Papers by Drosos Karageorgopoulos
Scientometrics, 2009
English is becoming the international language in numerous fields of human civilization. We sough... more English is becoming the international language in numerous fields of human civilization. We sought to evaluate the extent of use of English in the field of biomedical publications. We searched in PubMed for the number of articles written in the 57 indexed languages, during each one of the four past 10-year periods. The extent of use of English as the
International Journal of Antimicrobial Agents, 2009
The optimal choice of antibacterial therapy among the few available options for infections caused... more The optimal choice of antibacterial therapy among the few available options for infections caused by pathogens with advanced antimicrobial drug resistance is fundamental to maximize clinical effectiveness and minimize the likelihood for further resistance development. We herein review the available data on the effectiveness of antibiotics introduced in clinical practice during the past 10 years for specific clinical indications. Quinupristin-dalfopristin, linezolid, daptomycin and tigecycline have increased the available therapeutic options against specific types of meticillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium infections. The newer fluoroquinolones, moxifloxacin and gemifloxacin, along with the ketolide telithromycin and the oral third-generation cephalosporin cefditoren are particularly valuable for the treatment of specific types of multidrug-resistant Streptococcus pneumoniae infections. Tigecycline appears as a promising therapeutic option for infections caused by Enterobacteriaceae producing extendedspectrum β-lactamases (ESBLs), or multidrug-resistant Acinetobacter baumannii. Ertapenem and doripenem may be particularly useful against infections caused by ESBL-producing Enterobacteriaceae and multidrugresistant Pseudomonas aeruginosa, respectively.
Internal Medicine Journal, 2010
Whether the journal impact factor (JIF) indicator reflects the number of citations to an average ... more Whether the journal impact factor (JIF) indicator reflects the number of citations to an average article of a journal in different subject categories is controversial. We sought to further investigate this issue in general and internal medicine journals. We selected to evaluate three journals of the above subject category, in each of three different JIF levels (high: 15.5-28.6, moderate: 4.4-4.9 and low: 1.6). Using the Scopus database, we retrieved the original research articles (after detailed screening) and review articles (as classified by Scopus) that were published in the selected journals in 2005 along with the number of citations they received in 2006 and 2007. We pooled the citations for articles of the same type in journals with the same JIF level into distinct variables. There was no marked association between the distribution of citations per article published in general medical journals and their JIF. All distributions studied were skewed to the right (higher number of citations). Specifically, 16-22% of the original research articles accounted for 50% of the total citations to this type of article for all three categories of studied journals; 34-37% of original research articles accounted for 75% of citations. The respective values for review articles were 12-18% and 29-39%. The distribution of citations received by articles published in high, moderate and low impact factor journals in clinical medicine seems similar. The JIF is not an accurate indicator of the citations the average article receives; articles published in low impact factor journals can still be highly cited and vice versa.
Expert Review of Anti-infective Therapy, 2013
The alarmingly increasing antimicrobial resistance raises global concerns regarding the impact on... more The alarmingly increasing antimicrobial resistance raises global concerns regarding the impact on patients with multidrug-resistant (MDR) infections. Important efforts have been made to study the clinical outcomes among patients infected with such pathogens, showing higher mortality and more frequent treatment failure among them compared with those infected with the susceptible isolates [1,2]. Apart from the worse clinical outcomes, MDR infections are expected to be more costly for healthcare systems than the susceptible ones, due to the higher length of stay (LOS) in the hospital associated with the infection [3,4]. A previous study has focused on the impact of common MDR Gram-negative (Gram[-]) bacilli, including the associated costs [5]. However, many new studies have been published since then and a cumulative collection and presentation of this important data has not yet been performed. In this context, the authors aimed to systematically review and evaluate the available evidence in order to determine the impact of antimicrobial multidrug resistance on the inpatient care costs. Methods Literature search The authors performed a systematic search in the PubMed and Scopus (Health Sciences and Life Sciences subject areas) databases in May 2012. The following search pattern was applied to all published articles: '(MDR or multidrugresistant or extended-spectrum b-lactamase (ESBL) or carbapenem-resistant or imipenemresistant or meropenem-resistant or MRSA) and (cost or economic or 'charges')'. In addition, the bibliographies of relevant studies were handsearched in order to identify further studies potentially eligible for inclusion. Articles published in languages other than English, French, German, Spanish, Italian or Greek were not evaluated. Study selection Any article comparing the inpatient care costs of infection with MDR organisms (MDROs) with the costs of the non-MDRO of the same species was considered eligible for inclusion in
