1.1 Using quorum sensing to treat infections
On its own, a single bacterium cannot cause an infection but, just like the bacteria in Activity 1, pathogenic bacteria use quorum sensing to coordinate their behaviour and attack together. Disrupting this coordinated response by blocking quorum sensing could help to treat infections, as you will see next.
Activity 2 Preventing infections by disrupting quorum sensing
Allow about 15 minutes
Watch part of the video in the following link in which Bonnie Bassler explains how quorum sensing antagonists (drugs that disrupt quorum sensing) can prevent infections by Vibrio cholerae.
Preventing infections by disrupting quorum sensing. Watch from 54:50 until 57:05.
Now answer the following questions, based on the video.
- What effect would a quorum-sensing antagonist have on bacteria?
Answer
The correct answer is (b) it blocks their ability to communicate with each other.
- What effect does the quorum-sensing antagonist have on the fluorescence of Vibrio fischeri bacteria?
Answer
The correct answer is (a) it stops them fluorescing.
- How many people die from Vibrio cholerae infections?
Answer
The correct answer is (c) over 100 000 people per year.
- What is the first step in a Vibrio cholerae infection?
Answer
The correct answer is (b) expression of a virulence protein that allows the bacteria to stick to the gut.
- How does blocking quorum sensing affect the expression of this protein and the Vibrio cholerae infection?
Answer
The correct answer is (b) it decreases protein expression and prevents the infection.
OpenLearn - Understanding antibiotic resistance
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