Of note, virulent S. suis strains that do not produce Sly may still be invasive in pigs, possibly best exemplified by Allen et al (2001) [58] who reported that an isogenic S. suis sly mutant, lacking of the hemolytic characteristics, was nearly as invasive as the wild-type parental strain in a pig infection studies after bacteria intravenous injection. This evidence concerns the gene SASH3 and infection.