Infection Route of Parvimonas micra: A Case Report and Systematic Review

Parvimonas micra (P. micra), a bacterium that colonizes the gastrointestinal tract, is often isolated from periodontitis and abscesses as part of a complex bacterial infection. However, reports of monobacterium infections due to P. micra are limited. Here, we report a case of monobacterial bacteremia caused by P. micra with the aim of identifying the source of the invasion and clarifying the clinical features. A 54-year-old patient presented with bacteremia due to P. micra and with an oral invasion that we suspected resulted from prior dental treatment. Using PubMed and Google Scholar databases, we undertook a systematic review of monobacteremia caused by P. micra. We identified 26 patients (mean age, 70.15 years) in our systematic review. P. micra bacteremia and its associated phenotypes were most frequently identified in spinal discitis, followed by epidural and lumbar abscesses, and infective endocarditis. The major risk factors were malignancy, diabetes mellitus, and post-arthroplasty. When P. micra is detected in blood cultures, evaluation and intervention for oral contamination may be indicated.