Antimicrobial effects of cefotaxime as studied by the potentiometric measurement of lipoic acid reduction in Escherichia coli cultures.

Continuous potential-time measurements of lipoic acid reduction by cultures of Escherichia coli were carried out in the presence of increasing amounts of cefotaxime. Original information on the kinetics of action and antibacterial activity of the drug was deduced from the resulting potential-time curves and confirmed by classical measurements of bacterial growth and substrate consumption. In particular, surprisingly stimulative effects of cefotaxime on the reductive activity of organisms were elicited by the potentiometric technique, and are discussed at the cellular level.