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KORTEN, VOLKAN

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Subject: ANTIMICROBIAL RESISTANCE ×

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Now showing 1 - 5 of 5
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    Susceptibility of bacterial isolates from Turkey - A report from the Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Program
    (TAYLOR & FRANCIS LTD, 2007) KORTEN, VOLKAN; Eraksoy, H.; Basustaoglu, A.; Korten, V.; Kurt, H.; Ozturk, R.; Ulusoy, S.; Yaman, A.; Yuce, A.; Zarakolu, P.
    The study monitored the susceptibility of nosocomial pathogens to meropenem and comparator antimicrobial agents isolated as part of the Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Program from Turkish university hospitals. In terms of minimum inhibitory concentration 90% (MIC90) values, meropenem was two- and eight-fold more active than imipenem against Escherichia coli and Klebsiella pneumoniae, respectively. 40.5% of K. pneumoniae, 23.1% of Klebsiella oxytoca and 15.3% of E. coli isolates were extended-spectrum P-lactamase (ESBL) producers. Piperacillin/tazobactam was the most active agent against isolates of Pseudomonas aeruginosa, followed by meropenem and imipenem. Against Acinetobacter baumannii isolates, meropenem and imipenem were the most active agents. Continued surveillance by the MYSTIC Program appears to be prudent to help focus on effective empiric treatment regimens.
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    Antibiotic resistance surveillance over a 4-year period (2000-2003) in Turkey: results of the MYSTIC Program
    (ELSEVIER SCIENCE INC, 2007) KORTEN, VOLKAN; Korten, Volkan; Ulusoy, Sercan; Zarakolu, Pinar; Mete, Birgul
    The Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Program is a global study that provides antimicrobial susceptibility data in centers prescribing meropenem. The activity of meropenem and 7 broad-spectrum antimicrobials have been examined against 5208 bacterial isolates from 9 Turkish centers between 2000 and 2003. Cumulative susceptibility rates against all species of Enterobacteriaceae combined were ranked as follows: meropenem (99.3%), imipenem (97.6%), cefepime (80.0%), piperacillin-tazobactam (73.6%), ceftazidime (70.3%), ciprofloxacin (70.1%), cefotaxime (66.9%), and tobramycin (67.2%). The production of extended-spectrum beta-lactamases (ESBLs) was detected in 48.7% of Klebsiella pneumoniae and in 19.5% of Escherichia coli isolates. Of ESBL producing K. pneumoniae isolates, 75.7% were resistant to tobramycin, 40.3% to ciprofloxacin, and 48.3% to piperacillin-tazobactam. Only piperacillin/ tazobactam and carbapenems were active against more than 50% of Pseudomonas aeruginosa at the National Committee for Clinical Laboratory Standards-susceptible breakpoint, and the carbapenems were the most active compounds against Acinetobacter spp. These data confirm the continued potency of meropenem against Enterobacteriaceae in units where it is actively being prescribed. (c) 2007 Elsevier Inc. All rights reserved.
