Staphylococcus caprae bone and joint infections: a re-emerging infection?

Staphylococcus caprae has been recently classified as a human pathogen, but the incidence of S. caprae in human bone and joint infections (BJIs) is under-reported. In this study, we report 25 cases of S. caprae BJI, and we review the 31 cases published in the literature. Molecular techniques and matrix-assisted laser desorption ionization time-of-flight mass spectrometry improved the identification of clinically relevant S. caprae strains. In this study, 96% of S. caprae BJIs were localized to the lower limbs, and 88% of the cases involved orthopaedic device infections. S. caprae joint prosthesis infections (JPIs), internal osteosynthesis device infections (I-ODIs) and BJIs without orthopaedic device infections were recorded in 60%, 28% and 12% of cases, respectively. Ten (40%) S. caprae BJIs were polymicrobial infections. These infections were associated with past histories of malignancy (p 0.024). Of the 14 bacterial species related to S. caprae BJI, 57% were staphylococci. I-ODIs were significantly associated with polymicrobial infections (p 0.0068), unlike JPIs, which were monomicrobial infections (p 0.0344). Treatment with rifampicin and fluoroquinolone was recorded in 40% of cases. Surgical treatment was performed in 76% of cases, e.g. prosthesis removal (36%), osteosynthesis device removal (24%), and surgical debridement (16%). Thirty per cent of cases were not treated. Relapses were observed mainly in the patients treated by surgical debridement only (p 0.033). In summary, S. caprae BJI is an underestimated hospital-acquired emerging infection. S. caprae BJI is correlated with infections in orthopaedic devices, which must be removed to control the infection.

[Prolonged suppressive L-thyroxine therapy. Longitudinal study of the effect of LT4 on bone mineral density and bone metabolism markers in 71 patients]. / Traitement prolongé par L-thyroxine à visée suppressive. Etude longitudinale de l'influence de la LT4 sur la densité minérale osseuse et les marqueurs osseux métaboliques chez 71 patients.

OBJECTIVES: A prospective longitudinal study was conducted to investigate the influence of prolonged suppressive L-thyroxin therapy on bone density and biochemical markers of bone remodeling. PATIENTS AND METHODS: Seventy-one patients (including 28 menopaused women) taking long-term L-T4 for thyroid carcinoma were divided into 3 groups according to their TSH level: low (TSH < 0.04 mlU/l), moderate (0.04 TSH < or = 0.10 mlU/l) and high (TSH > 0.10 mlU/l). Bone density was measured in lumbar vertebrae annually for a mean 4.5 years. Bone metabolism markers were measured over a 4 year period. Bone density measurements of the femur were also obtained for 2 years in 16 menopaused women. RESULTS: Lumbar bone density did not decline whatever the TSH level or the duration of L-T4 treatment. Likewise for menopaused women without substitution estroprogesterone therapy. Over the 4 years, biochemical markers of bone formation, including bone alkaline phosphatases and osteocalcin, or of bone resorption, including urinary hydroxyprolin, did not vary. In addition, in menopaused women, femoral bone density was not significantly lowered over the 2 years follow-up. No lumbar or femoral osteopenia was observed in these patients taking L-thyroxin, even for those with complete TSH blockade. Biochemical markers did not demonstrate a significant acceleration of bone turnover during prolonged administration of L-T4 at suppressive levels.