Browsing by Author "Ormen, Bahar"

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    Molecular Characterization of Drug Resistance in Hepatitis B Viruses Isolated from Patients with Chronical Infection in Turkey
    (2018) Aydin, Mehtap; Asan, Ali; Sayan, Murat; Akhan, Sila; Koruk, Suda Tekin; Aygen, Bilgehan; Sirmatel, Fatma; Eraksoy, Haluk; Tuna, Nazan; Kose, Sukran; Kaya, Ali; Tulek, Necla Eren; Demir, Nazlim Aktug; Mistik, Resit; Ormen, Bahar; Korkmaz, Fatime; Yildirmak, Taner; Ural, Onur; Turgut, Huseyin; Gunal, Ozgur; Demirtuk, Nese
    Background: Hepatitis B virus (HBV) has a high mutation rate due to its unusual replication strategy leading to the production of a large number of virions with single and double mutations. The mutations, in turn, are associated with the development of drug resistance to nucleos(t)ide analogs (NUCs) in patients before and during NUCs therapy. Objectives: The current study aimed at investigating the molecular characterization of HBV in Turkish patients with chronic hepatitis B (CHB) infection. Methods: Polymerase chain reaction (PCR) amplification and direct sequencing procedures were used to analyze mutations. The detected drug resistance mutations were divided into the nucleos(t) ide analogs primary, partial, and compensatory resistance groups. The amino acid substitutions of hepatitis B surface antigen (HBsAg) were categorized into antiviral drug - associated potential vaccine-escape mutations (ADAPVEMs) and typical HBsAg amino acid substitutions, which included hepatitis B hyperimmunoglobulin (HBIg) - selected escape mutation, vaccine escape mutation, hepatitis B misdiagnosis, and immune - selected amino acid substitutions. Results: The number of patients included in the study was 528 out of which 271 (51.3%) were treatment - naive and 351 (66.3%) were hepatitis B e antigen (HBeAg) - negative. Moreover, 325 (61.6%) were males with a mean age of 38 years (range: 18 - 69). Primary, partial, and compensatory resistance to NUCs was reported in 174 (32.9%) patients. Six different ADAPVEM motifs were determined in both treatment - naive and treatment - experienced patients, namely, sF161L/rtI169X, sE164D/rtV173L, sL172L/rtA181T, sL173F/rtA181V, sS195M/rtM204V, and sS196L/rtM204I. The prevalence of ADAPVEMs and typical HBsAg escape mutations was 5.3% (n = 28) and 34.8% (n = 184), respectively. Conclusions: The analysis of drug resistance should constitute a fundamental part of the follow - up period of patients with CHB undergone treatment with NUCs. The surveillance of development of drug resistance mutations, while receiving treatment for hepatitis B is of paramount importance to monitor and control the emerging resistance.
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    Variables Determining Mortality in Patients With Acinetobacter Baumannii Meningitis/Ventriculitis Treated With Intrathecal Colistin
    (2017) Ceylan, Bahadir; Arslan, Ferhat; Sipahi, Oguz Resat; Sunbul, Mustafa; Ormen, Bahar; Hakyemez, Ismail N; Turunc, Tuba; Yildiz, Yesim; Karsen, Hasan; Karagoz, Gul; Tekin, Recep; Hizarci, Burcu; Turhan, Vedat; Senol, Sebnem; Oztoprak, Nefise; Yilmaz, Mesut; Ozdemir, Kevser; Mermer, Sinan; Kokoglu, Omer F.; Mert, Ali; 28013184
    Aim: To examine the variables associated with mortality in patients with Acinetobacter baumannii-related central nervous system infections treated with intrathecal colistin. Materials and methods: This multi-centre retrospective case control study included patients from 11 centres in Turkey, as well as cases found during a literature review. Only patients with CNS infections caused by multidrug-resistant or extensively drug-resistant Acinetobacter baumannii treated with intrathecal colistin were included in this study. The variables associated with mortality were determined by dividing the patients into groups who died or survived during hospitalisation, and who died or survived from Acinetobacter meningitis. Results: Among the 77 cases enrolled in the study, 35 were found through a literature review and 42 were cases from our centres. Forty-four cases (57.1%) were male and the median age was 48 years (range: 20-78 years). Thirty-seven patients (48%) died during hospitalisation. The variables associated with increased all-cause mortality during hospitalisation included old age (odds ratio, 1.035; 95% confidence interval (Cl), 1.004-1.067; p = 0.026) and failure to provide cerebrospinal fluid sterilisation (odds ratio, 0.264; 95% confidence interval, 0.097-0.724; p = 0.01). There is a trend (P=0.062) towards higher mortality with using of meropenem during meningitis treatment. Fifteen cases (19%) died from meningitis. There were no significant predictors of meningitis-related mortality. Conclusions: The mortality rate for central nervous system infections caused by multidrug-resistant or extensively drug-resistant Acinetobacter baumannii is high. Old age and failure to provide CSF sterilisation are associated with increased mortality during hospitalisation. (C) 2016 Published by Elsevier B.V.