Action of iron and iron-complexes on Klebsiella pneumoniae (Klebsiella aerogenes).
Iron In the Fe(III) oxidation state had a negligible effect on the growth of Klebsiella pneumoniae even at the highest concentration (0.45 mM) obtainable without precipitation in a minimal medium containing glucose and inorganic salts together with Tris as the buffer and glycerol 2-phosphate as the phosphorus source. Nevertheless in its presence the toxic action of Cd2+, Zn2+ and Cu2+ was antagonized while that of Co2+ and Ni2+ was potentiated. Higher iron levels were obtained by supplementing the minimal medium with fructose, glycine, gluconate, tartrate and citrate at a range of concentrations. With fructose and glycine all of the resulting solutions were red-brown and non-toxic. This was also found with the other complexing agents when the ligand:iron were low, but at higher ligand:iron ratios the solutions were green and toxic. Iron-citrate systems were especially toxic but resistance developed and was of the graded type. The results are discussed with particular reference to earlier physico-chemical studies by other workers and it is concluded that the red-brown colour is characteristic of the presence of polymers of high molar mass and that the green colour signifies the formation of low molar mass species.
D004347:Drug Interactions; D007501:Iron / Q000494:pharmacology*; D007502:Iron Chelating Agents / Q000494:pharmacology*; D007711:Klebsiella pneumoniae / Q000187:drug effects*; D008670:Metals / Q000494:pharmacology; D010084:Oxidation-Reduction
D007502:Iron Chelating Agents; D008670:Metals; D007501:Iron