Search results for "Nitrocefin"
showing 2 items of 2 documents
Further development of the β-lactamase MutaGen assay and evaluation by comparison with Ames fluctuation tests and theumu test
2005
A rapid, high-throughput bacterial mutagenicity test system has been developed (MutaGen test) that detects reversions of inactivating base-pair substitutions and frameshifts in a TEM-1 class A β-lactamase (ampicillinase) gene. To quickly and sensitively detect mutagens, the system utilises a series of plasmids that contain the mutated ampicillinase gene and the mucAB operon. Inactivating mutations in the ampicillinase gene include frameshifts integrated into repetitive GC-sequences and G-runs known to be mutagenic hot-spots, and base-pair substitutions inserted in or around the β-lactamase active site. Frameshift mutations completely inactivated the enzyme only when located downstream of th…
Amperometric detection of extended-spectrum β-lactamase activity : application to the characterization of resistant E.coli strains
2015
EA MERS CT3; International audience; The amperometric detection of extended-spectrum β-lactamase (ESBL) with carbon screen-printed sensors was investigated in the presence of the Nitrocefin, a commercially-available β-lactamase chromogenic cephalosporin substrate. Using an ESBL isolated from a clinical sample, it was shown for the first time that the intensity of a specific anodic pic current (EP = [similar]+0.3 V vs. Ag/AgCl) resulting from the catalytic hydrolysis of the β-lactam ring was proportional to the amount of ESBL. The proof-of-principle of a novel susceptibility assay for the rapid and accurate identification of ESBL- producing bacteria was then demonstrated. The detection schem…