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Featured researches published by Levent Gorenek.


Antimicrobial Agents and Chemotherapy | 2012

Efficacy and Tolerability of Antibiotic Combinations in Neurobrucellosis: Results of the Istanbul Study

Hakan Erdem; Aysegul Ulu-Kilic; Selim Kilic; Mustafa Kasım Karahocagil; Ghaydaa A. Shehata; Funda Yetkin; Mustafa Kemal Celen; Nurgul Ceran; Hanefi Cem Gül; Gürkan Mert; Suda Tekin-Koruk; Murat Dizbay; Ayse Seza Inal; Saygın Nayman-Alpat; Mile Bosilkovski; Dilara Inan; Nese Saltoglu; Laila Abdel-Baky; Maria Teresa Adeva-Bartolome; Bahadir Ceylan; Suzan Sacar; Vedat Turhan; Emel Yilmaz; Nazif Elaldi; Zeliha Kocak-Tufan; Kenan Ugurlu; Basak Dokuzoguz; Hava Yilmaz; Sibel Gundes; Rahmet Guner

ABSTRACT No data on whether brucellar meningitis or meningoencephalitis can be treated with oral antibiotics or whether an intravenous extended-spectrum cephalosporin, namely, ceftriaxone, which does not accumulate in phagocytes, should be added to the regimen exist in the literature. The aim of a study conducted in Istanbul, Turkey, was to compare the efficacy and tolerability of ceftriaxone-based antibiotic treatment regimens with those of an oral treatment protocol in patients with these conditions. This retrospective study enrolled 215 adult patients in 28 health care institutions from four different countries. The first protocol (P1) comprised ceftriaxone, rifampin, and doxycycline. The second protocol (P2) consisted of trimethoprim-sulfamethoxazole, rifampin, and doxycycline. In the third protocol (P3), the patients started with P1 and transferred to P2 when ceftriaxone was stopped. The treatment period was shorter with the regimens which included ceftriaxone (4.40 ± 2.47 months in P1, 6.52 ± 4.15 months in P2, and 5.18 ± 2.27 months in P3) (P = 0.002). In seven patients, therapy was modified due to antibiotic side effects. When these cases were excluded, therapeutic failure did not differ significantly between ceftriaxone-based regimens (n = 5/166, 3.0%) and the oral therapy (n = 4/42, 9.5%) (P = 0.084). The efficacy of the ceftriaxone-based regimens was found to be better (n = 6/166 [3.6%] versus n = 6/42 [14.3%]; P = 0.017) when a composite negative outcome (CNO; relapse plus therapeutic failure) was considered. Accordingly, CNO was greatest in P2 (14.3%, n = 6/42) compared to P1 (2.6%, n = 3/117) and P3 (6.1%, n = 3/49) (P = 0.020). Seemingly, ceftriaxone-based regimens are more successful and require shorter therapy than the oral treatment protocol.


Burns | 2014

Nosocomial infection characteristics in a burn intensive care unit: Analysis of an eleven-year active surveillance

Oral Oncul; Sinan Oksuz; Ali Acar; Ersin Ülkür; Vedat Turhan; Fatih Uygur; Asim Ulcay; Hakan Erdem; Mustafa Özyurt; Levent Gorenek

AIMS The objective of this study was to describe nosocomial infection (NI) rates, risk factors, etiologic agents, antibiotic susceptibility, invasive device utilization and invasive device associated infection rates in a burn intensive care unit (ICU) in Turkey. METHODS Prospective surveillance of nosocomial infections was performed according to Centers for Disease Control and Prevention (CDC) and National Healthcare Safety Network (NHSN) criteria between 2001 and 2012. The data was analyzed retrospectively. RESULTS During the study period 658 burn patients were admitted to our burn ICU. 469 cases acquired 602 NI for an overall NI rate of 23.1 per 1000 patient days. 109 of all the cases (16.5%) died. Pseudomonas aeruginosa (241), Acinetobacter baumannii (186) and Staphylococcus aureus (69) were the most common identified bacteria in 547 strains. CONCLUSION Total burn surface area, full thickness burn, older age, presence of inhalation injury were determined to be the significant risk factors for acquisition of NI. Determining the NI profile at a certain burn ICU can lead the medical staff apply the appropriate treatment regimen and limit the drug resistance. Eleven years surveillance report presented here provides a recent data about the risk factors of NI in a Turkish burn ICU.


