Cellulitis with bacteremia caused by Pseudomonas mosselii in a Japanese patient: A case report

Pseudomonas mosselii is a glucose-nonfermenting, rod-shaped, Gram-negative bacterium commonly found in soil and water. There are only a few cases of P. mosselii infection. Here, we present a case of cellulitis with bacteremia caused by P. mosselii. A 63-year-old Japanese woman with a history of stasis dermatitis, lower extremity ulcers, and poorly controlled diabetes presented to the emergency department with fever and left lower leg pain. She was diagnosed with cellulitis. Gram-negative rods were detected in one aerobic blood culture bottle and subsequently identified as P. mosselii using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and 16S ribosomal RNA (16S rRNA) gene sequencing. She was initially treated with cefepime. Based on the antibiotic susceptibility of P. mosselii, treatment was switched to ceftazidime. Antibiotics were administered for 14 days. However, due to cellulitis recurrence, antibiotic therapy was resumed for an additional 14 days. She was subsequently discharged from the hospital with no further recurrence. Accurate identification of P. mosselii using MALDI-TOF MS and 16S rRNA gene sequencing facilitated appropriate clinical management. Furthermore, this case suggests that P. mosselii may inhabit human environments and can cause community-acquired infections.