Browsing by Author "Ozdemir, Mehmet"

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Detection of the Frequency of Per-1 Type Extended-Spectrum Β-Lactamase Acinetobacter Baumannii Clinical Isolates in Turkey: a Multicenter Study
(Tubitak Scientific & Technological Research Council Turkey, 2014) Asik, Gulsah; Ozdemir, Mehmet; Kurtoglu, Muhammet Guzel; Yagci, Server; Oksuz, Lutfiye; Gul, Mustafa; Ciftci, Ihsan Hakki
Background/aim: beta-Lactamases are an important resistance mechanism in Acinetobacter baumannii. Pseudomonas extended-resistance (PER-1) type beta-lactamase-producing strains have been reported from various geographic locations; however, PER-1 type beta-lactamases from Turkish hospitals have not been investigated extensively. The aim of this study was to determine the prevalence of PER-1 type beta-lactamases in A. baumannii isolates in various regions of Turkey. Materials and methods: A total of 763 clinical A. baumannii isolates were collected from 9 university hospitals and 2 state hospitals between 2008 and 2011. Molecular amplification of the OXA-51 gene from the A. baumannii genome was performed in order to verify identification of the species. Real-time polymerase chain reaction was used to detect bla(PER-1) genes. Results: PER-1 was detected in 24.6% of the isolates. The annual frequencies of the PER-1 enzyme were detected as 52.2%, 35.9%, and 8.3% in 2008, 2009, and 2010, respectively. PER-1 prevalence decreased gradually over time. The differences observed in PER-1 prevalence among the regions of Turkey were statistically significant (chi-square test; P < 0.001). Conclusion: These data demonstrate that the frequency of detection of PER-1 type beta-lactamases in A. baumannii species has decreased in Turkey. However, the increased carbapenem resistance, together with multidrug resistance, has created a worrisome situation regarding this pathogen.
A Multicenter Evaluation of Blood Culture Practices, Contamination Rates, and the Distribution of Causative Bacteria
(Briefland, 2016) Altindis, Mustafa; Koroglu, Mehmet; Demiray, Tayfur; Dal, Tuba; Ozdemir, Mehmet; Sengil, Ahmet Zeki; Karabay, Oguz
Background: The prognostic value of blood culture testing in the diagnosis of bacteremia is limited by contamination. Objectives: In this multicenter study, the aim was to evaluate the contamination rates of blood cultures as well as the parameters that affect the culture results. Materials and Methods: Sample collection practices and culture data obtained from 16 university/research hospitals were retrospectively evaluated. A total of 214,340 blood samples from 43,254 patients admitted to the centers in 2013 were included in this study. The blood culture results were evaluated based on the three phases of laboratory testing: the pre-analytic, the analytic, and the post-analytic phase. Results: Blood samples were obtained from the patients through either the peripheral venous route (64%) or an intravascular catheter (36%). Povidone-iodine (60%) or alcohol (40%) was applied to disinfect the skin. Of the 16 centers, 62.5% have no dedicated phlebotomy team, 68.7% employed a blood culture system, 86.7% conducted additional studies with pediatric bottles, and 43.7% with anaerobic bottles. One center maintained a blood culture quality control study. The average growth rate in the bottles of blood cultures during the defined period (1259 -26,400/year) was 32.3%. Of the growing microorganisms, 67% were causative agents, while 33% were contaminants. The contamination rates of the centers ranged from 1% to 17%. The average growth time for the causative bacteria was 21.4 hours, while it was 36.3 hours for the contaminant bacteria. The most commonly isolated pathogens were Escherichia coli (22.45%) and coagulase-negative staphylococci (CoNS) (20.11%). Further, the most frequently identified contaminant bacteria were CoNS (44.04%). Conclusions: The high contamination rates were remarkable in this study. We suggest that the hospitals' staff should be better trained in blood sample collection and processing. Sterile glove usage, alcohol usage for disinfection, the presence of a phlebotomy team, and quality control studies may all contribute to decreasing the contamination rates. Health policy makers should therefore provide the necessary financial support to obtain the required materials and equipment.