[Combined action of aminoglycoside group antibiotics and bile acids on staphylococci].

The results of in vitro studies on the potentiating effect of cholic, taurocholic, glycocholic and desoxicholic acids on the bacteriostatic and bactericidal activity of aminoglycoside antibiotics are presented. Ten fresh isolates of staphylococci were used in the experiments. Sensitivity of the isolates to the antibiotics and bile acids and their combinations was determined by the method of serial dilutions. Investigation of the combined effect of gentamicin, monomycin, kanamycin and neomycin with the bile acids showed that all of them had potentiating effect on the antimicrobial activity of the antibiotics. The potentiating effect of different acids and antibiotics was not the same. The highest potentiating activity was observed with the use of gentamicin or neomycin in combination with desoxycholic and cholic bile acids. Desoxycholic acid increased the bacteriostatic activity of gentamicin and neomycin by 781.3 and 2083.3 times respectively and cholic acid increased it by 382.7 and 2083.3 times. Cholic and desoxycholic acids potentiated also the bactericidal effect of gentamicin and neomycin. Taurocholic and glycocholic acids produced potentiation of various antibiotics by 8 to 60 times.