An unusual presentation of Pseudomonas citronellolis bacteraemia and Campylobacter gastroenteritis infection in a human – a case report and literature review

INTRODUCTION. Pseudomonas citronellolis is an unusual pathogen in humans and has not been extensively described in the scientific literature. Herein, we present a case of bacteremia and septic shock due to Pseudomonas citronellolis following Campylobacter species gastroenteritis in a patient with immunosuppression. CASE PRESENTATION. An 80-year-old man with myeloproliferative disorder on ruxolitinib presented with several days of worsening abdominal pain, which rapidly developed into septic shock with multi-organ failure and explosive diarrhea. Gram-negative bacilli observed on Gram staining of his blood culture broth were later identified as Pseudomonas citronellolis and Bacteroides thetaiotaomicron . Repeated abdominal imaging revealed no evidence of intestinal perforation or megacolon. In addition, stool PCR was positive for Campylobacter species. His clinical course improved after 14 days of meropenem with complete resolution of his symptoms and organ failure. CONCLUSION. P. citronellolis is a rare infection in humans. We postulate that Janus Associated Kinase (JAK) inhibition in myeloproliferative disorders heightened this patient’s risk of bacterial translocation and severe illness in the setting of Campylobacter gastroenteritis. P. citronellolis may be identified more frequently as a pathogen in humans as more advanced diagnostic technologies become increasingly available in clinical microbiology.