Mixta calida, not only an environmental bacterium, but a potential opportunistic threat: Case report of an osteitis with skin necrosis and mini review of the literature

Background

Mixta calida, previously known as Pantoea calida, is an environmental bacterium rarely associated with human pathologies. Rare case reports mention sepsis, meningitis and implantable defibrillator infection.

Case presentation

A 67-year-old female with multiple comorbidities was referred to the emergency room for a comminuted fracture of both right tibial plateaus secondary to a fall and for which she benefited from an external fixator. After removal of the fixator, failure of osteosynthesis and placement of a new fixator, a skin necrosis appeared and a propeller distal anteromedial thigh perforator flap was performed. After 6 weeks, she presented a necrosis of the flap and an osteitis. The bone biopsy was positive with pure M. calida. The patient underwent an above-knee amputation, but 6 weeks later the wound was dehiscent and again positive with pure M. calida.

Conclusions

Serious infections due to M. calida are uncommon but can occur in immunocompromised patients. This case illustrates the first reported osteitis and skin necrosis due to M. calida.