First case of Pseudomonas guariconensis post-traumatic infection with bacteremia following agricultural machinery trauma.

Abstract

Agricultural machinery-related injuries pose unique challenges due to contamination with diverse environmental pathogens. We report the first documented case of Pseudomonas guariconensis bacteremia following an agricultural machinery-related trauma. An 81-year-old man sustained bilateral lower extremity injuries from a portable cultivator, including a Gustilo type IIIA open fracture of the left tibial plateau. Prompt and thorough debridement with copious irrigation was performed, followed by prophylactic cephalosporin monotherapy. On day 4 of hospitalization, the patient developed fever and signs of wound infection in both lower extremities. Blood and wound cultures yielded P. guariconensis, identified by MALDI-TOF mass spectrometry. Antimicrobial susceptibility testing revealed minimum inhibitory concentrations (MICs) of 16/4 mg/L for piperacillin-tazobactam (PIPC/TAZ) and 8 mg/L for meropenem (MEPM). The modified carbapenem inactivation method (mCIM) and the Xpert® Carba-R assay were performed; however, all results were negative. Treatment was initiated with PIPC/TAZ. Although additional debridement and skin grafting were required, the patient showed gradual clinical improvement. PIPC/TAZ therapy was continued for 21 days and resulted in complete resolution of the infection. Post-traumatic infections following agricultural machinery-related injuries typically involve diverse organisms, including anaerobes and gram-negative bacteria. This case highlights the potential for rare environmental pathogens such as P. guariconensis to emerge as causative agents in post-traumatic infections as identification technologies like mass spectrometry continue to advance. Recognizing such organisms may become increasingly important in managing heavily contaminated wounds.