Linezolid penetration into cerebrospinal fluid and brain tissue.

The aim of the study was to evaluate the penetration of linezolid into cerebrospinal fluid (CSF) and brain tissue after a single i.v. dose of 600 mg. The penetration of linezolid into cerebrospinal fluid and brain tissue was studied in 18 patients undergoing a neurosurgical procedure. Linezolid 600 mg i.v. was given with the induction of anesthesia. Mean concentrations of linezolid 2h after the final dose, in serum, cerbrospinal fluid and brain tissue were assayed by HPLC. CSF/serum and brain/serum ratios were 69.57% and 44.66% respectively. Concentrations of linezolid were above the MIC(90s )for staphylococci and streptococci. The concentrations obtained indicate good penetration of linezolid into CSF and brain tissue and support its use in the management of multidrug-resistant Gram-positive CNS infections.

Occurrence of Bartonella henselae and Bartonella quintana among human immunodeficiency virus-infected patients.

The purpose of this study was to determine the seroprevalence against Bartonella henselae and Bartonella quintana among a risk group, patients with HIV infection, and to identify the epidemiological factors involved. Our data indicate that the prevalence of Bartonella infection among HIV-infected patients is much greater than that in the healthy population of the same area and that Bartonella infection should be considered in the differential diagnosis for patients with HIV disease.

Comparative in vitro activity of linezolid and five other antimicrobials against nosocomial isolates of methicillin-resistant Staphylococcus aureus, methicillin-resistant Staphylococcus epidermidis and vancomycin-resistant Enterococcus faecium.

The activity of linezolid in comparison to vancomycin, teicoplanin, oxacillin, clindamycin and gentamicin was tested against 60 strains of methicillin-resistant Staphylococcus aureus, 60 strains of methicillin-resistant Staphylococcus epidermidis isolated from patients with nosocomial infections and 24 strains of vancomycin-resistant Enterococcus faecium isolated from feces of hospitalized patients. Minimum Inhibitory Concentrations (MICs) were determined by the Epsilometer test method. All tested strains were sensitive to linezolid and specifically all methicillin-resistant S. aureus had MIC range 0.25-3.00, MIC50 = 0.75, MIC90 = 1.5, all methicillin-resistant S. epidermidis had MIC range 0.125-1.5, MIC50 = 0.5, MIC90 = 1 and all vancomycin-resistant E. faecium had MIC range 0.5-1.5, MIC50 = 1, MIC90 = 1. Linezolid is the first of a novel antimicrobial class, the oxazolidinones, which is a promising treatment for serious Gram-positive infections, including multiresistant strains.

In-vitro activity of clinafloxacin compared to ciprofloxacin against Acinetobacter baumannii strains isolated from intensive care unit patients.

The activity of clinafloxacin was compared to that of ciprofloxacin against 154 Acinetobacter baumannii strains isolated from patients treated in Intensive Care Units. Minimum inhibitory concentrations (MICs) were determined by the Epsilometer test method. The majority (87.6%) of the A. baumannii strains tested were resistant to ciprofloxacin (MIC range 0.125->32, MIC50 = >32, MIC90 = >32). On the contrary, only 9.7% of the strains tested were resistant to clinafloxacin (MIC range 0.023->4, MIC50 = 0.75, MIC90 = 2). Due to its superior activity shown against A. baumannii strains, compared to ciprofloxacin, clinafloxacin may be added to the therapeutic armamentarium for hospital-acquired infections caused by A. baumannii in Intensive Care Units.

Comparative in vitro activity of quinupristin/dalfopristin and seven other antimicrobials against methicillin-susceptible and methicillin-resistant nosocomial Staphylococcus aureus bloodstream isolates.

Staphylococcus aureus strains resistant to a variety of antimicrobial agents are often found in the hospital environment and are responsible for many life-threatening infections. The activity of quinupristin/dalfopristin against 84 Staphylococcus aureus bloodstream isolates (both methicillin resistant and methicillin sensitive) was compared to the activity of vancomycin, teicoplanin, erythromycin, oxacillin, clindamycin, gentamicin, rifampicin. The Minimum Inhibitory Concentrations of these agents was evaluated with the Epsilometer Test. Quinupristin/dalfopristin inhibited all methicillin-sensitive strains at 1mg/L, and 75% of methicillin-resistant strains at 1.5mg/L. According to these results, quinupristin-dalfopristin shows promising in-vitro activity and may be a welcome alternative treatment for methicillin-resistant staphylococcal infections, resulting in reduced use of glycopeptides.