Can the pan-immune-inflammation value predict gram negative bloodstream infection-related 30-day mortality in solid organ transplant patients?

BACKGROUND: The recently used pan-immune-inflammation value (PIV) has not been adequately studied as a predictive marker for mortality in immunosuppressed patients. The aim of this study was to evaluate the usefulness of baseline PIV level as a predictor of 30-day mortality in solid organ transplant (SOT) recipients with gram negative bloodstream infections (GN-BSI). METHODS: This retrospective, cross-sectional study was conducted between January 1, 2019, and December 31, 2022, in 1104 SOT recipients. During the study period, 118 GN-BSI were recorded in 113 patients. Clinical, epidemiological, and laboratory data were collected, and mortality rates (30-day and all-cause) were recorded. RESULTS: The 113 recipients had a median age of 50 years [interquartile range (IQR) 37.5-61.5 years] with a male predominance (n = 72, 63.7%). The three most common microorganisms were as follows: 46 isolates (38.9%) of Escherichia coli, 41 (34.7%) of Klebsiella pneumoniae, and 12 (10.2%) of Acinetobacter baumannii. In 44.9% and 35.6% of the isolates, production of extended-spectrum beta-lactamases and carbapenem resistance were detected, respectively. The incidence of carbapenem-resistant GN-BSI was higher in liver recipients than in renal recipients (n = 27, 69.2% vs n = 13, 17.6%, p < 0.001). All-cause and 30-day mortality rates after GN-BSI were 26.5% (n = 30), and 16.8% (n = 19), respectively. In the group with GN-BSI-related 30-day mortality, the median PIV level was significantly lower (327.3, IQR 64.8-795.4 vs. 1049.6, IQR 338.6-2177.1; p = 0.002). The binary logistic regression analysis identified low PIV level [hazard ratio (HR) = 0.93, 95% confidence interval (CI) 0.86-0.99; p = 0.04], and increased age (HR = 1.05, 95% CI 1.01-1.09; p = 0.002) as factors associated with 30-day mortality. The receiver operating characteristic analysis revealed that PIV could determine the GN-BSI-related 30-day mortality with area under curve (AUC): 0.723, 95% CI 0.597-0.848, p = 0.0005. CONCLUSIONS: PIV is a simple and inexpensive biomarker that can be used to estimate mortality in immunosuppressed patients, but the results need to be interpreted carefully.

[Investigation of the Frequency of Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis and Mycoplasma genitalium in Men Living with HIV in Terms of Sociodemographic Characteristics and Behavioral Risk Factors]. / HIV ile Yasayan Erkeklerde Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis ve Mycoplasma genitalium Sikliginin Sosyodemografik Özellikler ve Davranissal Risk Faktörleri ile Birlikte Arastirilmasi.

The aim of this study was to investigate the frequency of Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis and Mycoplasma genitalium in men living with HIV in terms of sociodemographic characteristics and behavioral risk factors. In this cross-sectional, single center study, all HIV-infected male patients, aged ≥ 18 years, including those being followed-up (n= 142) and the new admissions (n= 16) at Hacettepe University, Department of Infectious Diseases between March 1st, 2017 and May 1st, 2018 were included. After obtaining the informed consent form; age, follow-up days in STI-clinic, marital status, education, employment status; STI-related sign and symptoms, prior STI diagnosis, multiple sexual partners during the last year, exchanging sex for money, sexual orientation, drug use, condom use with regular and casual partner and also risk factors regarding partners were inquired as behavioural risk factors. A sample of first-voided urine of each participant was tested for the presence of Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis and Mycoplasma genitalium by using nucleic acid amplification test (NAAT) (BD-MAX system, BD Diagnostics, USA) and BD MAX Mycoplasma-Ureaplasma-OSR for BioGX, (BD Diagnostics, The Netherlands). All participants living with HIV, men who have sex with men (MSM) and heterosexual men were grouped as STI-positive and STI-negative and compared. For all statistical analysis, SPSS 24 software was used. During the period of 14 months; the data was determined as follows: median follow-up time was 1138 (IQR= 159.5- 1494.5) days, median age was 35 (IQR= 28-42) years, 73.3% were single, 68.3% were at least college graduates or had higher educational attainment, 78.1% were currently employed. Of the participants, 26.9% reported STI-related sign and symptoms, 50.0% at least one STI episode in the past. Nine (5.6%) M.genitalium, five (3.1%) N.gonorrhoeae, and four (2.5%) C.trachomatis were detected in the urine samples of 17 (10.7%) individuals. N.gonorrhoeae and C.trachomatis were detected simultaneously in only one patient's urine sample. STI-positive patients (n= 17) were determined to be younger compared to STI-negative group [(p= 0.02; 27 years (IQR= 24-37) vs 35 years (IQR= 28-42)], had prominent STI-related signs and symptoms (p< 0.001) and had more multiple sexual partners (p= 0.03). The median CD4+ T lymphocyte count were relatively lower (p= 0.03) in STI-positive patients and plasma HIV RNA level was higher compared to the STI-negative participants (p= 0.05). STI-positive MSM group were younger [p= 0.01; 26 years (IQR= 23.5-29) vs 33 years, (IQR= 28-40)], STI-related signs and symptoms were more prominent (p= 0.02), the frequency of exchanging sex for money/drugs among their partners (p= 0.03) was higher compared to their STI-negative counterparts. Among STI-positive heterosexual patients, the presence of STI-related signs and symptoms (p= 0.04), drug use among their partners (p= 0.04) and plasma HIV RNA level (p<0.01) were significantly higher. STI was identified as an important health problem in this series of men living with HIV, 63.0% of whom had MSM and had a relatively high education level and socioeconomic status. Young age, having multiple partners, drug use, exchanging sex for money/drugs were prominent among the participants and their partners. Public health studies should focus on preventing STIs in young people living with HIV who have behavioral risk factors.

