SKU: sku-2568
For selective isolation and enumeration of Salmonella typhi and other Salmonella species.     Xylose Lysine Deoxycholate Agar (Veg) is prepared by replacing sodium deoxycholate by synthetic detergent, which makes the medium free of BSE/TSE risks. Xylose Lysine Deoxycholate Agar (Veg) is modification of Xylose Lysine Deoxycholate Agar which is a selective as well as differential medium formulated by Taylor for the isolation and identification of enteric pathogens especially Shigellae from stool samples. This medium is an ideal medium for screening samples containing mixed flora of enteric pathogens as recovery of Salmonellae and Shigellae is not conspicuous by even profuse growth of other species. This medium can be used as a diagnostic aid in the identification of Enterobacteriaceae.     The medium contains yeast extract, which provides nitrogen and vitamins required for growth. Te sugars xylose,  lactose  and  sucrose  provide  sources  of  fermentable  carbohydrates.  Sodium  chloride  maintains the osmotic balance of the medium.       Synthetic  detergent  inhibits  gram-positive  microorganisms.  Xylose  is  fermented  by  almost  all  the enteric  bacteria  except Shigellae  which  enables  the  differentiation  of Shigellae from Salmonellae.Salmonellae metabolize the xylose and after Salmonellae exhaust the supply of xylose, they decarboxylate lysine and thus change the pH to alkaline and mimic Shigellae reaction. However to prevent this reaction by lysine positive coliforms, lactose and sucrose are added in excess to produce acid and hence nonpathogenic hydrogen sulphide (H2S) producers do not decarboxylate lysine. Thiosulphate and ferric ammonium citrate are the hydrogen sulphide (H2S) indicators in the medium. Phenol red is the pH indicator.
Product Code: 
TMV 492