2.1 Classification
There are numerous different antibiotics, some of which are naturally occurring while others are semi- or fully synthetic. Don’t worry if you don’t understand these terms, as they will be explained later. One of the most useful ways of classifying antibiotics is by chemical structure because structurally similar antibiotics tend to have similar antibacterial activity.
Examples of common antibiotic classes are shown in Table 1.
| Antibiotic class | Example | Cellular process targeted* | Effect on bacteria** |
|---|---|---|---|
| ß-Lactams (penicillins) | ampicillin | bacterial cell wall synthesis | bactericidal |
| ß-Lactams (cephalosporins) | cephazolin | bacterial cell wall synthesis | bactericidal |
| ß-Lactams (carbapenems) | imipenem | bacterial cell wall synthesis | bactericidal |
| Glycopeptides | vancomycin | bacterial cell wall synthesis | bactericidal |
| Aminoglycosides | streptomycin | protein synthesis | bactericidal |
| Macrolides | azithromycin | protein synthesis | bacteriostatic |
| Tetracyclines | tetracycline | protein synthesis | bacteriostatic |
| Oxazolidinones | linezolid | protein synthesis | bacteriostatic |
| Fluoroquinolones | ciprofloxacin | DNA synthesis | bactericidal |
| Rifamycins | rifampicin | RNA synthesis | bactericidal |
| Not applicable | trimethoprim | metabolic reactions | bactericidal |
(Source: OpenStax College Microbiology, n.d.)