Does shortening the duration of radiotherapy treatment in breast cancer increase the risk of radiation pneumonia: A retrospective study.

Randomized studies evaluating hypofractionation and conventional fractionation radiotherapy treatments (RT) in patients with breast cancer have shown that hypofractionation achieves similar results to conventional fractionation in terms of survival and local control rates. It has also been shown that their long-term toxicities are similar. This study aimed to evaluate the effects of hypofractionated radiotherapy (H-RT) and conventional radiotherapy (C-RT) on lung toxicity and identify factors affecting this toxicity in patients with breast cancer. The study included 118 patients who underwent adjuvant RT following breast-conserving surgery (BCS). Out of these, 63 patients were assigned to receive C-RT, while the remaining 55 were assigned to receive H-RT. To clarify, we treated 63 patients with C-RT and 55 patients with H-RT. 60 patients were treated using 3-dimensional conformal radiotherapy (3DCRT) and 58 patients were treated using intensity modulated radiotherapy (IMRT). The patients were evaluated weekly for toxicity during radiotherapy (RT) treatment and were called every 3 months for routine controls after the treatment. The first control was performed 1 month after the treatment. Statistical analysis was performed using the SPSS20 program, and a P value of <.005 was considered statistically significant. The study found that the median age of the participants was 54.9 years and tomographic findings were observed in 70 patients. Radiological findings were detected at a median of 5 months after RT. The mean lung dose (MLD) on the treated breast side (referred to as ipsilateral lung or OAR) was 10.4 Gy for the entire group. Among patients who received 18 MV energy in RT, those with an area volume (V20) of the lung on the treated breast side >18.5%, those with a mean dose of the treated breast side lung (ipsilateral lung) >10.5 Gy, and those who received concurrent hormone therapy had significantly more tomographic findings. However, patients treated with YART had fewer tomographic findings. No symptomatic patients were observed during the follow-up period. Our findings show that the risk of lung toxicity is similar with H-RT and C-RT, and H-RT can be considered an effective and safe treatment option for breast cancer. The key factors affecting the development of lung toxicity were found to be the type of RT energy used, RT to the side breast, volume receiving 20 Gy in the side lung, side lung mean dose, and simultaneous hormonal therapy.

Changes in Place of Death of Older Adults during the COVID-19 Pandemic: A Retrospective Study from an Aging Country.

In the COVID-19 pandemic, due to the difficulties in patients' applications to health centres, changes have occurred in the places of death of older adults. It is aimed to investigate the change in the places of death of older adults in Turkey, which is one of the countries most affected by the pandemic. Patients admitted to the geriatric outpatient clinic of a university hospital from 01.01.2013 to 29.02.2020 were included. Place and date of death were recorded as hospital or out-of-hospital death. According to results, while the median age of those who died during the pandemic was higher than before (p < 0.001) and during the pandemic, the hospital mortality ratio was higher than before. During the pandemic period, the hospital mortality ratio of older adults has increased in Turkey. This situation, which has occurred despite the increasing healthcare burden, can show the importance of the measures taken and robust health infrastructure.

