Lesions in Escherichia coli cell walls caused by the action of mouse complement.

Characteristic lesions formed by mouse complement were visible in electron micrographs of cell walls treated with aminoethylisothiouronium bromide and then incubated with normal mouse serum . However, lesions could not be detected in cell walls recovered from the blood of normal mice after intravenous injection. Lesions were not produced by either heated or complement deficient mouse sera in any of the experiments.

In vivo bactericidal activity of mouse complement against Escherichia coli.

Live of complement sensitive and resistant strains were labelled with C and injected i.v. into normal mice and into a co-isogenic strain deficient in C′5.

Nature and Heterogeneity of the Antigens of Neisseria gonorrhoeae Involved in the Serum Bactericidal Reaction.

Sixty strains of Neisseria gonorrhoeae have been classified into four main groups according to their resistance to killing by human complement together with either normal human or immune rabbit antibodies. The rabbit antisera had been raised against 10 of the strains tested. The normal human antibodies had probably been formed against cross-reacting organisms since they could be removed by absorption with N.

The sensitivity to complement of strains of Escherichia coli related to their K antigens.

We have confirmed that K antigens influence the sensitivity to complement of strains of . Resistant strains bound more polycation and by inference therefore had a higher surface negative charge than sensitive strains. Extracts containing K antigen non-specifically inhibited red cell agglutination and this inhibitory activity was roughly proportional to complement resistance.

The effect of acriflavine on complement sensitive and resistant strains of Escherichia coli and on complement resistant mutants.

Complement sensitive and resistant smooth strains of have been distinguished by their different reaction with acriflavine analysed spectrophotometrically. Resistant mutants of sensitive strains were obtained and found to react like wild type resistant strains.

The complement lysozyme sequence in immune bacteriolysis.

Suspensions of were not affected by lysozyme alone, but in solutions of appropriate pH and ionic strength some lysozyme was bound to the bacterial surface and remained available for action if the bacteria were subsequently treated with antibody and complement. In the presence of antibody, complement had a relatively prolonged action on ending in lysis. However, from an early stage in the reaction this lysis could be accelerated by adding lysozyme.

A kinetic study of the bacteriolytic and bactericidal action of human serum.

The killing and lysis of by human serum have been measured simultaneously at frequent intervals for periods of 30–60 minutes. The kinetic effects of varying the amounts of lysozyme, antibacterial antibody and complement have been studied. The rate of lysis is largely controlled by the lysozyme concentration but complement is also necessary.

Serological properties of gamma-A antibodies to Escherichia coli present in human colostrum.

Antibodies against WF 96 and WF 61 present in human colostrum and serum were fractionated by DEAE-cellulose chromatography. Using the haemagglutination test it was found that the antibodies present in colostrum were recovered in the fraction containing the bulk of γA-globulin, whereas the antibodies present in serum were recovered in the fraction containing the bulk of γM-globulin. In the presence of human or guinea-pig complement the antibodies present in colostrum did not lyse red cells coated with bacterial polysaccharides whereas the antibodies present in serum were lytic.

STUDIES WITH AN ANTIBODY TO RAT LYSOZYME.

An antibody to rat lysozyme has been prepared and its activity and specificity studied by inhibition and double diffusion techniques. By means of this antibody together with fluorescent anti-rabbit globulin, the distribution of lysozyme in rat and mouse polymorphs and macrophages has been examined and some changes which follow phagocytosis demonstrated.