Expert Review of Anti-infective Therapy, 2013
The authors sought to study whether extended or continuous infusion of cephalosporins is associat... more The authors sought to study whether extended or continuous infusion of cephalosporins is associated with better clinical outcomes than short-term infusion. PubMed and Scopus databases were systematically searched. Studies reporting the clinical outcomes of patients receiving extended or continuous infusion (≥3 or 24 h, respectively) versus short-term infusion (≤1 h) of cephalosporins were considered eligible. Eleven studies (1250 clinically evaluable patients) were included. Clinical cure and mortality were not statistically different between the compared groups (risk ratio: 1.14; 95% CI: 0.94-1.37 and risk ratio: 0.96; 95% CI: 0.80-1.15, respectively). This meta-analysis did not show a difference in clinical cure or mortality regarding extended or continuous versus short-term intravenous infusion of cephalosporins. However, in most of the included studies, patients in the extended/continuous infusion group received a substantially lower total dosage of antibiotic than those in the short-term group for the total duration of treatment.
Expert Review of Anti-infective Therapy, 2012
We sought to review the potential role of isepamicin against infections with contemporary Gram-ne... more We sought to review the potential role of isepamicin against infections with contemporary Gram-negative bacteria. We searched PubMed and Scopus databases to identify relevant microbiological and clinical studies published between 2000 and 2010, and we retrieved 11 and three studies, respectively. A total of 4901 isolates were examined in the in vitro studies. Isepamicin had higher in vitro activity compared with amikacin in four studies, was as active as amikacin in six studies and in the remaining study both were inactive. Regarding specifically the studies that included multidrug-resistant bacteria, isepamicin appeared superior to amikacin in two studies, as active as amikacin in one study and both did not exhibit activity in one study. In the clinical studies, isepamicin was as active as amikacin for the treatment of 55 children with urinary tract infections. In conclusion, isepamicin might be active in vitro against Gram-negative bacteria with resistance to amikacin and other aminoglycosides.
European Journal of Clinical Microbiology & Infectious Diseases, 2013
Prulifloxacin, the prodrug of ulifloxacin, is a broadspectrum fluoroquinolone rather recently int... more Prulifloxacin, the prodrug of ulifloxacin, is a broadspectrum fluoroquinolone rather recently introduced in certain European countries. We compared the antimicrobial potency of ulifloxacin with that of other fluoroquinolones against common urinary and respiratory bacterial pathogens. The microbial isolates were prospectively collected between January 2007 and May 2008 from patients with communityacquired infections in Greece. Minimum inhibitory concentrations (MICs) were determined for ciprofloxacin, levofloxacin, moxifloxacin (for respiratory isolates only), and ulifloxacin using the E-test method. The binary logarithms of the MICs [log 2 (MICs)] were compared by using the Wilcoxon signed-ranks test. A total of 409 isolates were studied. Ulifloxacin had the lowest geometric mean MIC for the 161 Escherichia coli, 59 Proteus mirabilis, and 22 Staphylococcus saprophyticus urinary isolates, the second lowest geometric mean MIC for the 38 Streptococcus pyogenes respiratory isolates (after moxifloxacin), and the third lowest geometric mean MIC for the 114 Haemophilus influenzae and the 15 Moraxella catarrhalis respiratory isolates (after ciprofloxacin and moxifloxacin). Compared with levofloxacin, ulifloxacin had lower log 2 (MICs) against E. coli (p<0.001), P. mirabilis (p<0.001), S. saprophyticus (p<0.001), and S. pyogenes (p < 0.001). Compared with ciprofloxacin, ulifloxacin had lower log 2 (MICs) against P. mirabilis (p<0.001), S. saprophyticus (p=0.008), and S. pyogenes (p<0.001), but higher log 2 (MICs) against H. influenzae (p<0.001) and M. catarrhalis (p=0.001). In comparison with other clinically relevant fluoroquinolones, ulifloxacin had the most potent antimicrobial activity against the community-acquired urinary isolates studied and very good activity against the respiratory isolates.
