What agar can confirm an identification of Salmonella enterica?

BGA agar – Colonies appear as red-pink, 1-3 mm in diameter, surrounded by brilliant red zones in the agar. Salmonella species should agglutinate with Polyvalent O antiserum. Some serotypes e.g. Salmonella Typhi may produce a Vi antigen, which can prevent agglutination with Polyvalent O antiserum.

What type of agar is used for Salmonella?

BS agar is the medium of choice for the isolation of Salmonella enterica serovar Typhi, and it is used for the isolation of atypical salmonellae, such as those which ferment lactose (7).

Which selective media is used for Salmonella isolation from stool sample?

The most commonly used media for selective enrichment are Rappaport-Vassiliades soy broth, selenite cysteine broth, and tetrathionate broth. Modified semisolid Rappaport-Vassiliades is another selective media particularly useful for detecting salmonella in feces and environmental samples.

Which medium is used for enrichment of Salmonella?

Selective enrichment broths lead to increased salmonella numbers because contain inhibitory compounds that limit non-salmonella microorganisms. At present, enrichment broths containing selenite, and both brilliant green and malachite green are recommended (5).

Does Salmonella grow on MacConkey Agar?

Principle of MacConkey Agar Sodium chloride maintains the osmotic balance in the medium. Lactose fermenting strains grow red or pink. Non-lactose fermenting bacteria such as Salmonella, Proteus, Pseudomonas aeruginosa, and Shigella cannot utilize lactose and will use peptone instead.

Is Salmonella typhi citrate positive?

Some citrate negative organisms may grow weakly on the surface of the slant, but they will not produce a color change. When Simmons Citrate agar is inoculated with Salmonella typhimurium , the medium turns royal blue. This is a positive result for the citrate test.

What is DCA agar used for?

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

Is Salmonella Shigella Agar selective or differential?

Salmonella Shigella (SS) Agar is moderately selective and differential medium for the isolation, cultivation and differentiation of Salmonella spp. and some strains of Shigella spp. SS Agar is a modification of the Desoxycholate Citrate Agar.

Why selenite-F or tetrathionate broths are recommended for the enrichment of Salmonella spp?

Selenite-F Broth was devised by Leifson, who demonstrated that selenite was inhibitory for coliforms and certain other microbial species, such as fecal streptococci, present in fecal specimens, and thus, was beneficial in the recovery of Salmonella species.

Can Salmonella grow on MacConkey Agar?

Principle of MacConkey Agar Sodium chloride maintains the osmotic balance in the medium. Lactose fermenting strains grow as red or pink. Non-lactose fermenting bacteria such as Salmonella, Proteus, Pseudomonas aeruginosa and Shigella cannot utilize lactose, and will use peptone instead.

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.

Does Micrococcus luteus grow on MacConkey agar?

MacConkey Agar (MAC) is a selective and differential medium designed to isolate and differentiate enterics based on their ability to ferment lactose. Bile salts and crystal violet inhibit the growth of Gram positive organisms. Micrococcus luteus does not grow in the presence of bile salts and crystal violet.

How to select atypical Salmonella colonies on selective agar?

In addition to the positive control cultures (typical Salmonella; lactose negative, H2S positive), 3 additional Salmonella cultures are recommended to assist in the selection of atypical Salmonella colony morphology on selective agars.

Does Salmonella produce H2S in TSI agar?

Salmonella in culture typically produces alkaline (red) slant and acid (yellow) butt, with or without production of H 2 S (blackening of agar) in TSI. In LIA, Salmonella typically produces

Can Salmonella be grown on swarm agar?

The Salmonella is grown over night on a non-selective agar medium. Swarm agar is the best suited medium for growing cultures for H typing, but H antigens can be serotyped from a non-selective agar medium if the H antigens are well expressed.

What is the color of Salmonella colonies on XLD agar?

Many cultures of Salmonella may produce colonies with large, glossy black centers or may appear as almost completely black colonies. Xylose lysine desoxycholate (XLD) agar. Pink colonies with or without black centers. Many cultures of Salmonella may produce colonies with large, glossy black centers or may appear as almost completely black colonies.