Hypervirulent group A Streptococcus emergence in an acaspular background is associated with marked remodeling of the bacterial cell surface.

Hypervirulent group A Streptococcus emergence in an acaspular background is associated with marked remodeling of the bacterial cell surface. PLoS One. 2018;13(12):e0207897 Authors: Galloway-Peña J, DebRoy S, Brumlow C, Li X, Tran TT, Horstmann N, Yao H, Chen K, Wang F, Pan BF, Hawke DH, Thompson EJ, Arias CA, Fowler VG, Bhatti MM, Kalia A, Flores AR, Shelburne SA Abstract Inactivating mutations in the control of virulence two-component regulatory system (covRS) often account for the hypervirulent phenotype in severe, invasive group A streptococcal (GAS) infections. As CovR represses production of the anti-phagocytic hyaluronic acid capsule, high level capsule production is generally considered critical to the hypervirulent phenotype induced by CovRS inactivation. There have recently been large outbreaks of GAS strains lacking capsule, but there are currently no data on the virulence of covRS-mutated, acapsular strains in vivo. We investigated the impact of CovRS inactivation in acapsular serotype M4 strains using a wild-type (M4-SC-1) and a naturally-occurring CovS-inactivated strain (M4-LC-1) that contains an 11bp covS insertion. M4-LC-1 was significantly more virulent in a mouse bacteremia model but caused smaller lesions in a subcutaneous mouse model. Over 10% of the genome showed significantly different transcript levels in M4-LC-1 vs. M4-SC-1 strain. Notably, the Mga regulon and multiple cell surface protein-encoding genes were...
Source: Genomics Proteomics ... - Category: Genetics & Stem Cells Authors: Tags: PLoS One Source Type: research