Atahan Cagatay
Istanbul University
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Featured researches published by Atahan Cagatay.
Antimicrobial Agents and Chemotherapy | 2008
Amélie Carrër; Laurent Poirel; Haluk Eraksoy; Atahan Cagatay; Selim Badur; Patrice Nordmann
ABSTRACT The first outbreak of carbapenem-resistant Klebsiella pneumoniae isolates producing the plasmid-encoded carbapenem-hydrolyzing oxacillinase OXA-48 is reported. The 39 isolates belonged to two different clones and were collected at the University Hospital of Istanbul, Turkey, from May 2006 to February 2007, and they coproduced various β-lactamases (SHV-12, OXA-9, and TEM-1 for clone A and CTX-M-15, TEM-1, and OXA-1 for clone B).
BMC Infectious Diseases | 2001
Atahan Cagatay; Serkan Oncu; Semra Calangu; Taner Yildirmak; Halit Ozsut; Haluk Eraksoy
BackgroundMucormycosis (or zygomycosis) is the term for infection caused by fungi of the order Mucorales. Mucoraceae may produce severe disease in susceptible individuals, notably patients with diabetes and leukemia. Rhinocerebral mucormycosis most commonly manifests itself in the setting of poorly controlled diabetes, especially with ketoacidosis.Case PresentationA 31-year-old diabetic man presented to the outpatient clinic with the following signs and symptoms: headache, periorbital pain, swelling and loss of vision in the right eye. On physical examination his right eye was red and swollen. There was periorbital cellulitis and the conjunctiva was edematous. KOH preparation of purulent discharge showed broad, ribbonlike, aseptate hyphae when examined under a fluorescence microscope. Cranial MRI showed involvement of the right orbit, thrombosis in cavernous sinus and infiltrates at ethmoid and maxillary sinuses. Mucormycosis was diagnosed based on these findings. Amphotericin B (AmBisome®; 2 mg/kg.d) was initiated after the test doses. Right orbitectomy and right partial maxillectomy were performed; the lesions in ethmoid and maxillary sinuses were removed. The duration of the liposomal amphotericin B therapy was approximately 6 months and the total dose of liposomal amphotericin B used was 32 grams. Liposomal amphotericin B therapy was stopped six months later and oral fluconazole was started.ConclusionsAlthough a total surgical debridement of the lesions could not be performed, it is remarkable that regression of the disease could be achieved with medical therapy alone.
Medical Principles and Practice | 2007
Atahan Cagatay; Perihan Ergin Özcan; Leyla Gulec; Nurhan Ince; Simru Tugrul; Halit Ozsut; Nahit Çakar; Figen Esen; Haluk Eraksoy; Semra Calangu
Objective: The aim of this study was to follow critically ill patients prospectively in intensive care units (ICUs) to determine risk factors for mortality and outcome associated with nosocomial bacteraemia (NB). Subjects and Methods: A case-control study of 176 patients was conducted to identify the risk factors for mortality of NB in ICU patients. The study was performed in emergency, surgical and general surgical ICUs with 23 beds during a 15-month period. A total of 1,450 patients were admitted to the ICUs during the study period. The USA Center for Disease Control and Prevention definitions were used to diagnose nosocomial infections. Nosocomial bacteraemia was defined as the isolation of one or more organisms from blood cultures taken at least 48 h after admission, which were not related to a problem present on admission. An assessment of whether the isolated organisms represented true bacteraemia rather than contamination was made by clinical or laboratory evidence of infection. Results: A total of 214 bacteraemia episodes were found in the 176 patients (64 female, 112 male; 51.3 ± 21.3 years old), 90 of whom died and 86 survived. The bacteraemia rate was 12.1%. The most common etiological agents of bacteraemia were Klebsiella pneumoniae: 46 (21.5%), methicillin-resistant Staphylococcus aureus: 46 (21.5%), Pseudomonas aeruginosa: 32 (14.9%), and Escherichia coli: 20 (9.3%). Multivariate analysis showed that the requirement of mechanical ventilation for more than 7 days (p < 0.001), total parenteral nutrition (p = 0.034), inotropic drug (p < 0.001), and increased creatinine level (p = 0.034) were independent risk factors for mortality of NB in ICUs. Conclusions: Nosocomial infections caused by Gram-negative bacteria continue to be one of the major sources of morbidity and mortality.
