Examples of Evolution: Antibiotic Resistance

My AP Biology Thoughts Unit 7 Natural Selection EPISODE TITLE: Antibiotic Resistance

Welcome to My AP Biology Thoughts podcast, I am Emily Greenberg and I am Angelina Graf and we will be your hosts for “Unit 7 Heredity: Examples of Evolution-antibiotic resistance”. In episode 113, we will be discussing antibiotic resistance and how it relates to the AP Biology Curriculum.

Segment 1: Overview of antibiotic resistance

• Antibiotics are drugs that fight infections that are caused by bacteria
• Antibiotic resistance is when bacteria and germs build up resistance to the medications that are meant to kill them
• Antibiotic resistant germs are often very difficult to treat and dangerous infections can emerge
• A common misconception is that antibiotic resistance means that the body is resisting antibiotics, however it is actually the bacteria that is becoming resistant to antibiotics
• Overuse of antibiotics is one of the main causes of antibiotic resistance

Segment 2: Evidence that supports antibiotic resistance

• Antibiotics also kill good bacteria that help to protect the body from infection
• Antibiotic resistant germs can spread throughout healthcare facilities, the environment, and other communities.
• The action of an antibiotic is an environmental pressure
• Species have to adapt and evolve in order to survive these pressures
• We know that evolution is happening because bacterial infections can continue to spread even with the presence of antibiotics
• Penicillin resistance:
• In WWI, penicillin treatment was used to treat the wounded and by some smaller civilian populations
• Biochemists began reporting resistance to it before the war was over and found a penicillin-inactivating enzyme secreted from a particular bacteria.
• Over the next few decades, overuse and repeated exposure to antibiotics helped the selection and replication of antibiotic resistant strains of bacteria

Segment 3: Connection to the Course

• Antibiotic resistance evolves as a result of natural selection and genetic mutation
• Bacteria that develop mutations that are resistant to antibiotics are more likely to survive and reproduce; this means that they are more fit
• If resistant bacteria reproduce with other resistant bacteria, their offspring will be fully resistant and this trait will become more frequent in the gene pool