Specific Antibodies to Staphylococcus aureus Biofilm Are Present in Serum from Pigs with Osteomyelitis

The Achilles heel in osteomyelitis is that bacteria, primarily Staphylococcus aureus, grow as a biofilm in the bone lesions.In the present study, we explored the serum level of specific antibodies to S. aurues biofilm in porcine models of osteomyelitis.Significantly increased levels of antibodies towards the specific biofilm antigen SA0688 were measured in serum from pigs with S. aureus-associated acute and chronic osteomyelitis 5-7 and 10-14 days after inoculation, respectively. Simultaneously with raised antibody levels, an increase in serum interleukin 6 (IL 6) levels was also seen.The observed biofilm-specific antibody response represents a T-helper cell 17 (Th17) response and potentially a T-helper cell 1 (Th1) response. This is in agreement with previous studies in mice and rabbits speculating that S. aureus induces a Th1- and Th17-biased adaptive immune response, instead of a protective Th2 response, in order to evade the immune system, resulting in a chronic infection.