| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2005: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2004: ¥2,900,000 (Direct Cost: ¥2,900,000)
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| Research Abstract |
Encapsulated bacteria are frequently associated with serious diseases in both man and animals. The capsular polysaccharides (CPs) of the pathogenic bacteria confer resistance to complement-mediated opsonophagocytosis. In addition, some bacteria have CPs that mimic host molecules to avoid the specific immune system of the host. Bacterial CPs are generally composed of repeating oligosaccharides, consisting of two to ten monosaccharides and are sometimes complemented with other components. In this study, we tried to detect the capsular polysaccharides from Streptococcus anginosus and S. intermedius. By using specific antisera against these bacteria, we could detect high molecular weight products (about 700 kD) in gelfiltration experiment. Since the peak did not disappear even after treatments with Proteinase K, DNase I and RNase, the high molecular weight products seemed to be capsular polysaccharides. We next tried to isolate capsular polysaccharide synthesis genes from these bacteria. Since cpsE gene, which codes for glycosyltransferase for the first step of capsular synthesis, is conserved in all streptococcal capsular polysaccharide synthesis operons, we performed southern hybridization experiments on the genome of S.anginosus and S.intermedius using the cpsE gene of S.agalactiae as a probe. As a result, we could detect the cpsE gene from S.anginosus.
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