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  • PublicationOpen Access
    Clostridium difficile Colonization Before and After Hospitalization in Children
    (2021-11-01T00:00:00Z) Rzayev, Turkay; YÜKSEL MAYDA, PELİN; ERKAN, Tülay; KOCAZEYBEK, Bekir Sami; KUTLU, Hüseyin Tufan; YÜKSEL MAYDA, PELİN
    Background: Beginning in the early 2000s, Clostridium difficile infection has become a major health problem in the United States, Canada, and in most European countries and has not only increased in incidence but also the severity. There are 2 conditions for the development of C. difficile infection: disruption of the normal gastrointestinal flora, and exogenous ingestion of the microorganism. We aimed to study C. difficile colonization in hospitalized children. We identified 2 issues: (1) the relationship between risks before hospital admission and colonization on the first day of hospitalization and (2) the effect of the factors that patients are exposed to during hospitalization on the colonization status at discharge. Methods: Patients aged between 2 and 18 years who were hospitalized with various diagnoses were included in this study. C. difficile toxin A/B was investigated in the stool samples taken on the admission and discharge days. Results: One hundred six patients were included in the study, of whom 24.5% and 48.1% of hemato-oncology patients were positive for C. difficile toxin A/B. Antibiotic usage within 1 month preceding hospitalization and the presence of underlying disease impact the C. difficile colonization status on the first day of hospitalization. Conclusion: Toxigenic C. difficile colonization prevalence is high in hospitalized children, especially in the hemato-oncology patient group.
  • PublicationMetadata only
    Point Mutations at gyrA and gyrB Genes of Levofloxacin Resistant Helicobacter pylori Strains and Dual Resistance with Clarithromycin
    (2021-01-01T00:00:00Z) Ziver-Sarp, Tevhide; YÜKSEL MAYDA, PELİN; Saribas, Suat; DEMİRYAS, Süleyman; Gareayaghi, Nesrin; ERGİN, Sevgi; TAŞÇI, İhsan; Ozbey, Dogukan; BAL, Kadir; Erzin, Yusuf; AKKUŞ, Seher; BAHAR TOKMAN, Hrisi; Demirci, Mehmet; Tufan-Kocak, Banu; KOCAZEYBEK, Bekir Sami; YÜKSEL MAYDA, PELİN
    Background: Spontaneous point mutations in genes encoding gyrA/B subunits of DNA gyrase are responsible for fluoroquinolone resistance. We aimed to determine the clarithromycin and levofloxacin resistance phenotypically in H. pylori strains and to investigate the mutations responsible for levofloxacin resistance and the effects of these mutations on dual antibiotic resistance. Methods: A total of 65 H. pylori isolates were included. The E-test method was used for the clarithromycin and le-vofloxacin antimicrobial susceptibility test. Real-time PCR was used to detect the point mutations. Results: Twenty-four (36.9%) of 65 H. pylori strains were phenotypically resistant to clarithromycin and 14 (21.5%) to levofloxacin. The phenotypic levofloxacin resistance rate of strains with Asn87Lys and Asp91Asn mu-tations were significantly higher (gyrA gene) (p < 0.05). The phenotypic levofloxacin resistance rate of strains with Arg484Lys and Asp481Glu mutations were significantly higher (gyrB gene) (p < 0.05). The Asn87Lys mutation in-creased the risk of phenotypes being resistant to levofloxacin 70.156 times and Asp91Asn mutation increased 125,427 times higher. Seven (10.8%) of 65 H. pylori strains showed dual resistance to both levofloxacin and cla-rithromycin. The rate of being dual resistant with A2143G mutation (clarithromycin resistance) was found to be significantly higher (p < 0.05). Conclusions: The Asn87Lys and Asp91Asn mutations in the gyrA gene had a phenotypically enhancing effect on levofloxacin resistance, while the presence of Asp481Glu and Arg484Lys mutations in the gyrB gene did not. The existence of dual resistance was developed with the increase in clarithromycin and levofloxacin resistance rates. (Clin. Lab. 2021;67:2369-2377. DOI: 10.7754/Clin.Lab.2021.210843)