The metallo-beta-lactamase produced by Chryseobacterium (formerly Flavobacterium) meningosepticum, which is the flavobacterial species of greatest clinical relevance, was purified and characterized. The enzyme, named BlaB, contains a polypeptide with an apparent Mr of 26000, and has a pI of 8.5. It hydrolyses penicillins, cephalosporins (including cefoxitin), carbapenems and 6-beta-iodopenicill...

Endodontic infections are mixed aerobic-anaerobic infections and several microbial groups associated to these pathologies are also involved in orofacial infections. The goal of this study was to evaluate the susceptibility of microorganisms isolated from endodontic infections to beta-lactams and metronidazole and verify the production of beta-lactamases. Clinical specimens were collected from 5...

Two potent antibacterial agents designed to undergo enzyme-catalyzed therapeutic activation were evaluated for their mechanisms of action. The compounds, NB2001 and NB2030, contain a cephalosporin with a thienyl (NB2001) or a tetrazole (NB2030) ring at the C-7 position and are linked to the antibacterial triclosan at the C-3 position. The compounds exploit beta-lactamases to release triclosan t...

background and objectives : the rapid emergence and dissemination of carbapenemase-producing klebsiella pneumoniae strains and other members of the enterobacteriaceae poses a considerable threat to the care of hospitalized patients and to public health. the aim of this study was to determine the frequency of metallo-β-lactamases (mbl) and vim-1 gene in multidrug-resistant strains of k. pneumoni...

In a survey of resistance to amoxicillin among clinical isolates of Proteus mirabilis, 10 TEM-type beta-lactamases were characterized: (i) the well-known penicillinases TEM-1 and TEM-2, the extended-spectrum beta-lactamases (ESBLs) TEM-3 and TEM-24, and the inhibitor-resistant TEM (IRT) TEM-44 and (ii) five novel enzymes, a penicillinase TEM-57 similar to TEM-1, an ESBL TEM-66 similar to TEM-3,...