Enzyme-linked immunosorbent assay for detection of antibodies to Staphylococcus aureus cell walls in experimental osteomyelitis

Abstract

An enzyme-linked immunosorbent assay was used to evaluate and compare the immunoglobulin G antibody response to Staphylococcus aureus cell walls of rabbits with either chronic staphylococcal osteomyelitis or subcutaneous abscesses. Osteomyelitis of the femur was produced by the intramedullary application of a sclerosing agent (3% sodium tetradecyl sulfate) and S. aureus. Radiographic evidence of osteomyelitis was observed in 10 of the 13 animals that survived the 10-week experimental period, and the diagnosis was confirmed by histopathology in 8 of the 10 instances. Abscess formation was initiated in a separate group of rabbits by the subcutaneous injection of S. aureus cells. All 10 of these rabbits subsequently developed abscesses, which usually resolved spontaneously within 3 to 5 weeks. Elevated levels of immunoglobulin G antibodies to the cell wall antigen were detected in 7 of 10 rabbits with osteomyelitis at 21 days postinfection, and these animals continued to display high antibody levels even at 59 days postinfection. In contrast, elevated levels of anti-cell-wall antibodies were only detected in 1 of 10 rabbits with subcutaneous abscesses. The enzyme-linked immunosorbent assay was found to be a rapid and sensitive serological technique for the detection of cell wall antibodies in this experimental osteomyelitis model and may be useful for the diagnosis of staphylococcal bone infections in humans.

Analysis of various models of chronic osteomyelitis in experimental animals

“…Bone cement was injected through the same opening into the canal to promote the formation of osteomyelitis. Jacob et al [33] reported their model of osteomyelitis on the femur in 1985 according to the method of Norden and Kennedy. Osteomyelitis was caused by intramedullary injection of a sclerosing agent (3% sodium tetradecyl sulfate) and S. aureus (5×106 CFU).…”

Antibody response to teichoic acid and peptidoglycan in Staphylococcus aureus osteomyelitis

“…The serological diagnosis of deep-seated S. aureus infections has been the subject of intensive investigation. Whereas earlier assays measured antibodies to extracellular S. aureus, products, notably alpha and gamma hemolysins (13,23), more recently the focus has shifted toward the detection of antibodies to cell-associated components, including TA (8,10,15,25,31,36), PG (2,26,27,30,35), and cell walls (12). These previous studies have shown that significantly elevated levels of antibodies to TA or PG can be detected in the vast majority of patients with complicated S. aureus bacteremia as measured by gel diffusion, ELISA, or radioimmunoassay.…”

“…Osteomyelitis model. The method used to create osteomyelitis has been previously described in detail (12). Briefly, the right midfemur of each anesthetized rabbit was exposed surgically, and a duct was created in the medullary cavity with an activated high-speed drill.…”

“…In a previous investigation, we reported on the development of an experimental staphylococcal osteomyelitis model for rabbits that closely resembles the clinical, radiographic, and histological features associated with this type of infection in humans (12). The purpose of the present study was to evaluate the immunoglobulin G (IgG) response to S. aureus crude TA and PG in both rabbits and humans with osteomyelitis by an ELISA.…”