Antibiotics used by humans or non-humans have the potential to develop resistant bacteria. When administered to treat bacterial infections, the objective is to stop/limit/kill/eliminate the bacteria causing the infection or illness.
Many of the antibiotics used in food animal production, such as penicillins, tetracyclines, macrolides and sulfonamides are identical to, or from the same family as, drugs used in human medicine to cure serious diseases. Because these classes of antibiotics are similar, bacteria resistant to antibiotics used in animals will also be resistant to antibiotics used in humans.
If all of that particular bacteria are not eliminated, the surviving bacteria may grow and become resistant to the next treatment by that antibiotic. This can also happen if the correct dosage and time of administration length are not followed (i.e. take all of the prescribed antibiotic as directed, even if you feel better after a couple of days). Bacteria have the ability to mutate, or change, even if they are susceptible to the antibiotic. Without effective antibiotics, modern medical treatments such as surgery and transplants will become all but impossible.
According to the Transatlantic Taskforce on Antimicrobial Resistance (TATFAR), which is supported by the Centers for Disease Control and Prevention, the key area focus to reduce the threat of antibiotic resistance are:
1. Improve appropriate therapeutic use of antimicrobial drugs in medical and veterinary communities.
2. Prevent healthcare and community-associated drug-resistant infections.
3. Develop strategies for improving the pipeline of new antimicrobial drugs.