Browsing by Author "Gocmen, Julide Sedef"

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Antibiotic resistance of streptococcus pneumoniae and haemophilus influenzae isolated from respiratory tract specimens
(2016) Aliskan, Hikmet Eda; Colakoglu, Sule; Gocmen, Julide Sedef
Purpose: Streptococcus pneumoniae and Haemophilus influenzae are two of the major pathogens in respiratory infections, treatment is usually started empirically. The aim of this study was to detect in vitro resistance rates of S. pneumoniae and H. influenzae strains isolated from different lower respiratory clinical samples to the antibotics which are used for therapy of infections due to these pathogens. Material and Methods: Seventy seven S. pneumoniae and 117 H. influenzae strains, isolated from patients were included in the study. S. pneumoniae isolates which gave an inhibition zone diameter of > 20 mm for oxacillin were considered susceptible for penicilin. For the isolates which had an oxacillin zone diameter of <20 mm, MIC values of penicillin and cefotaxime were obtained by E-test method (bioMerieux, Marcy-l'Etoile, France). Results: Of 77 S. pneumoniae isolates, 24.6 % were resistant (MIC> 2 mg/l) and 31.1 % were intermediately resistant to parenteral penicillin. Resistance rates to antibiotics were as follows: erythromycin 40 %, trimethoprim/sulphametoxazole (TMP/SMX) 54.5 % and ofloxacin 6.4%. beta-lactamases were detected in 15.6% of the H. influenzae isolates by nitrocefin positivity. Conclusion: H. influenzae strains (8.6%) were identified as beta-lactamase negative ampicillin resistant (BLNAR) strains. Resistance rates for other antibiotics were as follows: ampicillin 28.6%, cefaclor 36.5%, cefuroxime 30.1%, clarithromycin 9.6%, cloramphenicol 7% and TMP-SMX 43.9%.
Biofilm Formation Research of Coagulase-Negative Staphylococci Isolates' Isolated from Blood and Hand Culture at Nanofilm Covered Micro Plaques by Plasma Polymerization Technique: An Experimental Model
(2017) Hortac Istar, Elvan; Gocmen, Julide Sedef; Cokeliler, Dilek; Mutlu, Mehmet; Kaleli Can, Gizem; Alparaslan, Sezin; Cetin, Ceren; Kartal, Naz; Ozcelik, Ugur Can; Aycan, Cagri; 0000-0002-4335-6897; 0000-0001-6423-7523; AAP-6138-2021
Introduction: Coagulase-negative staphylococci (CNS) can protect themselves from the effects of antibiotics by producing biofilms through breeding on biomaterials, medical equipment and devices. It is possible to influence biofilm formation with the aid of various surface modifications. In our study, plasma polymerization method, which is a surface modification technique, was used. The plasma polymerization technique is an environmentally-friendly technique that allows you to modify the nanometer level only at the surface without affecting the stack using the fourth state of the material. The possibility to generate surfaces with different properties (hydrophilic, hydrophobic, biocompatible etc.) by the help of various monomers and gases has made this technique more popular. In this study, the effect of the microplate surfaces modified by three different monomers on the biofilm formation of CNS was investigated. Materials and Methods: A total of 60 isolated CNS isolates from blood and hand cultures were included into the study. As control strains, Staphylococcus epidermidis ATCC 35984, known to be biofilm positive, and S. epidermidis ATCC 12228 which do not form biofilm, were used. Slime formation was determined by the quantitative plaque assay method described by Christensen. In microplates, which were plain or modified by three different monomers, the biofilm formation behavior of all strains was investigated simultaneously and comparatively. Results: There was no difference in biofilm positivity between strains isolated from hand and blood. A total of 71.6% biofilm formation was observed on microplates, which were not coated with plasma technique, and on plasma-modified microplated surfaces, 80% (monomer: 3- mercaptopropionic acid), 65% (monomer: 2-hydroxyethyl methacylate) and 31.6% (monomer: ethylene glycol dimethacylate) biofilm formation was observed, respectively. It was found that ethylene glycol dimethacrylate in three monomers significantly inhibited biofilm formation when compared to other monomers. Conclusion: In recent years CNS, especially S. epidermidis has become the most frequently isolated bacteria in catheter infections and responsible for the 28% of nosocomial bacteremia. The widespread use of prosthetic and permanent devices has been shown as a reason for the increase in the frequency of this effect. In 90% of patients with S. epidermidis bacteremia, there is an intravascular catheter history. Biofilm is an extracellular structure containing water, proteins and carbohydrates and is responsible for the unwanted adhesion of microorganisms to host cells and artificial surfaces. The biofilm mechanism can be altered by the interaction between the material surface and the bacterial surface. In our study, in-vitro results were obtained showing the potential to reduce the risk of biofilm-associated infection by microorganism biofilm formation on modified surfaces with appropriate monomer selection.
