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Öğe Antimicrobial resistance and underlying mechanisms in Staphylococcus aureus isolates(Wolters Kluwer Medknow Publications, 2017) Yilmaz, Ebru Sebnem; Aslantas, OzkanObjective: To investigate the antimicrobial susceptibility of 97 clinical Staphylococcus aureus (S. aureus) strains against 14 antimicrobials and corresponding resistance mechanisms. Methods: The antimicrobial susceptibility of the isolates was determined using a disk diffusion method and antimicrobial resistance genes were screened by polymerase chain reaction. Mutations responsible for ciprofloxacin and rifampicin resistance were investigated by polymerase chain reaction and DNA sequencing. Results: All isolates were found to be susceptible to vancomycin. Various rates of resistance to penicillin (83.5%), ampicillin (77.3%), erythromycin (63.9%), tetracycline (16.5%), amoxicillin/ clavulanic acid (16.5%), ciprofloxacin (15.5%), trimethoprim/sulfamethoxazole (15.5%), oxacillin (13.4%), fusidic acid (12.4%), rifampin (6.2%), clindamycin (6.2%), gentamicin (6.2%) and mupirocin (5.2%) were determined. In addition, different combinations of resistance genes were identified among resistant isolates. Ciprofloxacin resistant isolates had mutations in codon 84 (Ser84Leu) and 106 (Gly106Asp) in the gyrA gene. Mutations in grlA were mostly related to Ser80Phe substitution. Leu466Ser mutation in the rpoB gene was detected in all rifampin resistant isolates. All methicillin resistant S. aureus isolates were SCCmec type V. Conclusions: In conclusion, it was determined that the isolates were resistant to different classes of antimicrobials at varying rates and resistance was mediated by different genetic mechanisms. Therefore, continuous monitoring of resistance in S. aureus strains is necessary to control their resistance for clinically important antimicrobials.Öğe Antimicrobial susceptibility pattern and SCCmec types of methicillin-resistant coagulase-negative staphylococci from subclinical bovine mastitis in Hatay, Turkey(Natl Veterinary Research Inst, 2014) Aslantas, Ozkan; Yilmaz, Mehmet Ali; Yilmaz, Ebru Sebnem; Kurekci, CemilEighty-nine isolates of coagulase-negative staphylococci (CoNS) of eight species from subclinical bovine mastitis were screened for the phenotypic and genotypic methicilline-resistance. In addition, all methicillin-resistant (MR) isolates indicating the mecA gene were examined by PCR for the antimicrobial susceptibility patterns, and staphylococcal cassette chromosome mec (SCCmec) types were also determined by multiplex PCR. A total of 21 (23.6%) CoNS isolates were found to be resistant to oxacillin in broth microdilution assay. All isolates phenotypically resistant to oxacillin did not have the mecA gene, which was only found in 14.6% (13) of the isolates. Most MR-CoNS isolates were highly resistant to erythromycin (92.3%), fusidic acid (84.6%), penicillin (76.9%), and rifampycin (61.5%), and susceptible to mupirocin (100%), tetracycline (100%), vancomycin (100%), clindamycin (92.3%), and sulfamethoxazole-trimethoprim (69.2%). In conclusion, a high rate of antimicrobial resistance among MR-CoNS isolated from food producing animals emphasises the need for periodic surveillance of their resistance.Öğe Antimicrobial, Antioxidant Activity of the Essential Oil of Bay Laurel from Hatay, Turkey(Taylor & Francis Ltd, 2013) Yilmaz, Ebru Sebnem; Timur, Mahir; Aslim, BelmaThe aim of this study was to evaluate the antimicrobial and antioxidant activity of the essential oil (EO) extracted from the leaves of Laurus nobilis L. The oil was analyzed by gas chromatography and mass spectrometry (GC-MS). Twenty seven components were identified, representing 96.6 % of the EO. The main compounds identified were 1,8-cineole (51.8 %), alpha-terpinyl acetate (11.2 %), and sabinene (10.1 %). The oil was screened for possible antioxidant activity using two complementary test systems: DPPH (2,2-diphenylpicrylhydrazyl) free radical-scavenging and the beta-carotene/linoleic acid assay. Both of these in vitro methods showed that the EO was a less powerful reducing agent than the well-known synthetic antioxidants, butylated hydroxytoluene and ascorbic acid. Also, the antimicrobial activity of the EO was tested against a panel of food-spoiling bacteria and one yeast strain. The minimum inhibitory concentration values for microorganisms that were sensitive to L. nobilis EO ranged from 125-2000 mu g/mL.