UvA - DARE ( Digital Academic Repository ) Identification of virulence factors of Streptococcus suis

In this study, we describe the first response regulator of S. suis serotype 2, designated RevS. RevS was cloned and the sequence was determined. No histidine kinase was found in the vicinity of revS, therefore RevS was considered to be an orphan response regulator. An isogenic knock-out mutant of RevS was shown to be attenuated in colonizing the S. suis specific organs in a competitive assay in four piglets, indicating that RevS plays a role in the pathogenesis of S. suis infections. We analyzed the protein expression profiles of various fractions of the wild-type strain 10 and the mutant strain lOARevS. The expression of known virulence factors of S. suis by wild-type and the mutant strain, was not different. However, one protein in the protoplast fraction with unknown identity was shown to be repressed by revS in the exponential growth phase of the mutant.