[Effect of proteolytic enzymes on the antimicrobial activity of antibiotics].

The results of the studies on the effect of chemotripsin on the antimicrobial activity of monomycin against laboratory cultures, such as Staph. aureus 209 P, E. coli M38 and Streptococcus zymogenes and 20 clinical strains isolated from patients with purulent peritonitis are presented. The studies were performed with the method of two-fold serial dilutions. It was found that chemotripsin decreased 3.2.10-2.6.10(5) times the MIC (minimum inhibitory concentration) and the bactericidal concentration of monomycin. The presence of fibrin in the medium inhibited 4-128 times the antibacterial effect of monomycin. The potentiating effect of chemotripsin on monomycin could be explained by both a better "contact" of the antibiotic with the microbes and an direct increase in the antibiotic sensitivity of the microbial cells. Combination of monomycin with chemotripsin provided the use of decreased doses of the antibiotic. It is an effective means of overcoming the antibiotic resistance in pathogenic microbes.