An antibiotic is a substance produced naturally by a microorganism that selectively inhibits the growth of another microorganism. Alexander Fleming derived the first antibiotic, Penicillin, in 1928 from a fungi called Penicillium. In recent times, antibiotics have been produced in laboratories. Antibiotics play a pivotal role in treating a wide variety of diseases known to man today. For example, Erythromycin is an antibiotic that is used for several bacterial infections such as skin infections, respiratory infections, etc.