Antibiotic resistance Flashcards
Mechanisms of acquired antibiotic resistance?
Antibiotic inactivation
Alteration of antibiotic target
Decreased antibiotic uptake
Antibiotic efflux pump
Mechanisms of transference of resistance between bacteria?
Conjugation - plasmid transference between bacteria
Transformation - DNA in milleu –> picked up by bacteria
Transduction - Bacteriophage transfers DNA from 1 bacteria to another
What is NORSA?
Why is it important?
Non-multiply resistant, oxicillin resistant staph aureus
MSM, prisoners, athletes, indigenous, children
Important cause of skin infections and necrotising pnuemonia
Frequently susceptible to clinda, co-trimaxazoe, macrolides, gentamycin
What is VISA and why is it important?
Staph aureus with reduced vancomycin suspectibility
Thickened cell wall –> vancomycin fails
Dialysis patients or infected foreign bodies
Treat with linezolid
What is VRSA?
Vancomycin resistant staph aureus
Associated with VAN genes from VRE
Not in Australia
What is VRE and why is it important?
E. Faecalis and E. faecium
Van A and van B genes –> Vancomycin resistance
Treat with Linezolid, daptomycin or tigecycline
Penicillin non-suspectible Strep. Pneumoniae
Altered PBPs –> resistance
Important if meningitis
Increased rates with increased antibiotic use
Children in daycare, recent azithromycin use
ESCAPPM gram negative bacteria resistance
Inducible beta lactamase resistance when treated with cephalosporins
–> treat with aminoglycoside or carbapenum
ESBL - why important?
Mediated by mutations or plasmid transfer
Klebsiella, E. Coli, Salmonella, Proteus, Enterobacter, Citrobacter, Serratia, Pseudomonas
UTIs +++
Treat with carbapenems, colistin, amikacin
Metallo-beta-lactamases?
Pseudomonas and acinetobacter
Plasmid mediated
Usually in travellers - India or hospital acquired
Sensitive to EDTA
