How does bismuth sulfite agar work?

How does bismuth sulfite agar work?

Bismuth sulfite agar is a type of agar media used to isolate Salmonella species. It uses glucose as a primary source of carbon. BLBG and bismuth stop gram-positive growth. Bismuth sulfite agar tests the ability to use ferrous sulfate and convert it to hydrogen sulfide.

How does bismuth sulfite agar selective for Salmonella and Shigella species?

Bismuth sulfite agar is selective due to the presence of inhibitors and is differential on the basis of hydrogen sulfide ( H2S) production.

Which diseases are caused by the bacteria isolated using bismuth sulphite agar?

The presence of bismuth sulphite and brilliant green make this medium highly selective for salmonellae. Salmonella infection (salmonellosis) is a common bacterial disease that affects the intestinal tract.

What is Wilson Blair Agar?

Wilson and Blair Agar was formulated by Wilson and Blair (1) for isolating Salmonella species especially Salmonella serotype Typhi from clinical specimens. Ferrous sulphate is reduced by Salmonella species in presence of bismuth sulphite and dextrose to form iron sulphide, indicated by black coloured colonies.

What is the use of bismuth?

Bismuth finds its main uses in pharmaceuticals, atomic fire alarms and sprinkler systems, solders and other alloys and pigments for cosmetics, glass and ceramics. It is also used as a catalyst in rubber production.

Is BSA agar selective or differential?

Uses of Bismuth Sulphite Agar (BSA) Bismuth Sulphite Agar is recommended for the selective isolation and preliminary identification of Salmonella Typhi and other Salmonellae from pathological materials, sewage, water supplies, food etc.

Why is salmonella black on BSA?

Principle of Bismuth Sulphite Agar (BSA) Dextrose is the carbon source. Typhimurium typically grow as black colonies with a surrounding metallic sheen resulting from hydrogen sulphide production and reduction of sulphite to black ferric sulphide. Salmonella Paratyphi A grows as light green colonies.

What makes hektoen enteric agar selective and differential?

Principle. Hektoen enteric agar is a selective as well as differential media for the isolation and differentiation of enteric pathogens from clinical specimens. The presence of the bile salts and dyes inhibits most gram-positive organisms allowing only gram-negative rods to grow on HE agar.

What is bismuth preparations?

Bismuth subsalicylate is an over-the-counter medication used for treatment of diarrhea, gas, upset stomach, indigestion, heartburn, nausea and as a prophylaxis for traveler’s diarrhea. Bismuth subsalicylate is also used in conjunction with other medications to treat H. pylori.

What are the characteristics of bismuth?

Bismuth is a rather brittle metal with a somewhat pinkish, silvery metallic lustre. Bismuth is the most diamagnetic of all metals (i.e., it exhibits the greatest opposition to being magnetized). It is hard and coarsely crystalline. It undergoes a 3.3 percent expansion when it solidifies from the molten state.

Is salmonella a typhi?

Salmonella Typhi (S. Typhi) are bacteria that infect the intestinal tract and the blood. The disease is referred to as typhoid fever.