Common questions

What species of Proteus is indole positive?

What species of Proteus is indole positive?

Other Proteus spp. are indole positive, e.g., P. vulgaris and P. penneri.

Is Proteus indole positive?

P. mirabilis and P. penneri are indole-negative, while other Proteus species are indole-positive.

Does Proteus mirabilis produce indole?

Thirteen indole-producing, swarming strains of Proteus were identified by additional biochemical testing as being Proteus mirabilis. These indole-positive strains are similar to indole-negative P. mirabilis and are distinctly different from P. vulgaris.

Is Proteus mirabilis indole positive or negative?

Proteus mirabilis (indole negative) is the most frequent Proteus species associated with urinary tract infections, but indole-positive Proteus species like Pr. vulgaris, which are more often resistant to ampicillin, may also cause urinary tract infections. These species are often associated with an alkaline urine.

Is Proteus mirabilis serious?

Proteus is found abundantly in soil and water, and although it is part of the normal human intestinal flora (along with Klebsiella species, and Escherichia coli), it has been known to cause serious infections in humans.

What tests are used to identify Proteus mirabilis?

Biochemical Test and Identification of Proteus mirabilis

Basic Characteristics Properties ( Proteus mirabilis )
Gram Staining Negative (-ve)
Growth in KCN Positive (+ve)
H2S Positive (+ve)
Indole Negative (-ve)

Is Proteus oxidase positive or negative?

Proteus species do not usually ferment lactose, but have shown to be capable glucose fermenters depending on the species in a triple sugar iron (TSI) test. Since it belongs to the order Enterobacterales, general characters are applied on this genus. It is oxidase-negative but catalase- and nitrate-positive.

How is the spot indole test used for swarming Proteus?

The spot indole test for identification of swarming Proteus The authors evaluated the use of the spot indole test for rapid speciation of swarming Proteus from the primary isolation plate. One hundred seventy-two consecutive isolates of swarming Proteus were studied, 163 Proteus mirabilis and nine Proteus vulgaris.

How many indole positive strains of Proteus are there?

Thirteen indole-producing, swarming strains of Proteus were identified by additional biochemical testing as being Proteus mirabilis. These strains were characterized by 40 biochemical tests and by susceptibility testing to 11 antibiotics. All produced ornithine decarboxylase and were susceptible to …

Why do Proteus colonies not swarm after incubation?

MacConkey agar: Proteus produces individual non-lactose fermenting colonies after over night incubation at 35-37°C and swarming is prevented due to bile salt present in the medium. CLED agar: Blue gray translucent colonies and absence of swarming is due to electrolyte deficient.

What makes a Proteus different from A mirabilis?

P. mirabilis and P. vulgaris are known for their swarming ability over blood agar as shown above image. The distinctive characters of the genus are PPA, urease and H 2 S positive. Indole helps to differentiate P. vulgaris ( positive) from P. mirabilis ( negative).

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