Fungi are absorptive feeders and thus must colonize and ramify through their substrate to survive. In so doing they are in competition, particularly in the soil, with myriad microbes. These microbes use xenobiotic compounds as offensive weapons to compete for nutrition, and fungi must be sufficiently resistant to these xenobiotics. One prominent mechanism of xenobiotic resistance is through pro...

AmpC beta lactamase producing Gram-negative bacteria have emerged worldwide. It is important to distinguish plasmid mediated AmpC β lactamases from chromosomally mediated enzymes for surveillance, epidemiology and hospital infection control as plasmid mediated genes can spread to other organisms. Occurrence of blaCMY-1 AmpC β-lactamase, a plasmid mediated cephamycinase was studied in 100 consec...

OBJECTIVES To characterize the naturally occurring β-lactamase gene identified from a clinical isolate belonging to a novel enterobacterial species that is closely related to Rahnella spp. and Ewingella spp. METHODS Shotgun cloning and expression in Escherichia coli were performed in order to characterize this resistance determinant. Enzymatic activities were measured by UV spectrophotometry ...

BACKGROUND Production of β-lactamase enzymes is the most common and important mechanism of resistance in Gram-negative bacteria. The objective of this study was to assess frequency of three main β-lactamase enzymes, including extended spectrum β-lactamases (ESBLs), metallo-β-lactamase (MBL), and Klebsiella pneumoniae carbapenemase (KPC) enzymes in Escherichia coli and Klebsiella spp. isolated f...

The increasing incidence and prevalence of multi-drug resistance (MDR) among contemporary Gram-negative bacteria represents a significant threat to human health. Since their discovery, β-lactam antibiotics have been a major component of the armamentarium against these serious pathogens. Unfortunately, a wide range of β-lactamase enzymes have emerged that are capable of inactivating these powerf...

BACKGROUND Extended-spectrum AmpC (ESAC) β-lactamase enzymes, which are either chromosomally encoded or plasmid encoded, have minor structural changes that broaden their substrate hydrolysis profile. The derepressed AmpC enzyme found once in Enterobacter cloacae CHE was shown to contain a six residue deletion in the H-10 helix in close proximity to the active site. Avibactam is a non-β-lactam i...

Background: β-lactams and carbapenems are the major antibiotics used to treat gram-negative bacteria non-fermenting bacilli. However, increasing production of β-lactamase carbapenemase limits therapeutic options. Our study aims determine resistant phenotypes these while describing their epidemiological aspect. Material Methods: This was a cross-sectional by consecutive enrollment from January 2...

This review covers the uses of fluorescence polarization and anisotropy for the investigation of bacterial penicillin binding proteins (PBPs), which are the targets of β-lactam antibacterial drugs (penicillins, cephalosporins, carbapenems, and monobactams), and of the β-lactamase enzymes that destroy these drugs and help to render bacterial pathogens resistant to them. Fluorescence polarization...

TEM-154, identified in Portugal in 2004, associated the substitutions observed in the extended-spectrum β-lactamase (ESBL) TEM-12 and in the inhibitor-resistant penicillinase (IRT) TEM-33. This enzyme exhibited hydrolytic activity against ceftazidime and a low level of resistance to clavulanic acid. Surprisingly, the substitution Met69Leu enhanced the catalytic efficiency of oxyimino β-lactams ...