In vitro antimicrobial activity of tigecycline against Gram negative and Gram positive pathogens collected in Northen Italy (T.E.S.T. program 2010)

Background. In this study (part of the global T.E.S.T. program) was evaluated the in vitro activity of tigecycline, member of a new class of antimicrobial agents, the glycylcyclines, against clinical isolates collected in Italy. Methods. A total of 194 clinical isolates were collected and identified in our Institution during 2010. Minimum inhibitory concentrations (MICs) of the antimicrobial agents were determined by the CLSI (2010) recommended broth microdilution method. Results. Globally 129 Gram negative and 65 Gram positive pathogens were evaluated.Tigecycline demonstrated excellent inhibitory activity against Escherichia coli, Haemophylus influenzae, Enterococcus spp., Staphylococcus aureus MetS, Streptococcus pneumoniae and Streptococcus agalactiae with MIC90 1mg/l. Conclusion. Tigecycline exhibited potent in vitro antibacterial activity (comparable to or greater than most commonly employed antimicrobials) against both Gram positive and negative clinical pathogens. These data suggest that tigecycline, with an expanded broad-spectrum antimicrobial activity, may be an effective empiric therapeutic option for the treatment of serious infections caused by clinically relevant pathogens.