European Journal of Clinical Microbiology & Infectious Diseases, 2013
Iron is a fundamental nutrient for human and microbial life. We sought to examine the association... more Iron is a fundamental nutrient for human and microbial life. We sought to examine the association of iron deficiency versus normal iron status with the susceptibility to infections. A systematic search in the PubMed and Scopus databases was performed to identify relevant clinical studies. Six studies (including a total of 1,422 participants) met the inclusion criteria: four prospective cohort (859 participants), one retrospective case-control (115 participants), and one retrospective cohort study (448 participants). Intensive care unit (ICU)-acquired and postoperative infections were more common in patients with iron deficiency than among those with normal iron status in two studies, while no difference was reported in another study. In one study examining pregnant women with normal mean iron values, higher soluble transferrin receptor values independently predicted vaginosis-like microflora. Iron deficiency anemia was an independent predictor of respiratory tract infections in one study, and postoperative urinary tract infections were more common in patients with iron deficiency anemia in another. The limited available evidence suggests that individuals with iron deficiency and those with iron deficiency anemia may be more susceptible to infections than patients with normal iron status. Future studies should elucidate further these findings.
European Journal of Clinical Microbiology & Infectious Diseases, 2011
Combination antimicrobial therapy represents common practice in the treatment of febrile neutrope... more Combination antimicrobial therapy represents common practice in the treatment of febrile neutropenia aiming to broaden the antimicrobial spectrum against Gram-negative pathogens. We did a prospective, non-randomized, comparative study to evaluate ceftazidime plus either levofloxacin or once-daily amikacin as empirical regimens for febrile neutropenia in patients with solid tumor or hematopoietic neoplasm in a region of high baseline resistance prevalence. We included 285 febrile neutropenic episodes in 235 individual patients. One hundred forty-eight cases received levofloxacin and 137 received amikacin, both in combination with ceftazidime. More cases in the levofloxacin than the amikacin group had underlying hematological malignancy; most other characteristics of the two groups were well balanced. Nephrotoxicity requiring treatment discontinuation occurred in one case in the amikacin group. No difference in clinical success (79.7% vs. 80.3%, p&gt;0.99) or all-cause mortality (12.8% vs. 11.7%, p=0.86) was noted between the levofloxacin and the amikacin groups, even after adjustment for the independent predictor variables for each endpoint. Sepsis at presentation, presence of localizing symptoms/signs of infection, and isolation of a non-susceptible Gram-negative pathogen independently predicted both clinical success and all-cause mortality. Additionally, underlying solid tumor independently predicted clinical success, while poor prognosis of the underlying neoplasia and skin/soft tissue infection independently predicted mortality. Ceftazidime plus levofloxacin had similar effectiveness to ceftazidime plus amikacin as empirical regimens for febrile neutropenia. Nephrotoxicity with once-daily amikacin was minimal. Inappropriate empirical therapy was associated with worse prognosis.
European Journal of Clinical Microbiology & Infectious Diseases, 2011
Fosfomycin represents a potential last-resort treatment option for infections with certain multid... more Fosfomycin represents a potential last-resort treatment option for infections with certain multidrug-resistant (MDR) Gram-negative pathogens. We evaluated double-drug combinations of fosfomycin with imipenem, meropenem, doripenem, colistin, netilmicin, and tigecycline for in vitro synergy against 100 MDR Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa clinical isolates, using the Etest method. Synergy was defined as a fractional inhibitory concentration index ≤ 0.5. The isolates were consecutively collected at a university hospital in Greece from various clinical specimens. Against 50 serine carbapenemase-producing K. pneumoniae isolates, synergy of fosfomycin with imipenem, meropenem, doripenem, colistin, netilmicin, and tigecycline was observed for 74.0%, 70.0%, 74.0%, 36.0%, 42.0%, and 30.0% of the isolates, respectively. Against 14 extended-spectrum β-lactamase (ESBL)-producing K. pneumoniae isolates, synergy of fosfomycin with imipenem, meropenem, doripenem, colistin, netilmicin, and tigecycline was observed for 78.6%, 42.9%, 42.9%, 7.1%, 42.9%, and 21.4%, respectively; for 20 ESBL-producing E. coli isolates, the corresponding values were 55.0%, 25.0%, 30.0%, 15.0%, 25.0%, and 25.0%; and for 15 MDR P. aeruginosa isolates, the corresponding values were 46.7%, 53.3%, 73.3%, 13.3% , 13.3%, and 13.3%. Antagonism was not observed for any of the combinations tested. Further studies are needed in order to confirm the clinical relevance of the above findings.
