How does antibiotic resistance develop?
Reveal answer
Mutation → antibiotic kills others → resistant survive → reproduce.
Key words: mutation
4(b) INHERITANCE · RECALL
4.39 Antibiotic resistance in bacteria
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Name a resistant bacterium.
Reveal answer
MRSA.
Key words: MRSA
Why finish the course?
Reveal answer
Kill all bacteria → no resistant survivors.
Key words: all
Does the antibiotic cause the mutation?
Reveal answer
No — mutation is random; antibiotic only selects.
Key words: random
What is meant by the term antibiotic resistance?
Reveal answer
Ability of bacteria to survive or grow despite an antibiotic concentration that previously inhibited them.
Key words: antibiotic resistance
What is meant by the term horizontal gene transfer?
Reveal answer
Transfer of genetic material between organisms other than parent-to-offspring inheritance.
Key words: horizontal gene transfer
What is meant by the term antimicrobial stewardship?
Reveal answer
Careful use of antimicrobial medicines to preserve effectiveness.
Key words: antimicrobial stewardship
Resistance evolution sequence: for Before treatment, give the bacterial population and the antibiotic role.
Reveal answer
Bacterial population: Rare resistant variants may exist. Antibiotic role: No selection or low selection.
Key words: Before treatment
Resistance evolution sequence: for Treatment, give the bacterial population and the antibiotic role.
Reveal answer
Bacterial population: Susceptible cells die/inhibited. Antibiotic role: Selection pressure.
Key words: Treatment
Resistance evolution sequence: for Survival, give the bacterial population and the antibiotic role.
Reveal answer
Bacterial population: Resistant cells remain. Antibiotic role: Drug has reduced effect on them.
Key words: Survival
Resistance evolution sequence: for Reproduction/transfer, give the bacterial population and the antibiotic role.
Reveal answer
Bacterial population: Resistance genes spread. Antibiotic role: No new need-directed mutation required.
Key words: Reproduction/transfer
Resistance evolution sequence: for Later infection, give the bacterial population and the antibiotic role.
Reveal answer
Bacterial population: Resistant strain more common. Antibiotic role: Treatment may be less effective.
Key words: Later infection
True or false, and why? “Antibiotics make bacteria resistant on purpose.”
Reveal answer
False. They select bacteria that already have resistance variants or acquire genes.
True or false, and why? “People become resistant to antibiotics.”
Reveal answer
False. Bacteria become resistant; people may carry resistant bacteria.
True or false, and why? “Stopping antibiotics early is always harmless once symptoms improve.”
Reveal answer
False. Follow the prescriber’s instructions; inappropriate use can leave infection inadequately treated and select survivors.