BMC Infectious Diseases | 2005
Yasar Nakipoglu; Atahan Cagatay; Handan Katranci
BackgroundThe hetero-glycopeptide intermediate staphylococci is considered to be the precursor of glycopeptide intermediate staphylococci especially vancomycin intermediate Staphylococcus aureus (VISA). For this purpose, we aimed to investigate the heterogeneous resistance to glycopeptide and their frequencies in 135 Staphylococcus strains.MethodsHeterogeneous resistance of Staphylococcus strains was detected by inoculating the strains onto Brain Heart Infusion agar supplemented with 4 mg/L of vancomycin (BHA-V4). Agar dilution method was used for determining MICs of glycopeptides and population analysis profile was performed for detecting frequency of heterogeneous resistance for the parents of selected strains on BHA-4.ResultsEight (6%) out of 135 Staphylococcus strains were exhibited heterogeneous resistance to at least one glycopeptide. One (1.2%) out of 81 S. aureus was found intermediate resistance to teicoplanin (MIC 16 mg/L). Other seven strains were Staphylococcus haemolyticus (13%) out of 54 coagulase negative staphylococci (CoNS). Six of the seven strains were detected heterogeneously reducing susceptibility to vancomycin (MICs ranged between 5–8 mg/L) and teicoplanin (MICs ranged between 32–64 mg/L), and one S. haemolyticus was found heterogeneous resistance to teicoplanin (MIC 32 mg/L). Frequencies of heterogeneous resistance were measured being one in 106 – 107 cfu/ml. MICs of vancomycin and teicoplanin for hetero-staphylococci were determined as 2–6 folds and 3–16 folds higher than their parents, respectively. These strains were isolated from six patients (7%) and two (4%) of health care wokers hands. Hetero-VISA strain was not detected.ConclusionHeterogeneous resistance to glycopeptide in CoNS strains was observed to be significantly more emergent than those of S. aureus strains (vancomycin P 0.001, teicoplanin, P 0.007). The increase MICs of glycopeptide resistance for subpopulations of staphylococci comparing with their parents could be an important clue for recognizing the early steps in the appearance of VISA strains. We suggested to screen clinical S. aureus and CoNS strains, systematically, for the presence of heterogeneously resistance to glycopeptide.
European Journal of Gastroenterology & Hepatology | 2014
Resat Ozaras; Bilgul Mete; Bahadir Ceylan; Nail Ozgunes; Alper Gunduz; Hayat Kumbasar Karaosmanoglu; Atahan Cagatay; Kadir Gokturk; Levent Erdem; Funda Kocak; Ebubekir Senates; Fehmi Tabak
Background Hepatitis B virus (HBV) infection is a health problem worldwide. Current treatment options for chronic hepatitis B (CHB) are nucleoside or nucleotide analogues and pegylated interferons. Tenofovir and entecavir are much more commonly used as they have better efficacy, tolerability, and high genetic barriers to resistance. Aim The aim of this study was to assess the efficacies of tenofovir and entecavir in previously untreated CHB patients in a treatment cohort. Patients and methods We included CHB patients in a cohort including previously untreated HBeAg-positive and HBeAg-negative patients from 10 centers in Istanbul, Turkey. The patients were compared in terms of baseline characteristics, decrease in alanine transaminase (ALT), decrease in HBV-DNA to undetectable levels, HBeAg loss and anti-HBe development (among baseline HBeAg-positive patients), interventions to therapy because of lack of efficacy, side effects, severe side effects, and side effects that required change in treatment. Results The study included 121 patients who were administered tenofovir and 130 patients who were administered entecavir. The majority of patients were men, with mild to moderate histology in both treatment groups. The mean duration of follow-up was 18 and 20 months for tenofovir and entecavir, respectively. Patients receiving both drugs showed comparable rates of HBeAg loss, rates of undetectable HBV-DNA levels, rates of ALT normalization, ALT decrease, and decrease in HBV-DNA. Both drugs were well tolerated. Conclusion This study shows that although the baseline characteristics did not match, tenofovir and entecavir sustained comparable virological efficacies. More patients discontinued entecavir during follow-up. Both drugs provided effective viral control, with few side effects.