A Comparison of Er:YAG Laser with Photon-Initiated Photoacoustic Streaming, Nd:YAG Laser, and Conventional Irrigation on the Eradication of Root Dentinal Tubule Infection by Enterococcus faecalis Biofilms: A Scanning Electron Microscopy Study
(2017) Gulsahi, Kamran; Ungor, Mete; Ozkaya, Burcu Ozses; Gocmen, Julide Sedef; 0000-0003-3510-7265; 29279728; ABG-7526-2020; AAF-7291-2021; AAX-5565-2021
This study evaluated the antimicrobial efficacy of Er:YAG laser activation with photon-initiated photoacoustic streaming (PIPS), Nd:YAG laser disinfection, and conventional irrigation on Enterococcus faecalis biofilms using scanning electron microscopy (SEM). Biofilms were grown on 110 root halves and divided into the following: Groups 1 and 2 (saline and 1% NaOCl with apical position of PIPS, resp.), Groups 3 and 4 (saline and 1% NaOCl with coronal position of PIPS, resp.), Groups 5 and 6 (Nd: YAG laser after saline and 1% NaOCl irrigation, resp.) and Groups 7, 8, and 9 (conventional irrigation with 1% NaOCl, 6% NaOCl, and saline, resp.). SEM images of the apical, middle, and coronal levels were examined using a scoring system. Score differences between Groups 1 and 2 were insignificant at all levels in the remaining biofilm. Group 4 had significantly greater bacterial elimination than Group 3 at all levels. Differences in Nd: YAG laser irradiation between Groups 5 and 6 were insignificant. Groups 7 and 8 were insignificantly different, except at the middle level. Saline group had a higher percentage of biofilms than the others. In this study, PIPS activation with NaOCl eliminates more E. faecalis biofilms in all root canals regardless of the position of the fiber tip.
Determination of virulence and multidrug resistance genes with polymerase chain reaction method in vancomycin-sensitive and -resistant enterococci isolated from clinical samples
(2016) Saba Copur, Sukran; Sahin, Fikret; Gocmen, Julide Sedef; 27513269
Background/aim: Enterococci play an important role in nosocomial infections. Therefore, this study investigates multidrug resistance (MDR) 1 gene areas in the pathogenicity of enterococci and virulence genes in both vancomycin-sensitive enterococci (VSE) and vancomycin-resistant enterococci (VRE) strains. Materials and methods: Virulence genes and MDR genes of enterococci were investigated by polymerase chain reaction (PCR). Results: We evaluated a total of 116 isolates, 93 being VRE and 23 being VSE. In this study, 95.6% of VRE (n = 93) were Enterococcus faecium (n = 89) and 4.3% were E. faecalis (n = 4), while 17.4% of VSE (n = 23) were E. faecium (n = 4) and 82.6% were E. faecalis (n = 19). The vanA MDR1 gene was detected in all VRE isolates. Among virulence genes, esp and hyl were detected in E. faecium, an enterococcus with the highest resistance to vancomycin, and gelE was detected in E. faecalis, an enterococcus with the highest sensitivity to vancomycin. Three or more virulence genes were identified only in VSE strains. We consider that it is a significant result that VSE had more virulence genes than VRE. Only esp was seen in VRE E. faecium strains. Conclusion: This study includes experimental results on the association of virulence characteristics in VRE and VSE strains.
