Evolution of Antibiotic Resistance in Pathogenic Bacteria
Definition
Antibiotic resistance
Antibiotic resistance occurs when bacteria evolve mechanisms to survive exposure to antibiotics that would normally kill them.
- It evolves by natural selection, through four main mechanisms:
- Genetic Variation: Within a bacterial population, some cells carry mutations that make them less susceptible to antibiotics.
- Selective Pressure: When exposed to antibiotics, most bacteria die, but resistant ones survive.
- Survival and Reproduction: Resistant bacteria reproduce, passing on their advantageous traits.
- Spread of Resistance: Over time, the resistant strain becomes dominant in the population.
Antibiotic resistance is a growing threat, making once-treatable infections potentially deadly.
Evolution of Multiresistant Bacteria
Some bacterial strains have evolved resistance to multiple antibiotics, making them extremely difficult to treat.Example
MRSA (Methicillin-Resistant Staphylococcus aureus) is resistant to multiple antibiotics and poses a serious threat in healthcare settings.
Careful Use of Antibiotics Slows the Emergence of Resistance
- To slow the evolution of antibiotic resistance, antibiotics should be:
- Used only when necessary, and only for bacterial infections (not viral).
- Prescribed at the correct dose and for the full duration of treatment.
- Never shared or used for conditions for which they are not prescribed.
- Regulated in agriculture, antibiotics should only treat infections, not promote growth in livestock.
Antibiotic resistance could return us to a "pre-antibiotic era," where even minor infections are life-threatening.
New Techniques: Searching For New Antibiotics
- The development of new techniques can lead to new avenues of research.
- Scientists are now searching through chemical libraries, vast collections of chemical compounds, to find substances with potential to fight bacterial infections.
- This technique is yielding new antibiotics that can combat resistant strains.
- In 2015, researchers discovered teixobactin, a new antibiotic effective against resistant strains like MRSA.
- This breakthrough was made possible by innovative techniques for culturing previously "unculturable" bacteria.
- The development of new antibiotics is costly and time-consuming, often taking over a decade.
- This underscores the importance of using existing antibiotics wisely.
- How does overuse of antibiotics contribute to antibiotic resistance?
- What are some strategies to prevent the spread of antibiotic resistance?