Öğe Biosynthesis of silver nanoparticles and their versatile antimicrobial properties(Iop Publishing Ltd, 2019) Some, Sudip; Sen, Ipsita Kumar; Mandal, Amitava; Aslan, Tugrul; Ustun, Yakup; Yilmaz, Ebru Sebnem; Kati, AhmetSilver nanoparticles (AgNP) have been used for over a century for many purposes including as germicides. Unique physical, chemical and biological properties of Ag NPs make them suitable for a wide range of applications in different industries and biomedical fields. Green nanobiotechnology with synthesis of NPs using biomolecules (protein, enzyme, DNAand plant extracts) have become a rapidly developing research area. Green synthesis methods have overcome the disadvantages of traditional physical and chemical synthesis approaches, such as high cost, long time scales and toxicity. In the green route, the biomolecules act as both reducing and/or stabilizing agents to produce biocompatible NPs. Promising results on antimicrobial activity of AgNP against several pathogenic microorganisms have been reported in literature. The growth of multiple antibiotic resistant bacteria could be inhibited by using Ag NP. This review mainly discusses the synthesis routes and characterization of biomolecules capped Ag NPs and their enhanced antimicrobial properties towards various human and plant pathogens.Öğe DETECTION OF EXTENDED-SPECTRUM ?-LACTAMASES IN ESCHERICHIA COLI FROM CAGE BIRDS(Elsevier Science Inc, 2017) Yilmaz, Ebru Sebnem; Dolar, AyseExtended-spectrum beta-lactamase (ESBL)-producing Escherichia coli or other Enterobacteriaceae spp. are considered a global emerging public health problem. The objective of this research study was to deteiniine the prevalence of ESBLs-producing E. coli in various pet birds in Hatay, Turkey. The 4 bacterial isolates obtained displayed different frequencies of antimicrobial susceptibility among 24 antibiotics. The 4 E. coli isolates were classified as group B1 based on phylogenetic analysis. Pulsed-field gel electrophoresis was used to detect molecular typing of the p-lactam resistance gene (bla(CIX-M)) isolates and 2 different pulsotypes were revealed from the same pet shop. All CTX-M-producing E. coli isolates showed almost identical genotypes. For the first time, the presence of fecal-origin ESBL-producing E. coli was isolated from cage birds in Turkey. These results confirm the presence of ESBL-producing E. coli in cage birds as a potential risk factor for humans and other animals. Thus, continuous monitoring of antimicrobial-resistant organisms, including ESBL-producing bacteria in pet birds, and promotion of the necessary hygiene for caregivers is required to control the dissemination of these microbes. Copyright (C) 2017 Elsevier Inc. All rights reserved.Öğe Evaluation of the antioxidant and cytotoxic potency of Euphorbia rigida and Arbutus andrachne methanol extracts in human hepatocellular carcinoma cell lines in vitro(Springernature, 2021) Aslanturk, Ozlem Sultan; Yilmaz, Ebru Sebnem; Celik, Tulay Askin; Guzel, YeldaBackground Ethnobotanical studies on plants and their active compounds take a great interest in traditional medicine. After pharmacological and toxicological studies, there will be a possibility to be used in therapy. This study aimed to examine the in vitro antioxidant and cytotoxic activity of the methanol extracts of Arbutus andrachne L. and Euphorbia rigida M.Bieb. 10, 25, 50, 75, 100 and 150 mu g mL(-1) concentrations of A. andrachne and E. rigida