An electron microscopic study of the effect of clindamycin therapy on bacterial adherence and glycocalyx formation in experimental Staphylococcus aureus osteomyelitis.

After induction of experimental osteomyelitis with Staphylococcus aureus in a rabbit tibia model, clindamycin phosphate (280 mg/kg/day) was used to treat the infected animals for 1, 2 and 3 week periods. Scanning electron microscopy of samples of infected bone tissue taken at necropsy revealed masses of coccoid profiles embedded in a matrix of condensed exopolysaccharide material which adhered to the bone in both infected control animals and in infected animals treated for 1 week with clindamycin phosphate. After 2 and 3 weeks of clindamycin phosphate treatment, the infecting bacteria could not be cultured from tissue samples, and scanning electron microscopy of these samples revealed few coccoid profiles adhering to the bone and marrow. Radiological, microbiological, clinical, histological and electron microscopic findings all indicated recovery from the diseased state with increased length of clindamycin phosphate treatment.