title: Cell cycle-independent lysis of Escherichia coli by cefsulodin, an inhibitor of penicillin-binding proteins 1a and 1b.
abstract: Cefsulodin lyses actively growing Escherichia coli by binding specifically to penicillin-binding proteins (PBPs) 1a and 1b. Recent findings (F. García del Portillo, M. A. de Pedro, D. Joseleau-Petit, and R. D'Ari, J. Bacteriol. 171:4217-4221, 1989) have linked cefsulodin-induced lysis to septation during the first division cycle after a nutritional shift-up or chromosome replication realignment. We synchronized cells by membrane filtration to determine whether cefsulodin-induced lysis depended on septation in normally growing cells. Populations of newly divided cells were allowed to grow for variable lengths of time. Cefsulodin was added to these synchronous cultures, which represented points in two to three rounds of the cell cycle. Since the cell numbers were small, a new lysis assay was developed that was based on the release of DNA measured by fluorometry. Lysis occurred at a constant time after addition of the antibiotic, regardless of the time in the cell cycle at which the addition was made. Thus, cefsulodin-induced lysis is not linked to septation or to any other cell cycle-related event.
authors.affiliation: Department of Microbiology and Immunology, University of North Dakota School of Medicine, Grand Forks 58202.
authors.forename: G H
authors.initials: GH
authors.lastname: Jacoby
authors.forename: K D
authors.initials: KD
authors.lastname: Young
mesh_terms: D001426:Bacterial Proteins; D002352:Carrier Proteins; D002441:Cefsulodin / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D004269:DNA, Bacterial / Q000032:analysis; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D006602:Hexosyltransferases / Q000037:antagonists & inhibitors*; D007700:Kinetics; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors*; D002267:Muramoylpentapeptide Carboxypeptidase; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases / Q000037:antagonists & inhibitors*; D013050:Spectrometry, Fluorescence
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D009097:Multienzyme Complexes; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase; D002441:Cefsulodin