were tested for antioxidant activity by using DPPH radical scavenging assays, total antioxidant capacity (phosphomolybdate assay) and and metal ion chelating activity. In addition, in vitro cytotoxic effects of this plants methanol extracts on Hep3B and HepG2 human hepatocellular carcinoma cell lines were evaluated at 24, 48 and 72 h. The cytotoxicity test was carried using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay. Results Methanol extract obtained from both plants showed increased antioxidant activity depending on the increase in concentration. When A. andrachne and E. rigida methanol extracts were compared in free DPPH scavenging activity, total antioxidant capacity and metal ion chelating activity, A. andrachne methanol extract was found more effective than E. rigida. Results from MTT assay revealed that except for 72 h treatment of HepG2 cells with 400 and 500 mu gmL(-1) extract concentrations, A. andrachne methanol extract did not show significant cytotoxic effects on either Hep3B or HepG2 cells at any concentration and treatment time. On the contrary, it significantly increased proliferation in Hep3B cells from 48 h and at a concentration of 100 mu g mL(-1). E. rigida methanol extract exhibited statistically significant cytotoxic activity on HepG2 cells after 48 and 72 h treatment. However, the treatment concentrations of E. rigida methanol extract were not as effective on Hep3B cells as on HepG2 cells. Conclusions According to our findings, it was determined that A. andrachne methanol extract did not have cytotoxic activity on neither Hep3B nor HepG2 cells, while E. rigida methanol extract had cytotoxic activity especially on HepG2 hepatocellular carcinoma cells. Further research is needed to identify and purify the active ingredients in E. rigida extracts.Öğe In vitro biofilm formation in ESBL producing Escherichia coli isolates from cage birds(Elsevier Sci Ltd, 2016) Yilmaz, Ebru Sebnem; Guvensen, Nur CeyhanObjective: To determine biofilm and hydrophobicity formation ratios in extended spectrum beta lactamases (ESBL) synthesizing Escherichia coli isolates which were isolated from feces samples of 150 cage bird species randomly taken from pet shops in Hatay province, Turkey. Methods: In vitro biofilm production of 4 ESBL positive isolates were performed by Congo Red Agar (CRA), Standard Tube (ST) and Microtitre Plate (MP) methods while their hydrophobicity were examined by bacterial adhesion to hydrocarbon (BATH) test. Results: In the examined isolates, while biofilm production was found to be negative by CRA method, highest biofilm producing strain, among 4 bacteria was determined to be A42 by ST and MP methods. The Scanning Electron Microscopy (SEM) also displayed these confirmed findings. The hydrophobicity values of strains were determined to be between 22.45% and 26.42%. Conclusions: As a result. biofilm formation in cage bird feces originated ESBL positive Escherichia coli isolates was performed for the first time in Turkey. In order to present the relation between pathogenicity and biofilm production in animal originated ESBL positive isolates, further studies are required.Öğe INVESTIGATION OF THE ANTIBIOTIC RESISTANCE AND BIOFILM FORMATION OF STAPHYLOCOCCUS AUREUS STRAINS ISOLATED FROM GANGRENOUS MASTITIS OF EWES(Akademiai Kiado Zrt, 2012) Tel, Osman Yasar; Aslantas, Ozkan; Keskin, Oktay; Yilmaz, Ebru Sebnem; Demir, CemilIn this study, Staphylococcus aureus strains (n = 110) isolated from seven ewe flocks in Sanliurfa, Turkey were screened for antibiotic resistance and biofilm-forming ability as well as for genes associated with antibiotic resistance and biofilm-forming ability. All isolates were found to be susceptible to oxacillin, gentamicin, clindamycin, cefoxitin, tetracycline, vancomycin, amoxicillin-clavulanic acid, ciprofloxacin and sulphamethoxazole-trimethoprim. The percent proportions of strains resistant to penicillin G, ampicillin and erythromycin were 27.2% (n = 