[Toxicity of Bacteroides intermedius surface extracts against mouse splenic lymphocyte].

The purpose of the present study is to clarify in vitro toxicity of surface sonic extracts from Bacteroides intermedius (B. intermedius) ATCC25611, B. intermedius ATCC 33563 and Bacteroides gingivalis (B. gingivalis) 381 against mouse splenic lymphocyte. Especially the surface extracts from B. intermedius ATCC 25611 were fractionated by high performance liquid chromatography (HPLC) on a column of DEAE. The following results were obtained: 1) The surface extracts from B. gingivalis 381 and B. intermedius ATCC 25611 presented remarkable lymphotoxicity, but B. intermedius ATCC33563 did not have it. 2) The surface extracts from B. intermedius ATCC 25611 was separated to 6 fractions by HPLC. 3) Two fractions isolated from B. intermedius ATCC 25611 surface extracts observed remarkable lymphotoxicity, and the one of their fractions, possibly including fimbriae showed a remarkably higher toxicity against mouse splenic lymphocyte.