Patent ID: 7776323

Claim:
A recombinant Streptococcus suis serotype 9 knockout mutant, wherein the knockout mutant is in the capsular polysaccharide (cps) gene cluster as set forth in SEQ ID NO:37, wherein the knockout mutant is in the cps9D gene encoding the cps9D protein as set forth in SEQ ID NO:38, the cps9E gene encoding the cps9E protein as set forth in SEQ ID NO:39, the cps9F gene encoding the cps9F protein as set forth in SEQ ID NO:40, the cps9G gene encoding the cps9G protein as set forth in SEQ ID NO:41, the cps9H gene encoding the cps9H protein as set forth in SEQ ID NO:42, or a combination of any thereof, wherein the knockout mutant is deficient in capsular expression.