BI302 Lecture 7: Antibiotic Resistance Mechanisms

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What is the main focus of Lecture 7 on Antibiotic resistance in Microbiology Bacteriology?

Exploring the development of bacterial resistance to antibiotics (correct)

Minimizing the impact of antibiotic resistance

Understanding the mechanisms of antibiotic resistance

Investigating bacterial adaptation to environmental changes

Based on the information provided, what is a key takeaway message regarding E.coli in the MEGA plate experiment?

Mutant strains of E.coli developed innate resistance to antibiotics

E.coli had an inherent resistance to the antibiotic used in the experiment

Initial mutations in E.coli led to enhanced growth rates

Bacteria adapted to antibiotics exhibit normal growth rates (correct)

Which of the following best describes the concept of antibiotic resistance as mentioned in the text?

Antibiotic resistance leads to faster growth rates in bacteria

Microbes adapt to antibiotics by becoming more vulnerable

Antibiotic resistance renders previously susceptible microbes unaffected by antibiotics (correct)

A microbe's susceptibility to antibiotics remains constant over time

Which of the following is NOT mentioned as a mechanism by which bacteria develop resistance to antibiotics?

Enhancing the efficacy of the antibiotic on bacteria Signup and view all the answers

What did the MEGA plate experiment reveal about bacterial adaptation to antibiotics?

Fully resistant bacteria showed reduced growth rates Signup and view all the answers

According to CDC's 2019 report, how is antibiotic resistance defined?

A microbe's susceptibility to antibiotics diminishes over time Signup and view all the answers

What does Resistance Transfer Factor (RTF) contain?

Genes required for plasmid transfer Signup and view all the answers

How are Resistance (R) genes primarily transferred to other bacteria?

Conjugation Signup and view all the answers

What distinguishes Conjugation from Transformation and Transduction?

It requires direct cell-to-cell contact Signup and view all the answers

What happens to costly plasmids in the absence of selection pressure?

They are purged from the population Signup and view all the answers

Which method involves bacteria taking up naked DNA fragments from their surroundings?

Transformation Signup and view all the answers

'Fitness cost for plasmid retention' refers to:

Energy consumption associated with retaining and replicating plasmids Signup and view all the answers

What is the process of transferring genetic information from a bacteriophage to a bacterium called?

Generalised transduction Signup and view all the answers

Which bacterial species are mentioned in the text as naturally capable of uptaking whole plasmids?

Bacillus Signup and view all the answers

What happens to DNA that is not integrated into the chromosome or a plasmid after being taken up by a bacterial cell?

It is degraded by bacterial restriction enzymes Signup and view all the answers

Which type of transduction allows for an equal chance for any piece of the original bacteria's DNA to be packaged by the phage?

Generalised transduction Signup and view all the answers

In the process of transduction, what might happen if the infected bacterial cell contains antibiotic resistance genes?

The antibiotic resistance genes are packaged in a new phage and introduced to another bacterial cell Signup and view all the answers

What is the main function of enzymes produced by bacteria in relation to antibiotics?

Generating resistance by degrading or modifying the antibiotic Signup and view all the answers

Which enzyme degrades penicillins and cephalosporins by hydrolysing the β-lactam ring?

β-lactamases Signup and view all the answers

How do aminoglycoside-modifying enzymes affect antibiotics?

Attaching chemical groups to the antibiotic's structure Signup and view all the answers

What contributes to B.subtilis being very resistant to ampicillin?

Possession of a gene encoding β-lactamase Signup and view all the answers

How is the gene for β-lactamase transmitted among bacteria?

Vertically from parent cell to progeny or horizontally between cells Signup and view all the answers

When may the effect of β-lactamase on bacteria be lost?

If there is no selective pressure on the bacteria Signup and view all the answers

What is the main difference between antibiotic tolerance and antibiotic persistence as described in the text?

Antibiotic tolerance refers to a population of bacteria without a resistance mechanism, while antibiotic persistence refers to persisters found within a susceptible population. Signup and view all the answers

In the context of minimizing the development of antibiotic resistance, why is it recommended to complete full courses of antibiotics?

To reduce the likelihood of resistance acquisition by inhibiting or killing the entire pathogenic bacteria population. Signup and view all the answers

How does administering two or more drugs simultaneously help in reducing the likelihood of resistance acquisition?

It creates a synergistic effect by targeting multiple bacterial components at once. Signup and view all the answers

How does limiting antibiotic use to essential cases help minimize antibiotic resistance development?

It prevents the transfer of antibiotic resistance between non-pathogenic and pathogenic bacteria. Signup and view all the answers

What does MDK99.9 stand for in the context of bacterial survival mechanisms?

Minimum duration for killing 99.9% of the population Signup and view all the answers

What is the purpose of targeting multiple bacterial components simultaneously with different drugs to reduce resistance?

To reduce the likelihood of bacteria developing resistance through multiple mechanisms simultaneously. Signup and view all the answers