Summary
Bacteria with resistance genes survive antibiotic use and multiply, making resistance more common.
In depth
Within a population some bacteria have mutations or plasmids conferring resistance. An antibiotic kills susceptible cells, so survivors reproduce and pass on the resistance. Overuse, incomplete courses and agricultural use accelerate selection. Resistance can spread between species by horizontal gene transfer.
MRSA and multidrug-resistant tuberculosis are serious examples.
Resistance spreads fast because of short generation times and huge populations, and by horizontal transfer of plasmids carrying resistance genes. Mechanisms include enzymes that destroy the drug (beta-lactamases), altered targets (MRSA's modified penicillin-binding protein), efflux pumps and reduced uptake. Overuse in medicine and farming accelerates selection.
The WHO considers resistance one of the top global health threats; drug-resistant infections were linked to about 1.27 million deaths in 2019. Responses include stewardship (right drug, dose and duration), infection control, new antibiotics, phage therapy and combination treatments.
Key idea: resistance is evolution happening in front of us; the antibiotic does not create the mutation, it selects it.
Frequently asked questions
What is Antibiotic Resistance Evolution?
Bacteria with resistance genes survive antibiotic use and multiply, making resistance more common.
Which area of biology covers Antibiotic Resistance Evolution, and how advanced is it?
Antibiotic Resistance Evolution is one of the 53 topics in Evolution. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Directional Selection, Evolution, Horizontal Gene Transfer.
Why does Antibiotic Resistance Evolution matter?
The WHO regards antimicrobial resistance as a major global threat, so stewardship is vital.
What should I learn before Antibiotic Resistance Evolution?
Antibiotic Resistance Evolution is a Beginner topic, so no earlier topic is required. Other Beginner topics in Evolution that pair well with it include Evolution, Natural Selection, Charles Darwin.
What topics are related to Antibiotic Resistance Evolution?
The closest topics to Antibiotic Resistance Evolution are Directional Selection, Evolution, Horizontal Gene Transfer, Ancient DNA. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Antibiotic Resistance Evolution?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Antibiotic Resistance Evolution. To practise the whole of Evolution, use the Evolution quiz.
How is Antibiotic Resistance Evolution different from Directional Selection?
Antibiotic Resistance Evolution: Bacteria with resistance genes survive antibiotic use and multiply, making resistance more common. Directional Selection: Selection favouring one extreme phenotype, shifting the population mean in one direction. Read both side by side and note what each one explains.
How should I study Antibiotic Resistance Evolution step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Directional Selection and explain the difference aloud. Finally, take the Evolution quiz and come back to this page for any question you miss.