Gutmann L, Kitzis M D, Billot-Klein D, Goldstein F, Tran Van Nhieu G, Lu T, Carlet J, Collatz E, Williamson R
Laboratoire de Microbiologie Médicale, Université Pierre et Marie Curie, Paris, France.
Rev Infect Dis. 1988 Jul-Aug;10(4):860-6. doi: 10.1093/clinids/10.4.860.
TEM-7, a novel TEM-type beta-lactamase (pI 5.41) encoded on a plasmid of approximately 85 kilobases, was found in a clinical isolate of Citrobacter freundii. Strains containing this enzyme exhibited decreased susceptibility to ceftazidime (64-fold) and aztreonam (16-fold) but not to other third-generation cephalosporins. Addition of a beta-lactamase inhibitor--clavulanic acid, sulbactam, or YTR 830--restored normal susceptibility to associated compounds such as ampicillin, piperacillin, ceftazidime, and aztreonam. DNA-DNA hybridization of an intragenic probe of TEM-1 occurred with a 19-kilobase EcoRI fragment of the plasmid encoding TEM-7. A TEM-2 derivative, TEM-201, with characteristics similar to those of TEM-7 was selected spontaneously in the presence of ceftazidime in vitro.
