Biology – Antibiotics | e-Consult
Antibiotics (1 questions)
Tetracyclines: Mechanism of Action and Antibiotic Resistance
Tetracyclines are a class of antibiotics that inhibit bacterial protein synthesis. They work by binding to the 30S ribosomal subunit of bacteria. This binding prevents the attachment of aminoacyl-tRNA to the ribosomal acceptor (A) site, thereby blocking the addition of new amino acids to the growing polypeptide chain. Essentially, they interfere with the formation of the peptidyl-tRNA bond, halting protein synthesis.
Development of Antibiotic Resistance: Antibiotic resistance arises through a process of natural selection. Bacteria can develop resistance mechanisms through several ways:
- Mutation: Random mutations in the bacterial DNA can alter the target site of the antibiotic (e.g., the ribosomal subunit) or encode enzymes that inactivate the antibiotic.
- Horizontal Gene Transfer: Bacteria can acquire resistance genes from other bacteria through mechanisms like conjugation (transfer of plasmids), transduction (transfer via bacteriophages), and transformation (uptake of free DNA). These resistance genes often encode enzymes that degrade the antibiotic or modify the antibiotic's target site.
- Enzymatic Inactivation: Some bacteria produce enzymes that break down the antibiotic molecule, rendering it ineffective. For example, beta-lactamases break down penicillin and other beta-lactam antibiotics.
Public Health Concern: The development of antibiotic resistance is a major public health concern because it makes bacterial infections increasingly difficult to treat. Antibiotics that were once highly effective are becoming less effective, leading to longer illnesses, higher medical costs, and increased mortality rates. Overuse and misuse of antibiotics in human medicine and agriculture have accelerated the development and spread of antibiotic-resistant bacteria. This necessitates the development of new antibiotics and the implementation of strategies to control antibiotic use, such as improved infection control measures and public awareness campaigns.