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    PublicationOpen Access
    Frequency and associated factors for carbapenem-non-susceptible Bacteroides fragilis group bacteria colonization in hospitalized patients: Case control study in a university hospital in Turkey
    (ELSEVIER, 2021-10) ÖZAYDIN, AYŞE NİLÜFER; Toprak, Nurver Ulger; Akgul, Oncu; Bilgin, Huseyin; Ozaydin, Ayse Nilufer; Gelmez, Gulsen Altinkanat; Sayin, Elvan; Sili, Uluhan; Korten, Volkan; Soyletir, Guner
    Purpuse: The carbapenem-resistant Bacteroides fragilis group (CR-BFG) bacteria have been reported in several countries recently with increasing global attention. The high incidence of CR-BFG isolated from our hospitalized patients has become an important problem. Therefore, we aimed to determine the frequency and associated factors for intestinal colonization by carbapenem-non-susceptible BFG (CNS-BFG) among adult patients hospitalized at intensive care units, neurosurgery and internal medicine wards in our hospital. Methods: Rectal swabs (n = 1200), collected from 766 patients between February 2014 and March 2015, were inoculated onto kanamycin-vancomycin-leaked blood agar containing 0.125 mg/L meropenem. The isolates were identified by MALDI-TOF MS. Susceptibility testing was performed by agar dilution method. The carbapenemase gene (cfiA) was detected by PCR. Logistic regression analysis was used to evaluate the associated factors for intestinal colonization by CNS-BFG. Results: A total 180 non-duplicate BFG isolates were obtained from 164 patients. Ten different species, including Parabacteroides distasonis (n = 46, 25.6%), and Bacteroides fragilis (n = 30; 16.6%), were identified. Twenty- five percent of the isolates were non-susceptible to meropenem (MIC >2 mg/L). The highest prevalence of meropenem resistant strains (MIC >8 mg/L) was detected among B. fragilis (n = 12), followed by Parabacteroides spp. (n = 4). All but one B. fragilis strains were cfiA gene positive. Hospital admission, increasing Charlson score, use of antibiotics; including carbapenems in past three months, colonization with other accompanying carbapenem-resistant Gram negative bacteria (Enterobacteriaceae, Acinetobacter baumannii and Pseudomonas aeruginosa), and having undergone surgical operations were significantly associated with RCS- BFG colonization. Conclusions: The high carriage rate of CNS-BFG in hospitalized patients may lead to worse clinical outcomes, such as serious infections and mortality, and deserves attention.
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    Epidemiology and susceptibility of pathogens from SMART 2011-12 Turkey: evaluation of hospital-acquired versus community-acquired urinary tract infections and ICU- versus non-ICU-associated intra-abdominal infections
    (OXFORD UNIV PRESS, 2017-01-25) DURMUŞOĞLU, LÜTFİYE; Koksal, Iftihar; Yilmaz, Gurdal; Unal, Serhat; Zarakolu, Pinar; Korten, Volkan; Mulazimoglu, Lutfiye; Tabak, Fehmi; Mete, Birgul; Oguz, Vildan Avkan; Gulay, Zeynep; Alp, Emine; Badal, Robert; Lob, Sibylle
    Objectives: To describe the epidemiology and susceptibility of pathogens (including ESBL producers) from hospital-acquired (HA) versus community-acquired (CA) urinary tract infections (UTIs) and ICU-versus non-ICU-associated intra-abdominal infections (IAIs) in Turkey as a part of the SMART study. Methods: For this report, Gram-negative pathogens (363 from UTIs and 458 from IAIs) were collected in 2011 and 2012 at six hospitals in Turkey. HA versus CA UTIs and ICU-versus non-ICU-associated IAIs were compared for the species isolated, percentage of ESBL-positive isolates by species and susceptibility for overall and individual Gram-negative species. Results: Escherichia coli was the most common pathogen identified in HA (40.2%) and CA (73.9%) UTIs and ICU-associated (25.8%) and non-ICU-associated (43.3%) IAIs. The rate of ESBL-positive E. coli was significantly higher in HA than in CA UTIs (50.5% versus 38.2%, P < 0.001) and in non-ICU-associated than in ICU-associated IAIs (52.5% versus 29.2%, P = 0.029). Of the drugs studied, only amikacin was active against >= 90% of pathogens in UTIs, while ertapenem, imipenem and amikacin were active against >= 90% of E. coli; and imipenem, amikacin and cefoxitin were active against >= 90% of Klebsiella pneumoniae in IAIs. Conclusions: Our findings demonstrated that E. coli continues to be the principal pathogen of UTIs and IAIs in Turkey. Along with a high rate of ESBL-positive isolates, high antimicrobial resistance among Gram-negative bacilli from either UTIs or IAIs was noted particularly in the case of HA UTIs and ICU-associated IAIs, with a higher likelihood of carbapenem-or amikacin-based therapy to provide the broadest activity against bacterial pathogens.