Antibiotic synergy with enterococcal endocarditis experienced a high relapse rate when penicillin G alone was used for treatment and a demonstrably lower relapse rate when streptomycin was combined with penicillin G to combat the infection. Since that time the research community has conducted numerous studies regarding the effects and possibilities of antibiotic combinations. Today, combination therapy is recognized as providing a broad spectrum of antibiotic coverage, effectively fighting polymicrobial infections, minimizing selection for antibiotic resistant strains, lowering dose toxicity where applicable, and in some cases providing synergistic activity. Antibiotic synergy is desirable in a clinic sense for several reasons. At the patient
Antibiotic prophylaxis to the serious problem of superbugs (which are bred in antibiotic-rich environments) the Food and Drug Administration issued a guidance document in December 2013. The chief public health officer of Canada said four months later that "antibiotics should only be used in animals to treat infection rather than guard against disease or promote growth." The Canadian guidance document calls for "the prudent use of antibiotics in animal agriculture and a gradual phasing out of growth promoting drugs in feed and water over the three years" ending in 2017. Producers will no longer be allowed to continuously feed animals doses of