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Murat Akova

Publications and source records attributed to Murat Akova.

15 recordsLinked to original sources
PubMed2007

Metallo-beta-lactamases as emerging resistance determinants in Gram-negative pathogens: open issues.

The rapid spread of acquired metallo-beta-lactamases (MBLs) among major Gram-negative pathogens is a matter of particular concern worldwide and primarily in Europe, one of first continents where the emergence of acquired MBLs has been reported and possibly the geographical area where the increasing diversity of these enzymes and the number of bacterial species affected are most impressive. This spread has not been paralleled by accuracy/standardisation of detection methods, completeness of epidemiological knowledge or a clear understanding of what MBL production entails in terms of clinical impact, hospital infection control and antimicrobial chemotherapy. A number of European experts in the field met to review the current knowledge on this phenomenon, to point out open issues and to reinforce and relate to one another the existing activities set forth by research institutes, scientific societies and European Union-driven networks.

Anti-Bacterial Agents↗
PubMed2006

Multidrug efflux inhibition in Acinetobacter baumannii: comparison between 1-(1-naphthylmethyl)-piperazine and phenyl-arginine-beta-naphthylamide.

OBJECTIVES: 1-(1-Naphthylmethyl)-piperazine (NMP) has been shown to reverse multidrug resistance (MDR) in Escherichia coli overexpressing RND-type efflux pumps but there are no data on its activity in non-fermenters like Acinetobacter. METHODS: Antimicrobial susceptibility in the absence and presence of NMP and, for comparison, phenyl-arginine-beta-naphthylamide (PAbetaN), another putative efflux pump inhibitor (EPI), was tested in laboratory and mutant strains with differing intracellular dye accumulation and expression of adeB, and in clinical isolates of Acinetobacter baumannii. RESULTS: Based on a 4-fold or greater MIC reduction, the effects of both EPIs at low concentrations (25 mg/L) were limited. PAbetaN had a highly selective action on the reduction in the MIC of rifampicin and clarithromycin. At a higher concentration of the putative EPIs (100 mg/L), NMP was more active than PAbetaN. This effect was not limited to strains with adeB overexpression, but affected the susceptibility to linezolid, chloramphenicol and tetracycline most, and was enhanced in clinical isolates with reduced fluoroquinolone susceptibility. CONCLUSION: NMP can partially reverse MDR in A. baumannii and differs substantially in its activity from that of PAbetaN.

Acinetobacter baumannii↗
PubMed2006

Developing and evaluating professionalism.

Professional behaviour, being one of the domains of professionalism, is an area of medical education that has long been of concern to medical educators. At Hacettepe University, our main goal is to have students become conscious of professional identity, values, responsibilities and the physician-patient relationship. We welcome our new students with an opening ceremony on their first day and two months later, the students start the course called "Health-Illness Concepts and Medical Professional Identity". Students are expected to discuss the subjects given to them as scenarios or arguments. The aim of our study is to determine whether the course leads to a positive change in students' attitudes, indicating the attainment of those attributes that reflect professionalism. On the first and the last days of the course, a questionnaire was delivered to the students. Any positive change in preferences between the two questionnaires is identified as an achievement of that attribute. As a result we found that in all of the seven attributes there were positive changes in the students' attitudes. Positive changes varied from 48% to 84% and all were statistically significant. Using more interactive techniques helped the students to make larger percentage changes in their awareness of these professional attributes.

Adult↗
PubMed2006

Treatment of invasive infections due to rare or emerging yeasts and moulds.

Emerging fungal infections represent a serious problem in an immunocompromised host. Rapid developments in in vitro antifungal susceptibility testing and the availability of several new antifungal agents have provided excellent opportunities to treat infections that are caused by various Candida spp. and to some extend by Aspergillus spp. However, recently the epidemiology of fungal infections has significantly changed and several new pathogens have emerged. This article attempts to summarise the available data on the management of emerging infections with fungal infections that have recently gained importance. Updated recommendations on antifungal treatment are also discussed.

Amphotericin B↗
PubMed2005

Effect of 1-(1-naphthylmethyl)-piperazine, a novel putative efflux pump inhibitor, on antimicrobial drug susceptibility in clinical isolates of Enterobacteriaceae other than Escherichia coli.

