[Multicenter study of in vitro activity of tigecycline in clinical isolates from 30 centers in Spain]

In the last years, the increase of antibiotic resistances of gram-positive and gram-negative bacteria is an important therapeutic problem. The antimicrobial activity of tigecycline, a novel glycylcycline, was evaluated against 750 bacterial isolates from 30 centers in Spain.

Multicenter and retrospective study. In 2005, thirty laboratories participated in this study. Data collected in this study included antimicrobial susceptibilities for S.aureus resistant to methicillin (MRSA), ESBL- E. coli or ESBL- K. pneumoniae, E. coli resistant to quinolons (E.coli- QR), Klebsiella spp and E. faecalis. Trains were obtained of the each Hospital s collection (5 strains of each microorganisms). The susceptibility determinations were performed locally by each laboratory following the standard method usually performed. The tigecycline susceptibility determinations were performed with E/test.

Tigecycline was the most potent agent against MRSA, E. faecalis, E.coli-QR and ESBLs enterobacteriaceae; with MIC50-MIC90 values of: 0.125-0.25 g/ml; 0.125-0.5 g/ml; 0.25-0.75 g/ml and 0.38-1.5 g/ml; respectively.

The results of this study confirm the excellent in vitro activity of tigecycline against gram-positive and gram-negative pathogens, including multirresistant microorganisms.