Journal of Diabetes and Its Complications | 2012

How reliable are cultures of specimens from superficial swabs compared with those of deep tissue in patients with diabetic foot ulcers

Mesut Mutluoglu; Gunalp Uzun; Vedat Turhan; Levent Gorenek; Hakan Ay; Benjamin A. Lipsky

PURPOSE To assess the reliability of cultures of superficial swabs (SS) by comparing them with cultures of concomitantly obtained deep tissue (DT) specimens in patients with diabetic foot ulcers. METHODS We reviewed clinical and microbiological data from patients with diabetes who presented during a two-year period to our hyperbaric medicine center with a foot ulcer. We identified patients who had at least one concomitantly collected SS and DT pair of specimens sent for culture. RESULTS A total of 89 culture pairs were available from 54 eligible patients, 33 (61.1%) of whom were hospitalized. Wounds were infected in 47 (87.0%) of the patients and 28 (51.9%) patients had received antibiotic therapy within the previous month. Overall, 65 (73%) of the SS and DT pairs had identical culture results, but in 11 (16.9%) cases the cultures were sterile; thus, only 54 (69.2%) of the 78 culture-positive pairs had identical results. Compared with DT, SS cultures yielded ≥1 extra organism in 10 (11.2%) cases, missed at least one organism in 8 (9.0%), and were completely different in 6 (6.7%). When compared to DT culture results, SS cultures had a positive predictive value of 84.4%, negative predictive value of 44.0%, and overall accuracy of 73.0%. CONCLUSIONS In patients with diabetic foot ulcers, results of specimens for culture taken by SS did not correlate well with those obtained by DT. This suggests that SS specimens may be less reliable for guiding antimicrobial therapy than DT specimens.


Brazilian Journal of Infectious Diseases | 2010

HBV, HCV and HIV seroprevalence among blood donors in Istanbul, Turkey: how effective are the changes in the national blood transfusion policies?

Ali Acar; Sabri Kemahli; Husnu Altunay; Erdogan Kosan; Oral Oncul; Levent Gorenek; Saban Cavuslu

The national blood transfusion policies have been changed significantly in recent years in Turkey. The purpose of this study was to determine the prevalence of HBV, HCV, and HIV in blood donors at the Red Crescent Center in Istanbul and to evaluate the effect of changes in the national blood transfusion policies on the prevalence of these infections. The screening results of 72695 blood donations at the Red Crescent Center in Istanbul between January and December 2007 were evaluated retrospectively. HBsAg, anti-HCV, and anti-HIV-1/2 were screened by microparticle enzyme immunoassay (MEIA) method. Samples found to be positive for anti-HIV 1/2 and anti-HCV were confirmed by Inno-Lia HCV Ab III and Inno-Lia HIV I/II Score, respectively. The seropositivity rates for HBsAg, anti-HCV, and anti-HIV-1/2 were determined as 1.76%, 0.07%, and 0.008%, respectively. Compared to the previously published data from Red Crescent Centers in Turkey, it was found that HBV and HCV seroprevalances decreased and HIV seroprevalance increased in recent years. In conclusion, we believe that the drop in HBV and HCV prevalence rates are likely multifactorial and may have resulted from more diligent donor questioning upon screening, a higher level of public awareness on viral hepatitis as well as the expansion of HBV vaccination coverage in Turkey. Another factor to contribute to the decreased prevalence of HCV stems from the use of more sensitive confirmation testing on all reactive results, thereby eliminating a fair amount of false positive cases. Despite similar transmission routes, the increase in HIV prevalence in contrast to HBV and HCV may be linked to the increase in AIDS cases in Turkey in recent years.


