Lecture 22 - antibiotic resistance Flashcards
What is prophylatic treatment
low level antibiotics in feed to prevent infection in animals
But has led to a lot of antibiotic resistance in animals and humans
What is campylobacter jejuni
causes food poisoning
Reservoir in poultry
What is campylobacter jejuni
causes food poisoning
Reservoir in poultry
What type f antibiotic was used prophalactically to treat campylobacter
fluoroquinolones
E.g. Ciprofloxacin
And cuz of this, many bacteria are resistant to this antibiotic
what is the antibiotic resistome
reservoir of resistance (r) genes
existed in bacteria way before antibiotics arose
but becoming more prevalent cuz antibiotics give selection pressure
What is NDM-1 and where did it come from
New Delhi metallo-B-lactamase
an enzyme that gives antibiotic resistance
came from delhi duh
why is slamonella DT104 an ‘MAR’
resistant to 6 antibiotics (MAR - multiple antibiotic resistance)
examples of pathogenic bacteria that are resistant to antibiotic
- pneumococci = resis to penicillin
- mycobacteria = MAR
- MRSA = methicillin and vry rarely vancomycin
what are commensals
normal helathy bact in gut
why can commensals be a problem
pass their resistance to pathogenic bacteria
e.g. vancomyocin resistant enterococci transferring it to MRSA vry bad
4 ways bact can be resistant
- natural resis
- enzymatic inactivation
- modification of target
- efflux of antibiotic
why are mycoplasma pneumoniae resistant to penicillin
no cell wall
so no peptidoglycan
(pleimorphic)
= intrinsic resitance
3 ways r-genes can transfer
- transformation (naked DNA)
- transduction (bacteriophages)
- conjugation (plasmids)
process of conjugation
- donor cell form mating pairs with recipient cells
- pilus forms between them, plasmid travels through this
- pilus retracts
evidence that R plasmids existed before antibioitic era
E.coli freeze dried in 1946; R plasmid- tetracycline & streptomycin resistance (before antibiotics were developed)
