Antibiotic Resistance Flashcards
Antibacterials
= Antibiotics (products of natural organisms)
E.g. penicillin
+ synthetic drugs e.g. sulphonamides
- Commonly all termed antibiotics
- Also all termed antimicrobials, but this correctly includes antivirals and some parasiticides
How do antibiotics work
- either bacteriostatic (slow bac growth) or bacteriocidal (kill)
- static interfere with bac processes needed to multiply (DNA replication, metabolism, protein production)
- cidal kill bac e.g by preventing making cell wall
- penicillins are bacteriocidal
- broad spectrum = affect many bac including good (used incase specific bac species not known)
- narrow spec = only affect one or two types bac = better use as less disruption to biome
- most antibiotics no effect on immuesys
- not viruses = diff structure
~ incorporate into host cells to replicate
~ bacteriostatic antibiotics dont attack host cells so no affect on virus
~ no cell wall = cidal cant kill virus
Antibiotic resistance
= naturally evolve to resist action of antibiotics
- caused by genetic mutation in bac dna which changes
~ metabolism
~ cell wall structure
~ dna replication
~ protein production
- antibiotic no longer affect target structure or process
- resistant strains have selective advantage = survive and multiply
- gut ideal for antibiotic resistance = oral antibiotics via this route
- overuse/misuse = increase resistance levels
How does antibiotic resistance spread between bac
vertical or horizontal gene transfer
vertical gene transfer
- occur during reproduction
- genetic material passed to offspring
horizontal gene transfer
- occur between diff species
- mobile genetic elements transfered through:
~ transformation = uptake DNA into bacterium from surroundings
~ transduction = transfer of DNA by bacterophage virus from one bac to another
~ conjugation = direct transfer of DNA in form of plasmids between 2 bac
how does antibac resistance spread to others
(anti bac remain in body for up to a year)
- direct contact (touch)
how to take antibiotics correctly
- Only when bacterial infection diagnosed
- Only when infection is moderate or serious
- Take the correct amount for the correct time
- Complete the course prescribed
scale of antibiotic resistance problem - WHO by 2050
- 10 million deaths/yr globally
- Between 2 and 3.5% drop in GDP globally
- Lose between $600 and $1000 trillion economic output
- Some surgical procedures will pose too great a risk to be carried out electively
WHO global action plan (may 2015)
- Increase awareness and understanding of AMR
~ e.g. antibiotic awareness week (world but also in uk)
~ advertising - Conduct more surveillance and research to understand scale of problem
- Decrease incidence of infection
- Optimize use of antimicrobials
- Ensure sustainable investment
Antibiotic use in food producing animals - usage
- sale of antibiotics for food producing animals decreasing
- between 2014-2018
~ 53% reduction in sales of antibiotics
~ 66% reduction of highest priority critically important antibiotics
Antibiotic use in equines and royal society
- antibiotic use tool kit
- want vets to join AMR debate to improve usage for one health approach
One health
“the collaborative effort of multiple disciplines – working locally, nationally and globally – to attain optimal health for people, animals and the environment”
Staphylococci bacteria
- naturally part of skim flora (mammals/birds)
- oppertunistic pathogens
- colonise skin, mucous mem of , upper GIT, urogenital tract
- spread easily between animals and humans
- at least 48 species
- 3 important for vet medicine
~ staph. aureus
~ staph. hyicus
~ staph. intermedius
Staphylococcus aureus
- cause of Contagious bovine mastitis
- Humans – skin infections, osteomyelitis, septicaemia – can be fatal
- One of the first bacteria in which development of resistance was noticed
- MRSA – Methicillin-Resistant Staph. aureus
- Often >90% S. aureus isolates penicillin-resistant
- (MSSA – Methicillin-sensitive Staph. aureus) - just as pathogeneic but easier to treat