Journal of Infection in Developing Countries | 2013

Increasing incidence of Gram-negative organisms in bacterial agents isolated from diabetic foot ulcers

Vedat Turhan; Mesut Mutluoglu; Ali Acar; Mustafa Hatipoglu; Yalcin Onem; Gunalp Uzun; Hakan Ay; Oral Oncul; Levent Gorenek

INTRODUCTION In the present study, we sought to identify the bacterial organisms associated with diabetic foot infections (DFIs) and their antibiotic sensitivity profiles. METHODOLOGY We retrospectively reviewed the records of wound cultures collected from diabetic patients with foot infections between May 2005 and July 2010. RESULTS We identified a total of 298 culture specimens (165 [55%] wound swab, 108 [36%] tissue samples, and 25 [9%] bone samples) from 107 patients (74 [69%] males and 33 [31%] females, mean age 62 ± 13 yr) with a DFI. Among all cultures 83.5% (223/267) were monomicrobial and 16.4% (44/267) were polymicrobial. Gram-negative bacterial isolates (n = 191; 61.3%) significantly outnumbered Gram-positive isolates (n = 121; 38.7%). The most frequently isolated bacteria were Pseudomonas species (29.8%), Staphylococcus aureus (16.7%), Enterococcus species (11.5%), Escherichia coli (7.1%), and Enterobacter species (7.1%), respectively. While 13.2% of the Gram-negative isolates were inducible beta-lactamase positive, 44.2% of Staphylococcus aureus isolates were methicillin resistant. CONCLUSIONS Our results support the recent view that Gram-negative organisms, depending on the geographical location, may predominate in DFIs.


Emerging Infectious Diseases | 2011

Hantavirus Infection in Istanbul, Turkey

Oral Oncul; Yunus Atalay; Yalcin Onem; Vedat Turhan; Ali Acar; Yavuz Uyar; Dilek Yagci Caglayik; Sezai Özkan; Levent Gorenek

