RESUMO
Nine patients developed P. aeruginosa bloodstream infection (BSI) in a neurosurgical intensive care unit (NSICU) during a 2-month period. Environmental strains were isolated from a plasma-expander solution and tap water. All clinical and plasma-expander strains displayed the same PFGE pattern, whereas the water strains were unrelated to the outbreak.
Assuntos
Bacteriemia/microbiologia , Infecção Hospitalar/microbiologia , Surtos de Doenças , Controle de Infecções/métodos , Substitutos do Plasma/efeitos adversos , Infecções por Pseudomonas/epidemiologia , Pseudomonas aeruginosa/patogenicidade , Bacteriemia/etiologia , Infecção Hospitalar/etiologia , Eletroforese em Gel de Campo Pulsado , Gelatina/efeitos adversos , Humanos , Procedimentos Neurocirúrgicos , Complicações Pós-Operatórias/microbiologia , Infecções por Pseudomonas/etiologia , Pseudomonas aeruginosa/classificaçãoRESUMO
Fosfomycin is a molecule that inhibits the early stage of peptidoglycan synthesis and shows a broad-spectrum bactericidal activity against Gram-positive and Gram-negative bacteria. Using the Killing-curve method, we tested the in vitro bactericidal activity of fosfomycin alone or in combination with vancomycin or teicoplanin at a concentration of 8 microg/mL, that is easily achievable in serum at standard dosing regimens, against seven methicillin-resistant Staphylococcus aureus strains, isolated from patients with well documented device-associated infections unresponsive to or relapsing after glycopeptide therapy. MICs of vancomycin ranged from 1 to 4 microg/mL, MICs of teicoplanin from 2 to 8 microg/mL; MICs of fosfomycin were 8 microg/mL for two strains and >128 microg/mL for the remaining strains. The seven strains proved tolerant when tested for vancomycin and teicoplanin used alone at 2x MIC concentration. Fosfomycin was bactericidal (reduction of 2 log of the inoculum) only against the two susceptible strains. In all cases both vancomycin and teicoplanin in combination with fosfomycin developed bactericidal synergism already at a concentration of 1x MIC. If these results are confirmed by in vivo experiments, the combination of fosfomycin with glycopeptides might be useful for treating device-associated infections, and in preventing the phenomenon of increasing MICs for glycopeptides.