Table 7.

Genes involved in the mechanism of MDR caused by DEC.

Gene	Protein/Enzyme Name	Pathway	Role	Reference
acrA	Multidrug efflux system protein AcrA	Efflux pump system	Component of AcrAB-TolC efflux pump, expels a wide range of antibiotics	42
acrB	Multidrug efflux system protein AcrB		Component of AcrAB-TolC efflux pump, expels a wide range of antibiotics	42
tolC	Outer membrane protein TolC		Outer membrane channel of AcrAB-TolC efflux pump	42
EmrE	Small multidrug resistance protein EmrE		Multidrug efflux pump	43
MdfA	Multidrug efflux pump MdfA		Multidrug efflux pump	43
NorE	Quinolone resistance protein NorE		Multidrug efflux pump	43
bla_TEM	Beta-lactamase TEM	Beta-lactamase production	Beta-lactamase enzyme, hydrolyzes beta-lactam antibiotics	44
bla_SHV	Beta-lactamase SHV		Beta-lactamase enzyme, hydrolyzes beta-lactam antibiotics	44
bla_CTX-M	Beta-lactamase CTX-M		Beta-lactamase enzyme, hydrolyzes beta-lactam antibiotics	44
aac(3)-II	Aminoglycoside 3’-phosphotransferase II	Aminoglycoside modification	Aminoglycoside acetyltransferase, modifies aminoglycosides	45
aac(6’)-Ib	Aminoglycoside 6’-N-acetyltransferase		Aminoglycoside acetyltransferase, modifies aminoglycosides	45
aadA	Aminoglycoside adenyltransferase A		Aminoglycoside adenyltransferase, modifies aminoglycosides	45
tetA	Tetracycline resistance protein TetA	Tetracycline resistance	Efflux pump for tetracycline	46
tetB	Tetracycline resistance protein TetB		Efflux pump for tetracycline	46
qnr	Quinolone resistance protein Qnr	Quinolone resistance	Protects DNA gyrase and topoisomerase IV from quinolones	47
gyrA	DNA gyrase subunit A		Target site mutation, reduces quinolone binding	48
parC	DNA topoisomerase IV subunit A		Target site mutation, reduces quinolone binding	49
sul1	Dihydropteroate synthase I	Sulfonamide resistance	Encodes an enzyme not inhibited by sulfonamides	50
sul2	Dihydropteroate synthase II		Encodes an enzyme not inhibited by sulfonamides	50
mphA	Macrolide 2’-phosphotransferase	Macrolide resistance	Macrolide phosphotransferase, inactivates macrolides	51
cat	Chloramphenicol acetyltransferase	Chloramphenicol resistance	Chloramphenicol acetyltransferase, inactivates chloramphenicol	52
intI1	Integrase 1	Integron-mediated gene capture	Integron integrase, captures and integrates resistance genes	53
csgD	Regulator of curli production	Biofilm formation	Regulator controlling curli and biofilm-associated genes	54
bcsA	Cellulose synthase catalytic subunit A		Catalytic subunit of cellulose synthase, contributes to biofilm matrix	55
pgaC	Poly-beta-1,6-N-acetyl-D-glucosamine synthase		Glycosyltransferase involved in PIA synthesis, part of biofilm matrix	56
fimH	Fimbrial adhesin		Type 1 fimbrial adhesin, important for initial attachment	57
luxS	Autoinducer 2 synthase		Synthesizes AI-2 for quorum sensing and biofilm regulation	58