DETECTION METHODS OF GENETIC DETERMINANTS OF ANTIMICROBIAL RESISTANCE Flashcards
What method is most commonly performed to detect genes with known antibiotic resistant properties?
PCR testing and other molecular methods
what gene in MRSA indicates drug resistance?
mecA gene
what method(s) are used to detect the mecA gene found in MRSA
-PCR- gene specific primers
-Enzymatic detection PCR- enzyme-labeled probes by immunosorbent assays
what gene indicates resistance to vancomycin?
vanA
what methods are used to detect presence of the vanA gene?
-PCR
-Pulse-field gel electrophoresis
-Multilocus enzyme electrophoresis
what occurs during pulse-field gel electrophoresis?
-separates organism DNA
-pattern produced in gel determines presence or absence of gene
what occurs during multilocus enzyme electrophoresis?
specific proteins separated in gel
-probe detects presence or absence of proteins
what is the beta-lactamase gene from K. pneumo?
blaKPC
what method is used to detect blaKPC gene?
real-time PCR with fluorescent labeled probe
*fluorescent probe allows for detection
what naturally occurring mechanisms induce antibiotic resistance?
-reduced outer membrane by porins
-efflux pumps actively pumping antibiotics out of the cell
-enzymes inactivating the drug
what are porins?
pores in the cell membrane
-allows molecules in/out of cell
what are efflux pumps?
in GN bacteria
found inside the cell and actively pump antibiotics out that have entered
What genes in E. coli exhibit patterns of intrinsic resistance?
AcrAB-TolC
what does the AcrAB-TolC gene cause?
-active efflux and inactivation of beta-lactams by beta-lactamase
-active efflux and limited uptake of tetracyclines and chloramphenicol
-active efflux, modified target, and limited uptake of fluoroquinolones
what genes in P. aeruginosa exhibit patterns of intrinsic resistance?
-mexAB
-mexXY
