| Literature DB >> 29244079 |
Claire Gendrin1, Jay Vornhagen1,2, Blair Armistead1,2, Pallavi Singh3, Christopher Whidbey1,2, Sean Merillat1, David Knupp3, Robert Parker3, Lisa M Rogers4,5, Phoenicia Quach1, Lakshminarayan M Iyer6, L Aravind6, Shannon D Manning3, David M Aronoff4,5, Lakshmi Rajagopal1,2.
Abstract
Group B streptococci (GBS) are Gram-positive bacteria that are a leading cause of neonatal infections. Most invasive isolates are β-hemolytic, and hemolytic activity is critical for GBS virulence. Although nonhemolytic GBS strains are occasionally isolated, they are often thought to be virulence attenuated. In this study, we show that a nonhemolytic GBS strain (GB37) isolated from a septic neonate exhibits hypervirulence. Substitution of tryptophan to leucine (W297L) in the sensor histidine kinase CovS results in constitutive kinase signaling, leading to decreased hemolysis and increased activity of the GBS hyaluronidase, HylB. These results describe how nonpigmented and nonhemolytic GBS strains can exhibit hypervirulence.Entities:
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Year: 2018 PMID： 29244079 PMCID： PMC5853813 DOI： 10.1093/infdis/jix646
Source DB: PubMed Journal: J Infect Dis ISSN： 0022-1899 Impact factor: 5.226