Enterobacter Sakazakii Chromogenic Medium

Item Code: CRM006

Usages:
For the identification and counting of E. sakazakii in infant formula and other foods sample.
 
Principle:
Peptone and beef extract powder to provide nitrogen, vitamins, amino acids and carbon; bile salts inhibit Gram-positive bacteria, sodium chloride maintains osmotic equilibrium; agar as medium coagulant; and citric acid, sodium thiosulfate ammonium iron for detecting hydrogen sulfide produced; chromogenic substrate 5-bromo-4-chloro-3-indolyl -?-D-glucoside and the E. sakazakii α- glucosidase reacts, hydrolysis of the substrate , the release of 5-bromo-chloro-3-indolyl color groups to produce yellowish green on the plate - blue-green colonies.
 
Formulation (per liter):
Tryptone: 15g
 Soy peptone :5g
 Sodium chloride: 5g
 Ferric ammonium citrate: 1g
Sodium deoxycholate:  1g
 Sodium thiosulfate: 1g
5-bromo-4-chloro-3-indolyl -?-D-glucoside :0.1g
Agar: 15g
Final pH 7.3 ± 0.2
 
How to use:
1.Suspend 43.1 g of the product, add 1 L of distilled or deionized water, ,heated to boiling stirring until completely dissolved, dispensing into flask, autoclave at 121 ? for 15minutes; cooled to 50 ?, shake down flat. Can be stored in the refrigerator for a day or stored at room temperature for several days (dark, 4 ?).
2.Take 333 g of sample and using MPN method taking 100 g, 10 g and 1 g aliquots in 2000ml, 250ml and 100ml Erlenmeyer flasks each of the three, the flask was equipped with a preheat in the warp of 45 ? 9/10 (1/10 samples) of sterile distilled water or buffered peptone water, shake cultured at 36 ? for 18-22 hours (SN and FDA methods).
3.The suspension was added to 10ml from each equipped 90mlEE broth (022160) / mLST-Vm (022212) in 150mL flasks, culture  at 36 ? / 44 ? for 18-22 hours.
4.Crossed or coating method to mix the broth inoculated onto E. sakazakii chromogenic agar, culture at 35-37 ? for 18-24 hours.
5. Use MicrogenTMGN-ID or API20E or biochemical test tube, suspected Enterobacter sakazakii colonies biochemical identification.
 
Quality control:
This product appears light yellow after pour on plate, these strains were inoculated after 36 ± 1 ? cultured for 18-24 hours growth in the following table:
Bacteria name           Number of inoculation(cfu/plate)  growth situation     feature
Enterobacter sakazakii ATCC51329     30 - 300            good       Green -Blue Green
Common variant of Bacillus HK7132   30 - 300             good           gray-black
Serratia bacteria Serratia HK7121        5000             not long            --
Enterococcus faecalis ATCC29212       5000             not long            --
 
Storage: Keep container tightly closed, store in a cool, dry place, away from bright light.