European Journal of Clinical Microbiology & Infectious Diseases, 2008
In this investigation, we sought to investigate the characteristics of Citrobacter spp. infection... more In this investigation, we sought to investigate the characteristics of Citrobacter spp. infections. A retrospective cohort study in a 700-bed, tertiary care, university hospital was carried out during the period from June 1994 to January 2006. Seventy-eight patients (70 adults) with Citrobacter spp. isolates were identified. C. freundii was more common (71.8%), followed by C. koseri (23.1%) and C. braakii (3.8%). The most common associated clinical syndromes were urinary tract infections (52.6% of cases, including eight cases of asymptomatic bacteriuria), as well as intra-abdominal (14.1%), surgical site (7.7%), skin and soft tissue (6.4%), and respiratory tract infections (6.4%). In 29.5% of patients, Citrobacter spp. isolates were associated to polymicrobial infections, principally at sites other than the urinary tract. Antibiograms of 38 consecutive Citrobacter spp. isolates (29 C. freundii) were available. Most active agents were colistin (100%), fosfomycin (100%), imipenem (97.4%), gentamicin (89.5%), nitrofurantoin (89.5%), ciprofloxacin (80.6%), and cefepime (73.7%). Most patients (82.1%) had at least one underlying illness. Combination antimicrobial therapy was administered in 28.2% of cases. One patient died during hospitalization. The length of hospital stay was longer in patients with polymicrobial compared to monomicrobial infections (23 versus 13 days, respectively, p = 0.02). The isolation of Citrobacter species, although rather infrequent, was clinically relevant in the great majority of cases. Further attention should be paid to these pathogens.
Critical Care Medicine, 2008
The emergence of multidrug-resistant Gram-negative bacteria has led to the re-use of colistin, bu... more The emergence of multidrug-resistant Gram-negative bacteria has led to the re-use of colistin, but resistance to this agent has already been reported. We aimed to investigate the potential risk factors for the isolation of colistin-resistant Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa from hospitalized patients. Design: Matched case-control study. Setting: Tertiary care hospital in Athens, Greece. Patients: Case patients were those who had provided a clinical specimen from which a colistin-resistant K. pneumoniae, A. baumannii, or P. aeruginosa was isolated. Controls were selected from a pool of patients who had susceptible to colistin isolates and were matched (1:1) to cases for species of microorganism and site of isolation. Susceptibility to colistin was determined with the Etest. Interventions: None. Measurements and Main Results: Data regarding patient demographics, comorbidities, admission to the intensive care unit, prior antibiotic use, and invasive procedures performed were analyzed as risk factors in a matched bivariable model. Variables significantly associated with colistin-resistant isolates (p < .05) were entered in a backward multivariable logistic regression model. Forty-one colistin-resistant unique patient isolates were identified from January 1, 2006, until March 31, 2007. These isolates represented infection in 35 of 41 patients. Risk factors significantly associated with the isolation of colistin-resistant isolates were age, duration of intensive care unit stay, duration of mechanical ventilation, surgical procedures, use of colistin, use of monobactams, and duration of use of third-generation cephalosporins. In the multivariable model, use of colistin was identified as the only independent risk factor (adjusted odds ratio ؍ 7.78, p ؍ .002). Conclusions: Colistin-resistant K. pneumoniae, A. baumannii, and P. aeruginosa pathogens may be encountered in clinical practice, in association with inappropriate colistin use. To prevent this phenomenon, colistin should be used judiciously, given that treatment options for colistin-resistant Gram-negative bacteria are limited.