To the Editor: More than 20 serotypes of hantavirus have been identified, and 11 infect humans. Puumala virus (PUUV), Dobrava virus (DOBV), and Seoul virus cause different forms of hemorrhagic renal syndrome (1,2). DOBV is endemic to Turkey and countries in the Balkan region. Approximately 10,000–12,000 cases of infection with PUUV and DOBV occur in European Russia each year (3). Initial case reports identified a hantavirus epidemic (laboratory confirmed) in February 2009 that involved 12 persons in Bartin and Zonguldak in western Turkey near the Black Sea. The hantavirus responsible for this epidemic was a PUUV subtype (4). We report a man infected with DOBV in Turkey who died 2 days after admission to an intensive care unit (ICU). The patient was a 22-year-old man who lived near Istanbul, Turkey. He was admitted to the Silivri State Hospital in March 2010 because of fatigue, diffuse pain, nausea, and vomiting. Approximately 2 hours after admission, ecchymotic rashes developed on his upper extremities and spread to other areas. His general condition worsened, and 15 hours later, he was transferred to the ICU of the Emergency Service of Gulhane Military Medical Academy Haydarpasa Training Hospital. His medical history did not include exposure to rodents or any travel. At admission to the ICU, his general condition was poor, and his speech was garbled and incoherent. He had a body temperature of 37.2°C, a pulse of 140 beats/min, an arterial blood pressure of 90/60 mm Hg, diffuse hemorrhagic foci, and a disseminated ecchymotic rash. Laboratory test results showed the following: 13,200 leukocytes/mm3, 92% polymorphonuclear leukocytes, hemoglobin 11.6 mg/dL, 385,000 platelets/mm3, alanine aminotransferase 62 IU/mL, aspartate aminotransferase 170 IU/mL, creatine phosphokinase 2,115 IU/L, lactate dehydrogenase 1,109 IU/L, urea 65 mg/dL, creatinine 3.78 mg/dL, prothrobin time 24.8 s, activated partial thromboplastin time 116.3 s, potassium 2.9 mEq/L, C-reactive protein 326 mg/dL, and erythrocyte sedimentation rate 132 mm/h. Subsequently, urinary output decreased and respiratory functions worsened. He then lost consciousness and was subjected to mechanic ventilation. Lumbar puncture was not performed because of risk for bleeding (high international normalized ratio values for blood coagulation and thrombocytopenia). Cranial computed tomographic scan did not show any pathologic changes. Treatment with ceftriaxone, 4 g/day intravenously, was initiated, and the dose was adjusted according to creatinine clearance because of suspected meningococcemia. A single dose of prednisolone, 80 mg intravenously, was given concomitantly. Bacterial growth was not observed in cultures of urine and blood samples. The Hanta Profile 1 EUROLINE Test (Euroimmun, Luebeck, Germany) was used to detect immunoglobulin (Ig) G and IgM against 3 hantavirus serotypes (PUUV, DOBV, and Hantaan virus). Results of a hantavirus IgM immunoblot test were positive for DOBV. The QIAamp viral RNA Mini Extraction Kit (QIAGEN, Hilden, Germany) was used for extraction of viral RNA. PUUV and DOBV RNA in serum and urine samples were investigated by using an in-house real-time PCR (Rotorgene; QIAGEN). DOBV RNA was detected in urine samples by PCR (Table). Table Detection of Dobrava virus in 22-year-old patient, Turkey* Meningococcemia, acute hemorrhagic fever, and Crimean-Congo hemorrhagic fever were considered in the differential diagnosis for the patient. Other diseases were excluded by biochemical, serologic, and microbiologic test results. Hantavirus infection was diagnosed in this patient on the basis of criteria recommended by the European Network for Diagnostics of Imported Viral Diseases (5). On the second day of treatment, the patient died of cardiopulmonary arrest. The patient had worked as a security guard in a new prison located in an area that had contained oak and hornbeam forests. DOBV is carried by rodents (Apodemus flavicollis), and the habitat of this rodent in Europe is open oak or beech forest. In a field study performed in rural areas of Turkey near the Black Sea and Aegean Sea, hantavirus was detected in Microtus spp. voles (6). In another study performed in regions near the Aegean Sea, DOBV was detected in 7 (3.5%) of 200 patients with acute or chronic renal failure (7). However, information about specific regions in Turkey in which hantavirus is endemic is limited. Hantavirus infections, which were first identified in northwestern Turkey in 2009 and subsequently in Istanbul, should be considered in the diagnosis of patients who have fever and bleeding. Because of recent emergence of hantavirus in Turkey, areas to which this virus is endemic and where risk for infection is highest have not been identified. Therefore, all inhabitants at high risk for infection (forest workers, military personnel, farmers, persons living in or near a forest, persons handling wood) should be informed about this risk.


Burns | 2011

Comparison of silver-coated dressing (Acticoat®), chlorhexidine acetate 0.5% (Bactigrass®) and nystatin for topical antifungal effect in Candida albicans-contaminated, full-skin-thickness rat burn wounds

Ali Acar; Fatih Uygur; Husrev Diktas; Rahmi Evinc; Ersin Ülkür; Oral Oncul; Levent Gorenek

