Project description:The anaerobic Gram-positive coccus Finegoldia magna is a rare cause of infections of bone and joints. The aim of this study was to describe the microbiological and clinical characteristics of orthopedic implant-associated infections caused by F. magna We retrospectively analyzed samples consisting of anaerobic Gram-positive cocci and samples already identified as F. magna from patients with orthopedic infections. The isolates found were determined to the species level using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). The antibiotic susceptibility pattern was determined by Etest. Whole-genome sequencing (WGS) was performed. Clinical data were extracted from each patient's journal. In nine patients, orthopedic joint implant-associated infections were identified as being caused by F. magna The isolates were susceptible to most of the antibiotics tested, with the exception of rifampin and moxifloxacin in a few cases. Five of the nine infections were monomicrobial. The most common antibiotic used to treat the infection was penicillin V, but five of the nine patients received a combination of antibiotics. Eight patients underwent surgical treatment, with extraction of the implant performed in seven cases and reimplantation in only two cases. The WGS showed a relatively small core genome, with 126,647 single nucleotide polymorphisms identified within the core genome. A phylogenomic analysis revealed that the isolates clustered into two distinct clades. Orthopedic implant-associated infections caused by F. magna are rare, but the bacteria are generally susceptible to antibiotics. Despite this, surgical treatment combined with long-term antibiotics is often necessary. The WGS analysis revealed a high heterogeneity and suggested the existence of at least two different Finegoldia species.
Project description:Finegoldia magna (formerly Peptostreptococcus magnus), a member of the Gram-positive anaerobic cocci (GPAC), is a commensal bacterium colonizing human skin and mucous membranes. Moreover, it is also recognized as an opportunistic pathogen responsible for various infectious diseases. Here, we report the complete genome sequence of F. magna ATCC 29328. The genome consists of a 1,797,577 bp circular chromosome and an 189,163 bp plasmid (pPEP1). The metabolic maps constructed based on the genome information confirmed that most F. magna strains cannot ferment most sugars, except fructose, and have various aminopeptidase activities. Three homologs of albumin-binding protein, a known virulence factor useful for antiphagocytosis, are encoded on the chromosome, and one albumin-binding protein homolog is encoded on the plasmid. A unique feature of the genome is that F. magna encodes many sortase genes, of which substrates may be involved in bacterial pathogenesis, such as antiphagocytosis and adherence to the host cell. The plasmid pPEP1 encodes seven sortase and seven substrate genes, whereas the chromosome encodes four sortase and 19 substrate genes. These plasmid-encoded sortases may play important roles in the pathogenesis of F. magna by enriching the variety of cell wall anchored surface proteins.