Wohlfahrtiimonas chitiniclastica Bacteremia Associated With Maggot-Infested Ulcers and Tumor Lysis Syndrome in Ohio, USA: A Case Report.

BACKGROUND: Wohlfahrtiimonas chitiniclastica is an emerging Gram-negative bacillus historically linked to larvae of the parasitic fly Wohlfahrtia magnifica. Although most human infections have been reported in Europe and Asia, cases are increasingly recognized in North America.

CASE SUMMARY: A 74-year-old man from Ohio presented with sepsis and maggot-infested decubitus ulcers. Blood cultures grew Gram-negative, oxidase-positive rods that could not be identified at the home institution. The isolate was referred to an outside hospital, where it was initially misidentified as Edwardsiella species before definitive identification as W. chitiniclastica by MALDI-TOF MS (Bruker MALDI Biotyper), confirmed by supplementary biochemical testing, 6 days after the initial culture draw. Additional testing identified the rare anaerobe Tissierella praeacuta. Blood cultures at the home institution also identified Proteus mirabilis and Staphylococcus aureus. The clinical course was complicated by metastatic cancer and spontaneous tumor lysis syndrome (uric acid 14.6 mg/dL, LDH 2157 U/L) that improved following rasburicase therapy. The patient received empiric intravenous piperacillin-tazobactam for approximately 24 days, followed by de-escalation to ceftriaxone. Follow-up blood cultures were sterile. Goals of care were transitioned to palliation, and the patient died on hospital day 30.

CONCLUSION: This case illustrates W. chitiniclastica bacteremia in Ohio, USA, and highlights diagnostic challenges including initial misidentification by conventional methods, the importance of MALDI-TOF MS for definitive identification, and possible vector adaptation to regional muscid fly species. The coisolation of T. praeacuta underscores the complex wound microbiome associated with chronic neglected ulcers.