30), 25.4% (n = 28) and 6.3% (n = 7), respectively. Regarding the antibiotic resistance genes, 32 (29%) isolates carried the blaZ and 8 (7.2%) the ermC gene. Other resistance genes were not detected in the isolates. All isolates showed biofilm-forming ability on Congo red agar (CRA), while 108 (98.18%) and 101 (91.81%) of them were identified as biofilm producers by the use of standard tube (ST) and microplate (MP) methods, respectively. All isolates carried the icaA and icaD genes but none of them harboured the bap gene. The results demonstrated that S. aureus isolates from gangrenous mastitis were mainly resistant to penicillins (which are susceptible to the staphylococcal beta-lactamase enzyme), and less frequently to erythromycin. Furthermore, all of the S. aureus isolates produced biofilm which was considered a potential virulence factor in the pathogenesis of staphylococcal mastitis.Öğe Investigation of Toxin Genes of Staphylococcus aureus Strains Isolated from Gangrenous Mastitis in Ewes(Kafkas Univ, Veteriner Fakultesi Dergisi, 2011) Tel, Osman Yasar; Aslantas, Ozkan; Keskin, Oktay; Yilmaz, Ebru Sebnem; Demir, CemilIn this study, it was aimed to determine staphylococcal enterotoxin (SE) genes, toxic shock syndrome toxin (TSST) gene and exfoliative toxin (ET) genes in 110 Staphylococcus aureus strains from gangrenous mastitis cases in seven ewe flocks in Sanliurfa, Turkey. Among investigated isolates, only sec and tst toxin genes were detected. The results of this study showed that the rates of enterotoxin production were high (100%) in S. aureus strains isolated from ovine gangrenous mastitis. Moreover, it was demonstrated that S. aureus causing gangrenous mastitis harboured sec and tst genes suggesting that these genes may have a role in ovine mastitis pathogenesis.Öğe Phylogenetic Group/Subgroups Distributions, Virulence Factors, and Antimicrobial Susceptibility of Escherichia coli Strains from Urinary Tract Infections in Hatay(Soc Brasileira Medicina Tropical, 2020) Yilmaz, Ebru Sebnem; Aslantas, OzkanIntroduction: Nosocomial and community acquired urinary tract infections (UTIs) are one of the most encountered infections in the world. Methods: This study aimed to determine the antibiotic susceptibility, phylogeny, and virulence genes of 153 Escherichia coli strains isolated from UTIs. Antimicrobial susceptibility of the isolates to different classes of antimicrobials was determined by the VITEK-2 automated system. Presence of virulence genes and phylogenetic groups were investigated by PCR. Results: Regarding susceptibility to antimicrobials, ampicillin resistance was most abundant (67.3%), followed by amoxicillin-clavulanic acid (50.9%); least abundant was resistance to amikacin (1.3%) and nitrofurantoin (1.3%). Multi drug resistance (MDR) was observed in 34.6% of the isolates, and all isolates were found to be susceptible to imipenem, meropenem and fosfomycine. The majority of the isolates belonged to the phylogenetic group B2(3) (35.9%), followed by Al (20.9%), D1 (18.9%), D2 (12.4%), A0 (%5.9), B1 (3.9%) and B2 (1.9%). Among E. coli strains examined, 49% had iucD, 32.7% papE-F, 26.1% papC, 15% cnf2. 11.1% sfa, 7.8% cnf1, 1.3% afaE, 1.3% afaD, 1.3% hlyA, 0.7%f17a-A, 0.7% clpG and 0.7% eae A genes. Conclusions: Our research demonstrated that virulence factors were distributed among different phylogroup/subgroups, which play a role in UTIs pathogenesis in humans. For this reason, complex and detailed studies are required to determine the relationship between virulence factors and specific E. coil strains that cause UTIs in humans.