Question

1. The use, overuse, and abuse of antibiotics are accredited with creating antibiotic-resistant strains of bacteria. Explain how this relates to natural selection.
2. Are there things that you can personally do to reduce your risk or even to reduce the spread of these dangerous microbes?

Answer 1

1.

• Antibiotic resistance may be generated in other bacteria due to :

1. Horizontal gene transfer- conjugation. Transformation, transduction between resistant and non-resistant bacteria, if they co-exist in same place.
2. Vertical gene transfer, due to repeated antibiotic use.
3. Mutations in bacterial genome, irregularity, dose incompletion.

• Thus, these conditions lead to recombination and altered genetic structures in bacteria creating an altered strain.
• The newly generated strain may be favorable to the bacterial species and thus evolution occurs by natural selection for the newly evolved strain
• Thus, antibiotic sensitive organism may evolve to antibiotic resistant strain, which is favored and hence, natural selection is observed.

2.

Antibiotic resistance in humans may be generated due to following conditions.

• Use or prescription of antibiotics when not needed.
• Regular or frequent exposure to antibiotics.
• Incomplete dose of prescribed or required antibiotics.
• Exposure through other agents like food sources, like in fruits, fishes, poultry, milk, etc.

These conditions should be avoided to prevent antibiotic resistance.