Diverse efficacy of CarbaNP test among OXA-48 carbapenemase producing Enterobacterales in an endemic region
(2021) Istar, Elvan Hortac; Aliskan, Hikmet Eda; Gocmen, Julide Sedef; 0000-0001-9060-3195; 33661134; AAE-2282-2021
After the first description of OXA-48 type carbapenemase, it has become endemic in Europe, Mediterranean and North African countries in a short time. OXA-48 carbapenemase is the most difficult type to determine and accurate diagnosis is crucial especially in endemic areas. The CarbaNP test was described as a rapid phenotypic evaluation method of carbapenemases activity. Sensitivity and specifity of this test were high within all carbapenemases genes. In our study, we evaluated the efficacy of CarbaNP test in routine laboratories located in an endemic area of OXA-48 producing Enterobacterales. A total of 53 Enterobacterales isolates were included in this study. Antimicrobial susceptibility of the isolates to imipenem, meropenem and ertapenem was determined. Polymerase Chain Reaction (PCR) was carried out for the detection of carbapenemases genes (bla(KPC), bla(NDM), bla(BIC), bla(IMP), bla(VIM), bla(SPM), bla(AIM), bla(DIM), bla(GIM), bla(SIM), and bla(OXA-48)). The Carba NP test was performed as in the protocol described previously. Altogether 31 isolates (58.4%) were bla(OXA-48) positive (18 Klebsiella pneumoniae, 8 Escherichia coli, 2 Serratia marcescens, 1 Enterobacter aerogenes, 1 Pantoea agglomerans and 1 Morganella morganii). Among these isolates 3 (5.6%) and 2 (3.7%) isolates were also positive for bla(VIM) and bla(SPM), respectively. The sensitivity and specifity of CarbaNP test were found 64.5, and 68.2% respectively. It was observed that determination of positive isolates is hard to distinguish and subjective. The CarbaNP test has suboptimal results and low of sensitivity and specifity for detection of OXA-48 producing Enterobacterales, and not suitable for detection of bla(OXA-48) positive isolates in routine laboratories in endemic areas.
Efficiency of piezosurgery technique in miniscrew supported en-masse retraction: a single-centre, randomized controlled trial
(2017) Tuncer, Nilufer Irem; Arman-Ozcirpici, Ayca; Oduncuoglu, Bahar Fusun; Gocmen, Julide Sedef; Kantarci, Alpdogan; 0000-0003-0647-9481; 0000-0002-9250-3689; 28402521; ABG-7526-2020; AAQ-4792-2020; AAF-7291-2021
Piezoelectric surgery is a newly introduced technique for rapid tooth movement. However, the efficiency of this technique has not been investigated on en-masse retraction cases yet. To investigate the efficiency of piezosurgery technique in accelerating miniscrew supported en-masse retraction and study the biological tissue response. In addition, to show if this technique induces a difference in dental, skeletal and soft tissue changes on lateral cephalograms, and in canine and molar rotations, besides intercanine and intermolar widths on dental casts. We conducted a randomized, single-centred, parallel-group, controlled trial, requiring upper right and left first premolar extractions on 30 patients above the minimum age of 14 years at the beginning of retraction. Piezosurgery-assisted versus conventional en-masse retraction anchored from miniscrews placed between second premolars and first molars, bilaterally. The main outcome was the en-masse retraction rate. Secondary outcomes were gingival crevicular fluid (GCF) volume and GCF content of receptor activator of nuclear factor kappa beta ligand (RANKL), changes regarding cephalometric and dental cast variables, and miniscrew success rates. Accomplished with opaque, sealed envelopes. Applicable for data assessment only. Commenced in February 2013 and ended in October 2014. Thirty-one patients were included in the study and divided into 2 groups of piezosurgery (n = 16) and control (n = 15). After 9.3 months of follow-up, no statistically significant difference was observed between groups for neither retraction rates (P = 0.958) nor GCF parameters (P > 0.05). Changes in lateral cephalometric and dental cast variables, and miniscrew success rates did not show significant differences either. Based on the results of this study, piezosurgery technique was found to be ineffective in accelerating en-masse retraction, and promoting a difference in the studied GCF parameters, skeletal and dental variables. The trial was not registered. The full protocol of this PhD thesis study can be accessed from tez.yok.gov.tr.