OBJECTIVES: 1-(1-Naphthylmethyl)-piperazine (NMP) has been shown to reverse multidrug resistance (MDR) in Escherichia coli overexpressing RND type efflux pumps, but there is no data on its activity in Enterobacteriaceae other than E. coli. METHODS: The antimicrobial susceptibilities of laboratory strains and 167 clinical isolates of Enterobacteriaceae to a variety of antimicrobial agents were determined in the absence and presence of NMP and, for comparison, of Phe-Arg-beta-naphthylamide (PAbetaN), another putative efflux pump inhibitor (EPI). A 4-fold or greater reduction of the MIC after EPI addition was considered significant. RESULTS: NMP consistently reduced the MIC of linezolid in Citrobacter freundii, Enterobacter aerogenes and Klebsiella pneumoniae clinical isolates. Significant effects of NMP addition in >50% of tested isolates were also seen for levofloxacin, tetracycline and chloramphenicol in E. aerogenes, and for levofloxacin and tetracycline in K. pneumoniae, whereas no or minor effects were observed in Serratia marcescens. MDR reversal by NMP was more likely in isolates with decreased susceptibility to fluoroquinolones. In most fluoroquinolone-resistant strains the activity was sufficient to render isolates drug-susceptible at clinically achievable concentrations. The activity of PAbetaN was different from that of NMP, suggesting different modes of action of the two putative EPIs. CONCLUSION: NMP has moderate activity in reversing MDR in many but not all members of the Enterobacteriaceae family including clinical isolates. Its effects on resistance reversal depend on bacterial species and drug, and are different from those seen with PAbetaN.

Anti-Bacterial Agents↗
PubMed2005

Infectious complications in patients with hematological malignancies consulted by the Infectious Diseases team: a retrospective cohort study (1997-2001).

In order to identify the characteristics of patients with hematological malignancies (HM) in the presence/suspicion of any accompanying infectious disease, and to find the predictors of mortality in this group, hospital charts of patients with HM consulted by the Infectious Diseases (ID) team for signs/symptoms of any infection between January 1, 1997 and December 31, 2001 were retrospectively reviewed. A total of 1,132 consultations were done for 641 patients: 59.4% of the patients were male and the mean (+/-standard deviation) age of the study participants was 47.9+/-1.4 years. The most common underlying diseases were non-Hodgkin's lymphoma (30.9%), acute myelogenous leukemia (26.2%), and multiple myeloma (10.9%). Clinically and microbiologically documented infections and fever of unknown origin were observed in 43.3%, 38.1%, and 18.5% of the participants, respectively. Bloodstream infections were detected in 134 episodes (20.9%): 56.5% were caused by gram-negative microorganisms. In logistic regression analysis, the presence of pneumonia (OR 7.56, 95% CI 4.84-12.486), invasive fungal infection (OR 4.12, 95% CI 1.78-9.55), relapse or recent diagnosis of the underlying disease (OR 2.82, 95% CI 1.53-5.21) and neutropenia (OR 2.70, 95% CI 1.70-4.31) were identified as statistically significant predictors of mortality.

Adolescent↗
PubMed2005

Log analysis of a Turkish web portal; febrile neutropenia.

In the last years, a lot of health portals have emerged which give service to health professionals. Neither number nor usage patterns of these portals have been well known. In this study, we analysed the usage patterns of a Turkish health portal. The main theme of the portal is febrile neutropenia.In a six months period, 714 users had visited the web site. 595 (83 %) of these users had three or more visits. During this period, 428 new web pages had entered the system. The most frequently visited pages were education materials and guidelines, whereas the least frequently visited pages were reviews and news. One hundred and ninety nine (27.8 %) of the users had one or more visit every week. After the web page was published, the mean of total number of the visits in first week was 40.1. The mean number fell to 1.0 in the fifth week.The users preferred to read concentrated resources as education materials and guidelines. Possibly they could not find sufficient time to read detailed texts in daily routine. Another result of our analysis is that, a web page gets "old" when it is one month old. The editors inform the users about the new pages by the e-mail postings. So, preparation of good content may not be sufficient alone, and the presence of the pages must be announced to possible readers.

Electronic Mail↗
PubMed2005

[Comparison of different phenotypic methods detecting extended spectrum beta-lactamases in Pseudomonas aeruginosa and Acinetobacter baumannii strains].

Pseudomonas aeruginosa and Acinetobacter baumannii which are of great concern as the frequent causative agents of nosocomial infections, frequently exhibit resistance to beta-lactam antibiotics. One of the most common causes of this resistance is the presence of extended spectrum beta-lactamases (ESBL). There is still no standardized method for the detection of ESBLs in P. aeruginosa and A.baumannii strains. The aim of this study was to compare the results of Epsilomer test (E-test), combined disk (CD) and double disk synergy (DDS) methods for the detection of ESBL in a total of 38 P. aeruginosa and 45 A.baumannii strains with ceftazidim or cefotaxime MIC > or = 1 microg/ml, isolated from different clinical samples. Cefepime was included in the group of indicator antibiotics and the distance between clavulanic acid containing disk and indicator antibiotic disks was reduced to increase the sensitivity of DDS test. Of the P. aeruginosa strains, 78.9% was detected as ESBL producers by ceftazidime/ ceftazidime-clavulanic acid and 21.1% detected by cefotaxime/cefotaxime-clavulanic acid ratio. Among this group of strains, 31.5% was positive by DDS test and 84.2% was positive by CD method. Of the A.baumannii strains, 93.3% of them was positive by ceftazidime/ceftazidime-clavulanic acid and 6.6% was positive by cefotaxime/cefotaxime-clavulanic acid ratio. DDS test detected 20% and CD method detected 53.3% of the strains positive by E-test method. The use of cefotaxime together with ceftazidime as an indicator antibiotic increased the sensitivity of detection of ESBL enzymes. Although inclusion of cefepime and reduction of the distance between disks increased the detection of ESBL by DDS method, it was still less effective than E-test. Although, 28.9% of the P. aeruginosa and 13.3% of the A. baumannii strains were susceptible to ceftazidime by in vitro tests, they were ESBL producers. In conclusion, E-test method was found to be the most sensitive phenotypic method for the detection of ESBL in our study collection.

