Antibiotic versus bacteria

In 1928, scientist Sir Alexander Fleming discovered an antibiotic, Penicillium, that is used to destroy bacteria colonies. The structure of Penicillium is C₆H₅CH₂ and contains the β-lactam ring that activates the antibiotic attack against the bacteria. However, some bacteria cannot be destroyed by the antibiotic because they have an enzyme, penicillinase, that can resist the β-lactam ring. Another antibiotic called Tigecycline can overcome the bacteria's enzyme to allow the attack against the bacteria. Hence this antibiotic can resist infections on the skin and internal organs. Hence, new antibiotics are created every year to help eliminating infections.

Reference

Vollhardt, Peter. Schore, Neil. Organic Chemistry 6th Edition. W.H. Freeman and Company. New York. 2011