BACKGROUND In this experimental animal study, the effects of three different topical antimicrobial dressings on Candida albicans contaminated full-thickness burn in rats were analyzed. METHODS In total 32 adult Wistar rats (body weight 200-220 g) were used. Silver-coated dressing (Acticoat™®), chlorhexidine acetate 0.5% (Bactigrass®) and Mycostatine (Nystatin®) were compared to assess the antifungal effect of a once-daily application on experimental rat 15% full-skin thickness burn wound seeded 24h earlier with a 10(8) CFU/mL standard strain of C. albicans ATCC 90028. All the animals were sacrificed at post burn day 7. The quantitative counts of seeded organism in burn eschar and subjacent muscle were determined, in addition to the cultures of left ventricle blood and lung biopsies. RESULTS While there were significant differences between Acticoat™® group (4 ± 10 × 10(4)) and control group (5 ± 6 × 10(6)), and between Nystatin group (4 ± 4 × 10(4)) and control group (P=0.01, P=0.01), there were no significant differences between chlorhexidine acetate 0.5% group (2 ± 3 × 10(4)) and control group (P=0.7) respectively. Acticoat™® and Nystatin were sufficient to prevent to C. albicans from invading to the muscle and from causing systemic infection. CONCLUSIONS The animal data suggest that nystatin is the most effective agents in the treatment of C. albicans-contaminated burn wounds, and Acticoat™® is a choice of treatment on fungal burn wound infection with antibacterial effect and the particular advantage of limiting the frequency of replacement of the dressing.


Transfusion Medicine | 2010

The significance of repeat testing in Turkish blood donors screened with HBV, HCV and HIV immunoassays and the importance of S/CO ratios in the interpretation of HCV/HIV screening test results and as a determinant for further confirmatory testing

Ali Acar; Sabri Kemahli; Husnu Altunay; Erdogan Kosan; Oral Oncul; Levent Gorenek; Saban Cavuslu

The purpose of this study was to investigate the intra‐assay correlations amongst initial reactive and repeat screening results used in enzyme immunoassays (EIAs) for hepatitis B virus (HBV), hepatitis C virus (HCV) and HIV in blood donors. This study evaluated the value of using the power of the signal to cut‐off (S/CO) ratio index for confirming anti‐HCV/HIV reactive screening results, thereby touching upon the utility of S/CO indices in determining whether further confirmatory testing was necessary. Screening test results of the 72 695 blood donors were evaluated over a 1‐year period. Correlation analysis among each initial test and retests was done by Pearson r test. Appropriate S/CO values to determine the need of the confirmation testing was investigated by ROC analyses. EIA intra‐assay correlations were of statistical significance and were determined as follows: 0·948 for anti‐HCV, 0·827 for anti‐HIV and 0·948 for HBsAg. The threshold S/CO ratio values which predicted more than 95% of the confirmation test result were 3·8 for HCV and 5·6 for HIV. We were able to demonstrate a strong level of intra‐assay correlation amongst EIAs, thereby eliminating the need for repetition of the screening test. Hence, we suggest that repeat screening should only be limited to HBV and HIV tests with low EIA S/CO ratios. Thus, using the power of the S/CO ratio in determining the need for HCV confirmation testing can be a cost‐effective measure, especially if the S/CO value is ≥3·8.


Clinical Microbiology and Infection | 2014

Genitourinary brucellosis: results of a multicentric study

H. Erdem; Nazif Elaldi; Oznur Ak; Serda Gulsun; Recep Tekin; Mehmet Ulug; Fazilet Duygu; Mahmut Sunnetcioglu; Necla Tulek; S. Guler; Yasemin Cag; Selçuk Kaya; Nesrin Türker; Emine Parlak; Tuna Demirdal; C. Ataman Hatipoglu; A. Avci; Cemal Bulut; Meltem Avci; Abdullah Umut Pekok; Umit Savasci; Hamdi Sözen; Meltem Tasbakan; Tumer Guven; Sibel Bolukcu; Salih Cesur; Elif Sahin-Horasan; Esra Kazak; Affan Denk; Ibak Gonen

