Optimizing the treatment of osteomyelitis with antimicrobial drugs: current concepts

Abstract

The success of osteomyelitis treatment, particularly in cases related to implants, depends on extensive surgical debridement and adequate and effective antibiotic therapy. Direct administration of antimicrobial agents through their incorporation into orthopaedic cement is an important adjuvant therapy. The capacity for biofilm to form by causative agents of osteomyelitis is an obstacle to antimicrobial treatment of these infections. Bacteria present in biofilm usually has greater bacterial resistance and higher expression of virulence factors than sessile bacteria, as well as mechanisms to escape the host immune response. The ability of causative agents of infection, particularly Staphylococcus aureus, to form small colony variants (SCV), a phenotype capable of invading and infecting osteoblasts, is another important mechanism that contributes to exacerbation of osteomyelitis to a chronic state. To optimize the antimicrobial treatment of osteomyelitis and improve patients’ prognosis, it is fundamental to consider these complicating factors, as well as the antimicrobial susceptibility profile of the causative microorganisms. Rifampicin should always be considered as part of the therapeutic regimen because it presents good bone concentration and has proven capacity to act on strains present in biofilm and in SCV.