[Action in vitro of disodium ethylenediaminetetraacetic acid (Na2EDTA) and antibiotics on resistant strains of staphylococcus aureus].

The investigation of action of Na2EDTA and doxycycline on strains of staphylococci resistant to doxycycline was performed by two methods: serial dilutions of tested substances in the fluid and solid medium. MIC values for Na2EDTA, doxycycline and both substances together were determined. Both methods resulted in an observation that for majority of tested doxycycline-resistant strains, application of various concentrations of doxycycline together with Na2EDTA resulted in a change of sensitivity of bacteria to the antibiotic by lowering concentration needed for bacterial growth inhibition. It seems that in further studies laborious and time-consuming method of serial dilutions in the fluid medium, should be replaced by more convenient and easier to perform method of serial dilutions of drugs in solid agar medium.