This study reviewed the clinical, laboratory, therapeutic and prognostic data on genitourinary involvement of brucellosis in this largest case series reported. This multicentre study pooled adult patients with genitourinary brucellar involvement from 34 centres treated between 2000 and 2013. Diagnosis of the disease was established by conventional methods. Overall 390 patients with genitourinary brucellosis (352 male, 90.2%) were pooled. In male patients, the most frequent involved site was the scrotal area (n=327, 83.8%), as epididymo-orchitis (n=204, 58%), orchitis (n=112, 31.8%) and epididymitis (n=11, 3.1%). In female patients, pyelonephritis (n=33/38, 86.8%) was significantly higher than in male patients (n=11/352, 3.1%; p<0.0001). The mean blood leukocyte count was 7530±3115/mm3. Routine laboratory analysis revealed mild to moderate increases for erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). The mean treatment duration and length of hospital stay were significantly higher when there were additional brucellar foci (p<0.05). Surgical operations including orchiectomy and abscess drainage were performed in nine (2.3%) patients. Therapeutic failure was detected in six (1.5%), relapse occurred in four (1%), and persistent infertility related to brucellosis occurred in one patient. A localized scrotal infection in men or pyelonephritis in women in the absence of leucocytosis and with mild to moderate increases in inflammatory markers should signal the possibility of brucellar genitourinary disease.


American Journal of Infection Control | 2015

Surgical site infection rates in 16 cities in Turkey: findings of the International Nosocomial Infection Control Consortium (INICC)

Hakan Leblebicioglu; Nurettin Erben; Victor D. Rosenthal; Alper Sener; Cengiz Uzun; Gunes Senol; Gulden Ersoz; Tuna Demirdal; Fazilet Duygu; Ayse Willke; Fatma Sirmatel; Nefise Oztoprak; Iftihar Koksal; Oral Oncul; Yunus Gurbuz; Ertugrul Guclu; Huseyin Turgut; Ata Nevzat Yalcin; Davut Ozdemir; Tanıl Kendirli; Turan Aslan; Saban Esen; Fatma Ulger; Ahmet Dilek; Hava Yilmaz; Mustafa Sunbul; Ilhan Ozgunes; Gaye Usluer; Metin Otkun; Ali Kaya

BACKGROUND Surgical site infections (SSIs) are a threat to patient safety; however, there were no available data on SSI rates stratified by surgical procedure (SP) in Turkey. METHODS Between January 2005 and December 2011, a cohort prospective surveillance study on SSIs was conducted by the International Nosocomial Infection Control Consortium (INICC) in 20 hospitals in 16 Turkish cities. Data from hospitalized patients were registered using the Centers for Disease Control and Prevention (CDC) National Healthcare Safety Network (NHSN) methods and definitions for SSIs. Surgical procedures (SPs) were classified into 22 types according to International Classification of Diseases, Ninth Revision criteria. RESULTS We recorded 1879 SSIs, associated with 41,563 SPs (4.3%; 95% confidence interval, 4.3-4.7). Among the results, the SSI rate per type of SP compared with rates reported by the INICC and CDC NHSN were 11.9% for ventricular shunt (vs 12.9% vs 5.6%); 5.3% for craniotomy (vs 4.4% vs 2.6%); 4.9% for coronary bypass with chest and donor incision (vs 4.5 vs 2.9); 3.5% for hip prosthesis (vs 2.6% vs 1.3%), and 3.0% for cesarean section (vs 0.7% vs 1.8%). CONCLUSIONS In most of the 22 types of SP analyzed, our SSI rates were higher than the CDC NHSN rates and similar to the INICC rates. This study advances the knowledge of SSI epidemiology in Turkey, allowing the implementation of targeted interventions.

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Ali Acar

Military Medical Academy

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Oral Oncul

Military Medical Academy

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Vedat Turhan

Military Medical Academy

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Hakan Erdem

Military Medical Academy

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Asim Ulcay

Military Medical Academy

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Selçuk Kaya

Karadeniz Technical University

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