title: Timentin and beta-lactamases.
abstract: Ticarcillin is resistant to the action of cephalosporinases, which explains its biological activity on a large number of bacterial species, including cephalosporinase-producing Enterobacteriaceae and Pseudomonas aeruginosa. Nevertheless, its antibacterial activity is often limited by the action of some beta-lactamases, mostly plasmid-mediated penicillinases. Clavulanic acid by itself has poor antibacterial activity, but its most important property is to inhibit and inactivate beta-lactamases. The inhibitory properties of clavulanic acid were studied on a large number of beta-lactamases. The penicillinases produced by Staphylococcus aureus, the plasmid-mediated beta-lactamases such as the TEM-type, the chromosomally-mediated penicillinases from Klebsiella pneumoniae and other closely-related beta-lactamases, and a few chromosomally-mediated cephalosporinases, such as that produced by Proteus vulgaris, are powerfully inhibited by clavulanic acid. The plasmid-mediated penicillinases of OXA type and most of the chromosomally-mediated cephalosporinases, such as that produced by Escherichia coli (Amp C), are less or poorly inhibited. Moreover, clavulanic acid has some cephalosporinase-inducing properties. These properties are in good agreement with the bacteriological properties of Timentin.
mesh_terms: D001426:Bacterial Proteins / Q000037:antagonists & inhibitors*; D002969:Clavulanic Acids / Q000494:pharmacology*; D004338:Drug Combinations / Q000494:pharmacology; D004357:Drug Synergism; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000201:enzymology; D010403:Penicillin Resistance; D010406:Penicillins / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000201:enzymology; D013982:Ticarcillin / Q000378:metabolism / Q000494:pharmacology*; D065093:beta-Lactamase Inhibitors
chemical_list: D001426:Bacterial Proteins; D002969:Clavulanic Acids; D004338:Drug Combinations; D010406:Penicillins; D065093:beta-Lactamase Inhibitors; C043215:ticarcillin-clavulanic acid; D013982:Ticarcillin