BUFFERED PEPTONE WATER (as per ISO) (VEG.)

Microorganisms that are subjected to environmental stresses may become structurally or metabolically damaged or injured. These microorganisms are unable to replicate in selective environments. Therefore, these injured organisms must be resuscitated or permitted to repair the damage by incubation in an appropriate, non-selective environment. Edel and Kampelmacher noted that sublethal injury to Salmonellae may occur in many food preservation processes. Enriching injured cells in Lactose Broth (pH 6.9) may be further detrimental to their recovery. Buffered Veg Peptone water is prepared by replacing casein enzymic hydrolysate with Veg hydrolysate to avoid BSE/ TSE risks associated with animal based peptones. Pre enrichment in Buffered Veg Peptone Water at 35?C for 18-24 hours results in repair of injured cells.

Inoculate 10 grams of specimen in 50 ml of Buffered Veg Peptone Water and incubate at 35?C for 18 hours. Transfer 10 ml from this medium to 100 ml of Rappaport Vassiliadis Soya Broth (RVS Broth) and incubate at 43?C for 24-48 hours and then subculture on selective media like XLD Veg Agar. Examine the plates for colonies of Salmonella species.

for pre enrichment of injured Salmonella species prior to selective enrichment and isolation