Macrolide and clindamycin resistance in Staphylococcus aureus isolates and antibiotic use in a Veterans Affairs Medical Center.

A retrospective analysis of 13,946 Staphylococcus aureus isolates revealed a stable incidence of isolates that were resistant to both clindamycin and erythromycin, but a significantly increasing incidence of isolates that were susceptible to clindamycin and resistant to erythromycin during 1991-1995, 1996-2000, and 2001-2005. The use of macrolides and clindamycin also increased during 1996-2005. The incidence of S. aureus isolates with inducible clindamycin resistance increased steadily and significantly during the period from August 2004 through December 2005.