Strains of Escherichia coli, Enterobacter aerogenes, and Enterobacter cloacae that were resistant to ceftazidime (MIC greater than 16 micrograms/ml) but susceptible to BMY 28142 (MIC less than 4 micrograms/ml) were found to contain higher levels of beta-lactamase activity (50- to 3,340-fold) than control strains of the corresponding species. Ceftazidime was at least as resistant as BMY 28142 to...

beta-Lactamases are the main cause of bacterial resistance to penicillins and cephalosporins. Class A beta-lactamases, the largest group of beta-lactamases, have been found in many bacterial strains, including mycobacteria, for which no beta-lactamase structure has been previously reported. The crystal structure of the class A beta-lactamase from Mycobacterium fortuitum (MFO) has been solved at...

β-Lactamase-mediated resistance is a growing threat to the continued use of β-lactam antibiotics. The use of the β-lactam-based serine-β-lactamase (SBL) inhibitors clavulanic acid, sulbactam, and tazobactam and, more recently, the non-β-lactam inhibitor avibactam has extended the utility of β-lactams against bacterial infections demonstrating resistance via these enzymes. These molecules are, h...

Mox-1 is a unique plasmid-mediated class C β-lactamase that hydrolyzes penicillins, cephalothin, and the expanded-spectrum cephalosporins cefepime and moxalactam. In order to understand the unique substrate profile of this enzyme, we determined the X-ray crystallographic structure of Mox-1 β-lactamase at a 1.5-Å resolution. The overall structure of Mox-1 β-lactamase resembles that of other AmpC...

This study determined the presence of Amp C beta lactamase producing Pseudomonas aeruginosa among the seventy four uropathogens studied using standard techniques. Results obtained revealed that the studied isolates show an alarming rate of resistance to the extended spectrum beta lactam antibiotics and the penicillin derivatives tested. The combination of piperacillin and tazobactam was however...

BACKGROUND The beta-lactamase landscape is changing radically, with CTX-M types now the most prevalent extended-spectrum beta-lactamases (ESBLs) worldwide, except maybe in the USA. In addition, there are growing numbers of Enterobacteriaceae with KPC and metallo-carbapenemases. We examined whether combinations of oxyimino-cephalosporins with NXL104, a novel non-beta-lactam beta-lactamase inhibi...

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...

The infections that causes by Pseudomonas aeruginosa is usually responsible for the nosocomial of United States. Occurs in each year approximality 51,000 cases P. , and persons most risk infection are those exposer into equipment hospital has not well desinfection such as ventilation mechanical catheters.Some strains mutate or production β-Lactamase enzymes resistance penicillins.The acts on di...

β-lactamase hydrolyses amide bond of β-lactam ring. antibiotics are the main arsenal in antibiotic regime. High degree mutation and genetic variation enzymes have elevated resistance towards inhibitors. There 4 classes β-lactamase, namely Class A, C, D which Serine proteases B is Metallo proteases. The most documented one TEM, where water molecules (315, 319, 440, 441) play an important role bi...