Antibiotic resistance Flashcards
What are the three ways bacteria are antibiotic resistant ?
Intrinsic: inherited structure
Acquired: plasmid, phage mediated
Tolerance: biofilm, persister cells
Why is horizontal transfer more common in biofilms ?
dense cultures
What are the 3 horizontal gene transfer methods?
transformation, transduction and conjugation
What is transformation?
dead free DNA with virulent genes are added to living nonvirulent
What is transduction?
phage picks up resistant genes in capsid, phage NDA enter recipient cell
what is gram -ve conjugation?
physically touch by fimbriae ( short and attach to surface) and pili ( longer and used for DNA exchange)
What is gram +ve conjugation?
tetracycline bearing plasmid in enterococcus faecalis in biofilm
What are the genotypic resistance mechanisms ?
tetracycline resistance
What are the 3 structural families of MDR anti transporters?
H+
Na+
ATP- binding cassette
which of the structural families of MDR anti transporters offers small multidrug resistance ?
H+
which of the structural families of MDR anti transporters offers multi drug and toxin compound exclusion ?
Na+
How do rhamnolipids help biofilm structure ?
maintain water channels
What is the DLVO theory?
net energy given by sum of double layer repulsion van Der Waals attraction forces
Describe PA biofilm antibitoic resistance
- ndv8 produce gluons which bind to amino glycosides
- sequestration in periplasm ( stop antibiotics reaching active site)
-8 ethanol oxidation genes (tobramycin resistance)
- PpoS to deal with stress
What are the toxin-antitoxin systems involved in persister formation?
RelE + MazF = dormancy by cleaving DNA
HipA inhibits translation by phosphorylating elongation factor Ef-tu
TisB forms pores which decreases ATP
