Lecture Notes: Antibiotic Resistance and Natural Selection

Introduction

Strep throat is a bacterial infection that often requires antibiotics.
Antibiotics kill prokaryote cells (bacteria) but not eukaryote cells (human cells).
A major concern today is antibiotic resistance in bacteria.

Natural selection is a process that illustrates evolution over time.
Example: Frogs with different color variations.
- Darker frogs are less visible to predators and have higher fitness (more offspring).
- Lighter frogs are more visible and have lower fitness.
- Over time, the darker trait may become more common due to natural selection.
Traits and genes:
- Not willed by the organism, but random.
- Can be neutral, negative, or positive in terms of fitness.
- Positive traits become more common over generations.

Variations exist in bacteria as well (e.g., cell wall thickness, enzyme production).
Environmental changes caused by antibiotics lead to selection pressure.
- Bacteria with resistance traits survive and reproduce.
- Non-resistant bacteria die and do not reproduce.
Bacteria can transfer resistant genes to other bacteria.

Healthcare settings face challenges with resistant bacteria.
Good hygiene practices are essential to prevent the spread of resistant infections.

Scientists are developing new antibiotics to stay ahead of bacterial resistance.
Proper use of antibiotics is crucial:
- Use only for bacterial infections, not viruses.
Vaccines like DTaP can prevent serious bacterial infections.

Antibiotic resistance exemplifies natural selection and evolution in bacteria.
Important to use antibiotics responsibly and maintain hygiene in healthcare to combat resistance.
Stay curious and informed about developments in this field.