The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, today announced four new contracts for large-scale clinical trials that address the problem of antimicrobial resistance. Over the next five to six years, these new clinical trials will evaluate treatment alternatives for diseases for which antibiotics are prescribed most often, including acute otitis media (middle ear infections), community-acquired pneumonia and diseases caused by Gram-negative bacteria, which frequently are resistant to first-line antibiotics. Each trial will enroll at least 1,000 participants who have been diagnosed with these illnesses and diseases.