Lesitin İçeren Antibiyotik Kilit Çözeltilerinin Klebsiella pneumoniae Biyofilmi Üzerine in vitro Etkileri

Amaç: Gram negatif, genellikle kapsüllü, hareketsiz, sporsuz, çomak şeklinde bir bakteri olan Klebsiella pneumoniaegünümüzde toplum ve hastane kökenli enfeksiyonların önemli etkenlerinden biridir. Bu bakteri kateter yüzeyinde birmikrobiyal biyofilm oluşturarak kateter ilişkili enfeksiyonlara neden olabilmektedir. Kateter ilişkili enfeksiyonlarıntedavisinde en etkili tedavi yöntemi enfekte kateteri çıkarmak ve sistemik antibiyotik tedavisine başlamak olsa da buişlem hastanın sağlık durumu ile ilgili nedenlerle her zaman yapılamamaktadır. Enfekte kateterin çıkartılamadığıhastalarda sistemik antimikrobiyal tedavi ile birlikte yardımcı bir tedavi seçeneği olarak antibiyotik kilit (AK) tedavisikullanılması Infectious Diseases Society of America ve Centers for Disease Control and Prevention gibi sağlıkkuruluşları tarafından önerilmektedir.Gereç ve Yöntemler: Çalışmamızda, in vitro yöntemle santral venöz kateter (SVK) modeli oluşturularak biyofilmoluşturduğu tespit edilen iki SVK ilişkili bakteriyemi enfeksiyon etkeni Klebsiella pneumoniae suşuna karşı bir yüzeyaktif ajan olan lesitinin tek başına ve çeşitli antibiyotiklerle kombinasyonlarının 96 saatlik etkisi araştırılmıştır.Bulgular: Çalışmamızdan elde ettiğimiz sonuçlara göre, lesitin+tobramisin ve lesitin+doripenem kombinasyonlarınıiçeren AK çözeltisinin her iki suş içinde en az 2-log10’luk bir artış sağlayarak biyofilme gömülmüş suşlar üzerindeantagonist etki oluşturduğu, lesitin+kolistin, lesitin+tigesiklin ve lesitin+siprofloksasin içeren AK çözeltilerinin ise heriki suşa ait kateter biyofilm modelinde antibiyotiklerin tek başına oluşturduğu etkiden daha az etki gösterdiğisaptanmıştır.Sonuç: Çalışmamızda lesitin+tobramisin ve lesitin+doripenem kombinasyonlarının antagonist etki göstermesi günlükhayatta tükettiğimiz pek çok üründe gıda takviyesi olarak bulunan lesitinin enfeksiyon hastalıklarının tedavisindekietkilerinin ortaya koyulması açısından önemli olduğu düşüncesindeyiz

In vitro activities of ceftazidime/avibactam alone or in combination with antibiotics against multidrug-resistant Acinetobacter baumannii isolates

WOS: 000471951900029PubMed ID: 30576787Objectives: Infections caused by multidrug-resistant (MDR) Acinetobacter baumannii (A. baumannii) are a growing problem because of the limited options for treatment. The number of antimicrobials that are currently being developed is still insufficient to control this global threat. Combination therapies of antibiotics with different antimicrobial mechanisms have been proposed as the best options for treating MDR A. baumannii infections. The objective of this study was to investigate the in-vitro effectiveness of ceftazidime/avibactam alone or in combination with antibiotics against MDR A. baumannii isolates using time-kill assays. Methods: Forty clinical MDR strains were screened, and minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of ceftazidime/avibactam, colistin, levofloxacin, meropenem, tigecycline, and tobramycin were determined by microbroth dilution method. The in-vitro synergistic activities of ceftazidime/avibactam with antibiotic combinations were determined by time-kill assays at 1 x MIC and 4 x MIC against five MDR A. baumannii isolates. Results: Based on MIC results, all isolates of A. baumannii were resistant to ceftazidime/avibactam, except for AB-5. All isolates were found to be resistant to meropenem and levofloxacin. At 4 x MIC, all of the tested antibiotics showed bactericidal effect (>= 3 log (10) killing). The synergistic activities of ceftazidime/avibactam + colistin, ceftazidime/avibactam + tobramycin and ceftazidime/avibactam + tigecycline combinations at 1 x MIC were observed against studied 5/5, 4/5 and 4/5 strains, respectively. Furthermore, all of the tested combinations at 4 x MIC were additive at 24 h. No antagonism was observed. Conclusions: The findings of this study suggest that a significant bactericidal effect was seen with all tested combinations. These findings present significant implications for antibiotic choice for the treatment of infections caused by MDR A. baumannii.Research Fund of the University of Istanbul (Istanbul, Turkey) [21897]This work was supported by a grant from the Research Fund of the University of Istanbul (Istanbul, Turkey). Project number: 21897

In vitro synergistic effect and mutant prevention concentrations of cefepime alone or in combination with sulbactam against OXA-48-positiveKlebsiella pneumoniaeIsolates

The aim of this study is to investigate the combination of cefepime and sulbactam. Sulbactam, when administered , will effectively inhibit all Extended-spectrum beta lactamases (ESBLs) of the microorganism, while cefepime will inhibit the growth of the resistant microorganisms since it will not be hydrolyzed by OXA-48. Forty OXA-48-producingK. pneumoniaestrains were investigated for their Minimum inhibitory concentrations (MICs) for carbapenems, cefepime, and cefepime + sulbactam by broth microdilution method. Also, the mutant prevention concentration (MPC)s of cefepime alone or in combination with sulbactam was determined. Additionally, the bactericidal activities of cefepime and cefepime + sulbactam were evaluated by the time-kill curve (TKC) assay against selected strains. Also, the in vitro synergistic activity of cefepime + sulbactam combination was determined by TKC. Based on MIC results, up to 35/40 and 34/40 of the strains were resistant to carbapenems and cefepime, respectively. Cefepime + sulbactam MIC range was lower than those for cefepime alone against all the studied isolates. Moreover, cefepime + sulbactam combination presented lower MPC values than cefepime alone. The synergistic interactions of cefepime + sulbactam were also achieved against studied strains at 24 h. No antagonism was observed against studiedK. pneumoniaestrains. The findings of this study displayed that cefepime + sulbactam combination had synergistic or additive effect against OXA-48-producingK. pneumoniaestrains. Additionally, it was first observed that this combination could display a lower MPC than cefepime alone. Further investigations may be helpful for understanding the effectiveness of cefepime + sulbactam combinations for OXA-48-positive carbapenem-resistantK. pneumoniaeisolates.Istanbul Universit