New antibiotics: optimal use in current clinical practice.

The optimal choice of antibacterial therapy among the few available options for infections caused by pathogens with advanced antimicrobial drug resistance is fundamental to maximize clinical effectiveness and minimize the likelihood for further resistance development. We herein review the available data on the effectiveness of antibiotics introduced in clinical practice during the past 10 years for specific clinical indications. Quinupristin-dalfopristin, linezolid, daptomycin and tigecycline have increased the available therapeutic options against specific types of meticillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium infections. The newer fluoroquinolones, moxifloxacin and gemifloxacin, along with the ketolide telithromycin and the oral third-generation cephalosporin cefditoren are particularly valuable for the treatment of specific types of multidrug-resistant Streptococcus pneumoniae infections. Tigecycline appears as a promising therapeutic option for infections caused by Enterobacteriaceae producing extended spectrum beta-lactamases (ESBLs), or multidrug-resistant Acinetobacter baumannii. Ertapenem and doripenem may be particularly useful against infections caused by ESBL-producing Enterobacteriaceae and multidrug-resistant Pseudomonas aeruginosa, respectively.