SHM Converge Scientific Abstract ePoster Gallery-Clostridium Innocuum Bacteremia: When Opportunity Strikes

Pdf Summary

This case report describes <strong>Clostridium innocuum bacteremia</strong>, a rare but increasingly recognized opportunistic infection. Although C. innocuum is normally a harmless gut commensal, it has been linked to serious infections such as endocarditis, osteomyelitis, and bacteremia, particularly in immunocompromised patients.

The patient was a <strong>90-year-old woman</strong> with a history of <strong>complicated diverticulitis with partial colectomy</strong> and <strong>Waldenstrom’s macroglobulinemia</strong>, who had recently received <strong>cyclophosphamide and dexamethasone</strong>. She presented with <strong>abdominal pain, bloody diarrhea, vomiting, and chills</strong>. On exam she was tachycardic and diffusely tender. Labs showed <strong>leukocytosis</strong> and <strong>elevated lactate</strong>, and CT imaging demonstrated <strong>long-segment colitis</strong>. She was initially treated for sepsis with <strong>IV vancomycin and piperacillin-tazobactam</strong>, and because <strong>C. difficile PCR</strong> was positive, she was started on <strong>oral vancomycin</strong>. Blood cultures first appeared to show gram-positive bacilli and were initially assumed to be C. difficile, but ultimately identified <strong>Clostridium innocuum</strong>. Her antibiotics were changed to <strong>oral metronidazole and oral vancomycin</strong>, and she improved clinically.

The discussion emphasizes that C. innocuum bacteremia is rare, with only about <strong>13 reported cases</strong> in immunocompromised patients, and none previously reported in Waldenstrom’s macroglobulinemia. Some studies suggest higher mortality compared with other Clostridial infections. Because C. innocuum may be <strong>vancomycin resistant</strong>, <strong>metronidazole</strong> may be a more effective treatment due to its high oral bioavailability.

Overall, the report highlights the importance of recognizing <strong>C. innocuum as an emerging invasive pathogen</strong> in immunocompromised hosts, especially in patients with recent or concurrent <strong>C. difficile diarrhea</strong> who fail to improve on oral vancomycin.

Asset Subtitle

Arian Mostofi

Meta Tag

Author List Arian Mostofi, Meghna Trivedi, Stephanie LaFollette

Category Clinical Vignettes

Concept Clostridium innocuum

Concept Bacteremia

Concept Immunocompromised State

Concept Antimicrobial Therapy

Concept Immunosuppression

Distinguished Non-Finalist

Presenter Organization University of Massachusetts Chan Medical School

Presenting Author Arian Mostofi

Track Adult

Keywords

Clostridium innocuum

bacteremia

immunocompromised host

Waldenstrom macroglobulinemia

vancomycin resistance

metronidazole

Clostridium difficile

colitis

sepsis

opportunistic infection

Clostridium innocuum

Bacteremia

Immunocompromised State

Antimicrobial Therapy

Immunosuppression