Uptake of antibodies in gram-negative bacteria exposed to EDTA-Tris.

Ethylene diamine tetra-acetic acid disodium salt (3.22 mM) and Tris (hydroxymethyl aminomethane) (50 mM) was found to cause potentiation of antibiotic actions and/or increased uptake of antibiotics when assessed by bacterial inhibition kinetic studies and uptake of radiolabeled antibiotics. Solutions of EDTA-Tris potentiate the effect of tetracycline, dihydrostreptomycin and penicillin when reacted with Escherichia coli. A similar effect was observed for tetracycline when incubated with Proteus vulgaris and penicillin, chloramphenicol, dihydrostreptomycin and tetracycline when incubated with Pseudomonas aeruginosa. These effects were noted by decreasing bacterial counts in the bacterial inhibition kinetic studies and increased uptake of radiolabeled antibiotics.