Polymyxin B: similarities to and differences from colistin (polymyxin E).

Hospital-acquired infections due to multidrug-resistant gram-negative bacteria constitute major health problems, since the medical community is continuously running out of available effective antibiotics and no new agents are in the pipeline. Polymyxins, a group of antibacterials that were discovered during the late 1940s, represent some of the last treatment options for these infections. Only two polymyxins are available commercially, polymyxin E (colistin) and polymyxin B.

The use of intravenous and aerosolized polymyxins for the treatment of infections in critically ill patients: a review of the recent literature.

Intravenous and aerosolized polymyxins are being used increasingly, especially in the critical care setting, for treating patients with infections due to multidrug-resistant Gram-negative bacteria, mainly Acinetobacter baumannii and Pseudomonas aeruginosa. Recent literature suggests that intravenous colistin and polymyxin B have acceptable effectiveness for the treatment of patients with bacteremia, as well as infections of various systems and organs, including pneumonia, bacteremia, skin and soft tissue, and urinary tract infections. Although data from recent studies have suggested that the toxicity of intravenous polymyxins is probably less than reported in the older literature, caution should be taken to monitor the renal function of patients who receive these antibiotics.

Secular trends of antimicrobial resistance of blood isolates in a newly founded Greek hospital.

Background: Antimicrobial resistance is one of the most challenging issues in modern medicine.

Methods: We evaluated the secular trends of the relative frequency of blood isolates and of the pattern of their in vitro antimicrobial susceptibility in our hospital during the last four and a half years.

Results: Overall, the data regarding the relative frequency of blood isolates in our newly founded hospital do not differ significantly from those of hospitals that are functioning for a much longer period of time.

Limitations in the management of aortic graft infections.

The use of aortic allografts has emerged as a management option in patients with aortic graft infections. We present a patient with a history of Takayasu's disease whose aortic graft infection was controlled with replacement of the excised infected aortic graft with an allograft. However, the patient died 9 months later after the rupture of a large anastomotic aortic aneurysm.

Comparison of mortality of patients with Acinetobacter baumannii bacteraemia receiving appropriate and inappropriate empirical therapy.

Objectives: To evaluate the effect of inappropriate empirical antimicrobial treatment on the mortality of patients with Acinetobacter baumannii bacteraemia.

Methods: Retrospective cohort study of patients with A. baumannii bacteraemia hospitalized at the Henry Dunant hospital from January 2002 to December 2004.

Toxicity of polymyxins: a systematic review of the evidence from old and recent studies.

Background: The increasing problem of multidrug-resistant gram-negative bacteria causing severe infections and the shortage of new antibiotics to combat them has led to the re-evaluation of polymyxins. These antibiotics were discovered from different species of Bacillus polymyxa in 1947; only two of them, polymyxin B and E (colistin), have been used in clinical practice. Their effectiveness in the treatment of infections due to susceptible gram-negative bacteria, including Pseudomonas aeruginosa and Acinetobacter baumannii, has not been generally questioned.

Continuous versus intermittent intravenous administration of antibacterials with time-dependent action: a systematic review of pharmacokinetic and pharmacodynamic parameters.

We performed a systematic review of randomised clinical trials to evaluate the comparative pharmacokinetic and pharmacodynamic properties of the continuous versus intermittent mode of intravenous administration of various antibacterials. Data were identified from PubMed (January 1950 to January 2005), Current Contents, the Cochrane central register of controlled trials, and references from relevant articles and reviews. Seventeen randomised clinical trials comparing continuous with intermittent intravenous administration of the same antibacterial regimen and examining the pharmacokinetic and pharmacodynamic properties were included in this systematic review.

Nephrotoxicity of intravenous colistin: a prospective evaluation.

Twenty-one patients who received intravenous colistimethate sodium (CMS) for at least 7 days for the treatment of multidrug-resistant Gram-negative bacterial infections were included in a prospective cohort study at 'Henry Dunant' Hospital in Athens, Greece. The mean (+/- standard deviation) and median daily doses, cumulative doses and duration of treatment of intravenous CMS were, respectively, 5.5 (+/- 1.

Cure of multidrug-resistant Acinetobacter baumannii fixation device-related orthopedic infections in two patients with intravenous colistin.

We report our experience with two cases of fixation device-related orthopedic infections due to multidrug-resistant Acinetobacter baumannii strains. Both patients were successfully treated with intravenous administration of colistin, despite the reported poor penetration of this medication to these tissues, in the old literature. No serious colistin-associated toxicity developed and no recurrence of the infection occurred on follow up.

Ciprofloxacin vs an aminoglycoside in combination with a beta-lactam for the treatment of febrile neutropenia: a meta-analysis of randomized controlled trials.

Objective: To compare the effectiveness and toxicity of ciprofloxacin vs an aminoglycoside, both in combination with a beta-lactam, for the treatment of febrile neutropenia in the inpatient setting.

Methods: For this meta-analysis of randomized controlled trials (RCTs) that compared the ciprofloxacin/beta-lactam combination vs an aminoglycoside/beta-lactam combination for the treatment of febrile neutropenia and reported data on effectiveness, mortality, and/or toxicity, we searched PubMed (1950-2004), Current Contents, Cochrane Central Register of Controlled Trials, and reference lists of retrieved articles, including review articles, as well as abstracts presented at international conferences. Data for 3 primary and 2 secondary outcomes were extracted by 2 investigators.

