The bacterial ferrous iron acquisition protein FeoB assembles as a homotrimer that is predicted to form a central pore lined by conserved cysteine residues. Structure-function analysis of FeoB indicates a putative mechanism more akin to a GTP-gated channel than a transporter.

Time-tested treatments for chronic osteomyelitis involve prolonged courses of costly antibiotic treatment. Although such treatment remains unquestioned in acute osteomyelitis, it is an excessive regiment for chronic osteomyelitis. With appropriate surgical debridement and careful operative care, antibiotic treatment can be truncated in diagnoses of chronic osteomyelitis. This study represents the clinical practice of the pressure ulcer management program at Rancho Los Amigos National Rehabilitation Center in dealing with this difficult problem. One hundred fifty-seven patients with similar pressure ulcer wounds were studied retrospectively. Three groups of patients with pathologic diagnoses of acute osteomyelitis, chronic osteomyelitis, and negative osteomyelitis were compared for (1) postoperative stay, (2) wound infection, (3) wound breakdown requiring reoperation, and (4) same-site ulcer recurrence. In all cases, shallow bone shavings were sent for diagnosis via histologic study, and deep shavings were also sent to ensure adequate bone debridement and microbiologic study. All ulcers were subsequently closed with muscle and/or myocutaneous flaps. The negative and chronic osteomyelitis groups were treated with 5 to 7 days of IV antibiotics, whereas the acute group underwent a full 6-week course according to bone bacteriological culture and sensitivity. There was no statistical difference between the chronic osteomyelitis group and the control (negative) osteomyelitis group with respect to postoperative stay (70 days for chronic group, 72.4 for control), wound breakdown rate (10.7% for chronic, 10.2% for control), or ulcer recurrence (1.8% for chronic, 4.1 for control). The acute osteomyelitis group incurred longer hospital stays, greater incidence of wound breakdown, and statistically significantly greater ulcer recurrence (78.6 days, 13.2% and 17.0%, respectively). In cases of pressure ulcer management with bony involvement, bone pathologic diagnosis of chronic osteomyelitis allows for a shorter antibiotic course with better results when the offending tissue has been adequately debrided and closed with viable tissue flap coverage, than simple long-term (4-6 weeks) antibiotic treatment. Because of the extreme contaminated nature of these wounds, if such therapy works in these patients, it may be applicable to chronic osteomyelitis in more varied contaminated surgical cases involving bone.

Fig 3. Computed tomography of the chest revealed an area of cavitation adjacent to inhaled foreign object which likely represented traumatic pneumatocele, with surrounding ground-glass opacity, demonstrating haemorrhage.