Violet Red Bile 2 Agar for Stressed Coliforms

Abstract

Counts on a new, autoclave-sterilizable violet red bile (VRB-2) agar were compared with counts on freshly boiled VRB agar. Yields on VRB-2 agar averaged 217, 180, 130, and 112% of counts obtained on the control medium for samples of water, cottage cheese, frozen vegetables, and raw milk, respectively. The general principle used for the development of VRB-2 agar could be applied to many other kinds of selective plating media.

Application of atmospheric cold plasma, ultraviolet radiation, or natural antimicrobials for control of foodborne pathogenic and spoilage microorganisms

“…Enterobacteriaceae were enumerated by pour plating samples in TSAYE, holding the agar plates for ambient temperature for one hour, overlaying the plates with violet red bile (VRB) agar (Hartman et al, 1975) and incubation at 35 °C for 24 h. Yeast and molds were enumerated by surface plating samples on Dichloran Rose Bengal Chloramphenicol Agar (DRBC) and incubation at 25 ºC for 5 days.…”