To the Editors:
Osteomyelitis of the foot represents a common and serious problem especially in elderly diabetic patients. Infection generally develops by spread of contiguous soft tissue to underlying bone and is usually caused by Staphylococcus aureus.1 We present the first case of osteomyelitis in a diabetic patient caused by Morganella morganii (MM).
A 70-year-old man with a 3 years' history of diabetes mellitus type II and diabetic nephropathy presented with acute pain, warmth, edema, and erythema of the right foot. He recently had a traumatic pedicure, and a few days after, he presented with malaise and spiking fever with chills. On examination, there was a purulent discharging ulcer on the right fifth phalanx with edema and erythema and a 50% to 70% limitation in extension and flexion of the right foot.
Laboratory data showed leukocytosis (white blood cell count of 18,440 cells/μL with 84.3% polymorphonuclear cells), an erythrocyte sedimentation rate of 104 mm/h, and a C-reactive protein of 348 mg/dL. His creatinine level was 2.6 mg/dL, and he presented with proteinuria (3.29 g/24 h). Radiographs of the right foot revealed soft tissue swelling with the presence of air and osteopenia of the right small phalanx, and the magnetic tomography imaging of the same region revealed periosteal reaction, cortical destruction, and soft tissue involvement. The culture of the pus obtained by an open drainage from the base of the ulcer near the bone and an aseptic bone specimen obtained during debridement were positive for MM. The blood cultures were negative. The diagnosis of osteomyelitis was made, and treatment with parenteral ciprofloxacin (600 mg/d) and ceftriaxone (2 g/d) was initiated together with surgical debridement of the trauma. Doppler examination of the arterial vessels was normal. Four weeks later, despite conservative treatment, an amputation of the fifth phalange of the right foot had to be performed. The patient is now well after 1-year follow-up.
Musculoskeletal complications due to MM may sometimes occur, and sporadic cases of septic arthritis without bone involvement have been described.2 This is the first report of acute osteomyelitis due to MM. Our patient was susceptible to infections due to the preexisting complicated diabetes mellitus, with diabetic nephropathy, possible neuropathy and small vessels arteriosclerosis, and the recent foot trauma. He underwent targeted antibiotic treatment and surgical therapy (as suggested by the recent Infectious Diseases Society of America diabetic foot guidelines)3 and finally had a good outcome. The culture of the causative organism in an aseptically obtained curettage specimen is considered very important to initiate the correct antimicrobial treatment.4
Therefore, MM should be considered as a potential pathogen for osteomyelitis in patients with diabetes mellitus.
Spyros P. Dourakis
Athanasios J. Archimandritis
Second Department of Medicine,
University of Athens Medical School,
Hippocration General Hospital,
1. Cunha BA. Osteomyelitis in elderly patients. Clin Infect Dis
. August 1, 2002;35(3):287-293. E-pub July 11, 2002.
2. Gautam V, Gupta V, Joshi RM, et al. Morganella morganii
-associated arthritis in a diabetic patient. J Clin Microbiol
3. Lipsky BA, Berendt AR, Deery HG, et al. Diagnosis and treatment of diabetic foot infection. Clin Infect Dis
. October 2004;39:885-910.
4. Gentry LO. Osteomyelitis: options for diagnosis and management. J Antimicrob Chemother
. April 1988;21(suppl C):115-131.