Broad-spectrum antibiotic their greater potential to disrupt a larger variety of normal human flora. After continued exposure to an antibiotic, bacteria may develop changes in their structure or function that make them resistant to the antibiotic. These resistant organisms will live, while the susceptible organisms will die, leaving the population of bacteria entirely resistant to a given antibiotics. For example, after the discovery of penicillin and its subsequent use to treat bacterial infections, bacteria were found to have begun producing an enzyme, penicillinase, which rendered the penicillin molecule inactive. In response to this newly-acquired resistance, newer penicillins were produced that could not
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