Staphylococcus simulans septicemia in a patient with chronic osteomyelitis and pyarthrosis

Abstract

Staphylococcus simulans was identified as the etiological agent of osteomyelitis and septic arthritis in an adult male who had sustained a fracture of the fibula and syndesmosis separation which required the installation of orthopedic hardware. Identifying characteristics and antibiograms for this organism, recovered from blood, wound exudate, and deep tissue samples, were determined. Recent evidence has linked slime production (adherence to smooth surfaces) by coagulase-negative staphylococci to infections by these organisms at sites where foreign bodies had been inserted. Tests for adherence showed this S. simulans strain to be a strong slime producer. This is the first reported case of osteomyelitis and septicemia due to S. simulans.

Update on clinical significance of coagulase-negative staphylococci.

“…By the 1980s, the range of infections believed to be caused by CNS, and especially by S. epidermidis, was quite wide and included bacteremia (24,207); native valve endocarditis (NVE) and prosthetic valve endocarditis (7,11,260); osteomyelitis (204,233); pyoarthritis (204); peritonitis during continuous ambulatory dialysis (182,267); mediastinitis (34); prostatitis (45, 310); infections of permanent pacemakers (48), vascular grafts and intravascular catheters (242,243), cerebrospinal fluid shunts (100), and prosthetic joints and a variety of orthopedic devices (38,54,218); and UTIs (148, 156,192). The CNS species S. saprophyticus was often regarded as a more important opportunistic pathogen than S. epidermidis in human UTIs, especially in young, sexually active females (3,206,307).…”

“…Some of the earlier reports indicating an association of S. hominis with infections may have been in error due to the confusion of this species with phosphatase-negative strains of S. epidermidis (171). S. simulans has been associated with some cases of chronic osteomyelitis and pyarthrosis (204).…”

Specimen Collection and Processing

“…By the 1980s, the range of infections believed to be caused by CNS, and especially by S. epidermidis, was quite wide and included bacteremia (24,207); native valve endocarditis (NVE) and prosthetic valve endocarditis (7,11,260); osteomyelitis (204,233); pyoarthritis (204); peritonitis during continuous ambulatory dialysis (182,267); mediastinitis (34); prostatitis (45,310); infections of permanent pacemakers (48), vascular grafts and intravascular catheters (242,243), cerebrospinal fluid shunts (100), and prosthetic joints and a variety of orthopedic devices (38,54,218); and UTIs (148,156,192). The CNS species S. saprophyticus was often regarded as a more important opportunistic pathogen than S. epidermidis in human UTIs, especially in young, sexually active females (3,206,307).…”

“…Some of the earlier reports indicating an association of S. hominis with infections may have been in error due to the confusion of this species with phosphatase-negative strains of S. epidermidis (171). S. simulans has been associated with some cases of chronic osteomyelitis and pyarthrosis (204). The largest populations of human staphylococci are usually found in regions of the skin and mucous membranes surrounding openings to the body surface (165,172).…”

Mutagenesis and structural analysis of the Staphylococcus Aureus Sae two-component system reveals the intricate nature of virulence regulation

“…simulans was originally isolated from the human skin, suggesting it is a human commensal, but it is also capable of causing invasive disease (144,145). Most of the documented human cases are associated with bone and joint infections, although a few reports stated S. simulans was isolated from blood and tracheal aspirations as well (145)(146)(147). Humans are not the only host for S. simulans.…”