Öğe Physiological and gene expression differences of wheat varieties under different waterlogging treatments(Elsevier Sci Ltd, 2011) Erayman, Mustafa; Ergun, Nuray; Yilmaz, Ebru Sebnem; Ilhan, Emre; Ozcubukcu, Serhat; Eren, Abdil Hakan; Hancer, Tugce[Abstract Not Available]Öğe POTENTIAL OF NICKEL(II) REMOVAL BY SYNECHOCYSTIS SP ISOLATES(Parlar Scientific Publications (P S P), 2012) Yilmaz, Ebru Sebnem; Aslim, Belma; Cansunar, EmirThe removal of heavy metal ions by microorganisms may present an alternative method for their removal from wastewater. In this study, 10 cyanobacteria were isolated from Kucukcekmece Lagoon (Turkey). All the isolates were examined for nickel(II) concentrations in the range of 5-25 mg/L. EC50 values of the isolates were determined by probit analysis. Synechocystis sp. BASO403 (EC50 of 17.41 mg/L) and Synechocystis sp. BASO404 (EC50 of 2.56 mg/L) were selected among the isolates based on their capacity to produce extracellular polysaccharides (EPS; 143 mg/L and 44 mg/L), respectively, for removal at 15 mg/L Ni(II) concentration. The BASO404 isolate displayed a higher Ni(II) removal (95%), especially on the cell surface, than BASO403 (51%) after a 7-days incubation period. A reverse relationship between EPS capacity and Ni removal (p<0.01) was indicated, but a positive correlation was observed between EPS capacity and Ni toxicity (p<0.01). It is suggested that EPS from two isolates of Synechocystis sp. play a protective role for Ni(II) toxicity.Öğe Potential of nickel(II) removal by synechocystis sp. Isolates(2012) Yilmaz, Ebru Sebnem; Aslim, Belma; Cansunar, EmirThe removal of heavy metal ions by microorganisms may present an alternative method for their removal from wastewater. In this study, 10 cyanobacteria were isolated from Kucukcekmece Lagoon (Turkey). All the isolates were examined for nickel(II) concentrations in the range of 5-25 mg/L. EC 50 values of the isolates were determined by probit analysis. Synechocystis sp. BASO403 (EC50 of 17.41 mg/L) and Synechocystis sp. BASO404 (EC50 of 2.56 mg/L) were selected among the isolates based on their capacity to produce extracellular polysaccharides (EPS; 143 mg/L and 44 mg/L), respectively, for removal at 15 mg/L Ni(II) concentration. The BASO404 isolate displayed a higher Ni(II) removal (95%), especially on the cell surface, than BASO403 (51%) after a 7-days incubation period. A reverse relationship between EPS capacity and Ni removal (p<0.01) was indicated, but a positive correlation was observed between EPS capacity and Ni toxicity (p<0.01). It is suggested that EPS from two isolates of Synechocystis sp. play a protective role for Ni(II) toxicity. © by PSP.Öğe Prevalence and Characterization of ESBL- and AmpC-producing Escherichia coli from Cattle(Kafkas Univ, Veteriner Fakultesi Dergisi, 2017) Aslantas, Ozkan; Elmacioglu, Sibel; Yilmaz, Ebru SebnemIn this study, it was aimed to determine the prevalence of extended spectrum beta-lactamase (ESBL) and/or AmpC type beta-lactamase (AmpC) producing Escherichia coli from cattle in Hatay. For this purpose, 312 rectal swabs samples were collected from apparently healthy cattle. ESBL production was phenotypically investigated by disc combination method and double disc synergism test and beta-lactamase genes (bla(CTX-M), bla(CMY-2), bla(SHV), bla(OXA), and bla(TEM)) and plasmid mediated quinolone resistance (PMQR) genes (qnrA, qnrB, qnrS and aac(6')-Ib) were screened by polymerase chain reaction (PCR) and subsequent sequence analysis. Antimicrobial susceptibility of the isolates were determined using disc diffusion method and their phylogenetic groups were also searched by PCR. Twenty six (8.3%) isolates were found to be ESBL producer by phenotypic tests. The following ESBL/AmpC genes were detected: bla(CTX-M-15) (n=12), bla(CTX-M-1) (n=11), bla(CTX-M-3) (n=2), and bla(CMY-2) (n=1). PMQR genes were detected in 11 (42.3%) ESBL producing E. coli isolates and these isolates were only positive for aac(6')-Ib-cr and qnrS1 genes. Twenty two (84.6%) of the isolates exhibited multidrug resistance (MDR) phenotype. ESBL/AmpC producing E. coli isolates were observed to be belonged to B1 (50%), A (34.6%) and D (15.4%) phylogroups. This study was the first to describe the presence of CTX-M-15, CTX-M-3, CTX-M-1 and CMY-2 producing E. coli in cattle in Turkey and the co-existence of aac(6')-Ib-cr and qnrS1 genes in some isolates.