Healthcare associated infections Flashcards
5 mechanisms of antibiotic resistance
- Restrict access of the antibiotic
- Get rid of the antibiotic - efflux pumps in cell wall
- Change or destroy the antibiotic - enzymes
- Bypass the effects of the antibiotic - alternative reaction pathways
- Change the targets for the antibiotic - changing shape of target site so enzymes can no longer bind
3 ways resistance passes between bacteria
- Transduction via phages
- Conjugation
- Transformation - picking up resistant genes from dead of bacteria
5 moments of hand hygiene
- Before touching a patient
- Before aseptic procedures
- After body fluid exposure
- After touching patient
- After touching patient’s surroundings
6 parts of the chain of infection
- Reservoir
- Portal of exit
- Mode of transmission
- Portal of entry
- Host
- Infectious agent
What are the 2 direct and 3 indirect modes of transmission?
Direct:
- Direct contact
- Droplet spread
Indirect:
- Airborne
- Vehicle-borne (object)
- Vector-borne
Mechanism of sulphonamides
Sulfa drugs work by binding and inhibiting (competitive) a specific enzyme called dihydropteroate synthase(DHPS). This blocks the formation of dihydropteroate used in the formation of folates.
Mechanism of trimethoprim
Binds to dihydrofolate reductase preventing the conversion of dihydrofolate to tetrahydrofolate which is another step in the synthesis of folates.
Mechanism of quinolones
Prevent unwinding of DNA by binding to topoisomerase 4 or DNA gyrase.
Mechanism of rifamycins
Prevents RNA synthesis by binding to RNA polymerase.
What are the 4 antibiotics that inhibit protein synthesis in ribosomes?
Aminoglycosides, chloramphenicol, macrolides, tetracyclines
Mechanism of glycopeptides
Bind to d-acyl-d-alanyl-d alanine inhibiting synthesis of peptioglycan. Includes vancomycin and used in MRSA infection.
3 examples of beta lactams and their function
- Penicllins
- Carbapenems
- Cephalosporins
Bind to penicillin binding proteins inhibiting the crosslinking of peptidoglycan in bacterial cell wall.
Mechanism of lipopeptides
Disrupts gram positive cell membranes
Mechanism of polymyxins
Binds to lipopolysaccharides in gram negative bacteria disrupting cell membranes.
What is co-amoxiclav?
A combination of amoxicillin and clavulanic acid. The clavulanic acid stops the bacteria from breaking down the amoxicillin by inhibiting beta lactamase allowing amoxicillin to bind to penicillin binding proteins.
