What grows on DCA agar?

What grows on DCA agar?

Coliform bacteria and gram-positive bacteria are inhibited or greatly suppressed due to sodiumdeoxycholate, sodium citrate, and ferric ammonium citrate….Composition of Deoxycholate Citrate Agar (DCA)

What is DCA agar used for?

DCA agar (deoxycholate citrate agar) is a solid bacteriological growth medium used for isolation of enteric pathogens.

How do you make a DCA agar?

Preparation and Method of Use of Deoxycholate Citrate Agar (DCA)

1. Cool to 45-50°C.
2. Dry the agar surface before use.
3. Inoculate the medium heavily with feces or rectal swabs, spreading part of the original inoculum in order to obtain well-separated colonies on some portion of the plate.
4. Incubate for 18-24 hours at 35°C.

Is XLD selective or differential?

XLD Agar is both a selective and differential medium. It contains a yeast extract as a source of nutrients and vitamins. It uses sodium deoxycholate as a selective agent and is therefore inhibitory to Gram-positive microorganisms.

What is Salmonella Shigella Agar used for?

SS Agar (Salmonella Shigella Agar) is a differential selective media used for the isolation of Salmonella and some Shigella species from pathological specimens, and suspected foods. The peptic digest of animal tissue and beef extract provide essential growth nutrients. Lactose is the fermentable carbohydrate.

What is brilliant green agar?

BD Brilliant Green Agar is a highly selective medium used for the isolation of salmonellae other than S. Typhi from feces and other clinical specimens. PRINCIPLES AND EXPLANATION OF THE PROCEDURE. Microbiological method.

What are yellow colonies on XLD agar?

Result interpretation

What grows black on XLD agar?

Colony Characteristics of XLD Agar Hydrogen sulfide production under alkaline conditions causes colonies to develop black centers. This reaction is inhibited by the acid conditions that accompany carbohydrate fermentation.

What is the difference between Salmonella and Shigella?

Salmonella will not ferment lactose, but produce hydrogen sulfide (H2S) gas. The resulting bacterial colonies will appear colorless with black centers. Shigella do not ferment lactose or produce hydrogen sulfide gas, so the resulting colonies will be colorless.

Is Shigella gram-positive or negative?

Nonetheless, Shigella species are Gram-negative, facultatively anaerobic, nonsporulating, nonmotile rods in the family Enterobacteriaceae. They do not decarboxylate lysine or ferment lactose within 2 days.

Does E coli grow on brilliant green agar?

Salmonella sp. has been cultivated on plate C. Note that the colour of this plate has changed from yellowish-red to dark red and that the colonies are pink. E. coli does only grow poorly on BG agar.

What bacteria can grow on brilliant green agar?

Result Interpretation on Brilliant Green Agar