COVID-19-Related Rhino-Orbital-Cerebral Mucormycosis in a Renal Transplant Recipient.

Coronavirus disease 2019 increases transplant recipients' susceptibility to rare opportunistic infections as a consequence of the impairment that COVID-19 can cause in the immune system. Mucormycosis is a rare complication but has a high risk of fatal outcome. A 50-year-old woman who received a kidney transplant 10 years previously was admitted to the hospital with COVID-19. During follow-up by the inpatient service, the patient developed pain, edema, and proptosis in the right eye. She was diagnosed with rhino-orbitalcerebral mucormycosis. This is the first reported case of rhino-orbital-cerebral mucormycosis in a renal transplant recipient with COVID-19 infection.

A COVID-19 first evaluation clinic at a university hospital in Turkey.

BACKGROUND: We aimed to analyze the usefulness of such a reserved area for the admission of the patients' symptoms suggesting COVID-19 and compare the demographic and clinical characteristics of the patients with COVID-19 and without COVID-19 who were admitted to C1 during the first month of the COVID-19 outbreak in our hospital. METHODS: A new area was set up in Hacettepe University Adult Hospital to limit the contact of COVID-19 suspicious patients with other patients, which was named as COVID-19 First Evaluation Outpatient Clinic (C1). C1 had eight isolation rooms and two sampling rooms for SARS-CoV-2 polymerase-chain-reaction (PCR). All rooms were negative-pressurized. Patients who had symptoms that were compatible with COVID-19 were referred to C1 from pretriage areas. All staff received training for the appropriate use of personal protective equipment and were visited daily by the Infection Prevention and Control team. RESULTS: One hundred and ninety-eight (29.4%) of 673 patients who were admitted to C1were diagnosed with COVID-19 between March 20, 2020, and April 19, 2020. SARS-CoV-2 PCR was positive in 142 out of 673 patients. Chest computerized tomography (CT) was performed in 421 patients and COVID-19 was diagnosed in 56 of them based on CT findings despite negative PCR. Four hundred and ninety-three patients were tested for other viral and bacterial infections with multiplex real-time reverse-transcriptase PCR (RTPCR). Blood tests that included complete blood count, renal and liver functions, d-dimer levels, ferritin, C- reactive protein, and procalcitonin were performed in 593 patients. Only one out of 44 healthcare workers who worked at C1 was infected by SARS-CoV-2. DISCUSSION: Early diagnosis of infected patients and ensuring adequate isolation are very important to control the spread of COVID-19. The purpose of setting up the COVID-19 first evaluation outpatient clinic was to prevent the overcrowding of ER due to mild or moderate infections, ensure appropriate distancing and isolation, and enable emergency services to serve for real emergencies. A wellplanned outpatient care area and teamwork including internal medicine, microbiology, and radiology specialists under the supervision of infectious diseases specialists allowed adequate management of the mild-to-moderate patients with suspicion of COVID-19.

Factors Associated with Gram-Negative Bacteremia and Mortality in Neutropenic Patients with Hematologic Malignancies in a High-Resistance Setting.

Objective: Patients with hematological malignancies (HMs) have a substantial incidence of febrile neutropenic episodes. Gram-negative bacteremia (GNB) is still the major cause of these episodes. We evaluated the factors associated with GNB and mortality of bacteremic patients with HMs in a high-resistance setting. Materials and Methods: We conducted a prospective cohort study from March 2018 to June 2019 with 66 bacteremic and 132 non-bacteremic patients. Regression analyses were used to identify factors associated with GNB and 30-day mortality. Results: The mean age was 53.83±15.21 years, and 129 (65.2%) of the patients were male. In multivariable analysis, factors independently associated with GNB were male gender, duration of hospitalization and neutropenia before the febrile neutropenic episode, leukemias and allogeneic transplant recipients, radiotherapy, receiving glucocorticosteroids, colonization with resistant microorganisms. All-cause mortality and 30-day mortality were 47.0% and 30.3% in cases of GNB, compared to non-bacteremic controls 25.0% and 10.6%, respectively. Sepsis, duration of hospitalization before the febrile neutropenic episode, carbapenem-resistant GNB, and inappropriate empirical antibiotic treatment was found as factors associated with 30-day mortality. Prior antibiotic exposure particularly beta-lactamase inhibitor combinations and carbapenems during the past 30 days was more frequent in the bacteremic group. An increasing trend was observed in multidrug-resistant (MDR) bacteria (p=0.03) and carbapenem-resistant Enterobacterales (p=0.02) over the years. Conclusion: By considering the risk factors associated with GNB and 30-day mortality that we detected in our study among neutropenic patients, a personalized approach for the management of febrile neutropenic patients can be designed by means of an effective antimicrobial stewardship program including the appropriate use of broad-spectrum antibiotics.