Acinetobacter baumannii↗
PubMed2004

A European Organization for Research and Treatment of Cancer-International Antimicrobial Therapy Group Study of secondary infections in febrile, neutropenic patients with cancer.

BACKGROUND: Neutropenic patients with cancer may develop several episodes of fever and infection during chemotherapy-induced myeloaplasia. METHODS: To identify risk factors for secondary infectious episodes among patients who responded to initial antibiotic therapy, we retrospectively analyzed 2 consecutive, prospective, randomized clinical trials performed by the International Antimicrobial Therapy Group of the European Organization for Research and Treatment of Cancer during 1991-1994. RESULTS: Of 1720 patients with their first episode of febrile neutropenia, 836 responded to the initial antibiotic regimen and were therefore suitable for our analysis. A secondary infection was observed in 129 (15%) of 836 patients that occurred at a median of 10 days (range, 1-28 days) after the onset of the primary febrile episode. Factors at both baseline and day 4 were analyzed. Age of >16 years (odds ratio [OR], 3.46; P<.001), acute leukemia in first induction (OR, 3.17; P<.001), presence of intravenous line (OR, 1.88; P=.04), severe neutropenia (defined as an absolute granulocyte count of <100 cells/mm(3)) on day 4 (OR, 2.72; P<.001), and type of documentation of the primary episode (i.e., microbiologically documented cause or unexplained fever; OR, 2.56; P=.001) were found to be risk factors for secondary infection. The risk of death was higher among patients who developed a secondary infectious episode than among those who did not (5.4% vs. 1.4%; P<.01). CONCLUSIONS: The clinical parameters described above may help to identify neutropenic patients at risk of developing secondary infection.

Adolescent↗
PubMed2002

Hospital-acquired respiratory tract infections: clinical experience with beta-lactam/beta-lactamase inhibitors.

The treatment of nosocomial pneumonia presents a major treatment challenge and one complicated by the rising prevalence of multidrug resistance among nosocomial pathogens. Contemporary treatment strategies for nosocomial pneumonia, which is most often attributable to Gram-negative bacilli or Staphylococcus aureus, mandate early empiric therapy with broad-spectrum antibacterial agents. The choice of agents for empiric therapy is fundamental to outcome, and the selection of inappropriate agents, to which pathogens are resistant, contributes significantly to morbidity and mortality. The adoption of practice guidelines, such as those proposed by the American Thoracic Society, can help to guide antibiotic selection, especially when combined with knowledge of local patterns of infection and antimicrobial susceptibility. Beta-Lactam/beta-lactamase inhibitor combinations, particularly those with activity against Pseudomonas aeruginosa, are among the core antibiotic agents considered suitable for empiric therapy of nosocomial pneumonia. They are particularly suited to use in hospitals with high rates of beta-lactamase-mediated resistance, especially resistance due to extended-spectrum beta-lactamases, infections with Acinetobacter spp. and those of mixed aetiology.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Antimicrobial susceptibility of phenotypically extended spectrum beta-lactamase producing Pseudomonas aeruginosa and Acinetobacter baumannii isolates].

The aim of this study was to investigate the antimicrobial susceptibilities of Pseudomonas aeruginosa and Acinetobacter baumannii strains that were identified as producers of extended spectrum beta-lactamases (ESBL) phenotypically. Fifty three P. aeruginosa and 53 A. baumannii strains that were isolated from patients with hospital infections followed-up by Infectious Diseases Unit of Hacettepe University Adult Hospital in 2002-2004, were included in the study. The susceptibilities of the isolates to ceftazidime, cefotaxime, cefepime, tobramycin, ciprofloxacin, piperacillin-tazobactam, imipenem and meropenem were determined by Etest (AB Biodisk, Solna, Sweden) method. The susceptibility rates of A. baumannii isolates against tobramycin and carbapenem group were 54.7% and 49.1%, respectively; whereas for the rest of the antimicrobial agents tested, these rates were lower than 25 percent. The susceptibility rates of P. aeruginosa isolates against ciprofloxacin, carbapenem group, piperacillin-tazobactam and tobramycin differed between 35-38 percent. Of the P. aeruginosa isolates, 37.5%, and of the A. baumannii isolates 37.7% were resistant against imipenem/meropenem, piperacillin-tazobactam, ciprofloxacin and tobramycin simultaneously. As a result, phenotypically ESBL producing P. aeruginosa and A. baumannii isolates were found highly resistant not only against the third and fourth generation cephalosporins, but also to the antibiotics currently used in the therapy including carbapenemes.

Acinetobacter baumannii↗