What is it about?
Desulfovibrio is a group of anaerobic bacteria that normally inhabits the human gut. We identified 8 episodes of Desulfovibrio bacteremia — bloodstream infection caused by these bacteria — at a tertiary-care hospital in Japan between 2020 and 2025. All patients were older than 65 years (median age 81 years), and abdominal infection was the presumed source in 7 of the 8 episodes. Using 16S rRNA gene sequencing and whole-genome sequencing, we confirmed four species: D. desulfuricans, D. fairfieldensis, D. falkowii, and D. legallii. Routine MALDI-TOF mass spectrometry failed to identify D. falkowii and D. legallii, revealing a diagnostic gap in standard laboratory methods. Antimicrobial susceptibility testing showed low MICs for metronidazole and ampicillin/sulbactam, whereas piperacillin/tazobactam MICs were high across all isolates. Beta-lactamase genes were detected in five isolates.
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Why is it important?
Desulfovibrio bacteremia is rarely reported, and its species diversity and antibiotic resistance profiles are not well characterized. This case series reveals broader species diversity than previously recognized and highlights that standard identification methods can miss clinically relevant species. Knowing that piperacillin/tazobactam is unreliable while metronidazole and ampicillin/sulbactam retain activity has direct implications for empiric antibiotic selection in affected patients.
Perspectives
In elderly patients with abdominal infection and anaerobic bacteremia, Desulfovibrio should be considered even when routine identification is inconclusive. Curved gram-negative rods in anaerobic blood culture bottles combined with a positive desulfoviridin assay may prompt early suspicion and guide empiric therapy while confirmatory identification is pending. Molecular methods such as 16S rRNA gene sequencing and whole-genome sequencing are valuable tools for accurate species-level identification.
Dr Naoki Watanabe
Hirosaki University
Read the Original
This page is a summary of: Desulfovibrio
Bacteremia in Patients with Abdominal Infections, Japan, 2020–2025, Emerging Infectious Diseases, February 2026, Centers for Disease Control and Prevention (CDC),
DOI: 10.3201/eid3202.251581.
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