Antibiotic use promotes development of antibiotic-resistant bacteria. Antibiotic resistance occurs when bacteria change in some way that reduces or eliminates the effectiveness of drugs, chemicals, or other agents designed to cure or prevent infections. The bacteria survive and continue to multiply causing more harm. Widespread use of antibiotics promotes the spread of antibiotic resistance. While antibiotics should be used to treat bacterial infections, they are not effective against viral infections like the common cold, most sore throats, and the flu.
(Source: CDC website, www.cdc.gov)