Date of Award


Publication Type

Doctoral Thesis

Degree Name



Biological Sciences


Biology, Microbiology.




There are two types of antibodies to the alpha toxin of Staphylococcus aureus: the antibinding antibodies (AB-Ab) and the indirect hemagglutinating antibodies (IHA-Ab). Based on the results of fluorescence polarization immunoassay and precipitin reactions, the minimal number of antigenic deteminants for alpha toxin is 3; one IHA determinant and two antibinding determinants. The type types of antibodies were characterized in terms of antibody responses, neutralization, immunoglobulin classes, and complement fixation in vitro and in vivo. The antibody responses in rabbits immunized with alpha toxoid were readily demonstrable by the indirect hemagglutination test and by the complement fixation test but not by the neutralization test. The preimmune status of the animal appears to influence the course of the AB-Ab response. The proportion of the two populations of antibodies fluctuates among the different rabbits and with time in the same animal. I Ab appear to contribute a greater part of the neutralization capacity to whole sera. The neutralization capacity observed in antiserum is less than the sum of the neutralization capacities of the individual populations of antibodies because one toxin can bind more than one antibody. The binding of any one molecule of antibody (AB-Ab or IHA-Ab) is sufficient to neutralize a molecule of the toxin. No nonneutralizing antibody to the toxin was detected. Neutralizing antibodies are found in IgG, IgM and IgA classes. A serologic survey revealed that 72% of normal human sera were positive for complement-fixing antitoxins and 95% of these sera were positive for IHA-Ab. The fixation of complement by membrane-bound immune complexes does not result in lysis of the carrier erythrocytes. Both IHA-Ab and AB-Ab induced the reverse Arthus type of skin reaction in rabbit. This investigation revealed that the protective value of IHA-Ab is superior to that of AB-Ab.Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1984 .L64. Source: Dissertation Abstracts International, Volume: 45-04, Section: B, page: 1117. Thesis (Ph.D.)--University of Windsor (Canada), 1984.