Antibiotic resistance Flashcards
What are some challenges caused by antibiotic resistance ?
Increases mortality
Challenges control of infectious diseases
Threatens return of pre-antibiotic era
Increases healthcare cost
Treating resistance antibiotics are more expensive /may be more toxic and selective toxicity is harder.
What are the mechanisms of antibiotic resistance ?
SLIDE
What is drug inactivation ?
Some bacteria contains enzyme beta -lactamase
This means we can’t use beta lactam ring on penicillin which means these antibiotics cannot be used as the enzyme will degrade the structure.
No longer be a competitive inhibitor of the enzymes which create peptidoglycan
What are some targets which can be altered leading to antibiotic resistance?
Ribosome Porin PBPs Peptidoglycan synthesis DNA gyrase RNA polymerase Mcr1 and colistin
what are the three mechanisms of resistance ?
Natural resistance
Genetic mechanisms -acquired
Non-genetic mechanisms (growth phases)
What is natural resistance ?
Drugs need to reach their target and sometimes there are natural barriers such as porins , export pumps
Gram postive peptidoglycan -highly porous and have no barrier to diffusion
Gram -ves outer membrane -barrier resistance advantage
Outline how genetic mechanisms can lead to antibiotic resistance ?
Chromosome mediated Due to spontaneous mutation : target molecule Drug uptake system Mutants are selected not induced
Plasmid-mediated -gene exchange
Common in gram-negative
Transferred through conjugation
This can lead to multidrug resistance
Give a summary of bacteria gene transfer
This is the mechanism for gene heterogeneity and eviolution
Rapid cross-species
Virulence (toxins )
DNA
Transformation
Transduction
Conjugation
What is Augmentin made up off ?
This is also called co-amoxiclav and it is made up of
Clauvanic acid and amaxicillin
This drug binds to and inactivates beta-lactamases
No anti-bacterial activity of its own
