Klebsiella pneumoniae, yoğun bakım ünitelerinde sepsis, üriner sistem enfeksiyonu, kateter ilişkili enfeksiyonlar, pnömoni ve cerrahi alan enfeksiyonları gibi komplike ve tedavisi zor nozokomiyal enfeksiyonlardan sorumludur. K.pneumoniae ile ortaya çıkan enfeksiyonlarda yaşanan en büyük problem çoklu antibiyotik direnci nedeniyle tedavi seçeneklerinin kısıtlı olması ve bunun sonucunda morbidite ve mortaliteninartmasıdır. Karbapenemlerin yaygın ve uygunsuz kullanımı sonrası bu grup antibiyotiklere karşı kazanılmışdirenç özellikle yoğun bakım ünitelerinde kontrolü zor salgınlara neden olabilmektedir. Karbapenemedirençli K.pneumoniae (KDKP) türlerinin neden olduğu salgınlar ve sporadik olgular son yıllarda tüm dünyada giderek artan sıklıkta bildirilmeye başlanmıştır. Bu çalışmada, bir üniversite hastanesi anestezi yoğunbakım ünitesinde gelişen K.pneumoniae ile ilişkili enfeksiyonlarda, karbapenem direnci ve hasta mortalitesi ile ilişkili risk faktörlerinin belirlenmesi amaçlanmıştır. Bu çalışma, 01.01.2016-31.12.2018 tarihleriarasında geriye dönük olarak, hasta ve laboratuvara dayalı sürveyans ile elde edilen veriler kullanılarakgerçekleştirilmiştir. Yoğun bakım ünitesine yatışından 48 saat sonra alınan kan, idrar, apse ve trakealaspirat örneklerinde K.pneumoniae üremesi olan, enfeksiyon odağı ile ilişkili etkene yönelik antibakteriyeltedavi başlanan erişkin hastalar (≥ 18 yaş) araştırmaya dahil edilmiştir. Kan örneği dışında kalan klinik örnekler, %5 koyun kanlı agar ve “eosin-methylene-blue (EMB)” agar besiyerlerine ekilmiştir. Kan örneklerikan kültür şişelerine ekilerek otomatize sistemde inkübe edilmiştir. Beş gün içerisinde üreme sinyali verenörnekler için Gram boyama yapılarak ön tanımlama yapılmış, daha sonra %5 koyun kanlı agar ve EMB agar besiyerlerine pasaj yapılarak 35.5-37°C’de 18-24 saat inkübe edilmiştir. İzolatların tanımlanması“matrix-assisted laser desorption/Ionization time-of-mass spectrometry (MALDI-TOF MS)” temelli BrukerIVD MALDI Biotyper 2.3 (Bruker Daltonik GmbH, Bremen, Almanya) cihazı kullanılarak gerçekleştirilmiştir.Çalışmamızda yer alan K.pneumoniae izolatları 2.0 ve üzeri güvenilirlik skorları elde edilmesiyle tanımlanmıştır. K.pneumoniae izolatlarında antibiyotik duyarlılık testleri Phoenix 100 (BD, New Jersey, ABD)otomatize sistemiyle gerçekleştirilmiş ve sonuçlar “European Committee on Antimicrobial SusceptibilityTesting (EUCAST)” önerilerine göre yapılmıştır. KDKP izolatlarında karbapenemaz varlığını göstermekiçin kombine disk difüzyon testi ve polimeraz zincir reaksiyonu temelli testler kullanılmıştır. K.pneumoniaeenfeksiyonu gelişen toplam 88 hasta çalışmaya dahil edilmiştir. Hastaların yaş ortalaması 74 ± 15 (yaşaralığı: 21-93) yıl ve %60.2’si kadınlardan oluşmuştur. KDKP 32 (%36.4) hastada, karbapeneme duyarlı/hassas K.pneumoniae (KHKP) 56 hastada saptanmıştır. KDKP saptanan olgularda kombine disk difüzyonyöntemi ile yapılan tarama testinde %68.8 oranında OXA-48 varlığı saptanmıştır. K.pneumoniae enfeksiyonu gelişen hastalar arasından KDKP gelişimi açısından son 3 aylık dönem içerisinde kolistin [Odds oranı(OR)= 19.108; %95 güven aralığı (GA)= 2.027-180.133; p= 0.010] ve aminoglikozit (OR= 12.189; %95GA= 1.256-118.334; p= 0.031) kullanımı bağımsız risk faktörleri olarak bulunmuştur. Çalışma döneminde 28 günlük mortalite oranları KDKP grubunda (23/32) %71.9, KHKP grubunda (21/56) %37.5 olarakbulunmuştur. Yirmi sekiz günlük mortalite gelişimi açısından KDKP varlığı (OR= 5.146; %95 GA= 1.839-14.398; p= 0.002) bağımsız risk faktörü olarak saptanmıştır. Bu çalışmada elde edilen veriler KDKP’dekiartışın önlenmesi için etkili ve sürekli sürveyans çalışmalarını yürütmek ve akılcı antibiyotik programlarınıuygulamak adına yol gösterici olacaktır.

