Review of Facklamia Species Involvement in Human Infection and Urological Disease.

Facklamia species are Gram-positive, catalase-negative cocci within the family Aerococcaceae. Historically misidentified as streptococci or enterococci due to phenotypic similarity and conventional biochemical testing limitations, their clinical significance remains incompletely defined. This narrative review synthesizes the current literature on the microbiology, epidemiology, clinical manifestations, diagnostic challenges, and antimicrobial susceptibilities of Facklamia infections, with emphasis on urogynecologic relevance. A structured literature search identified peer-reviewed reports of microbiologically confirmed human infection published through December 2025. These reports indicate global distribution and a broad clinical spectrum. Invasive infections were reported most often in older adults and individuals with structural abnormalities, chronic comorbidities, or recent surgical interventions; however, cases in otherwise healthy patients are described. Emerging microbiome data suggest that F. hominis may be enriched in adult females with lower urinary tract symptoms, supporting the possibility that the female urogenital tract functions as a potential reservoir and site of pathogenic activity. Antimicrobial susceptibility patterns vary, with documented resistance to penicillin, macrolides, clindamycin, and tetracyclines, and susceptibility to cephalosporins, vancomycin, and linezolid. Overall, Facklamia species should be recognized as underdiagnosed opportunistic pathogens with both invasive and urogynecologic relevance. Increased awareness, improved diagnostic identification, and systematic susceptibility profiling are needed to clarify their pathogenic role and guide appropriate antimicrobial therapy.