Improvement in antimicrobial properties of titanium by diethyl phosphite plasma-based surface modification
(2020) Kaleli-Can, Gizem; Ozguzar, Hatice Ferda; Kahriman, Selahattin; Turkal, Miranda; Gocmen, Julide Sedef; Yurtcu, Erkan; Mutlu, Mehmet
Titanium (Ti) has been commonly used as a biomaterial for dental applications. However, they have struggled with the formation of polymicrobial infections leading to peri-implantitis. In this research, antimicrobial activity of titanium modified via diethyl phosphite (DEP) plasma onto Staphylococcus aureus (S. aureus) and Candida albicans (C. albicans), the two most frequently encountered pathogens in peri-implantitis, were investigated. Surface modification with DEP was achieved with plasma polymerization technique in a low-pressure/radio-frequency plasma using 75 W of plasma power and 10 min of exposure time under 0.15 mbar. Hydrophilicity, surface energy and roughness of Ti surface was increased and anionic Ti surface became amphoteric after surface modification according to physical and chemical examinations. This process significantly enhanced the anti-microbial efficiency of Ti towards S. aureus and C. albicans cells compared to control groups via contact killing. Moreover, DEP coating shown excellent compatibility with 93 % of L929 fibroblast cell viability. These findings revealed that amphoteric plasma polymer prepared from DEP offers promising solution for preventing biofilm formation on Ti.
PCR investigation of Panton-Valentine leukocidin, enterotoxin, exfoliative toxin, and agr genes in Staphylococcus aureus strains isolated from psoriasis patients
(2015) Gocmen, Julide Sedef; Sahiner, Neriman; Kocak, Mukadder; Karahan, Zeynep Ceren; 26775393
Background/aim: Staphylococcus aureus colonization is a determiner of disease activation in psoriasis patients. Here we evaluate the presence of genes encoding Panton-Valentine leukocidin (PVL), enterotoxins, TSST-1, exfoliative toxins, and the accessory gene regulatory locus by polymerase chain reaction (PCR) in S. aureus isolates obtained from healthy and diseased skin regions and anterior nares of psoriasis patients and healthy controls. Materials and methods: The presence of PVL and toxin genes was investigated, and agr typing was performed by PCR. Results: Eighteen of the isolated strains carried the sei, 1 carried the seb-sec, and 1 carried the seg enterotoxin gene. Eight of the strains carrying enterotoxin genes were isolated from nasal swabs, 6 from diseased skin swabs, and 4 from healthy skin swabs. None of the strains isolated from the control group carried the agr locus. On the other hand, 11 of the S. aureus strains isolated from the patients carried type 1, 7 carried type 1 + 3, 4 carried type 2, 4 carried type 3, and 1 carried type 1 + 2 agr loci. Conclusion: Enterotoxin production and the carried accessory gene regulatory locus may be important in the aggravation of psoriasis.
Prevention of Candida biofilm formation over polystyrene by plasma polymerization technique
(2020) Kaleli-Can, Gizem; Hortac-Istar, Elvan; Ozguzar, Hatice Ferda; Mutlu, Mehmet; Mirza, Hasan Cenk; Basustaoglu, Ahmet; Gocmen, Julide Sedef; 0000-0002-8853-3893; 0000-0002-2571-0637; F-1232-2015; AAI-8926-2021
This work investigates the antifungal effect of plasma polymer films produced by low-pressure RF-generated plasma system using acrylic acid, 2-hydroxyethyl methacrylate, and diethyl phosphite (DEP). Unmodified and plasma-modified polystyrene (PS) microplate wells were tested by 30 biofilm-positive Candida spp. isolated from blood samples and two control strains using a quantitative plaque assay method. Regardless of the precursors and plasma parameters, biofilm formation was inhibited for all plasma-modified microplate wells. The most significant anti-biofilm effect was observed on PS modified by DEP at 90 W plasma power with the inhibition of all Candida species' biofilm formation.