Prosthetic Joint Infection Caused by Gardnerella vaginalis: Case Report and Review of the Literature.

Prosthetic joint infection is not uncommon, but Gardnerella vaginalis has been reported rarely as a causative agent. A 45-year-old patient with no remarkable history was admitted to the hospital ten months after total hip replacement because of loosening of the prosthesis. Initial culture grew S. anginosus. Repeated culture of the debridement material grew G. vaginalis. After adequate and effective treatment, he was discharged in good health. This is the first case of a male patient with prosthetic joint infection caused by G. vaginalis. This pathogen should be considered in the presence of slow-growing, gram-variable rods in culture.

[A Rare Yeast: Cases of Rhodotorula mucilaginosa Infection Followed Up in a Tertiary University Hospital]. / Nadir Etken Bir Maya: Üçüncü Basamak Üniversite Hastanesinde Izlenen Rhodotorula mucilaginosa Enfeksiyonu Olgulari.

Rhodotorula species are yeasts that are common in the environment,but are not frequently encountered as an infectious agent in humans. Rhodotorula mucilaginosa, Rhodotorula glutinis and Rhodotorula minuta are the species that cause disease in humans. Although its isolation from mucosa is doubtful in terms of the presence of true infection, it is more frequently encountered in daily practice due to the increasing number of invasive procedures, immune system deficiencies caused by immunosuppressive drugs and diseases. R.mucilaginosa growth isolated from various clinical samples between 2000 and 2018 in a tertiary university hospital was presented in this case report. The first case was an 82-year-old man with chronic lung disease, hypertension, congestive heart failure and acute leukemia causing severe immunosuppression. Use of broad spectrum antibiotics, history of immunosuppressive therapy, presence of jugular catheter were the risk factors in this patient. R.mucilaginosa was isolated from blood culture while the patient was receiving fluconazole treatment for Candida albicans grown in urine culture and the patient died before starting the treatment. The second case was a 34-year-old female patient with congenital heart disease. Discharge was observed at the intracardiac defibrillator site of the patient, a temporary pacemaker was inserted, and she used broad spectrum antibiotics for a long time. When the yeast growth was reported in the blood culture, caspofungin treatment was initiated. Although the treatment was switched to amphotericin B lipid complex after the culture result was reported as R.mucilaginosa, the patient died after 12 hours. The third case was a 70-year-old woman with hypertension, dementia, diabetes mellitus and rheumatoid arthritis admitted to the intensive care unit due to cerebrovascular accident. She received different immunosuppressive treatments and had invasive procedures. R.mucilaginosa was isolated from the blood culture taken from the patient's catheter, and there was no growth in the blood culture obtained from the peripheral vein. Anidulafungin was started empirically, which was changed to amphotericin B lipid complex after the identification of the yeast. The patient died for various reasons 10 days after the antifungal treatment was stopped. Our last case was a 55-year-old woman with metastatic ovarian cancer and secondary ascites. Broad-spectrum multiple antibiotics were used and invasive procedures were performed. R.mucilaginosa and C.albicans were isolated from the urine of the patient who had a urinary catheter. No growth was detected from urine after changing the urinary catheter. Therefore, growths were evaluated as colonization, and fluconazole was administered for C.albicans due to the high risk of invasive infection. The patient was lost for different reasons. The development and diversity of the treatment methods lead to the emergence of some opportunistic infectious agents that were not observed previously. Rhodotorula species are one of the rare agents that have increased over the years. Rhodotorula species should be considered as the cause of an infection if no clinical response is obtained after echinocandin and/or fluconazole treatment in patients with long-term immunosuppression and invasive procedures. Data on clinical pictures, treatment responses, follow-up and treatment results of this rare yeast are still limited. This case series was presented to draw attention to the risk factors related to R.mucilaginosa infection/colonization, clinical characteristics of the patients, follow-up results and treatment options and to contribute to the literature.