Archives of Disease in Childhood, 2009
To evaluate the effectiveness and safety of short-course antibiotic therapy for bacterial meningi... more To evaluate the effectiveness and safety of short-course antibiotic therapy for bacterial meningitis, by performing a meta-analysis of randomised controlled trials (RCT). PubMed and the Cochrane Central Register of Controlled Trials were searched for RCT on patients of all ages with community-acquired acute bacterial meningitis that compared treatment with the same antibiotics, in the same daily dosage, administered for a short course (up to 7 days) versus a longer course (2 days or more than corresponding short course). Five open-label RCT involving children (3 weeks to 16 years) were included. No difference was demonstrated between short-course (4-7 days) and long-course (7-14 days) treatment (intravenous ceftriaxone) regarding: end-of-therapy clinical success (five RCT, 383 patients, fixed effect model (FEM), odds ratio (OR) 1.24, 95% CI 0.73 to 2.11); long-term neurological complications (five RCT, 367 patients, FEM, OR 0.60, 95% CI 0.29 to 1.27); long-term hearing impairment (four RCT, 241 patients, FEM, OR 0.59, 95% CI 0.28 to 1.23); total adverse events (two RCT, 122 patients, FEM, OR 1.29, 95% CI 0.57 to 2.91); or secondary nosocomial infections (two RCT, 139 patients, random effects model, OR 0.45, 95% CI 0.05 to 3.71). The duration of hospitalisation was lower with short-course treatment (two RCT, 137 patients, FEM, weighted mean difference -2.17 days, 95% CI -3.85 to -0.50). The available data did not allow for analysis by causative organism. This meta-analysis of the rather limited available relevant data could not show differences between short and long-course antibiotic treatment for bacterial meningitis in children. Further research on this issue is required.
The American Journal of Medicine, 2008
Circulation, Oct 31, 2006
Annals of Translational Medicine, Nov 1, 2018
Ventilator-associated pneumonia (VAP) remains an important clinical problem globally, being assoc... more Ventilator-associated pneumonia (VAP) remains an important clinical problem globally, being associated with significant morbidity and mortality. As management of VAP requires adequate and timely antibiotic administration, global emergence of antimicrobial resistance poses serious challenges over our ability to maintain this axiom. Development of antimicrobials against MDR Gram-negative pathogens has therefore emerged as a priority and some new antibiotics have been marketed or approach late stage of development. The aim of this review is to analyse new therapeutic options from the point view of potential treatment of VAP. Among recently developed antimicrobials presented herein, it is obvious that we will have promising therapeutic options against VAP caused by Enterobacteriaceae excluding those producing metalloβ-lactamases, against which only cefiderocol and aztreonam/avibactam are expected to be active. Against infections caused by carbapenem non-susceptible Pseudomonas aeruginosa, ceftolozane/tazobactam and to a lesser extend ceftazidime/avibactam may cover a proportion of current medical needs, but there still remain a considerable proportion of strains which harbor other resistance mechanisms. Murepavadin and cefiderocol hold promise against this particularly notorious pathogen. Finally, Acinetobacter baummannii remains a treatment-challenge. Eravacycline, cefiderocol and probably plazomicin seem to be the most promising agents against this difficult-to treat pathogen, but we have still a long road ahead, to see their position in clinical practice and particularly in VAP. In summary, despite persisting and increasing unmet medical needs, several newly approved and forthcoming agents hold promise for the treatment of VAP and hopefully will enrich our antimicrobial arsenal in the next few years. Targeted pharmacokinetic and clinical studies in reallife scenario of VAP are important to position these new agents in clinical practice, whereas vigilant use will ensure their longevity in our armamentarium.
