The clinical strain Escherichia coli TO799 was resistant to penicillin-clavulanate combinations and ceftazidime and was not reproducibly detected as an extended-spectrum -lactamase (ESBL) according to the standards of the Clinical Laboratory Standards Institute (CLSI; formerly NCCLS) and the national guidelines of the French Society for Microbiology (Comité de l’Antibiogramme de la Société Fran...

The beta-lactamase stability and inhibitory activity of 1-oxa cephalosporin, (6R,7R)-7-[[carboxy(4-hydroxyphenyl)acetyl]amino]-7-methoxy-3-[[(1-methyl-1H-tetrazol-5-yl)thio]methyl]-8-oxo-5-oxa-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, was investigated and compared to that of cefoxitin and cefotaxime. There was no detectable beta-lactamase hydrolysis of 1-oxa cephalosporin, cefotaxime and ...

Definitions: Beta-lactam antimicrobials are characterized by having a four-membered cyclic amide (beta-lactam ring) as part of their chemical structure (Figure 1) [1]. This broad group includes the penicillins, cephalosporins, carbapenems, and monobactams [1]. All beta-lactams have a similar mechanism of action; they inhibit bacterial cell wall synthesis [1]. Resistance to beta-lactam antimicro...

Clavulanate is a broad-spectrum beta-lactamase inhibitor, with activity against many of the chromosomally and plasmid-mediated beta-lactamases of both Gram-positive and Gram-negative bacteria. Although clavulanate has minimal antibacterial activity in vitro, accumulating evidence suggests that it may have an effect on pathogenic bacteria regardless of beta-lactamase production. Like other beta-...

As the incidence of Gram-negative bacterial infections for which few effective treatments remain increases, so does the contribution of drug-hydrolyzing β-lactamase enzymes to this serious clinical problem. This review highlights recent advances in β-lactamase inhibitors and focuses on agents with novel mechanisms of action against a wide range of enzymes. To this end, we review the β-lactamase...

AmpC is a group I, class C -lactamase present in most Enterobacteriaceae and in Pseudomonas aeruginosa and other nonfermenting gram-negative bacilli. The β-lactam class of antibiotics is one of the most important structural classes of antibacterial compounds and act by inhibiting the bacterial D ,D - transpeptidases that are responsible for the final step of peptidoglycan cross-linking. Our mai...

The clinical strain Escherichia coli TO799 was resistant to penicillin-clavulanate combinations and ceftazi-dime and was not reproducibly detected as an extended-spectrum ␤-lactamase (ESBL) according to the standards of the Clinical Laboratory Standards Institute (CLSI; formerly NCCLS) and the national guidelines of the French Society for Microbiology (Comité de l'Antibiogramme de la Société Fr...

Klebsiella oxytoca strains are generally moderately resistant to amoxicillin and ticarcillin due to the activities of the chromosomally encoded OXY-1 and OXY-2 class A beta-lactamase families. These enzymes have the ability to hydrolyze not only penicillins but also cephalosporins, including cefuroxime, ceftriaxone, and aztreonam, and are inhibited by clavulanic acid. A Klebsiella oxytoca strai...

OBJECTIVE To determine the susceptibility pattern of beta-lactam beta-lactamase inhibitor combinations against extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae in urinary isolates. STUDY DESIGN Observational study. PLACE AND DURATION OF STUDY Ziauddin University Hospital, Karachi, from February to October 2008. METHODOLOGY A total of 190 consecutive non-duplicate isola...

New Delhi Metallo-β-lactamase (NDM-1) is an enzyme that hydrolyses a wide range of β-lactam antibiotics, including most carbapenems, leading to antimicrobial resistance. The development novel NDM-1 inhibitor for use in combination with carbapenems may help combat drug-resistant pathogens. Twenty compounds were designed based on the structural features active site inhibit bacterial and protect a...