M376I-500G LYSINE DECARBOXYLASE BROTH W/O PEPTONE, ISO HIMEDIA

NAME : LYSINE DECARBOXYLASE BROTH W/O PEPTONE, ISO
CODE : M376I-500G
BRAND : HIMEDIA
PACKING : 500G
MOHON CHAT TERLEBIH DULU UNTUK CEK KETERSEDIAAN BARANG DAN EXPIRED DATE

Lysine Decarboxylase Broth w/o Peptone are used for differentiating Salmonella Arizonae from the Bethesda Ballerup group of Enterobacteriaceae.

Decarboxylase media were first described by Moeller (1-3) for detecting lysine and ornithine decarboxylase and arginine dihydrolase. Falkow developed a lysine decarboxylase medium for the identification and differentiation of Salmonella and Shigella (4). Falkows Medium was further modified by Taylor (5) by deleting peptone from the formulation (M376I), thus eliminating false positives caused by Citrobacter freundii and its paracolons. Taylor's modification has same advantage of Falkow's formulation over Moeller; it does not require the special conditions of anaerobic culture and low pH. During the initial stages of incubation, fermentation of dextrose by the organisms, with acid production results in a colour change of the indicator to yellow. On further incubation, if L-Lysine is decarboxylated to cadaverine, there will be an alkaline reaction and the indicator colour will then revert back to purple. If the colour remains yellow, the decarboxylase reaction is negative. Yeast extract provide essential growth nutrients. Dextrose is the fermentable carbohydrate and bromo cresol purple is the pH indicator. Dextrose non-utilizers will not show any change in the medium colour. Use light inocula and do not read the tests under 24 hours incubation as some organisms require longer incubation time of upto 4 days. Inoculate 25 grams of the test sample into Buffered Peptone Water (M614S). After incubation at 35-37°C for 16-20 hours, inoculate into RVS Broth (M1491) and Fluid Selenite Cystine Broth (M1533I) and incubate at 35-37°C for 24-48 hours. From the second enrichment, streak a loopful on Brilliant Green Agar Base w/ phosphates (M971S).