Recent developments in macrolides and ketolides.

Emergence of bacterial resistance to macrolide antibiotics, particularly in Gram-positive bacteria, has been observed. Novel macrolides having C-4" carbamate functional groups and ketolides, the 3-keto derivatives of macrolides, have been found to have activities against macrolide-resistant strains. Several potential non-antibacterial activities of macrolides have been reported, such as inhibition of cytokine production, neutrophil attachment to human bronchial epithelial cells and vesicular transport.