Abstract: | Guinea pigs, previously injected with commercial staphylococcal allergen to induce delayed hypersensitivity, were infected by the intramuscular injection of S. aureus in a nonlethal dose. For control, the animals receiving only S. aureus were used. The dynamic study of the degree of septicemia and some lymphocytic characteristics in the animals was made. The study revealed that delayed hypersensitivity did not aggravate the course of the main disease; on the contrary, it rendered protection against the subsequent infection. Increased resistance to infection was manifested by a decrease in the degree of septicemia, determined from the decreased number of colony-forming units of S. aureus in the splenic tissue as assessed by inoculation into agar, as well as from a higher level of the activation of lymphocytes as assessed by rosette formation. |