ß-Lactams are the most widely used antibiotics, and ß-lactamases are the greatest source of resistance to them. Colorimetric tests are good, rapid, indicators of ß-lactamase production and its contingent resistance in Haemophilus, Moraxella and Neisseria spp. They can also be applied to Gram-negative bacilli but are less useful, since the usual question is not whether a ß-lactamase is produced ...

The widespread use of tracheal intubation and mechanical ventilation to support the critically ill patients increases the risk of development of tracheobronchitis and bronchopneumonia. This cross-sectional study was conducted with an aim to isolate and identify bacterial pathogens from tracheal aspirates producing extended-spectrum β -lactamase (ESBL), AmpC β -lactamase, and metallo- β -lactama...

Clinical use of beta-lactams has selected for beta-lactamase-producing organisms. Numerous beta-lactamases are known, and sequencing allows them to be divided into four Classes, A to D, with Classes A and C being the most important. Pharmaceutical chemists have responded to the spread of beta-lactamase-producing organisms by developing stable agents and inhibitors. Stability in penicillins and ...

Advances in genome engineering are attendant on the development of novel enzyme variants with programed substrate specificities and improved activity. We have devised a novel selection method, wherein the activity of a recombinase deletes the gene encoding an inhibitor of an enzyme conferring a selectable phenotype. By using β-lactamase and the β-lactamase inhibitor protein, the selection coupl...

BACKGROUND & OBJECTIVE Currently, the use of beta-lactamase inhibitors in combination with beta-lactam antibiotics represents an effective measure to combat a specific resistance mechanism of beta-lactamase producing organisms. Knowledge about the susceptibility profile of bacteria to different combination agents available is essential to guide appropriate treatment of severe infections in hosp...

Recent basic and clinical research efforts have shed more light on the taxonomy, microbiology, epidemiology, antimicrobial susceptibility and treatment of Bacteroides, Prevotella, and Porphyromonas species. Of all anaerobic bacteria, Bacteroides is the most frequently isolated pathogen from clinical specimens, including blood. Bacteroides, Prevotella and/or Porphyromonas species have been isola...

We investigated a series of sulfonamide boronic acids that resulted from the merging of two unrelated AmpC β-lactamase inhibitor series. The new boronic acids differed in the replacement of the canonical carboxamide, found in all penicillin and cephalosporin antibiotics, with a sulfonamide. Surprisingly, these sulfonamides had a highly distinct structure-activity relationship from the previousl...

In the Calgary Health Region during 2000-2003, prospective, active, population-based laboratory surveillance for all cefoxitin-resistant Escherichia coli isolates was performed. Isolates were screened with an inhibitor-based disk test, and plasmid-mediated types were identified by multiplex PCR with sequencing. A total of 369 AmpC beta-lactamase-producing E. coli isolates were identified; annua...