Clinical Microbiology and Infection | 2010
Hakan Erdem; Selim Kilic; O. Coskun; Y. Ersoy; Atahan Cagatay; P. Onguru; S. Alp
This investigation aimed both to delineate the current status of community-acquired acute bacterial meningitis and to produce data on the interrelationships between clinical, laboratory and therapeutic parameters in the elderly. This retrospective cohort study was conducted in 28 Turkish institutions in 159 culture-positive patients over the age of 50 years. Streptococcus pneumoniae was the most common pathogen (69.2%), followed by Listeria monocytogenes (8.8%). For this reason, antilisterial antibiotics such as ampicillin or benzylpenicillin should be added to the therapeutic regimen. Pathogen-specific mortality did not vary between S. pneumoniae and L. monocytogenes. The overall mortality was 2.5% at the third day, 12.6% at the seventh day, 20.1% at the 14th day and 21.4% at the 21st day. The risk factors for fatality were increasing age, the presence of stupor, sepsis and inappropriate antibiotic administration. Cerebrospinal fluid (CSF) leukocyte counts and CSF/blood glucose ratios were lower in patients who died. Fever did not differ between survivors and fatal cases. The mean duration of antibiotic therapy in survivors was 16.3 +/- 6.4 days. One-fifth of the patients had complications, and in 5.7% of the patients sequelae persisted at follow-up.
Journal of Aging Research | 2010
Atahan Cagatay; Fatih Tufan; Fehmi Hindilerden; Sibel Aydin; Omer Celal Elcioglu; Asli Karadeniz; Nilüfer Alpay; Suut Gokturk; Ozer Taranoglu
Introduction. Infectious diseases may present with atypical presentations in the geriatric patients. While fever is an important finding of infections, it may also be a sign of noninfectious etiology. Methods. Geriatric patients who were hospitalized for acute fever in our infectious diseases unit were included. Acute fever was defined as presentation within the first week of fever above 37.3°C. Results. 185 patients were included (82 males and 103 females). Mean age was 69.7 ± 7.5 years. The cause of fever was an infectious disease in 135 and noninfectious disease in 32 and unknown in 18 of the patients. The most common infectious etiologies were respiratory tract infections (n = 46), urinary tract infections (n = 26), and skin and soft tissue infections (n = 23). Noninfectious causes of fever were rheumatic diseases (n = 8), solid tumors (n = 7), hematological diseases (n = 10), and vasculitis (n = 7). A noninfectious cause of fever was present in one patient with no underlying diseases and in 31 of 130 patients with underlying diseases. Conclusion. Geriatric patients with no underlying diseases generally had infectious causes of fever while noninfectious causes were responsible from fever in an important proportion of patients with underlying diseases.
BMC Infectious Diseases | 2003
Atahan Cagatay; Tanil Kocagoz; Haluk Eraksoy
BackgroundResistance to contemporary broad-spectrum β-lactams, mediated by extended-spectrum β-lactamases (ESBL), is an increasing problem worldwide. Many of the emerging antimicrobial resistance problems of this decade have been characterized by difficulty in the recognition of resistance in the laboratory, particularly by rapid susceptibility test methods. The plasmid-encoded ESBL represent such a resistance phenomenon that is difficult to recognize.We compared Dio-Sensimedia-ES (DSM-ES; Diomed, Istanbul, Turkey) and Mueller-Hinton (MH) agar in the double-disk synergy test (DDST) as a novel rapid system for detecting ESBL directly from bacterial culture.MethodsSixty ESBL-producing Klebsiella pneumoniae isolates cultured from blood (30), endotracheal aspirates (20), urine (5) and pus (5), as well as 40 Escherichia coli isolates cultured from endotracheal aspirates (15), urine (10), blood (8) and pus (7) were studied. Isolates positive for ESBL by the combined disk tests were tested with the DDST using MH and DSM-ES agar to detect ESBL-mediated resistance in K. pneumoniae and E. coli. DSM-ES agar was also used to determine the susceptibility of Enterobacteriaceae and staphylococci.ResultsAmong 60 ESBL-producing K. pneumoniae isolates, 59 (98.3%) were identified as ESBL-positive by the DDST using MH, and 58 (96.6%), using DSM-ES agar. Of 40 ESBL-producing E. coli isolates, 38 (95%) were ESBL-positive by the DDST on MH agar, and 37 (92.5%), on DSM-ES agar. The average incubation period required for ESBL detection by the DDST on DSM-ES agar was 4 hours.ConclusionsSince the DDST results were available within 4 hours when DSM-ES agar was used, the use of this media may significantly lower the length of hospital stay, the total cost for patient care and even the mortality rate by fascilitating early treatment against ESBL-producing organisms.