Lancet Infectious Diseases, Dec 1, 2008
Institutional outbreaks caused by Acinetobacter baumannii strains that have acquired multiple mec... more Institutional outbreaks caused by Acinetobacter baumannii strains that have acquired multiple mechanisms of antimicrobial drug resistance constitute a growing public-health problem. Because of complex epidemiology, infection control of these outbreaks is diffi cult to attain. Identifi cation of potential common sources of an outbreak, through surveillance cultures and epidemiological typing studies, can aid in the implementation of specifi c control measures. Adherence to a series of infection control methods including strict environmental cleaning, eff ective sterilisation of reusable medical equipment, attention to proper hand hygiene practices, and use of contact precautions, together with appropriate administrative guidance and support, are required for the containment of an outbreak. Eff ective antibiotic treatment of A baumannii infections, such as ventilator-associated pneumonia and bloodstream infections, is also of paramount importance. Carbapenems have long been regarded as the agents of choice, but resistance rates have risen substantially in some areas. Sulbactam has been successfully used in the treatment of serious A baumannii infections; however, the activity of this agent against carbapenem-resistant isolates is decreasing. Polymyxins show reliable antimicrobial activity against A baumannii isolates. Available clinical reports, although consisting of smallsized studies, support their eff ectiveness and mitigate previous concerns for toxicity. Minocycline, and particularly its derivative, tigecycline, have shown high antimicrobial activity against A baumannii, though relevant clinical evidence is still scarce. Several issues regarding the optimum therapeutic choices for multidrug-resistant A baumannii infections need to be clarifi ed by future research.
Journal of Antimicrobial Chemotherapy, Aug 1, 2008
Antimicrobial drug resistance is spreading among Enterobacteriaceae, limiting the utility of trad... more Antimicrobial drug resistance is spreading among Enterobacteriaceae, limiting the utility of traditionally used agents. We sought to systematically review the microbiological activity and clinical effectiveness of tigecycline for multidrug-resistant (MDR) Enterobacteriaceae, including those resistant to broad-spectrum b-lactams due to the expression of extended-spectrum b-lactamases (ESBLs), AmpC enzymes and carbapenemases (including metallo-b-lactamases). Methods: PubMed was searched for articles including relevant data. Results: Twenty-six microbiological and 10 clinical studies were identified. Tigecycline was active against more than 99% of 1936 Escherichia coli isolates characterized by any of the above resistance patterns (including 1636 ESBL-producing isolates) using the US Food and Drug Administration (FDA) breakpoint of susceptibility (MIC 2 mg/L). Findings were not different using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoint (1 mg/L). Susceptibility rates for Klebsiella spp. with any of the above resistance patterns were 91.2% for 2627 isolates by the FDA criteria and 72.3% for 1504 isolates by the EUCAST criteria (92.3% for 2030 and 72.3% for 1284 ESBLproducing isolates, by the FDA and EUCAST criteria, respectively). The degree of microbiological activity of tigecycline against 576 MDR Enterobacter spp. isolates was moderate. In clinical studies, 69.7% of the 33 reported patients treated with tigecycline achieved resolution of an infection caused by a carbapenem-resistant or ESBL-producing or MDR Enterobacteriaceae. Conclusions: Tigecycline is microbiologically active against almost all of the ESBL or MDR E. coli isolates and the great majority of ESBL or MDR Klebsiella spp. isolates. Further evaluation of its clinical utility against such resistant Enterobacteriaceae, particularly regarding non-labelled indications, is warranted.
Journal of Neurosonology and Neuroimaging, 2021
Neurocysticercosis (NCC), the most common central nervous system (CNS) parasitic infection among ... more Neurocysticercosis (NCC), the most common central nervous system (CNS) parasitic infection among the immunocompetent population can imitate every clinical feature of brain-diseases accurately, drawing attention away from the real culprit and delaying the proper treatment. There are two types of NCC, the parenchymal and the extraparenchymal form. The extraparenchymal NCC include the ventricular cysticercosis, the subarachnoid cysts including giant cysts or racemose cysticercosis with chronic meningitis, the spinal (intra- or extramedullary) cysticercosis and the ophthalmic cysticercosis. It is estimated that about 30% of epilepsy cases in endemic countries are due to NCC and especially the racemose NCC is more aggressive and associated with higher mortality rates. There is a significant heterogeneity in clinical phenotypes, regarding the racemose NCC, which depends on the parasite load and evolutionary stage in association with its location in CNS and the host’s immune response. Cruc...
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Papers by Drosos Karageorgopoulos