title: [Specificities of antibacterial activity of zwitterionic 7-methoxyimino cephems (cephalosporins of fourth generation].
abstract: Zwitterionic 7-methoxyimino cephalosporins possess a variable substitution at C3 which contains a quaternary nitrogen. These cephalosporins display low affinities for class I beta-lactamase and rapid penetration through the outer membrane of Gram negative bacilli. Hence, they remain active against some, but not all, ceftazidime-resistant Enterobacteriaceae. Antipseudomonas activities are generally similar to that of ceftazidime except that cefelidin is more active. The new zwitterionic compounds express greater antistaphylococcal potency than does ceftazidime. On the basis of structural and antibacterial characteristics the expression "forth generation" is acceptable to describe the wzitterionic 7-methoxyimino cephalosporins.
authors: Département de Génétique et Microbiologie, Centre Médical Universitaire, Genève, Suisse.
authors: J C
authors: JC
authors: Pechère
mesh_terms: D000077723:Cefepime; D002442:Ceftazidime / Q000737:chemistry / Q000494:pharmacology*; D002511:Cephalosporins / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D016972:Enterobacter cloacae / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D066298:In Vitro Techniques; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D002511:Cephalosporins; D000077723:Cefepime; D002442:Ceftazidime
vernacular_title: Les spécificités de l'action antibactérienne des 7-methoxyimino cephèmes zwitterioniques ("céphalosporines de 4e génération").