Expect the unexpected: fungemia caused by uncommon Candida species in a Turkish University Hospital.

Fungemia caused by uncommon Candida species (UCS) (other than C.albicans, C.glabrata, C.parapsilosis, C.tropicalis, C.krusei) is a rare but emerging threat with their potential to exhibit reduced susceptibility or resistance to antifungal agents. We identified 25 patients with UCS fungemia (9 C.kefyr, 8 C.lusitaniae, 4 C.dubliniensis, 2 C.guilliermondii, 1 C.pelliculosa, 1 C.rugosa) through January 2011 and August 2018. Echinocandins were the most common administered agents, followed by fluconazole. Overall mortality was 44%. Echinocandins and voriconazole showed sufficient activity against all tested isolates. High fluconazole MICs among C.guilliermondii, C.pelliculosa, and C.rugosa were determined. MIC value of C.pelliculosa was above the epidemiological cut-off proposed for fluconazole.

Out-patient management of patients with COVID-19 on home isolation.

The rapidly increased number of patients with COVID-19 resulted in the shortage of hospital beds. An outpatient follow-up plan was developed for COVID-19 patients with stable clinical condition and no concomitant diseases. The records of COVID-19 first admission clinic were retrospectively reviewed to identify the COVID-19 patients who were followed on home isolation as outpatients between March 17, 2020 and April 18, 2020 in Ankara, Turkey. Demographic and clinical characteristics of the patients, compliance with isolation rules, re-admission rates, and outcomes were investigated. A total of 41 patients with COVID-19 were followed on home isolation without hospitalization. The median age of the patients was 36 years. Twenty-four (58.5%) of 41 patients were female. Twenty-nine (70.7%) patients were healthcare workers. The most common symptoms at admission were cough, myalgia/arthralgia, and loss of smell and/or taste. Fourteen (34.1%) patients were asymptomatic on the first admission. Anti-viral treatment was given to 27 (65.8%) of 41 patients. Four of 41 patients were readmitted to the outpatient clinic and hospitalized. Three patients had worsening respiratory symptoms and pneumonia was detected in CT scans. One patient was hospitalized because of disseminated herpes zoster infection. Two patients who jeopardized the isolation rules were isolated and monitored at another hospital by provincial health directorate teams. If adequate conditions are provided, follow-up on home isolation seems to be a feasible method in carefully selected patients. However, these patients should be monitored closely by an experienced team during the isolation period.

The effects of blood group types on the risk of COVID-19 infection and its clinical outcome

Background/aim: COVID-19 (Coronavirus disease of 2019) is an infectious disease outbreak later on declared as a pandemic, caused by the SARS-CoV-2 (severe acute respiratory syndrome coronavirus-2). It spreads very rapidly and can result in severe acute respiratory failure. The clinical studies have shown that advanced age and chronic diseases increase the risk of infection. However, influence of the blood groups on COVID-19 infection and its outcome remains to be confirmed. The aim of this study is to investigate whether there exists a relationship between the blood groups of the patients and risk of SARS-CoV-2 infection and the clinical outcomes in COVID-19 patients Material and method: 186 patients with PCR confirmed diagnosis of COVID-19 were included in this study. Age, sex, blood groups, comorbidities, need for intubation and intensive care unit follow up and mortalities of the patients were analyzed retrospectively. 1881 healthy individuals, who presented to the Hacettepe University Blood Bank served as the controls. Results: The most frequently detected blood group was blood group A (57%) amongst the COVID-19 patients. This was followed by blood group O (24.8%). The blood group types did not affect the clinical outcomes. The blood group A was statistically significantly more frequent among those infected with COVID-19 compared to controls (57% vs. 38%, P < 0.001; OR: 2.1). On the other hand, the frequency of blood group O was significantly lower in the COVID-19 patients, compared to the control group (24.8% vs. 37.2%, P: 0.001; OR: 1.8). Conclusions: The results of the present study suggest that while the blood group A might have a role in increased susceptibility to the COVID-19 infection, the blood group O might be somewhat protective. However, once infected, blood group type does not seem to influence clinical outcome.

Fungaemia due to rare yeasts in a tertiary care university centre within 18 years.