Klebsiella pneumoniae is the cause of complicated and difficult-to-treat nosocomial infections such as sepsis, urinary tract infection, catheter related infections, pneumonia and surgical site infections in intensive care units. The biggest problem in infections with K.pneumoniae is that treatment options are limited due to multiple antibiotic resistance and consequently the increased morbidity and mortality. The widespread and improper use of carbapenems can lead to epidemics that are difficult to control, especially in intensive care units because of the acquired resistance to this group of antibiotics. Outbreaks and sporadic cases caused by carbapenem resistant K.pneumoniae (CRKP) species have been reported all over the world in recent years with increased frequency. The aim of this study was to determine the risk factors related to carbepenem resistance and mortality caused by K.pneumoniae infections in a university hospital anesthesia intensive care unit. The study was conducted between January 1st, 2016, and December 31st, 2018. Retrospective data were obtained from the patient and laboratory-based surveillance records. Adult patients (≥ 18 years) with K.pneumoniae growth in the blood, urine, abscess and tracheal aspirate samples collected 48 hours after admission to the intensive care unit were considered as the relevant infection locus-related agent and treated with antibacterial therapy. Clinical samples collected from patients were inoculated onto 5% sheep blood and eosin-methylene-blue (EMB) agar except the blood samples. Blood samples were cultured in blood culture bottles and incubated in an automated system. Gram staining was performed for the samples showing growth signal within five days and then inoculated onto 5% sheep blood and EMB agar media and were incubated for 18-24 hours at 35.5-37°C. Identification of the isolates was performed using Bruker IVD MALDI Biotyper 2.3 (Bruker Daltonik GmbH, Bremen, Almanya) based on “matrix-assisted laser desorption/ionization time-of-mass spectrometry (MALDI-TOF MS)”. K.pneumoniae isolates were identified by obtaining reliability scores of 2.0 and above in the study. Antibiotic susceptibility tests were performed with Phoenix 100 (BD, New Jersey, ABD) automated system. Interpretations were made according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Combination disk diffusion test and polymerase chain reaction based tests were used to show the presence of carbapenemase in CRKP isolates. A total of 88 patients with K.pneumoniae infection were included in the study. The mean age of the patients was 74 ± 15 (range= 21-93) years and 60.2% were female. CRKP was detected in 32 patients (36.4%) and carbapenem-sensitive K.pneumoniae (CSKP) was detected in 56 patients. The presence of OXA-48 was found to be 68.8% in the carbapenem screening test performed by combination disc method in patients with CRKP. Multivariate logistic regression analysis showed that previous use of colistin [Odds ratio (OR)= 19.108; 95% confidence interval (CI)= 2.027-180.133; p= 0.010] and aminoglycoside (OR= 12.189; 95% CI= 1.256-118.334; p= 0.031) was an independent risk factor in terms of CRCP among the patients with K.pneumoniae infection. The 28-day mortality rates were 71.9% in the CRKP group (23/32) and 37.5% in the CSKP group (21/56). Presence of CRKP in terms of 28-day mortality (OR= 5.146; 95% CI= 1.839-14.398; p= 0.002) was an independent risk factor. The data obtained in this study will guide for conducting effective and continuous surveillance studies and implementing rational antibiotic programs to prevent the increase in CRKP.

The first Staphylococcus aureus strain with reduced susceptibility to vancomycin was reported from Japan in 1996, and since then an increasing numbers of cases had been reported from various countries. Along with the unfeasibility in the identification of these strains with routine laboratory methods, the use of glycopeptid antibiotics in infections due to these strains may result in therapeutic failure. The aim of this study was to investigate the prevalence of vancomycin intermediate staphylococcus (VIS) and heterogenous VIS (hVIS) strains with the use of agar screening, macro E-test, and population analysis profile (PAP-UC; population analysis profile-area under the curve) methods. A total of 148 methicillin-resistant staphylococcus strains isolated from different clinical samples (48 tracheal aspirate, 48 blood, 39 wound swabs, eight urine, two cerebrospinal fluid, two pleural fluid, one catheter tip sample) between November 2007 and May 2009, were included in the study. Of the isolates 107 were identified as S.aureus and 41 were coagulase-negative staphylococci (CNS; 23 Staphylococcus epidermidis, six Staphylococcus haemolyticus, five Staphylococcus chromogenes, three Staphylococcus hominis and four others) by API Staph kit (bioMerieux, USA). Methicillin resistance has been determined by standard disk diffusion method with oxacillin (1 μg) and cefoxitin (30 μg) disks, according to “Clinical and Laboratory Standarts Institute (CLSI)” guidelines. For the identification of VIS and hVIS strains, brain-heart infusion agar plates containing 6 μg/ml vancomycin (BHI-V6) were used for screening. The suspected VISA/hVISA strains which grew in this agar were further tested by macro E-test and PAP-AUC methods. Total VIS and hVIS rates among the tested isolates, were found as 3.4% (5/148) and 1.4% (2/148), respectively. These rates for CNS strains were 9.8% (4/41) and 2.4% (1/41), and for S.aureus strains were 0.9% (1/107) ve 0.9% (1/107), respectively. In the evaluation of the seven patients who were infected with VISA/hVISA strains, it was detected that all had history of use of glycopeptid antibiotics except one whose history was not reached, and all were hospitalized in intensive care units, except one who had an infected knee prosthesis. Since macro E-test and PAP-AUC methods could not be performed for all of the isolates, there was a probability that our resistance rates did not reflect the real results, nevertheless VIS and hVIS prevalence that we found in our study, seemed to be higher than those data reported previously from our country. In conclusion, since the number of VISA/hVISA strains may increase in time, surveillance for vancomycin resistance in methicillin-resistant staphylococci should be carried out in hospitals periodically.