Mechanisms of Antibacterial Action  (cont'd) Quinolone - Direct action on the bacterial DNA gyrase. Examples - Ciprofloxacin, ofloxacin, trevafloxacin. Amino-glycosides - Inhibition of protein synthesis. Examples - Amikacin, neomycin, etc. Chlor-hexadrine - Surfacant; disrupts bacterial membrane. Used at times for control of periodontal disease.