PC agar is a selective media for isolation of B.cepacia.What is the purpose of the polymixin B and ticarcillin in the media?
A)They provide nutrients to enrich the growth of B.cepacia.
B)They cause color change in the media from yellow to pink.
C)They inhibit growth of gram-positive and other gram-negative organisms.
D)They stabilize the media to support growth if prolonged incubation is needed.

Question

Quizplus · Accepted Answer

PC agar is a selective and differential media designed to enrich the growth of B.cepacia from respiratory specimens from CF patients.PC agar contains crystal violet,bile salts,polymyxin B,and ticarcillin to inhibit gram-positive and rapid-growing,gram-negative organisms.Inorganic and organic components,including pyruvate and phenol red,also are added.B.cepacia breaks down the pyruvate,creating an alkaline pH and resulting in a color change of the pH indicator (phenol red)from yellow to pink.

PC Agar Is a Selective Media for Isolation of B