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    Analysis of an outbreak of echinocandin-resistant clonal Candida parapsilosis complex harbouring ERG11Y132F and FKS1S656P mutations
    (W B Saunders Co Ltd, 2026) Kapmaza, M.; Dogan, O.; Irkoren, P.; Cam, K.; Tanriverdi, E. S.; Genc, Z.; Tas, E.
    Aim: We aimed to analyse echinocandin-resistant (ECR) Candida parapsilosis complex candidaemia episodes. Methods: A retrospective cohort study was conducted at Koc, University Hospital from 1st January 2018 to 30th March 2022, during the COVID-19 pandemic. A total of 307 candidaemia isolates were obtained from 249 patients. A total of 272 episodes had monocandidaemia, while 16 episodes had poly-candidaemia. Antifungal susceptibility with broth microdilution with environmental microbiological sampling were obtained. Sequencing and amplification of the resistance genes with genotyping were carried out, and pulse field gel electrophoresis was performed in the isolates. Results: Of the 272 isolates that caused mono-candidaemia, 139 (51.1%) were identified as C. parapsilosis complex, with 64 (46%) demonstrating micafungin resistance. The isolates yielded Y132F mutation in the ERG11, and S656P mutation in the FKS1 genes, primarily genotypes A and A1. The 30-day mortality rates were 51.6% (33/64) for ECR C. parapsilosis complex, 38.9% (14/36) for fluconazole-resistant C. parapsilosis complex, and 35.9% (14/ 39) for fluconazole-susceptible C. parapsilosis complex. Environmental cultures showed that 23 of 60 samples yielded ECR C. parapsilosis complex, predominantly from interior parts and handles of infusion pumps used in oncology wards with a total clonal similarity with the clinical isolates. Conclusions: This is the first report of the FKS1S656P mutation in ECR C. parapsilosis complex isolates from Turkey, and it highlights a significant outbreak associated with an unnoticed gap in cleaning of the interior parts of infusion pumps. Enhanced cleaning protocols, combined with on-site feedback, resulted in no new cases within the next 2 months.
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    Mono- and dinuclear Pd(II) complexes of different salicylaldimine ligands as catalysts of transfer hydrogenation of nitrobenzene with cyclohexene and Suzuki-Miyaura coupling reactions
    (Elsevier Science Sa, 2009) Tas, E.; Kilic, A.; Durgun, M.; Yilmaz, I.; Ozdemir, I.; Gurbuz, N.
    In this study, the synthesis, spectroscopic, catalytic, and electrochemical properties of salicylaldimine Schiff-base ligands (L-n) and their dinuclear Pd(II) complexes for L-1 and L-2 ligands with mononuclear Pd(II) complexes for L-3 and L-4 ligands were investigated. The ligands and their mono- or dinuclear Pd(II) complexes were characterized by FT-IR, UV-Vis, H-1 NMR and elemental analysis, as well as through magnetic susceptibility and spectroelectrochemical techniques. The catalytic studies showed that the introduction of tert butyl groups on the salicyl ring of the molecules increased the catalytic activity towards hydrogenation of nitrobenzene and cyclohexene in DMF at 25 and 45 degrees C. It was also observed that the steric hindered mono- and dinuclear Pd( II) complexes were thermally stable complexes and were not sensitive to air or the moisture. The complexes were easily prepared from cheap materials that could be used as versatile and efficient catalysts for different C-C coupling reactions (Suzuki-Miyaura reactions). (C) 2008 Elsevier B.V. All rights reserved.