Öğe Prevalence and molecular characterization of extended-spectrum ?-lactamase (ESBL) and plasmidic AmpC ?-lactamase (pAmpC) producing Escherichia coli in dogs(Japan Soc Vet Sci, 2017) Aslantas, Ozkan; Yilmaz, Ebru SebnemThis study aimed to determine the prevalence of fecal carriage of extended spectrum beta-lactamase (ESBL) and/or plasmidic AmpC beta-lactamase (pAmpC) producing Escherichia coli among dogs (n=428) in Turkey. Polymerase chain reaction (PCR) and sequencing were used to characterize genes encoding beta-lactamase and plasmid mediated quinolone resistance (PMQR). Antimicrobial susceptibility testing and PCRs for virulence genes and phylogenetic groups were also performed. Cefotaxime resistant E. coli isolates were detected in 95 (22.2%) of the swab samples. Sequencing analysis results showed occurrence of various beta-lactamase genes: bla(CTX-M-15) (62), bla(TEM-1b) (42), bla(CMY-2) (22), bla(CTX-M-3) (16), bla(CTX-M-1) (15), bla(OXA-1) (9) and bla(SHV-12) (3) alone or in combination. The most frequently encountered phylogenetic group was group A(1) (35.8%), followed by group D-2 (22.1%), B1 (15.8%), D-1 (9.5%), A(0) (7.4%), B2(2) (5.3%) and B2(3) (4.2%), respectively. PMQR genes, aac(6')-Ib-cr, qnrS1 and qnrB10 were detected in 25.3, 10.5 and 1.1% of the isolates, respectively. While all isolates were susceptible to imipenem and amikacin, resistance rates to non-beta-lactam antibiotics ranged from 20.0% for tobramycin to 56.8% for tetracycline. The virulence genes were only detected in 34 (36.2%) of the isolates and this isolates carried single or various combination of virulence genes of iucD, papC, papE, f17a-A and eaeA. Four isolates were identified as human virulent pandemic CTX-M-15 producing E. coli clone O25b:ST131/B2. To the best of our knowledge, this is the first study to show fecal carriage of ESBL/pAmpC type beta-lactamase producing E. coli isolates among dogs in Turkey.Öğe Prevalence of ?-Lactamase Producing Escherichia coli from Retail Meat in Turkey(Wiley, 2015) Onen, Sevda Pehlivanlar; Aslantas, Ozkan; Yilmaz, Ebru Sebnem; Kurekci, CemilExtended spectrum beta-lactamase (ESBL) and plasmid-mediated AmpC beta-lactamase (pAmpC) producing Escherichia coli have been shown to be present in humans and animals representing a significant problem worldwide. This study aimed to search the presence of ESBL and/or AmpC-producing E. coli in retail meats (chicken and beef) in Turkey. A total of 88 beta-lactamase-producing E. coli were isolated from chicken (n = 81/100) and beef meat (n = 7/100) samples and their susceptibility to several antimicrobials were tested using disc diffusion method. E. coli isolates were further characterized for their phylogenetic groups. beta-Lactamase encoding (bla(TEM), bla(SHV), bla(OXA), bla(CTX-M), and bla(AmpC)) and quinolone resistance genes (qnrA, qnrB, qnrS, qepA, and acc(6')-Ib-cr) were also secreened by polymerase chain reaction (PCR). However, in regard to beta-lactamase genes, 84 of 88 isolates were positive for bla(CTX-M-1) (n = 39), bla(CTX-M-3) (n = 5), bla(CTX-M-15) (n = 4), bla(TEM-1b) (n = 2), bla(SHV-12) (n = 1), bla(CTX-M-1/blaTEM-1b) (n = 10), bla(CTX-M-1)/bla(TEM-1b)/bla(SHV-5) (n = 1), bla(CTX-M-1)/bla(CMY-2) (n = 1) and bla(TEM-1b)/bla(CMY-2) (n = 6), bla(CTX-M-15)/bla(SHV-12) (n = 1), bla(CTX-M-15)/bla(TEM-1b) (n = 1), bla(TEM-1b)/bla(SHV-12) (n = 1), and bla(CMY-2) (n = 12) genes. Resistance to cefuroxime (75.6% and 85.7%), nalidixic acid (89% and 85.7%), tetracycline (91.4% and 100%), streptomycin (40.2% and 100%), and trimethoprim-sulfamethoxazole (36.6% and 85.7%) was observed among strains isolated from chicken and beef, respectively. However, all isolates were found to be susceptible to amikacin, imipenem, and cefepime. Resistance to ampicillin and cefoxitin was significantly linked to bla(CMY-2) gene, while there was a significant correlation between CTX-M type ESBL and antimicrobial resistance to cefuroxime and streptomycin (P < 0.05). The results of this study suggest that raw chicken retail meats are highly contaminated with ESBL-producing E. coli implementing a great risk to human health in Turkey.