ABSTRACTTo increase knowledge onBrevundimonaspathogens, we conducted in-depth genomic and phenotypic characterization of aBrevundimonasstrain isolated from the cerebrospinal fluid of a patient admitted in a neonatal intensive care unit. The strain was identified as a member of the genusBrevundimonasbased on Vitek 2 system results and 16S rRNA gene sequencing and presented a multidrug resistance profile (MDR). Several molecular and biochemical tests were used to characterize and identify the species for in-depth results. The draft genome assembly of the isolate has a total length of 3,261,074 bp and a G+C of 66.86%, similar to other species of the genus. Multilocus sequence analysis, Type (Strain) Genome Server, digital DNA-DNA hybridization, and average nucleotide identity confirmed that theBrevundimonassp. studied represents a distinct species, for which we propose the nameBrevundimonas brasiliensissp. nov.In silicoanalysis detected antimicrobial resistance genes (AMRGs) mediating resistance to β-lactams (penP,blaTEM-16, andblaBKC-1) and aminoglycosides [strA,strB,aac(6′)-Ib, andaac(6′)-Il]. We also found AMRGs encoding the AcrAB efflux pump that confers resistance to a broad spectrum of antibiotics. Colistin and quinolone resistance can be attributed to mutation inqseCand/orphoPand GyrA/GyrB, respectively. TheBrevundimonas brasiliensissp. nov. genome contained copies of type IV secretion system (T4SS)-type integrative and conjugative elements (ICEs); integrative mobilizable elements (IME); and Tn3-type and IS3, IS6, IS5, and IS1380families, suggesting an important role in the development and dissemination of antibiotic resistance. The isolate presented a range of virulence-associated genes related to biofilm formation, adhesion, and invasion that can be relevant for its pathogenicity. Our findings provide a wealth of data to hinder the transmission of MDRBrevundimonasand highlight the need for monitoring and identifying new bacterial species in hospital environments.IMPORTANCEBrevundimonasspecies is considered an opportunistic human pathogen that can cause multiple types of invasive and severe infections in patients with underlying pathologies. Treatment of these pathogens has become a major challenge because many isolates are resistant to most antibiotics used in clinical practice. Furthermore, there are no consistent therapeutic results demonstrating the efficacy of antibacterial agents. Although considered a rare pathogen, recent studies have provided evidence of the emergence ofBrevundimonasin clinical settings. Hence, we identified a novel pathogenic bacterium,Brevundimonas brasiliensissp. nov., that presented a multidrug resistance (MDR) profile and carried diverse genes related to drug resistance, virulence, and mobile genetic elements. Such data can serve as a baseline for understanding the genomic diversity, adaptation, evolution, and pathogenicity of MDRBrevundimonas.