title: Inhibition of cell division of Escherichia coli by a new synthetic penicillin, piperacillin.
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 mug/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.
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002473:Cell Wall / Q000187:drug effects / Q000378:metabolism; D004926:Escherichia coli / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D010406:Penicillins / Q000378:metabolism / Q000494:pharmacology*; D010457:Peptidoglycan; D010458:Peptidyl Transferases / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D010406:Penicillins; D010457:Peptidoglycan; D010458:Peptidyl Transferases