K. Iida, S. Hirata, S. Nakamuta
Aug 1, 1978
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Influential Citations
30
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Journal
Antimicrobial Agents and Chemotherapy
Abstract
The mechanism of the action of piperacillin against Escherichia coli was investigated. This drug converted cells to filaments, but did not show lytic action in a range of concentrations below 25 μg/ml. In some of the filaments, stretched constrictions with various diameters were observed. Addition of piperacillin to a synchronous culture inhibited cell division immediately at any stage of the cell cycle. The results of morphological examination of synchronous cultures show that the percentage of filaments with a stretched constriction corresponds to that of normally septated cells before addition of the drug. Furthermore, peptidoglycan synthesis and cross-linking were not inhibited by this drug. It is likely that this drug inhibits only septum formation, but not the growth of wall, and that stretched constrictions are a result of longitudinal growth of septation caused by the drug. Examination of affinity of the drug to penicillin-binding proteins shows that protein 3 is the most sensitive, proteins 2 and 7 are moderately so, and protein 1 is sensitive only to high concentrations of the drug.