Comparative pathogenomic characterization of a non-invasive serotype M71 strain Streptococcus pyogenes NS53 reveals incongruent phenotypic implications from distinct genotypic markers. Issue 5 (17th May 2017)

• Record Type: Journal Article
• Authors: Bao, Yun-Juan; Li, Yang; Liang, Zhong; Agrahari, Garima; Lee, Shaun W.; Ploplis, Victoria A.; Castellino, Francis J.
• Is Part Of: Pathogens and disease. Volume 75:Issue 5(2017:Jul.)
• Publication Date: 2017-05-17
• Subjects: Streptococcus pyogenes -- genetic markers -- virulence factors -- invasive -- phylogenetic structure; Medical microbiology -- Periodicals; Pathogenic microorganisms -- Periodicals; Communicable diseases -- Microbiology -- Periodicals; Communicable diseases -- Pathogenesis -- Periodicals; Host-parasite relationships -- Periodicals; Systems biology -- Periodicals; 616.904105
• DOI: 10.1093/femspd/ftx056
• Languages: English
• ISSNs: 2049-632X

Abstract

Abstract: The strains serotyped as M71 from group A Streptococcus are common causes of pharyngeal and skin diseases worldwide. Here we characterize the genome of a unique non-invasive M71 human isolate, NS53. The genome does not contain structural rearrangements or large-scale gene gains/losses, but encodes a full set of non-truncated known virulence factors, thus providing an ideal reference for comparative studies. However, the NS53 genome showed incongruent phenotypic implications from distinct genotypic markers. NS53 is characterized as an emm pattern D and FCT (fibronectin-collagen-T antigen) type-3 strain, typical of skin tropic strains, but is phylogenetically close to emm pattern E strains with preference for both skin and pharyngeal infections. We propose that this incongruence could result from recombination within the emm gene locus, or, alternatively, selection has been against those genetic alterations. Combined with the inability to select for CovS switching, a process is indicated whereby NS53 has been pre-adapted to specific host niches selecting against variations in CovS and many other genes. This may allow the strain to attain successful colonization and long-term survival. A balance between genetic variations and fitness may exist for this bacterium to form a stabilized genome optimized for survival in specific host environments. Abstract : The authors discuss the incongruent genotype:phenotype correlation in Streptococcus .