Action of lincomycin, chymotrypsin and their combinations on the course of experimental staphylococcal infection

The culture of Staphylococcus aureus was administered intraperitoneally in a dose of LD30 to albino mice. The animals of the 1st, 2nd and 3rd groups were treated with lincomycin, chymotripsin and combination of lincomycin with chymotripsin respectively. The animals of the 4th group were used as control and were not subjected to the treatment with the drugs. A part of the animals from every group was killed on the 3rd, 7th, 14th, 21st and subsequent days and their organs were investigated microscopically and bacteriologically. It was found that staphylococci was isolated from the control mice during a 50-day period after inoculation. Complete liberation of the organs from the causative agent within 25 days from the beginning of the experiment was registered in the animals treated with lincomycin. Isolation of the staphylococci was over by the 27th day in the animals treated with chymotrypsin. Liberation of the organs from the causative agent by the 17th day was observed in the albino mice treated with the combination of lincomycin with chymotrypsin. The combined use of lincomycin with chymotrypsin proved to be most effective: no death was registered among the albino mice, the levels of the pathogenicity and antibiotic resistance in the pathogenic staphylococci decreased.     

The course of experimental staphylococcal sepsis in opposite mouse strains and first-generation hybrids]

The survival time and histological lesions of the kidneys, liver, heart, and lungs were studied in CBA/Sto, C3HA/Mv and F1 (C3HA/Mv x CBA/Sto) mice for 15 days after i.v. injections with S. aureus pathogenic strains CFU B-243 in doses of 10(9), 10(8) and 2.5 x 10(8) microbial cells. CBA/Sto mice were found relatively resistant and C3HA/Mv mice, susceptible to infection caused by different doses of S. aureus, this being associated with different morphological picture in the viscera. F1 hybrids were at least as susceptible to the infections as any of the parent strains, suggesting recessive inheritance of resistance to staphylococcal infection.     

Effect of X-irradiation on the course of experimental vaccine anthrax

The author studied the course of vaccine anthrax infection in irradiated rabbits. The experiments show that infection of irradiated rabbits with a vaccine strain can give rise to a disease bacteriologically, clinically, histologically and biochemically identical with typical anthrax and that anthrax toxin can be demonstrated in the plasma of dead rabbits. The main cause of anthrax sepsis is not raised sensitivity to the toxin, but the high degree of proliferation of the microorganism in the irradiated organism. The significance of phagocytosis as a defence against vaccine anthrax infection and the significance of the capsule or of another somatic substance for the development of the anthrax syndrome are discussed.     

Effect of an autovaccine on the course of an experimental staphylococcal infection]

The effect of autovaccine on the state of cellular immunity in mice with staphylococcal infection was studied. The maximum decrease of staphylococcal dissemination in internal organs, espeically in the lungs, as well as an increase in the intensity of phagocytosis by peritoneal macrophages were observed after the administration of the vaccine by the method of inhalation. The intranasal administration of the vaccine also proved to be more effective than subcutaneous injection. The cumulation of immune response was more pronounced after the aerosol administration of autovaccine, especially in cases of pathological processes in the respiratory organs.     

Effect of hyperbaric oxygenation on the course of experimental staphylococcal infection and on the immune status of the animal body

In guinea pigs infected with staphylococci by subcutaneous injection a decreased content of T-lymphocytes, an increased number of B-lymphocytes and lower levels of lysozyme and complement were observed. When subjected to the action of hyperbaric oxygenation, the animals, both intact or infected with staphylococci, showed the aggravation of staphylococcal infection, a decrease in the number of T-lymphocytes and an increase in the content of B-lymphocytes. In the intact animals hyperbaric oxygenation stimulated the production of complement and lysozyme, produced a decrease in the number of T-lymphocytes and an increase in the number of B-lymphocytes.     

Changes in the immunotropic activity of neutrophilokins in the course of experimental staphylococcal infection

The influence of the products secreted by activated neutrophils (neutrophilokins) of mice, both intact and infected with staphylococci, on the activity of mouse spleen cells in the graft-versus-host reaction, immune response to sheep red blood cells and the antigen-presenting function of peritoneal macrophages was studied. Neutrophilokins of intact mice stimulated the activity of immunocompetent cells. Neutrophilokins obtained from infected mice on day 3 after infection produced an immunosuppressing effect. On day 7 after infection the immunostimulating activity of neutrophils was restored and showed practically no difference from the normal level.     

The effect of recombinant interleukin-2 on the course of experimental staphylococcal peritonitis in mice]

The effect of RIL-2 on the survival of mice with S. aureus--induced peritonitis was studied. Animals received bacterial suspension and RIL-2 as following: bacteria--on days 0, +2, RIL-2--day 0 (group 1); bacteria--days 0, +4, RIL-2--days 0, +2 (group 2); bacteria--days 0, +6, RIL-2--days 0, +2, +4 (group 3). RIL-2 exerted no protective effect in group 1. However, in groups 2 and 3, where the control animals survival was, resp., 56% and 38%, the RIL-2 treatment increased survival up to, resp., 84% and 70%. Antibiotics given instead of RIL-2 in analogous regimen decreased the survival in group 3 to the level of 25%. Thus, RIL-2 proved to be a potent therapeutic agent in the 2nd of 3d studied models of S. aureus--induced peritonitis in mice. The perspectives of RIL-2 use in the treatment of bacterial peritonitis, including porous ones, and of the immunodepression--aggravated conditions are discussed.