Abstracts of Papers Presented at the Third International Complement Workshop, Harvard Medical School, Boston, Massachusetts, June 3–5, 1968

[摘要] External components of Gram-negative organisms such as Escherichia coli and Salmonella typhi possess barrier function that may be destrcyed by EDTA treatment. The effect of such treatment, which is not bactericidal, upon the resistance of cells to the immune bactericidal reaction mediated by C′ was therefore determined. When the amount of antibody was limiting, as with absorbed guinea pig serum, there was a marked difference in the susceptibility of EDTA-treated and control cells. There was only a relatively slight difference in sensitivity of EDTA-treated and control organisms to untreated normal serum, however, and in the presence of excess antibody, no detectable difference. Apparently, an excess of antibody tends to nullify the increased sensitivity to C′ resulting from EDTA treatment. It was previously postulated that the reason for the insusceptibility of Gram-positive bacteria compared with Gram-negative bacteria was the greater thickness of the cell wall of Grampositive species, 15 to 50 mµ, compared to Gramnegative species with walls to 7.5 to 10 mµ.

[学科分类] 生物科学（综合）