ABSTRACT
Antibiotic resistance mechanisms fall into various categories for both resistance to specific antibiotics and for multidrug resistance.[1,2] In general, the mechanisms for resistance to specific antibiotics include: 1) mutations that prevent the antibiotic from affecting the target; 2) porins or other cytoplasmic membrane proteins that actively pump the antibiotic out of the cell; 3) enzymatic inactivation of the antibiotic; 4) modification or protection of the antibiotic target; 5) circumvention of the effects of the antibiotic; and 6) failure to activate the antibiotic. The mechanisms used for multidrug resistance include: 1) efflux pumps in the cytoplasmic membrane that actively pump multiple antibiotics out of the cell; 2) alterations to the cytoplasmic membrane or cell wall such that the antibiotics do not enter the cell; and 3) formation of protective biofilms that restrict exposure of the microbes to antibiotics.
