Cetrimide is a quaternary ammonium salt, which acts as a cationic detergent that reduces surface tension in the point of contact
and has precipitant, complexing and denaturing effects on bacterial membrane proteins. It exhibits inhibitory actions on a wide
variety of microorganisms including Pseudomonas species other than Pseudomonas aeruginosa . King et al developed
Medium A for the enhancement of pyocyanin production by Pseudomonas (1). Cetrimide Agar developed by Lowburry (2)
is a modification of Tech Agar (Medium A) with addition of 0.1% cetrimide for selective isolation of P.aeruginosa . Later,
due to the availability of the highly purified cetrimide, its concentration in the medium was decreased (3). The incubation was
carried out at 37°C for a period of 18-24 hours (4)