Differential arthritogenicity of Staphylococcus aureusstrains isolated from biological samples

Abstract

BackgroundStaphylococcus aureus is the most common agent of septic arthritis that is a severe, rapidly progressive and destructive joint disease. Superantigens produced by S. aureus are considered the major arthritogenic factors. In this study, we compared the arthritogenic potential of five superantigen-producing staphylococcal strains.MethodsMale C57BL/6 mice were intravenously infected with ATCC 19095 SEC+, N315 ST5 TSST-1+, S-70 TSST-1+, ATCC 51650 TSST-1+ and ATCC 13565 SEA+ strains. Clinical parameters as body weight, arthritis incidence and clinical score were daily evaluated. Joint histopathological analysis and spleen cytokine production were evaluated at the 14th day after infection.ResultsWeight loss was observed in all infected mice. ATCC 19095 SEC+, N315 ST5 TSST-1+ and S-70 TSST-1+ were arthritogenic, being the highest scores observed in ATCC 19095 SEC+ infected mice. Intermediate and lower clinical scores were observed in N315 ST5 TSST-1+ and S-70 TSST-1+ infected mice, respectively. The ATCC 13565 SEA+ strain caused death of 85% of the animals after 48 h. Arthritis triggered by the ATCC 19095 SEC+ strain was characterized by accentuated synovial hyperplasia, inflammation, pannus formation, cartilage destruction and bone erosion. Similar joint alterations were found in N315 ST5 TSST-1+ infected mice, however they were strikingly more discrete. Only minor synovial proliferation and inflammation were triggered by the S-70 TSST-1+ strain. The lowest levels of TNF-α, IL-6 and IL-17 production in response to S. aureus stimulation were found in cultures from mice infected with the less arthritogenic strains (S-70 TSST-1+ and ATCC 51650 TSST-1+). The highest production of IL-17 was detected in mice infected with the most arthritogenic strains (ATCC 19095 SEC+ and N315 ST5 TSST-1+).ConclusionsTogether these results demonstrated that S. aureus strains, isolated from biological samples, were able to induce a typical septic arthritis in mice. These results also suggest that the variable arthritogenicity of these strains was, at least in part, related to their differential ability to induce IL-17 production.

Inflammatory responses and histopathological changes in a mouse model of Staphylococcus aureus-induced bloodstream infections

“…Colavite-Machado et al described the weight loss after 3, 7, and 14 days of infection in S. aureus-infected mice [31]. Similarly, we observed a significant weight loss after 24 hours post-infection in BSI mice (p < 0.001) ( Table 1).…”

Staphylococcus aureus Infections: Epidemiology, Pathophysiology, Clinical Manifestations, and Management

“…In murine models, there is a rapid recruitment of neutrophils, mediated by formylated peptides (465), after S. aureus gains entry to the joint space. Activated macrophages and T cells are recruited as well, and a host of cytokines are induced, including tumor necrosis factor alpha (TNF-␣), gamma interferon (IFN-␥), interleukin-1 (IL-1), IL-2, IL-6, and IL-17 (466). Neutrophils, however, play a dual role.…”

Assay of Blood and Synovial Fluid of Patients With Rheumatoid Arthritis for Staphylococcus aureus Enterotoxin D: Absence of Bacteria But Presence of Its Toxin

“…The results of this study have confirmed the role of S. aureus in the development of RA disease. The results of another study revealed that intravenous administration of S. aureus strains such as ATCC 19095 SEC+, N315ST5 TSST-1+, and ATCC SEA+ could cause progressive arthritis in mice ( 13 ). On the other hand, the results of the research showed the staphylococcal superantigens arthrogenicity activity.…”

“…Meanwhile, we assume that the existence of superantigens in the body fluid of patients may have endogenous origin, because in previous studies, the existence of S. aureus enterotoxins in patients’ synovial fluid with RA was demonstrated ( 11 , 12 ). Moreover, superantigens produced by S. aureus are considered as major arthritogenic factors ( 13 ).…”