a new variant of the capsule 3 cluster occurs in streptococcus pneumoniae from deceased wild chimpanzees集群的一个新变体胶囊3发生在肺炎链球菌从已故的野生黑猩猩.pdfVIP

A New Variant of the Capsule 3 Cluster Occurs in Streptococcus pneumoniae from Deceased Wild Chimpanzees Dalia Denapaite, Regine Hakenbeck* Department of Microbiology, University of Kaiserslautern, Kaiserslautern, Germany Abstract ¨ ˆ The presence of new Streptococcus pneumoniae clones in dead wild chimpanzees from the Taı National Park, Cote d’Ivoire, with previous respiratory problems has been demonstrated recently by DNA sequence analysis from samples obtained from the deceased apes. In order to broadenour understanding on the relatedness of these pneumococcal clones to those from humans, the gene locus responsible for biosynthesis of the capsule polysaccharide (CPS) has now been characterized. DNA sequence analysis of PCR fragments identified a cluster named cps3 ¨ containing the four genes typical for serotype 3 CPS, Taı but lacking a 59-region of $2 kb which is degenerated in other cps3 loci and not required for type 3 biosynthesis. CPS3 is composed of a simple disaccharide repeat unit comprising glucose and glucuronic acid (GlcUA). The two genes ugd responsible for GlcUA synthesis and wchE encoding the type 3 synthase are essential for CPS3 biosynthesis, whereas both, galU and the 39-truncated gene pgm are not required due to the presence of homologues elsewhere in the genome. The DNA sequence of cps3 ¨ diverged considerably from those of other cps3 loci. Also, the gene pgm ¨ represents a full length Taı Taı version with a nonsense mutation at codon 17