Introduction of a hydroxyl group into the thiazole ring nitrogen of cephalosporins belonging to the cefotiam and cefotaxime families gave rise to products, better described by the tautomeric N-oxide form, which proved particularly active against Gram-negative bacteria. Cephems bearing a (Z)-alkoxyimino functionality are of special interest for broadness of spectrum; among them, 7 beta-[(Z)-2-(2...

The present mechanistic study comprehensively explores alternative scenarios for activation of the amine-linked allene C=C linkage toward nucleophilic amido attack in the intramolecular hydroamination of a prototypical 1,3-disubstituted aminoallene by a well-characterised samarocene-amido catalyst. Firstly, the non-insertive mechanism by Scott featuring C-N ring closure with concomitant amino p...

Cefroxadine (GCP-9000; CXD), 7 beta[D-2-amino-2-(1,4-cyclohexadienyl)-acetamido]-3-methoxy-ceph-3-em-carboxylic acid, is a new orally active cephalosporin derivative. The spectrum of antibacterial activity of CXD is identical with that of cephalexin (CEX), but CXD was twofold more effective than CEX against Escherichia coli and Klebsiella pneumoniae, CXD was as stable to penicillinase as CEX, b...

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...

OBJECTIVES To measure the effect of a voluntary ban on cephalosporin usage in the Danish pig production on the prevalence of extended-spectrum cephalosporinase (ESC)-producing Escherichia coli in pigs and pork. METHODS Data on cephalosporin consumption were obtained from the VetStat database. For detection of ESC-producing E. coli, three sampling types were included: at slaughter, caecal samp...