Exploring the arthritogenicity of Streptococcus dysgalactiae subspecies equisimilis

Abstract

BackgroundDuring the past decades, Streptococcus dysgalactiae subspecies equisimilis (SDSE) has been increasingly recognized as an important human pathogen. Osteoarticular infections is one of the predominant disease manifestations of SDSE, but the pathogenetic rationale for its arthritogenicity has yet to be unravelled. We aimed to explore if the rising incidence of osteoarticular infections caused by this pathogen in our region emanated from clonal expansion of strains with enhanced tropism for bone and joint tissue components or orthopaedic implants.ResultsTwenty-nine SDSE-isolates associated with osteoarticular infections were retrospectively identified. Their genomic content and affinity for fibronectin, collagen and stainless steel were compared to 24 temporally and geographically matched SDSE blood culture isolates obtained from patients without bone or joint infections.Despite a thorough genetic and phenotypic dissection, neither the presence or absence of any single gene, nor the binding abilities of the SDSE isolates, were predictive of clinical entity. SNP analysis revealed a heterogenous population, and a correlation between phylogenetic relationships and disease manifestation was not evident. However, we identified a strong concordance between phenotypic binding abilities and genetic variations in the pilus-region, also denoted as the FCT-region (Fibronectin binding, Collagen binding and T-antigen). This observation could be related to the ample and varied repertoire of putative adhesins residing within this region, including proteins predicted to adhere to fibronectin and collagen, as well as fibrinogen.ConclusionsSDSE strains associated with osteoarticular infections do not emanate from subpopulation characterized by distinct genetic or phenotypic traits. The genetic architecture of the pilus region was predictive of the adhesive properties of the SDSE-isolates, but its role in tissue tropism needs further investigation. To the best of our knowledge, this is the first comprehensive characterization of the genetic landscape of the SDSE pilus region.Electronic supplementary materialThe online version of this article (10.1186/s12866-018-1160-5) contains supplementary material, which is available to authorized users.

Inter-species gene flow drives ongoing evolution ofStreptococcus pyogenesandStreptococcus dysgalactiaesubsp.equisimilis

“…and sdn (all p <0.001, c 2 test of independence). In particular, the accessory FCT locus 34 , sil locus, gfbA, speG and drsG were frequently either present or entirely absent from different genome clusters. These findings suggest that the SDSE genetic population structure is characterised by distinct virulence repertoires.…”

Singularities of Pyogenic Streptococcal Biofilms – From Formation to Health Implication

“…Oliver- Kozup et al, 2011;Döhrmann et al, 2014;Lukomski et al, 2017 Collagen-like protein SclB (sclB) S. pyogenes, S. uberis, SDSE, SDSD, S. agalactiae, S. pneumoniae, and S. equi. Rato et al, 2011;Lukomski et al, 2017 FbaA Fibronectin and laminin-binding protein S. pyogenes; S. parasanguinis Chen et al, 2020 FbaB/PFBP/PrtF2 Fibronectin and laminin-binding protein S. pyogenes Rohde et al, 2011;Brouwer et al, 2016;Šmitran et al, 2016 Fbp54 Fibronectin and fibrinogen-binding protein S. pyogenes Raynes et al, 2018 FbsA, FbsB Fibronectin and fibrinogen-binding protein S. agalactiae Rosenau et al, 2007 FnbA, FnbB Fibronectin-binding proteins SDSD; SDSE O'Neill et al, 2009;Alves-Barroco et al, 2018 GfbA Fibronectin-binding proteins SDSE Lindgren et al, 1994;Oppegaard et al, 2018 Glyceraldehyde-3-phosphate dehydrogenase (plr)…”

Analysis of the Genomics and Mouse Virulence of an Emergent Clone of Streptococcus dysgalactiae Subspecies equisimilis

“…equisimilis strains to cause disease, the genomes of seven human infection isolates collected in French Brittany between 2010 and 2018 were determined by a combination of Illumina paired-end short-read and Oxford Nanopore long-read sequencing. The seven isolates included six group C strains of emm type stG62647 (MGCS35823, MGCS35922, MGCS35957, MGCS36044, MGCS36083, and MGCS36089), which were selected because strains with these characteristics have recently emerged in multiple countries as a cause of increased numbers of severe infections ( 9 , 36 , 43 ). One group G stC74a strain (MGGS36055) was selected as a comparator, because strains with these characteristics have been reported to be an abundant cause of human infections in multiple epidemiological studies ( 7 , 11 , 15 , 34 , 44 – 46 ).…”