Dissemination of the novel plasmid-mediated beta-lactamase CTX-1, which confers resistance to broad-spectrum cephalosporins, and its inhibition by beta-lactamase inhibitors.
The novel beta-lactamase CTX-1 (pI 6.3) encoded on a transferable 84-kilobase plasmid was found in six different bacterial species. It was responsible for a significant decrease in susceptibility towards most penicillins and cephalosporins, except imipenem, temocillin, and cephalosporins which have a 7-alpha-methoxy substituent. Synergy between either ampicillin, piperacillin, cefotaxime, ceftazidime, or aztreonam and three beta-lactamase inhibitors (clavulanic acid, sulbactam, and YTR 830) was generally found for different strains harboring CTX-1. This enzyme may be related to or derived from the TEM enzyme, since an intragenic probe of the TEM-1 gene hybridized with a fragment of the plasmid carrying CTX-1.
Kitzis
M D
MD
Laboratoire de Microbiologie Médicale, Hôpital Saint-Joseph, Paris, France.
Billot-Klein
D
D
Goldstein
F W
FW
Williamson
R
R
Tran Van Nhieu
G
G
Carlet
J
J
Acar
J F
JF
Gutmann
L
L
D002511:Cephalosporins / Q000494:pharmacology*; D002969:Clavulanic Acids / Q000494:pharmacology; D004269:DNA, Bacterial / Q000235:genetics; D004352:Drug Resistance, Microbial; D004357:Drug Synergism; D004755:Enterobacteriaceae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D005798:Genes, Bacterial; D006801:Humans; D009693:Nucleic Acid Hybridization; D010397:Penicillanic Acid / Q000494:pharmacology; D010403:Penicillin Resistance; D010406:Penicillins / Q000494:pharmacology*; D011815:R Factors; D013407:Sulbactam / Q000494:pharmacology; D000078142:Tazobactam; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000378:metabolism*
D002511:Cephalosporins; D002969:Clavulanic Acids; D004269:DNA, Bacterial; D010406:Penicillins; D065093:beta-Lactamase Inhibitors; D010397:Penicillanic Acid; C055184:beta-lactamase TEM-3; D001618:beta-Lactamases; D013407:Sulbactam; D000078142:Tazobactam