Functional Characterization of the Streptococcal CpsA Protein in Streptococcus agalactiae

Abstract

Streptococcus agalactiae (GBS) is a streptococcal pathogen. GBS is capable of causing systemic disease by utilizing a number of strategies for survival in the host. The most important survival strategy in GBS is the production of a polysaccharide capsule. Production of capsule by GBS allows for systemic disease by inhibiting phagocytosis and complementation by the immune system. The first gene of the capsule operon, cpsA encodes a putative membrane-bound transcriptional regulator of the capsule operon. CpsA contains a small intracellular domain and two conserved extracellular protein domains. GBS infection causes neonatal septicemia and meningitis. In recent years there has been an increase in the incidence of invasive disease in the elderly in first world countries like the United States. These observations demonstrate the need for further characterization of targets for antimicrobial therapy or vaccine generation. The extreme importance of the polysaccharide capsule during infection makes it a prime candidate for disruption and subsequent alleviation or prevention of disease.