Emergence of a new antibiotic resistance mechanism in India, Pakistan, and the UK: a molecular, biological, and epidemiological study. Lancet Infect Dis. 2010;10:597-602. [PMID: 20705517 PMCID: PMC2933358 DOI: 10.1016/s1473-3099(10)70143-2]

Activities of NXL104 combinations with ceftazidime and aztreonam against carbapenemase-Producing Enterobacteriaceae

Combinations of NXL104 with ceftazidime and aztreonam were tested against carbapenem-resistant members of the Enterobacteriaceae. Ceftazidime-NXL104 was active against strains with the OXA-48 enzyme or with combinations of impermeability and an extended-spectrum β-lactamase (ESBL) or AmpC enzyme and also against most Klebsiella spp. with the KPC enzyme, but metallo-β-lactamase producers were resistant. Aztreonam-NXL104 was active against all carbapenemase producers at 4 and 4 μg/ml, including those with metallo-β-lactamases.

Finding a niche with personalized generics: opportunities from systems-based therapeutic delivery in hypertension

A key principle in earlier eras of drug development was to deliver medicines with clinical benefits for populations. Individual patients frequently did not benefit, or experienced adverse drug reactions, and were at risk of exposure to a prolonged series of treatment trials before effective therapies were found, if available. A personalized medicines approach offers opportunities to select drugs likely to be effective or safer, based on knowledge, for example, of differences in disease-modulating receptors, in drug metabolism, or in drug transporters into cells and across tissue boundaries. This new genetic and phenotypic knowledge allows generics to be revisited and may also help to improve medicine adherence, by reducing predictable adverse effects from unwanted accumulation of a medicine or its metabolites. This review will consider effective population delivery of therapeutics to treat hypertension in order to illustrate the potential and current place of personalizing medicines to improve effective and safe use of therapeutics.

Polymyxins and their novel derivatives

The emerging very multiresistant Gram-negative bacteria cause remarkable therapeutic challenges. There are no novel classes of agents in clinical development for the treatment of Gram-negative infections. Polymyxins (polymyxin B and colistin) were abandoned in the seventies but are now back in the therapy as the last resort. Their nephrotoxicity may complicate the therapy or even necessitate its discontinuation. Less toxic polymyxin derivatives would be highly welcome. Novel derivatives lack in strategic positions two of the five cationic charges of polymyxins, differ from polymyxins in their renal handling and affinity to kidney brush-border membrane, and are in preclinical studies. Less characterized other recent derivatives, also reviewed here, have increased the collective knowledge on the structure-function relationships in polymyxins. Acquired resistance to polymyxins has been encountered. However, the resistance mechanism compromises the function of the bacterial outer membrane as a permeability barrier to other noxious agents.

Emergence of metallo-β-lactamase NDM-1-producing multidrug-resistant Escherichia coli in Australia

A multidrug-resistant Escherichia coli isolate recovered in Australia produced a carbapenem-hydrolyzing β-lactamase. Molecular investigations revealed the first identification of the bla(NDM-1) metallo-β-lactamase gene in that country. In addition, this E. coli isolate expressed the extended-spectrum β-lactamase CTX-M-15, together with two 16S rRNA methylases, namely, ArmA and RmtB, conferring a high level of resistance to aminoglycosides.