Antibiotic antibiotic therapy. The antibiotic treatment may select for bacterial strains with physiologically or genetically enhanced capacity to survive high doses of antibiotics. Under certain conditions, it may result in preferential growth of resistant bacteria, while growth of susceptible bacteria is inhibited by the drug. For example, antibacterial selection for strains having previously acquired antibacterial-resistance genes was demonstrated in 1943 by the Luria–Delbrück experiment. Antibiotics such as penicillin and erythromycin, which used to have a high efficacy against many bacterial species and strains, have become less effective, due to the increased resistance of many bacterial strains. Resistance may take the form
Subtherapeutic antibiotic use in swine animals. Some scientists argue that withdrawing antibiotic use will result in more diseased animals, which can result in an increased bacterial load on meat and an increased risk of food-borne illness. Opponents of such a ban argue that the economic implications would be devastating in terms of higher food prices. One study found that the price of pork would increase five cents a pound. Subtherapeutic antibiotic use in swine Antibiotics are commonly used in commercial swine production in the United States and around the world. They are used for disease treatment, disease prevention and control, and growth promotion. When used