Physicians have difficulties interpreting the isolation of Cutibacterium acnes in the spine tissue. Here we provide the experience of our center about this topic, adding data that can help physicians in their choices. Our results show that some clinical, radiological, and microbiological features can help distinguish patients to treat or not to treat. Moreover, treatment with parenteral beta-lactams appears to be effective, but targeted oral therapy could be a valid alternative.

This retrospective case-matched study evaluated males and females with staphylococcal PJI (periprosthetic joint infection) treated with two-stage exchange arthroplasty. We matched 156 males and females for age, type of staphylococcal infection, and joint involved. We compared clinical parameters related to presentation, treatment, and outcome. We did not find a statistically significant difference in outcome between males and females treated with the same surgical approach at our institution.

We present the first published case of bilateral extensor tenosynovitis caused by Coxiella burnetii. C. burnetii should be considered in patients with inflammatory osteoarticular disease, including tenosynovitis, when conventional cultures are negative especially in elderly, male, or immunocompromised patients with exposure to animals.

Despite a growing interest in oral therapy for native vertebral osteomyelitis, there is no evidence to recommend oral or parenteral therapy. From our single-center experience combined with a systematic review and a meta-analysis of the available literature, there is insufficient evidence to conclude that there is a difference in proportion of failure and relapse between an early switch to oral antibiotics and prolonged parenteral therapy. Further studies are needed to increase the evidence.

This paper describes five cases of prosthetic joint infection (PJI) caused by Mycobacterium avium complex (MAC). Infections occurred in both immune competent and immunosuppressed patients. Interestingly, using the Musculoskeletal Infection Society diagnostic criteria for PJI may miss some cases of MAC PJI. Treatment courses and outcomes are described.

Tenosynovitis due to Histoplasma capsulatum in an immunocompromised host warrants special attention. Following surgical debridement, the patient initially improved on antifungal therapy, but as immunosuppression was decreased, she presented with a flare, requiring further debridement. With negative fungal cultures and declining antigenemia, it was felt that her interim worsening was as a consequence of immune reconstitution inflammatory syndrome (IRIS).