcal enterotoxin genes (sea, seb, sec, sed, see, seg, seh, sei, sej, sek, sel, sem, sen, seo, sep, seq and seu), exfoliative toxin genes (eta and etb) and the toxic - shock syndrome toxin gene (tst). The PCR results showed that 53.3% of the isolates contained staphylococcal enterotoxin-like (SEl) toxin genes (seg, seh, sei, sej, sek, sel, sem, sen, seo, sep, seq and seu) which were more frequent than classical enterotoxin genes (sea to see). Furthermore, seo, sei, sem, seg, seu and sec were found in 37.0, 32.7, 30.4, 29.3, 29.3 and 27.2% of the isolates, respectively. The tst gene was detected and confirmed by DNA sequencing in 9 isolates. The presence of eta and etb were not found in the isolates. Enterotoxigenic capabilities of isolates with SEA-SEE were investigated by ELISA. Enterotoxigenic S. aureus isolates produced one to three enterotoxins, with the most frequently produced types being enterotoxin A and C. There was a correlation of 72.1% between production of a specific toxin and the presence of the respective genes. PFGE analysis was used to identify genetic-relatedness of enterotoxigenic S. aureus isolates and the results revealed that 13 groups of isolates from different or the same origin that contained the same genes showed 100% homology with indistinguishable band patterns. The other enterotoxigenic isolates showed related band patterns with 72-86% homology in sea-, 61-90% homology in sec-, 80-96% homology in seh-, and 69-96% homology in sep-positive isolates. To our knowledge, this is the first study to examine enterotoxins and related gene contents of S. aureus food isolates in the Marmara Region of Turkey.