SALT POLYMYXIN BROTH BASE (as per ISO 8914 : 1990)

Description

Vibrios are fairly easy to isolate from both clinical and environmental material, though some species may require growth factors and /or vitamins. Salt Polymyxin Broth is formulated as per the recommendation of APHA. ISO Committee has recommended a modification of this medium for detection and enumeration of salt tolerant Vibrio parahaemolyticus. Weigh 50 grams of sample into a blender. Add 450 ml phosphate buffer saline dilution water and blend for 1 minute at 8000 rpm. This constitutes 1:10 dilution. Prepare 1:100, 1:1000, 1:10000 dilutions or higher, if necessary, in PCB. Inoculate 3 x 10 ml portion of the 1 : 10 dilutions into 3 tubes containing 10 ml of enrichment broth i. e. Salt Polymyxin Broth Base-2x concentration. This represents the 1 gram portion. Similarly inoculate 3 x 1 ml of dilutions into 10 ml of single strength Salt Polymyxin Broth Base. Incubate tubes at 35 ? 2?C for 24 hours. After incubation a loopful is subcultured on solid medium such as TCBS Agar for further studies. V. parahaemolyticus appears as round, green or bluish colonies, 2-3 mm in diameter while V. cholerae forms yellow coloured colonies.