TR-Dizin İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/11727/4808
Browse
2 results
Search Results
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.Item Complicated left-sided infective endocarditis in chronic hemodialysis patients: a case report(2017) Gulmez, Oyku; Aydin, Mehtap; 0000-0002-9429-5430; 28106022; ABC-7134-2021; AAE-6201-2021Infective endocarditis (IE) is a serious infectious condition with high morbidity and mortality in patients with end-stage renal disease (ESRD). It has been particularly associated with recurrent bacteremia due to vascular access via lumen catheters. The most common pathogen is Staphylococcus (S.) aureus, and most affected valve is mitral valve, which frequently calcified. Two patients with ESRD who received hemodialysis treatment via tunneled catheters, aged 56 and 88 years, were admitted with fever and high troponin level. Blood cultures revealed growth of S. aureus. Good quality transthoracic echocardiography (TTE) displayed calcified mitral and aortic valves with no vegetation or abscess formation. Myocardial necrosis as result of catheter infection was considered. Both patients had persistent positive blood cultures 3 and 5 days after initiation of antibiotic treatment. Therefore, transesophageal echocardiogram (TEE) was scheduled. Results revealed perivalvular abscess in the older patient, and highly mobile vegetation in the younger patient. The older patient refused surgery and died soon after due to refractory shock. Mitral valve surgery was planned for the other patient; however, she developed left ventricular failure and bleeding, and also subsequently died as result of refractory shock. Patient evaluations were particularly unfavorable: they had catheter infection as primary focus, and TTE did not detect vegetation or annular abscess. Diagnosis of IE in patients with ESRD using Duke criteria is problematic; we have to keep use of TEE in mind to detect vegetation or abscess formation when there is clinical suspicion regarding ESRD patients even after good quality TTE.