PubMed Kapalı Erişimli Yayınlar
Permanent URI for this collectionhttps://hdl.handle.net/11727/10764
Browse
2 results
Search Results
Item Determination of Biofilm Formation Properties of Methicillin Sensitive and Resistant Staphylococcus aureus Isolates by Conventional and Molecular Methods(2020) Hortac Istar, Elvan; Aliskan, Hikmet Eda; Basustaoglu, Ahmet; 0000-0002-2571-0637; 0000-0001-9060-3195; 32723278; AAI-8926-2021; AAE-2282-2021Biofilm-related infections are considered as among the foremost causes of treatment failure nowadays. One of the most common causes of biofilm-related infections is Staphylococcus aureus. It becomes extremely difficult to determine the appropriate treatment protocol while biofilm-related infections are coexisting with bacterial methicillin resistance. The aim of this study was to observe the potential of biofilm formation of methicillin-sensitive and -resistant S.aureus strains isolated from different clinical specimens and to determine reliable and effective methods for biofilm detection. A total of 200 S.aureus strains (100 methicillin-resistant and 100 methicillin-susceptible) isolated from 107 wound, 93 blood and catheter specimens, which were accepted as causative agents, included in the study. In order to determine the methicillin sensitivity, oxacillin minimal inhibitory concentration value obtained by an automated system and cefoxitin disc diffusion method were evaluated together. Biofilm formation was investigated by modified Christensen (MC), MTT, BioTimer and Congo Red Agar (CRA) methods, and the presence of ica operon responsible for biofilm formation was also observed by polymerase chain reaction. It has been shown that methicillin-resistant isolates produce biofilms in a shorter time and higher rate, and their biofilm structure is denser than methicillin-sensitive isolates in all MC, MTT and BioTimer methods. There was no difference between blood and wound isolates in biofilm formation. The most sensitive and specific conventional methods were MTT and BioTimer methods respectively. There was no significant difference between the isolates containing a gene region of icaADBC operon and the biofilm forming isolates according to MC, MTT, BioTimer and CCA methods. There was a high correlation between the presence of biofilm and ica positivity, and the tendency to form biofilm augmented as the number of ica genes increased. It has been emphasized that more virulent strains such as methicillin-resistant S.aureus have a higher tendency to form biofilm, and these two resistance mechanisms have been shown to support each other as cascade. ica detection may be an important reagent in itself for the detection of virulent strains, thus detection of the ica presence may be an early marker of treatment decisions, determination of protection strategies, and struggle with biofilm-related infections. In cases where molecular methods are not available, the existence of quick, easy-to-apply and reliable conventional methods to detect biofilm formation is extremely important. All conventional methods used in this study seem to be sufficient in this respect. MC and MTT methods stand out in terms of biofilm quantitation. BioTimer method is a very new and remarkable test used to detect biofilm formation. In conclusion, determining the potential of biofilm formation of colonizing or causative agents and taking essential precautions before interventional procedures will decrease biofilm related infections and related morbidity and mortality.Item Evaluation of Blood Culture Practices: Use of System (Epicenter) Data(2019) Basustaoglu, Ahmet; Suzuk Yildiz, Serap; Mumcuoglu, Ipek; Karahan, Zeynep Ceren; Ogunc, Dilara; Kaleli, Ilknur; Kursun, Senol; Evren, Ebru; Ozhak, Baysal Betil; Demir, Melek; Murray, Patrick; 30683035Sepsis is a serious clinical problem and estimated to be responsible for 18 million annual deaths worldwide. Therefore, the use and the rapid processing of blood cultures are important for the transition from empiric therapy to directed therapy. The aim of this study was to assess the best blood culture practices in Turkey. We have examined the collection practices and techniques at four different hospitals, and a total of 165.443 blood culture bottles were evaluated (2013-2015). At the preanalytical phase most of the data which were important and which could support hospital quality systems/practices were not entered into the HIS and EpiCenter system. At the analytical phase loading of the bottles and removal of positive bottles primarily occurred between 6:00 and 9:00 AM but the positivity rate of the bottles showed a homogeneous distribution throughout the day. In other words, there were significant delays at processing positive blood culture bottles related to laboratory workers. The effect of education regarding best practices, transition from single bottle to two bottle cultures was successful in all hospitals. Single bottle usage decreased below 10% in all hospitals. Significantly more positive cultures were detected at multiple cultures when compared with the single bottle collection practice. In retrospective patient records, it was seen that all the laboratories reported the results of Gram staining to the clinics. However, these data were not recorded to the Epicenter. The contamination rates of Ankara Numune Hospital and Akdeniz University Faculty of Medicine Hospital are 6.2% and 5.4% respectively, contamination rates were not reported in other hospitals. The most common isolates detected in blood cultures were Escherichia coli, Klebsiella pneumoniae, Enterococcus faecium, Staphylococcus aureus, and Acinetobacter baumannii. The mean time for the detection of these organisms were less than 20 hours in the aerobic bottle and anaerobic bottles. A total of 79.6% of facultative anaerobic isolates were detected in both bottles; 9.8% were detected only in the aerobic bottles; 10.6% of the isolates were detected only in the anaerobic bottles. As a result, the educational efforts in Turkey have met with success for transition from collecting single bottle blood culture sets to two bottle blood cultures. However, further efforts are needed to increase the number of blood culture sets collected during a 24 hour's period. In addition, errors at the preanalytical, analytical and postanalytical periods (taking samples, loading bottles into the system and processing positive blood cultures) should be eliminated.