Journal of Microbiology

Research Support, Non-U.S. Gov't

Catabolite Control Protein A of Streptococcus suis Type 2 Contributes to Sugar Metabolism and Virulence: Yulong Tang , Wei Wu , Xiaoyan Zhang , Zhongyan Lu , Jianshun Chen , Weihuan Fang; J. Microbiol. 2012;50(6):994-1002. Published online December 30, 2012; DOI: https://doi.org/10.1007/s12275-012-2035-3

Abstract: Catabolite control protein A (CcpA) is the major transcriptional regulator in carbon catabolite repression in several Gram-positive bacteria. We attempted to characterize the role of a CcpA homologue of Streptococcus suis type 2 in sugar metabolism and virulence. Addition of glucose or sucrose to the defined medium significantly reduced the activity of raffinose-inducible α-galactosidase, cellobiose-inducible β-glucosidase, and maltose-inducible α-glucosidase of the wildtype strain by about 9, 4, and 2-3 fold, respectively. Deletion of ccpA substantially derepressed the effects of repressing sugars on α-galactosidase or β-glucosidase activity. The ccpA deletion mutant showed reduced expression of virulence genes sly and eno (P<0.05), decreased adhesion to and invasion into endothelial cells (P<0.05), and attenuated virulence to mice with significant reduction of death rate and bacterial burden in organs, as compared to the wild-type strain. Both the in vitro and in vivo defect phenotypes were reversible by ccpA complementation. Thus, this study shows that CcpA of S. suis type 2 plays an important role in carbon catabolite repression and virulence.

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