4 Types of antibiotic

So far in this course you have learned that antibiotics may be active against a wide range of bacteria (broad-spectrum) or just a few types (narrow-spectrum). You also know that antibiotics either kill bacterial cells (bactericidal) or stop them growing and dividing (bacteriostatic).

Factors that determine the spectrum of antibiotic activity include:

• ability to penetrate the bacterial cell – since most bacterial targets are located in the cell’s interior
• how widespread the target is among different bacterial species
• bacterial resistance to the antibiotic (discussed in Weeks 3 and 4).