An Unexpected Cause of Diabetic Foot Ulcer Infection: Pasteurella multocida

Diabetic foot infection (DFI) is a common complication of diabetes mellitus and a major cause of preventable morbidity and mortality in individuals with diabetes. Superficial DFI can lead to contiguous spread to soft tissue and bone as well as hematogenous spread and sepsis. It frequently involves typical pathogens such as Staphylococcus aureus and Pseudomonas aeruginosa, or it may be polymicrobial, involving Gram-negative bacilli and anaerobes. Atypical organisms can also be responsible, especially when environmental exposures are present. We report a rare case of Pasteurella multocida osteomyelitis in a 75-year-old man with diabetes with a chronic foot ulcer. The infection likely developed from indirect exposure to his household dog after a piece of dog food became trapped in his shoe, which went undetected due to peripheral neuropathy. After failing outpatient management, he presented with worsening foot swelling, erythema, and purulence and was admitted for intravenous antibiotics. His clinical status stabilized, and antibiotics were narrowed after the culture results, but ultimately, he was recommended to undergo a below-the-knee amputation. Amputation was done for definitive source control, and the patient had an uncomplicated post-surgical recovery. Although Pasteurella multocida is an uncommon cause for infection, it can lead to significant morbidity and mortality, and possible hematogenous spread and sepsis. This case study highlights the importance of thorough exposure history and culture-guided therapy in DFI, and it reviews aspects of Pasteurella infections that are associated with different outcomes.