Continuous versus intermittent intravenous administration of antibiotics: a meta-analysis of randomised controlled trials.

Intermittent intravenous administration of antibiotics is the first-line approach in the management of severe infections worldwide. However, the potential benefits of alternate modes of administration of antibiotics, including continuous intravenous infusion, deserve further evaluation. We did a meta-analysis of randomised controlled trials comparing continuous intravenous infusion with intermittent intravenous administration of the same antibiotic regimen.

Combination therapy with intravenous colistin for management of infections due to multidrug-resistant Gram-negative bacteria in patients without cystic fibrosis.

Colistin, an antibiotic almost abandoned for intravenous administration for many years due to its reported toxicity, has been recently reintroduced in clinical practice due to the emergence of multidrug-resistant gram-negative bacteria and the lack of development of new antibiotics to combat them. To assess the safety and effectiveness of intravenous colistin, in combination with other antimicrobial agents, in the treatment of serious infections in patients without cystic fibrosis, a retrospective cohort study in a 450-bed tertiary-care hospital in Athens, Greece, was performed. Patients who were hospitalized from 1 October 2000 to 31 January 2004 and received intravenous colistin for more than 72 h were further analyzed.

Regression of skin lesions of Kyrle's disease with clindamycin: implications for an infectious component in the etiology of the disease.

We report our experience with the management of a 44-year-old man with manifestations of Kyrle's disease. The patient presented to us with skin lesions of two different types. The old lesions were large hyperkeratotic plaques with burrows without signs of inflammation.

From conference abstract to full paper: differences between data presented in conferences and journals.

Background: We studied the type and frequency of differences between data presented in conference abstracts and subsequent published papers in the fields of infectious diseases and microbiology.

Methods: We reviewed all abstracts from the first session of 7 of 15 major research categories presented in the 1999 and 2000 Interscience Conference on Antimicrobial Agents and Chemotherapy. For each selected pair of abstract and related published paper, two independent investigators performed a detailed data comparison.

Cure of post-traumatic recurrent multiresistant Gram-negative rod meningitis with intraventricular colistin.

A 28-year-old man developed five episodes of meningitis, all due to multiresistant Gram-negative rods during his 7-month hospitalisation after head trauma. This patient's recurrent meningitis was solved only when colistin and amikacin were given by the intraventricular in addition to the intravenous route for a long period of time, specifically 6 weeks.

Effusive-constrictive calcific pericarditis associated with Streptococcus salivarius. Case report and review of the literature.

We report the case of a 40-year-old patient presenting with a 6-month history of dyspnea and edema, with significant worsening of his clinical manifestations for the 2 weeks before admission to our department. During this 14-day preadmission period, continuous positive airway pressure (CPAP) was prescribed elsewhere for management of a working diagnosis of obstructive sleep apnea. The patient presented to us hemodynamically compromised.

Colistin: the revival of polymyxins for the management of multidrug-resistant gram-negative bacterial infections.

The emergence of multidrug-resistant gram-negative bacteria and the lack of new antibiotics to combat them have led to the revival of polymyxins, an old class of cationic, cyclic polypeptide antibiotics. Polymyxin B and polymyxin E (colistin) are the 2 polymyxins used in clinical practice. Most of the reintroduction of polymyxins during the last few years is related to colistin.

Outcome of infections due to pandrug-resistant (PDR) Gram-negative bacteria.

Background: The increasing problem of infections due to multidrug-resistant Gram-negative bacteria has led to re-use of polymyxins in several countries. However, there are already clinical isolates of Gram-negative bacteria that are resistant to all available antibiotics, including polymyxins.

Methods: We present a case series of patients with infections due to pathogens resistant to all antimicrobial agents tested, including polymyxins.

Cure of multidrug-resistant Acinetobacter baumannii bacteraemia with continuous intravenous infusion of colistin.

Continuous intravenous colistin (2,000,000 units per 24 h) was administered in a 41-y-old patient with Acinetobacter baumannii bacteraemia, which led to the cure of the infection. The isolated microorganism was a multi-resistant strain (it was sensitive only to colistin). In addition, the patient had developed allergic reactions to previously administered antimicrobial agents of several classes during his hospitalization.

Aerosolized colistin for the treatment of nosocomial pneumonia due to multidrug-resistant Gram-negative bacteria in patients without cystic fibrosis.

Introduction: The clinical and economic consequences of the emergence of multidrug-resistant Gram-negative bacteria in the intensive care unit (ICU) setting, combined with the high mortality rate among patients with nosocomial pneumonia, have stimulated a search for alternative therapeutic options to treat such infections. The use of adjunctive therapy with aerosolized colistin represents one of these. There is extensive experience with use of aerosolized colistin by patients with cystic fibrosis, but there is a lack of data regarding the use of aerosolized colistin in patients without cystic fibrosis.

Toxicity after prolonged (more than four weeks) administration of intravenous colistin.

Background: The intravenous use of polymyxins has been considered to be associated with considerable nephrotoxicity and neurotoxicity. For this reason, the systemic administration of polymyxins had been abandoned for about 20 years in most areas of the world. However, the problem of infections due to multidrug-resistant (MDR) Gram-negative bacteria such us Pseudomonas aeruginosa and Acinetobacter baumanniii has led to the re-use of polymyxins.