A new natural TEM derivative with extended-spectrum β-lactamase activity, TEM-134, was identified in a ceftazidime-resistant clinical isolate of Citrobacter koseri. Compared to TEM-1, TEM-134 contains the following mutations: Q39K, E104K, R164H, and G238S. The blaTEM-134 gene was not transferable by conjugation and, apparently, was chromosomally encoded. Expression studies with Escherichia coli revealed efficient cefotaximase and ceftazidimase activity for TEM-134.
ASJC Scopus subject areas
- Pharmacology (medical)