Macrolide antibiotics enzymatic inactivation

The mechanisms of microbial resistance to antibiotics are generally due to alterations of the antibiotic s target site, enzymatic inactivation of the antibiotic, cell impermeability, reduced cellular uptake, or increased efflux of antibiotic from cells [218]. The occurrence of these mechanisms in macrolide-resistant organisms has been reviewed [219-221]. The most widespread mechanism is modification of the macrolide s ribosomal... 

Among other modifications of the neutral sugar (cladinose), three fermentation-derived 3"- and 4"-esters of erythromycin D have been isolated [60]. In contrast to studies on modification of cladinose, fewer modifications of the amino sugar (desosamine) have been reported in recent years. Enzymatic phosphorylation of the 2 -hydroxyl group of several macrolides was performed by cell-free extracts of Streptomyces coelicolor this was suggested as a potential mechanism of bacterial inactivation of antibiotic activity [61, 62]. 

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