Background: Bordetella trematum is an infrequent Gram-negative coccobacillus, with a reservoir, pathogenesis, a life cycle and a virulence level which has been poorly elucidated and understood. Related information is scarce due to the low frequency of isolates, so it is important to add data to the literature about this microorganism.
Case presentation: We report a case of a 74-year-old female, who was referred to the hospital, presenting with ulcer and necrosis in both legs. Therapy with piperacillin-tazobactam was started and peripheral artery revascularization was performed. During the surgery, a tissue fragment was collected, where Bordetella trematum, Stenotrophomonas maltophilia, and Enterococcus faecalis were isolated. After surgery, the intubated patient was transferred to the intensive care unit (ICU), using vasoactive drugs through a central venous catheter. Piperacillin-tazobactam was replaced by meropenem, with vancomycin prescribed for 14 days. Four days later, levofloxacin was added for 24 days, aiming at the isolation of S. maltophilia from the ulcer tissue. The necrotic ulcers evolved without further complications, and the patient's clinical condition improved, leading to temporary withdrawal of vasoactive drugs and extubation. Ultimately, however, the patient's general condition worsened, and she died 58 days after hospital admission.
Conclusions: Despite being a rare finding, B. trematum is typically associated with the clinical manifestation of disorders that predispose to ulcer development, which can be infected by microorganisms. The combination of antibiotic therapy and surgical debridement plays a key role in preventing systemic infections. Monitoring the appearance of new cases of B. trematum is essential, since it can be an emerging microorganism. Isolating and defining the clinical relevance of unusual bacteria yields a more accurate perspective in the development of new diagnostic tools and allows for assessment of proper antimicrobial therapy.
Keywords: Antimicrobial; Bordetella infection; Foot ulcer, diabetic; Susceptibility breakpoint determination.