Browsing by Author "Olmez, Serpil"

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Comparison of Conventional Methods, Automated Systems, and Dna Sequence Analysis Methods in the Identification of Corynebacterium Afermentans and Corynebacterium Mucifaciens Bacteria Isolated From Blood and Catheter Culture Samples
(Mary Ann Liebert, inc, 2021) Olmez, Serpil; Tuncer, Ozlem; Parlak, Mehmet; Bicakcigil, Asiye; Gursoy, Nafia Canan; Otlu, Baris; Sancak, Banu
The aim of this study is to compare different methods due to the difficulties in identifying coryneform bacteria to species level and to determine antibiotic resistance profiles. Isolates identified as Turicella otitidis (n:45) by VITEK 2 Compact and Corynebacterium mucifaciens (n:1) by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), isolated from blood and catheter cultures between 2015 and 2017 were included in the study. For identification of the isolates, conventional tests and 16S rDNA sequence analysis were performed. Antibiotic susceptibilities of the isolates were determined by Etest. The isolates identified as T. otitidis with VITEK 2 Compact could not be identified by MALDI-TOF MS and described as C. mucifaciens/Corynebacterium afermentans spp. by 16S rDNA sequence analysis. One isolate identified as C. mucifaciens by MALDI-TOF MS could not be identified with VITEK 2 Compact and described as C. mucifaciens by 16S rDNA sequence analysis and conventional methods. All isolates (n:45) described as C. mucifaciens/C. afermentans spp. by 16S rDNA sequence analysis were identified as C. afermentans subsp. afermentans with conventional methods. All 45 isolates identified as C. afermentans subsp. afermentans were resistant to penicillin, erythromycin, and clindamycin and were susceptible to vancomycin and daptomycin, whereas 31 (69%) were resistant to trimethoprim-sulfamethoxazole (TMP-SXT). The isolate identified as C. mucifaciens was susceptible to penicillin, vancomycin, daptomycin, and TMP-SXT; it was resistant to erythromycin and clindamycin. In this study, we reported 45 C. afermentans isolates misidentified as T. otitidis in routine laboratory processes. To our knowledge, this is the first study to include the highest number of C. afermentans blood isolates.
The Microbiological Analysis of a Rhizobium Radiobacter Outbreak After Intravitreal Injection
(Ankara Microbiology Soc, 2020) Parlak, Mehmet; Batur, Muhammed; Olmez, Serpil; Guducuoglu, Huseyin; Otlu, Baris
Rhizobium radiobacter, which is found in nature and causes tumorigenic plant diseases can lead to opportunistic infections, especially in people with underlying diseases. In our study, endophthalmitis that observed in ten patients caused by R.radiobacter bacteria after intravitreal ranibizumab injection in Ophthalmology Clinic were examined microbiologically. Vitreous fluid samples of 13 patients who received intravitreal ranibizumab injection were sent to the Microbiology Laboratory from Van Yuzuncu Yil University Faculty of Medicine's Ophthalmology Clinic for microbiological examination in December 21, 2016. Samples were examined under microscope after staining with Gram and cultured with 5% sheep blood agar and Eosin Methylene Blue (EMB) agar. The culture plates were incubated for 18-24 hours at 37 degrees C in 5% CO2. At the end of this period, catalase, oxidase, and urease tests were performed on the colonies. The identification and antibiotic susceptibility tests of microorganisms growing in vitreous fluid samples were performed using BD Phoenix (Becton Dickinson, USA), Vitek 2 Compact (BioMerieux, France), and Vitek MS (BioMerieux, France) systems. In addition, 16S rDNA sequence analysis was performed and the pulsed field gel electrophoresis (PFGE) method was used to determine the clonal relationship between the isolates. After growing in cultures (one day after the procedure), culture samples were collected from the objects, medical tools and equipment, hands of healthcare staff and a new injection solution in the area where the procedure was performed. R.radiobacter was isolated in 10 of the vitreous fluid samples of 13 patients, and no bacterial growth was detected in 3. The microorganisms were found to be gram-negative bacilli, non-fermenter, motile, catalase/oxidase/urease positive, in compliance with R.radiobacter. All isolates were identified as R.radiobacter by BD Phoenix (Becton Dickinson, USA), Vitek 2 Compact (BioMerieux, France), and Vitek MS (BioMerieux, France) (database v2.0) systems. R.radiobacter isolates were found to be resistant to ampicillin, amoxicillin/clavulanate, trimethoprim/sulfamethoxazole, cefotaxime and ceftazidime; susceptible to cefuroxime, cefepime, amikacin, gentamicin, imipenem, meropenem, ciprofloxacin, levofloxacin and piperacillin/tazobactam. The isolates were identified as R.radiobacter by 16S rDNA sequence analysis. PFGE showed that all isolates had the same band profile. R.radiobacter isolates with the same band profile likely revealed that the contamination was from the same source. However, the growth of R.radiobacter was not detected in the cultures made from the objects, medical instruments and supplies, the hands of healthcare professionals and the new injection solution in the area where the procedure was performed, and the source of the agent could not be determined. The results have shown that intravitreal injection procedure carries a risk for R.radiobacter infection. Disinfection and antisepsis conditions, before and during the procedure, is important for the prevention of such infections. This study is the first epidemic outbreak report of endophthalmitis caused by the same strain of R.radiobacter and the second article in which R.radiobacter was reported as the cause of endophthalmitis after intravitreal injection.