BACKGROUND: Fungaemia due to rare yeasts has been recognised as an emerging, clinically relevant, but less investigated condition. Intrinsic resistance or reduced susceptibility of these species to echinocandins or fluconazole remains as a challenge in empirical treatment. OBJECTIVES: To describe the clinical characteristics, administered antifungal agents, outcomes of patients with rare yeasts other than Candida (RY-OTC) fungaemia and determine the antifungal susceptibility profiles of the isolates. PATIENTS AND METHODS: RY-OTC fungaemia between January-2001 and December-2018 were retrospectively evaluated. Antifungal susceptibility tests were performed according to CLSI M27-A3. RESULTS: We identified 19 patients with fungaemia due to 20 RY-OTC (8 Trichosporon asahii, 4 Cryptococcus neoformans, 4 Saprochaete capitata, 3 Rhodotorula mucilaginosa, 1 Trichosporon mucoides) with an incidence of 2.2% among 859 fungaemia episodes. Haematological malignancy was the most common (42%) underlying disorder. In 6 patients, RY-OTC fungaemia developed as breakthrough infection while receiving echinocandins, amphotericin B or fluconazole. Amphotericin B, fluconazole or voriconazole were the drugs of choice for the initial treatment of breakthrough fungaemia. Among patients without previous exposure to antifungals, the most common empirical treatment was an echinocandin (50%), followed by fluconazole (42%) and amphotericin B (8%). Overall mortality was 47%. Worse outcome was most common among patients receiving echinocandins (83% vs 25%, P < .05). Voriconazole and posaconazole showed the highest in vitro activity against all the isolates tested. Amphotericin B MICs were relatively higher and the degree of activity of fluconazole and itraconazole was variable. CONCLUSIONS: Early recognition of RY-OTC and knowledge about their susceptibility patterns remain crucial in initial treatment pending susceptibility data of isolates.

[Various antibiotic combinations against carbapenem resistant Acinetobacter baumannii infections and in vitro synergy test results (2002-2016)]. / Karbapeneme dirençli Acinetobacter baumannii enfeksiyonlarinin tedavisinde kullanilan çesitli antibiyotik kombinasyonlari ve in vitro sinerji test sonuçlari (2002-2016).

Carbapenem resistant Acinetobacter baumannii is a bacterium that causes various hospital acquired infections, primarily ventilator-associated pneumonia and bloodstream infections. The multidrug resistance problem of the bacteria all over the world, is also a problem in our center. As the treatment options are decreasing combination therapies become a current issue. It is believed that in vitro synergy tests may guide to the selection of antibiotic combinations. The aim of this study was to present the antibiotic combinations used in the treatment of carbapenem resistant A.baumannii infections and the synergy test results of these combinations. A total of 71 carbapenem-resistant A.baumannii isolates from various clinical samples of patients in Hacettepe University Adult and Oncology Hospitals was included in the study. All isolates were from nosocomial infections that were being requested for synergy testing by the consulting physicians in the Department of Infectious Diseases and Clinical Microbiology between January 2002 and December 2016. Only one isolate from one patient was included in the analysis. The synergy test for these isolates was performed by E-test method. Of the total, 41 (58%) isolates were from various clinical samples of patients in intensive care units and 30 (42%) were from patients in different wards. Twenty-three of the isolates were obtained from bronchoalveolar lavage (BAL) fluid, 18 from pus, 14 from deep tracheal aspirate, 6 from central venous catheter, 5 from blood and 5 from other various samples. The fractional inhibition concentration (FIC) index for each combination was calculated and the results were interpreted as synergistic, additive, indifferent and antagonist. A total of 38 different combinations of antibiotics were tested. According to the frequency of synergistic activity, the combinations were; meropenem-colistin (11/12), meropenem-amikacin (7/9), meropenem-tobramycin (9/13), rifampicin-colistin (7/11), cefaperazone-sulbactam-tobramycin (8/16) and sefaperazon-sulbactam-amikacin (5/10). The most common antagonistic combinations were tigecyclin-colistin (2/6), meropenem-tobramycin (3/13), cefepim-tobramycin (4/19), rifampicin-colistin (2/11) combinations. In our center, different combinations of antibiotics are being used for the treatment of carbapenem-resistant A.baumannii due to the changing and increasing antibiotic resistance of the bacteria over the years. Sensitivity tests as well as synergy tests are used when selecting different combinations of antibiotics. However generalizability of the synergistic effect of combinations is limited. It is important to repeat these studies at regular intervals. In addition there is also a need for further studies to evaluate the correlation between in vitro laboratory results and in vivo clinical compliance.