Toward New Therapeutics for Skin and Soft Tissue Infections: Propargyl-Linked Antifolates Are Potent Inhibitors of MRSA and Streptococcus pyogenes

Hospital- and community-acquired, complicated skin and soft tissue infections, often attributed to Staphylococcus aureus and Streptococcus pyogenes, present a significant health burden that is associated with increased health care costs and mortality. As these two species are difficult to discern on diagnosis and are associated with differential profiles of drug resistance, the development of an efficacious antibacterial agent that targets both organisms is a high priority. Herein we describe a structure-based drug development effort that has produced highly potent inhibitors of dihydrofolate reductase from both species. Optimized propargyl-linked antifolates containing a key pyridyl substituent display antibacterial activity against both methicillin-resistant S. aureus and S. pyogenes at MIC values below 0.1 µg/mL and minimal cytotoxicity against mammalian cells. Further evaluation against a panel of clinical isolates shows good efficacy against a range of important phenotypes such as hospital- and community-acquired strains as well as strains resistant to vancomycin

Intra-abdominal infections

Contribtution to: Koda-Kimble MA, Young LY, Alldredge BK, Corelli RL, Guglielmo BJ, Kradjan WA, Williams BR, eds. Applied therapeutics: the clinical use of drugs. 9th ed. Baltimore: Lippincott, Williams, and Wilkins; 2008:63.1-63.13

Antibiotics in the clinical pipeline in 2011

Potential research participants may assume that randomized trials comparing new interventions with older interventions always hypothesize greater efficacy for the new intervention, as in superiority trials. However, antibiotic trials frequently use "noninferiority" hypotheses allowing a degree of inferior efficacy deemed "clinically acceptable" compared with an older effective drug, in exchange for nonefficacy benefits (eg, decreased adverse effects). Considering these different benefit-harm trade-offs, proper informed consent necessitates supplying different information on the purposes of superiority and noninferiority trials