13-Deoxytetrodecamycin, a new tetronate ring-containing antibiotic that is active against multidrug-resistant Staphylococcus aureus
The Journal of Antibiotics advance online publication, May 27 2015. doi:10.1038/ja.2015.60
Authors: Tomas Gverzdys, Michael Kamin Hart, Sheila Pimentel-Elardo, Geoffrey Tranmer & Justin R Nodwell
First total synthesis of (+)-epogymnolactam, a novel autophagy inducer
The Journal of Antibiotics advance online publication, May 27 2015. doi:10.1038/ja.2015.63
Authors: Yuji Okado, Kengo Shigetomi, Shinya Mitsuhashi & Makoto Ubukata
All clinical isolates of group B Streptococcus (GBS; Streptococcus agalactiae) are considered uniformly susceptible to β-lactams, including penicillins. However, GBS with reduced penicillin susceptibility (PRGBS) were first identified by our group in Japan and have also been reported from North America. PRGBS are non-susceptible to penicillin because of acquisition of amino acid substitutions near the conserved active-site motifs in PBP2X. In particular, V405A and Q557E are considered the key amino acid substitutions responsible for penicillin non-susceptibility. We revealed that in addition to the substitutions in PBP2X, an amino acid substitution in PBP1A confers high-level cephalosporin resistance in GBS. As the number of publications on GBS with reduced β-lactam susceptibility (GBS-RBS), especially PRGBS, and concomitantly the need for a systematic classification of GBS-RBS is increasing, we propose here a classification of GBS-RBS based on the amino acid substitutions in their PBPs.
The global burden of antibiotic resistance is tremendous and, without new anti-infective strategies, will continue to increase in the coming decades. Despite the growing need for new antibiotics, few pharmaceutical companies today retain active antibacterial drug discovery programmes. One reason is that it is scientifically challenging to discover new antibiotics that are active against the antibiotic-resistant bacteria of current clinical concern. However, the main hurdle is diminishing economic incentives. Increased global calls to minimize the overuse of antibiotics, the cost of meeting regulatory requirements and the low prices of currently marketed antibiotics are strong deterrents to antibacterial drug development programmes. New economic models that create incentives for the discovery of new antibiotics and yet reconcile these incentives with responsible antibiotic use are long overdue. DRIVE-AB is a 9.4 million public–private consortium, funded by the EU Innovative Medicines Initiative, that aims to define a standard for the responsible use of antibiotics and to develop, test and recommend new economic models to incentivize investment in producing new anti-infective agents.
Antimalarial drugs (e.g. chloroquine and its close structural analogues) were developed primarily to treat malaria; however, they are beneficial for many dermatological, immunological, rheumatological and severe infectious diseases, for which they are used mostly today. Chloroquine and hydroxychloroquine, two of the most fascinating drugs developed in the last 50 years, are increasingly recognized for their effectiveness in myriad non-malarial diseases. In advanced research, chloroquine and hydroxychloroquine have been shown to have various immunomodulatory and immunosuppressive effects, and currently have established roles in the management of rheumatic diseases, lupus erythematosus (different forms) and skin diseases, and in the treatment of different forms of cancer. Recently, chloroquine analogues have also been found to have metabolic, cardiovascular, antithrombotic and antineoplastic effects. This review is concerned with the lysosomotropic, anti-inflammatory and immunomodulatory mechanisms of chloroquine, hydroxychloroquine, quinacrine and related analogues, and the current evidence for both their beneficial effects and potential adverse manifestations in various diseases.