Öğe Prevalence, antimicrobial resistance and virulence traits in enterococci from food of animal origin in Turkey(Elsevier Science Bv, 2016) Yilmaz, Ebru Sebnem; Aslantas, Ozkan; Onen, Sevda Pehlivanlar; Turkyilmaz, Suheyla; Kurekci, CemilThe objective of this work was to investigate the antibiotic susceptibility, the mechanisms implicated and the potential virulence genes (gelatinase [ge/E], cytolysins [cylA, cylM, cylB], cell wall adhesins [efaAfs and efaAfrn], enterococcal surface protein [esp], sex pheromones [cpd, cob, ccf], enhanced expression of pheromone [eep], aggregation substance [aggA]) in enterococci isolated from retail chicken and beef meat samples in Hatay, Turkey. Hundred-one (96%) isolates from chicken meat and sixty-three (63%) from minced meat isolates showed resistance to at least one of the 12 antimicrobial agents tested. The highest frequency of resistance was against tetracycline (89.5% and 53%), erythromycin (59% and 2%), ciprofloxacin (35.2% and 12%) and trimethoprim/sulfamethoxazole (34.3% and 7%) for isolates from chicken and beef samples, respectively. The ermB, tetM and tetL genes were predominantly detected by PCR. Five enterococci from chicken meat were found to be phenotypically resistant to vancomycin and carried the vanA gene. The presence of virulence genes including gelE, ccf, cpd, efaAfs, and aggA were frequently detected. The results of this study show that retail chicken and beef meat is source of concern for public health due to having high prevalence of antibiotic resistance and as well as harbouring virulence factors. (C) 2015 Elsevier Ltd. All rights reserved.Öğe Production of Rhamnolipid (A Biosurfactant) Using Free and Immobilized Cells of Pseudomonas sp.(Kafkas Univ, Veteriner Fakultesi Dergisi, 2012) Sidal, Ugur; Yilmaz, Ebru SebnemThis study presents a method for the production of rhamnolipid, a biosurfactant, by Pseudomonas sp. Pseudomonas sp. cells that were grown in nutrient agar were inoculated into sterile liquid medium. Following an incubation period of 24 h, 2 ml of cells were inoculated into a different liquid medium and the results were obtained at the end of 26 hours incubation time. In our study, the effects of temperature, pH, and glucose concentration on rhamnolipid production were also investigated. Later, the same procedure was applied to immobilized cells that were kept away from the free microorganisms. The production of rhamnolipid by free cells was found to be much higher than that of immobilized cells. Free cells could be used for rhamnolipid production effectively.Öğe A rare agent in diabetic foot wounds: Corynebacterium striatum(Cukurova Univ, Fac Medicine, 2018) Yilmaz, Ebru Sebnem; Cetin, Serpil Kuvvet; Duran, Nizami[Abstract Not Available]Öğe Synthesis of metallic and metal oxide nanomaterials(Wiley Blackwell, 2020) Demirbas, Ayse; Karaytuğ, Tuna; Arabaci, Nihan; Yilmaz, Ebru Sebnem; Ocsoy, IsmailMaterials in nano size called "nanomaterials" convey novel and enhanced properties based upon their size, shape, morphology, and component and have been intensively employed in a variety of scientific and industrial fields. Specifically, nanomaterials have been exposed to humans, plants, and animals, so toxicity of nanomaterials is a crucial issue that must be investigated and documented when exposed to living organisms. Researchers have focused on various surfactants, surface engineering strategies, and synthesis methods to create less harmful or biocompatible nanomaterials. This present review comprehensively and comparatively focuses on most rapid growth and exciting research on a variety of nanomaterials, their synthesis methods, and nanomaterial surface designing strategies. © 2021 John Wiley & Sons Ltd.
