[Screening of effective agents for decreasing microorganism resistance to antibiotics]

The effect of bile acids on antibiotic resistant strains of Staphylococcus, Proteus, E. coli and Ps. aeruginosa isolated from patients with different purulent inflammatory processes was studied. It was shown in vitro that glycocholic and deoxycholic acids lowered the resistance of the above microorganisms to some antibiotics. The exposure of the staphylococcal strains to deoxycholic or glycocholic acid lowered their resistance to streptomycin, neomycin and kanamycin on the average by 75-150, 125-500 and 55-60 times, respectively. The same tendency was observed in the penicillin and erythromycin resistant strains. A 2-hour incubation of E. coli strains in the presence of glycocholic or deoxycholic acid resulted in a decrease in the MIC of polymyxin B from 312.5 to 1.6 or 3.2 micrograms/ml, respectively. These acids increased bacterial sensitivity to streptomycin, chloramphenicol and neomycin by 8-16, 10-20 and 40-80 times, respectively. The effect of the bile acids on the resistant strains of E. coli and Proteus was less pronounced. It was shown that glycocholic and deoxycholic acids were able to inhibit the activity of staphylococcal beta-lactamase.