Flashcards in Mechanisms of Microbial Resistance Deck (15)
What are three ways bacteria can acquire genetic material?
-Transformation: Transfer of free DNA of resistant DNA from dead bacteria
-Conjugation: Plasmid transfer from another live bacteria
-Transduction: viral DNA inserted
What are the 5 targets of antimicrobial therapy?
-Nucleic acid synthesis
-Cell wall synthesis
What are the 5 mechanisms of antimicrobial action?
-Inhibit folate metabolism
-Inhibit DNA synthesis
-Inhibit protein synthesis
-Disrupt cell membrane
-Inhibit cell wall formation
Which drugs inhibit folate metabolism? (2)
Trimethoprim and sulfonamides
What drugs inhibit DNA synthesis? (2)
Quinolones and metronidazole
What drugs inhibit protein synthesis in bacteria? (5)
-Macrolides (e.g. Erythromycin and Azithromycin)
What drugs disrupt the bacterial cell membrane? (3)
What drugs inhibit bacterial cell wall synthesis? (4)
-Beta lactams: penicillins, cephalosporins, carbapenems
What are the 5 mechanisms of microbial resistance?
-Bypass metabolic pathway
What is an example the altered target mechanism of resistance? (5)
-penicillin binding protein enzyme
-DNA gyrase/topoisomerase IV
What is an example of bypassing a metabolic pathway in microbial resistance?
Enterococcus scavenging exogenous folate
What is an example of antibiotic inactivation? (2)
-aminoglycoside modifying enzymes
What is an example of a mechanism of decreased antibiotic influx?
P. aeruginosa has decreased production of OprD (carbapenem channel)
What is an example of increased drug efflux in microbial resistance?
-Multidrug pump: Mex-OPR in P. aeruginosa
-Single drug pumps: tet(tetracyclines), mef(macrolides), NorA(quinolones)