TEM- or SHV-type extended-spectrum beta-lactamases(ESBLs) are of clinical concern in Europe and the United States, whereas bacterial strains producing such types of ESBLs had not been reported in Japan for many years. Toho-1, a different type class A ESBL, has been reported in 1995, in which any prototypical enzyme has not been identified so far. At present Toho-1 is the major ESBL in Japan, ho...

A clinical isolate of Morganella morganii, with reduced susceptibility to expanded-spectrum cephalosporins and aztreonam, was found to produce an extended-spectrum beta-lactamase with a pI of 6.4. The nucleotide sequence of the encoding gene was that of the gene encoding TEM-21. This is the first molecular characterization of an extended-spectrum beta-lactamase in M. morganii.

Background: Production of β–lactamases by enterobacteriacea, especially Klebsiella pneumoniae, is one of the emerging health problems in the world. The purpose of this study was to assess the frequency of blaCTX-M15 gene in K. pneumoniae isolates and determine the molecular diversity of CTXM producing isolates. Methods: In...

Introduction: Production of extended-spectrum beta-lactamase enzymes (ESBLs) in E. coli creates many problems for patients. These enzymes are located on transferable elements and can hydrolyze penicillins, broad-spectrum cephalosporins, and aztreonam. This study aimed to determine the clinical isolates of E. coli producing ESBLs of blaSHV and blaTEM in the city of Zanjan. Methods: This cross...

Clavulanic acid, sulbactam, and tazobactam are inhibitors of a variety of plasmid-mediated beta-lactamases. However, inhibition data for these three inhibitors with a wide range of different plasmid-mediated beta-lactamases have not yet been compared under the same experimental conditions. A number of groups have inferred that clavulanic acid inhibits extended-spectrum TEM and SHV beta-lactamas...