Differential arthritogenicity of Staphylococcus aureus strains isolated from biological samples

Background: Staphylococcus 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.Methods: Male 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.Results: Weight 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+).Conclusions: Together 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. © 2013 Colavite-Machado et al.; licensee BioMed Central Ltd.

The role of cytokines in inflammatory bone loss

Chronic inflammatory processes close to bone often lead to loss of bone in diseases such as rheumatoid arthritis, periodontitis, loosened joint prosthesis and tooth implants. This is mainly due to local formation of bone resorbing osteoclasts which degrade bone without any subsequent coupling to new bone formation. Crucial for osteoclastogenesis is stimulation of mononuclear osteoclast progenitors by macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL) which induces their differentiation along the osteoclastic lineage and the fusion to mature, multinucleated osteoclasts. M-CSF and RANKL are produced by osteoblasts/ osteocytes and by synovial and periodontal fibroblasts and the expression is regulated by pro- and anti-inflammatory cytokines. These cytokines also regulate osteoclastic differentiation by direct effects on the progenitor cells. In the present overview, we introduce the basic concepts of osteoclast progenitor cell differentiation and summarize the current knowledge on cytokines stimulating and inhibiting osteoclastogenesis by direct and indirect mechanisms. © Informa Healthcare USA, Inc.

Ki-67 and CD100 immunohistochemical expression is associated with local recurrence and poor prognosis in soft tissue sarcomas, respectively

Soft tissue sarcomas (STSs) are a heterogeneous group of mesenchymal tumors of >50 subtypes. However, STSs represent <1% of types of cancer. Despite this low frequency, the disease is aggressive and treatment, when possible, is based on traditional chemotherapies. A number of cases of resistance to adjuvant therapies have been reported. Metastases are commonly identified in STS patients during diagnosis and the development of effective clinical parameters is crucial for correct management of the disease. The use of biological markers in cancer is a useful tool to determine patient prognosis. Ki--67 is a protein marker for proliferation of somatic cells and is widely used in prognostic studies of various types of tumor, including STSs. Cluster of differentiation 100 (CD100) is a member of the semaphorin family. The family was initially described as axon guidance molecules important for angiogenesis, organogenesis, apoptosis and neoplasia. CD100 was previously utilized as a prognostic factor in tumors and also in STSs. In the present study, protein expression of Ki--67 and CD100 was analyzed by immunohistochemistry in samples of STS patients of the Barretos Cancer Hospital (Barretos, Brazil) to establish prognostic criteria of the disease. Results demonstrate a correlation between CD100 expression and poor prognosis, consistent with a previous study. Moreover, the expression of Ki-67 was identified to correlate with presence of local or locoregional recurrence. To the best of our knowledge, no large casuistic study has revealed this correlation between Ki--67 and local recurrence in STSs. The use of Ki--67 and CD100 as markers in clinical pathological analysis may be suitable as a prognostic criterion in disease progression.

Expressão do gene FOXE1 em culturas de osteossarcoma canino

Pós-graduação em Medicina Veterinária - FMVZ

Carcinogênese quimicamente induzida por DMBA em glândulas salivares submandibulares de ratos (rattus norvegicus)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação do efeito trombogênico da perfusão regional intravenosa com gentamicina em equinos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise mutacional da região dos exons 5 a 8 do gene supressor de tumor p53 em neoplasias mamárias caninas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação radiográfica das articulações dos membros locomotores de cães naturalmente acometidos por leishmaniose visceral no município de Araçatuba-SP

Pós-graduação em Ciência Animal - FMVA

Estudo clínico-laboratorial das articulações de cães naturalmente infectados com leishmaniose visceral e experimentalmente inoculados com Leishmania chagasi por via intra-articular

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação radiográfica e ultra-sonográfica do aparato podotroclear dos cavalos da raça Quarto de Milha acometidos pela síndrome do navicular

Pós-graduação em Medicina Veterinária - FMVZ

Comparação entre as concentrações de tetraciclina no plasma, líquido sinovial e leite de vacas acometidas de dermatite digital papilomatosa, submetidas à administração intravenosa regional

Pós-graduação em Medicina Veterinária - FMVZ

Imunofenotipagem de lesões obtidas em carcinogênese quimicamente induzida por DMBA em glândulas salivares submandibulares e ratos (Rattus norvegicus)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência de patógenos periodontais na patogênese da artrite experimental

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Liquens de Mato Grosso do Sul: estudo químico e avaliação da atividade biológica

Pós-graduação em Química - IQ

Impacto do uso droga imunomoduladora no tratamento da artrite séptica por Staphylococcus aureus

Pós-graduação em Doenças Tropicais - FMB