{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T11:02:48Z","timestamp":1791198168937,"version":"4.1.0"},"reference-count":43,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T00:00:00Z","timestamp":1791158400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Cell. Infect. Microbiol."],"abstract":"<jats:p>\n                    <jats:italic>Parvimonas micra<\/jats:italic>\n                    (\n                    <jats:italic>P. micra<\/jats:italic>\n                    ), an anaerobic oral coccus long dismissed as a culture contaminant, is increasingly recognized as a causative agent of pyogenic central nervous system (CNS) infections, yet its neuropathogenesis remains poorly defined. This narrative review synthesizes 41 peer-reviewed studies identified via a structured comprehensive literature search of PubMed, Embase and Web of Science through June 2026. Epidemiologically, pooling available case reports and small series (n=64 confirmed CNS cases),\n                    <jats:italic>P. micra<\/jats:italic>\n                    is among the most frequently isolated Gram-positive anaerobic cocci in reported brain abscess series, with proportions ranging from approximately 4% to over 10% in individual cohorts; species-level data are inconsistently reported and a precise pooled estimate cannot be derived. A male predominance (approximately 2.7:1) is observed among reported cases, though this should be interpreted cautiously given the small sample size and potential reporting bias. Approximately two-thirds of patients have no documented immunosuppressive condition. Brain abscess represents ~80% of CNS manifestations, with 60\u201370% presenting as polymicrobial infection. We propose a five-step pathogenic cascade\u2014periodontal dysbiosis, epithelial barrier breach, intravascular survival, blood\u2013brain barrier (BBB) translocation, and intracranial suppuration\u2014as a conceptual framework. Virulence factors including the TmpC\u2013AppA axis and extracellular vesicle DnaK have been characterized in non-CNS models (oral carcinoma, periodontitis, oral lichen planus); their relevance to CNS infection is inferred, and BBB translocation mechanisms remain entirely hypothetical. Metagenomic next-generation sequencing (mNGS) outperforms conventional culture in selected brain abscess cohorts (~85% vs ~50% in pus; ~84% vs ~8% in CSF across CNS infections), though performance varies by specimen type, prior antibiotic exposure, and sequencing platform. All-cause mortality is 5\u201310% and 20\u201325% of survivors sustain neurological sequelae, though these estimates may overestimate true population rates due to publication bias.\n                    <jats:italic>P. micra<\/jats:italic>\n                    shows consistently low\n                    <jats:italic>in vitro<\/jats:italic>\n                    minimum inhibitory concentrations to metronidazole and \u03b2-lactams. Early empirical anaerobic coverage and consideration of mNGS as a complementary diagnostic tool are recommended for suspected odontogenic brain abscess.\n                  <\/jats:p>","DOI":"10.3389\/fcimb.2026.1971569","type":"journal-article","created":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T10:41:22Z","timestamp":1791196882000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Parvimonas micra and central nervous system infections: mechanisms of transformation from oral commensal to intracranial pathogen and clinical evidence"],"prefix":"10.3389","volume":"16","author":[{"given":"Cancan","family":"Gong","sequence":"first","affiliation":[{"name":"Department of Infectious Diseases, Yantaishan Hospital","place":["Yantai, Shandong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xubo","family":"Jing","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases, Yantaishan Hospital","place":["Yantai, Shandong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shanwei","family":"Jiang","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases, Yantaishan Hospital","place":["Yantai, Shandong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chaoxiao","family":"Yu","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases, Yantaishan Hospital","place":["Yantai, Shandong, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,10,5]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"42","DOI":"10.12691\/ajmcr-12-3-4","article-title":"Eikenella corrodens, Fusobacterium nucleatum and Parvimonas micra: a case of polymicrobial brain abscess","volume":"12","author":"Al Saleemi","year":"2024","journal-title":"Am. 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