Clinical Microbiology and Infection | 2015
Nese Saltoglu; Mucahit Yemisen; Onder Ergonul; Ayten Kadanali; Gül Karagöz; Ayse Batirel; Oznur Ak; Haluk Eraksoy; Atahan Cagatay; A. Vatan; Gonul Sengoz; Filiz Pehlivanoglu; Turan Aslan; Yasemin Akkoyunlu; Derya Ozturk Engin; Nurgul Ceran; B. Erturk; Lutfiye Mulazimoglu; Oral Oncul; Hakan Ay; Fatma Sargin; Nail Ozgunes; Funda Simsek; Taner Yildirmak; Nazan Tuna; Oguz Karabay; Kadriye Kart Yasar; Nuray Uzun; Yasar Kucukardali; M. Sonmezoglu
We aimed to investigate the predictors for limb loss among patients with diabetes who have complicated skin/soft-tissue infections. In this observational study, consecutive patients with diabetic foot infection (DFI) from 17 centres in Turkey, between May 2011 and May 2013 were included. The Turkish DFI Working Group performed the study. Predictors of limb loss were investigated by multivariate analysis. In total, 455 patients with DFI were included. Median age was 61 years, 68% were male, 65% of the patients were hospitalized, 52% of the patients had used antibiotics within the last month, and 121 (27%) had osteomyelitis. Of the 208 microorganisms isolated, 92 (44.2%) were Gram-positive cocci and 114 (54.8%) were Gram-negative rods (GNR). The most common GNR was Pseudomonas; the second was Escherichia coli, with extended spectrum β-lactamase positivity of 33%. Methicillin-resistant Staphylococcus species were found in 14% (29/208). Amputations were performed in 126/455 (28%) patients, 44/126 (34%) of these were major amputations. In multivariate analysis, significant predictors for limb loss were, male gender (OR 1.75, 95% CI 1.04-2.96, p 0.034), duration of diabetes >20 years (OR 1.9, 95% CI 1.18-3.11, p 0.008), infected ulcer versus cellulitis (OR 1.9, 95% CI 1.11-3.18, p 0.019), history of peripheral vascular disease (OR 2, 95% CI 1.26-3.27, p 0.004), retinopathy (OR 2.25, 95% CI 1.19-4.25, p 0.012), erythrocyte sedimentation rate >70 mm/hr (OR 1.6, 95% CI 1.01-2.68, p 0.05), and infection with GNR (OR 1.8, 95% CI 1.08-3.02, p 0.02). Multivariate analysis revealed that, besides the known risk factors such as male gender, duration of diabetes >20 years, infected ulcers, history of peripheral vascular disease and retinopathy, detection of GNR was a significant predictor of limb loss.
Mycoses | 2008
Atahan Cagatay; F. Cosan; Asli Karadeniz; S. K. Besısık; Halit Ozsut; M. Nalcaci; Y. Pekcelen; Haluk Eraksoy; G. Dincol; Semra Calangu
Invasive pulmonary aspergillosis (IPA) poses major management problems for clinicians caring for patients with haematological diseases. The clinical courses of patients with IPA who had been hospitalised in Hematology Unit, Bone Marrow Transplantation Unit and Infectious Diseases and Clinical Microbiology Unit between 1998 and 2005, the efficacy and adverse effects and costs of antifungal drugs (conventional amphotericin B deoxycholate, liposomal amphotericin B, amphotericin B lipid complex and caspofungin) used in the therapy of these patients were analysed in this study. Ninety‐three patients with IPA were reviewed retrospectively. Mean age of the patients was 40.4 ± 15.1 years (range 14–70 years). Fifty‐eight male patients and 35 female patients were included in the study. Manageable hypopotassemia, nausea/vomiting and headache were the most commonly observed side‐effects during antifungal (AF) therapy. While it was not found to be statistically significant with regard to the mean time to resolution of fever (P = 0.8), it was found to be statistically significant with regard to radiological regression at 30th day, and mean duration of therapy between patients who were dead or alive (P < 0.05, P < 0.001). Total cost of AF therapy for 93 patients was found to be US