TR-Dizin İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/11727/4808
Browse
4 results
Search Results
Item 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; 26775393Background/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.Item 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; 27513269Background/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.Item Antibiotic resistance of streptococcus pneumoniae and haemophilus influenzae isolated from respiratory tract specimens(2016) Aliskan, Hikmet Eda; Colakoglu, Sule; Gocmen, Julide SedefPurpose: 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%.Item 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-6138-2021Introduction: 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.