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beta-Lactamases represent the major resistance mechanism of gram-negative bacteria against beta-lactam antibiotics. The amino acid sequences of these proteins vary widely, but all are located in the periplasm of bacteria. In this study, we investigated the translocation mechanism of representative beta-lactamases in an Escherichia coli model. N-terminal(More)
Some Escherichia coli strains produce toxins designated cyclomodulins (CMs) which interfere with the eukaryotic cell cycle of host cells, suggesting a possible link between these bacteria and cancers. There are relatively few data available concerning the colonization of colon tumors by cyclomodulin- and genotoxic-producing E. coli. We did a qualitative and(More)
Five different strains of bacteria belonging to the family Enterobacteriaceae were isolated from two patients hospitalized in the intensive care unit of the Central Military Hospital of Algiers, Algeria. All five strains, one Providencia stuartii strain, two Escherichia coli strains, and two Klebsiella pneumoniae strains, were intermediate or resistant to(More)
The elimination of viral covalently closed circular DNA (CCC DNA) from the nucleus of infected hepatocytes is an obstacle to achieving sustained viral clearance during antiviral therapy of chronic hepatitis B virus (HBV) infection. The aim of our study was to determine whether treatment with adefovir, a new acyclic nucleoside phosphonate, the prodrug of(More)
Whole-cell fingerprinting by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) in combination with a dedicated bioinformatic software tool (MALDI Biotyper 2.0) was used to identify 152 staphylococcal strains corresponding to 22 staphylococcal species. Spectra of the 152 isolates, previously identified at the species(More)
We compared ChromID VRE medium with Enterococcosel containing vancomycin for the detection of vancomycin-resistant Enterococcus in 1,007 specimens. ChromID VRE in combination with Gram straining provided a higher specificity than Enterococcosel, irrespective of the incubation time and enrichment.
Extended spectrum beta-lactamases (ESBLs) confer bacterial resistance to third-generation cephalosporins, such as cefotaxime and ceftazidime, increasing hospital mortality rates. Whereas these antibiotics are almost impervious to classic beta-lactamases, such as TEM-1, ESBLs have one to four orders greater activity against them. The origins of this activity(More)
A random mutagenesis technique was used to predict the evolutionary potential of beta-lactamase CTX-M-9 toward the acquisition of improved catalytic activity against ceftazidime. Thirty CTX-M mutants were obtained during three rounds of mutagenesis. These mutants conferred 1- to 128-fold-higher MICs of ceftazidime than the parental enzyme CTX-M-9. The CTX-M(More)
Oxyimino-cephalosporin antibiotics, such as ceftazidime, escape the hydrolytic activity of most bacterial beta-lactamases. Their widespread use prompted the emergence of the extended-spectrum beta-lactamases CTX-Ms, which have become highly prevalent. The C7 beta-amino thiazol-oxyimino-amide side chain of ceftazidime has a protective effect against most(More)
Two clinical isolates of Escherichia coli, CF1179 and CF1295, were isolated from a patient hospitalized in the hematology unit of the University Hospital of Clermont-Ferrand, Clermont-Ferrand, France. They were resistant to penicillin-clavulanate combinations and to ceftazidime. The double-disk synergy test was positive only for isolate CF1179. Molecular(More)