ABSTRACT
We evaluated the antimicrobial activity of fosfomycin against a randomly selected sample of 30 Klebsiella pneumoniae, 30 Pseudomonas aeruginosa, and 30 Acinetobacter baumannii multidrug-resistant, clinical isolates from patients in a general tertiary care hospital in Athens, Greece. Standard laboratory methods were used for susceptibility testing to commonly used antibiotics and the detection of extended-spectrum-beta-lactamase (ESBL) and metallo-beta-lactamase (MBL) production. The minimum inhibitory concentration (MIC) of fosfomycin for each isolate was determined by the agar dilution method. All K. pneumoniae isolates were both ESBL and MBL producers; all P. aeruginosa isolates were ESBL producers. The K. pneumoniae strains had fosfomycin MICs distributed across a range of 8-64 microg/ml; MIC(50) was 16 microg/ml and MIC(90) 32 microg/ml. The fosfomycin MICs of the P. aeruginosa strains had a distribution across a range of 4 to over 512 microg/ml; MIC(50) was 32 microg/ml and MIC(90) 128 microg/ml. The fosfomycin MICs of the A. baumannii strains had a distribution across a range of 64 to over 512 microg/ml; MIC(50) was 256 microg/ml and MIC(90) more than 512 microg/ml. Although standardized fosfomycin MIC interpretative breakpoints for the species studied are lacking, the findings of our study support the idea that fosfomycin may be further investigated as one among a decreasing list of therapeutic options for the treatment of infections due to multidrug-resistant strains of, primarily, K. pneumoniae and, secondly, P. aeruginosa.
Subject(s)
Drug Resistance, Multiple, Bacterial , Fosfomycin/pharmacology , Gram-Negative Bacteria/drug effects , beta-Lactamases/metabolism , Anti-Bacterial Agents/pharmacology , Gram-Negative Bacteria/isolation & purification , Microbial Sensitivity Tests , beta-Lactam Resistance/genetics , beta-Lactamases/geneticsABSTRACT
The present study was conducted to investigate the increasing incidence of Achromobacter (previously Alcaligenes) xylosoxidans isolates being recovered from sputum samples of cystic fibrosis patients at a cystic fibrosis department for adults in Athens, Greece. During the 1-year study period, a total of 34 isolates were detected persistently in 9 of 71 cystic fibrosis patients. The isolates exhibited resistance to multiple antimicrobial agents. Isolates that were recovered repeatedly from each patient exhibited identical macrorestriction profiles with pulsed-field gel electrophoresis, indicating that the same strain persisted in the lungs of these patients. Isolates from five of the patients were genetically related, suggesting a common-source outbreak of Achromobacter xylosoxidans colonization or infection.
Subject(s)
Alcaligenes/isolation & purification , Anti-Bacterial Agents/pharmacology , Cystic Fibrosis/epidemiology , Gram-Negative Bacterial Infections/diagnosis , Gram-Negative Bacterial Infections/epidemiology , Adolescent , Adult , Age Distribution , Alcaligenes/drug effects , Anti-Bacterial Agents/therapeutic use , Cohort Studies , Colony Count, Microbial , Cystic Fibrosis/diagnosis , Drug Resistance, Bacterial , Electrophoresis, Gel, Pulsed-Field , Female , Follow-Up Studies , Gram-Negative Bacterial Infections/drug therapy , Greece/epidemiology , Humans , Male , Microbial Sensitivity Tests , Prevalence , Risk Assessment , Sex DistributionABSTRACT
Between September 1999 to February 2001, 25 glycopeptide-resistant Enterococcus faecium (GRE) isolates were recovered from a Greek hospital. The isolates exhibited 13 distinct chromosomal macrorestriction types by pulsed-field gel electrophoresis, and all were erythromycin and vancomycin resistant, carrying the genes vanA and ermB. Vancomycin resistance, always linked with erythromycin resistance, was transferable from 17 isolates. The dissemination of erythromycin-resistant GRE strains may, at least in part, reflect the extensive use of macrolides in husbandry in Greece.
