Is Klebsiella pneumoniae indole positive?

Abstract. Klebsiellae are an important cause of nosocomial infections. The two clinically relevant species, Klebsiella pneumoniae and Klebsiella oxytoca, are differentiated by the ability to produce indole from tryptophan, K. oxytoca being indole positive.

Is Klebsiella Variicola indole negative?

pneumoniae complex, K. variicola is positive for urease, ortho-nitrophenyl-β-galactoside (ONPG), the Voges-Proskauer test, and lysine decarboxylase but negative for indole and ornithine decarboxylase. Unlike the rest of the K. pneumoniae complex, both subspecies of K.

Is Klebsiella an indole?

Klebsiella oxytoca is a Gram-negative, rod-shaped bacterium that is closely related to K. pneumoniae, from which it is distinguished by being indole-positive; it also has slightly different growth characteristics in that it is able to grow on melezitose, but not 3-hydroxybutyrate.

Which bacteria gives indole test positive?

Bacteria that test positive for cleaving indole from tryptophan include: Aeromonas hydrophila, Aeromonas punctata, Bacillus alvei, Edwardsiella sp., Escherichia coli, Flavobacterium sp., Haemophilus influenzae, Klebsiella oxytoca, Proteus sp.

Is Klebsiella aerogenes indole positive or negative?

Klebsiella aerogenes, previously known as Enterobacter aerogenes, is a Gram-negative, oxidase negative, catalase positive, citrate positive, indole negative, rod-shaped bacterium. The bacterium is approximately 1-3 microns in length, and is capable of motility via peritrichous flagella.

Is Klebsiella pneumoniae a fermenter?

Klebsiella pneumoniae is a gram-negative, lactose-fermenting, non-motile, aerobic rod-shaped bacterium.

Is Klebsiella lactose fermenter?

Lactose usually is fermented rapidly by Escherichia, Klebsiella and some Enterobacter species and more slowly by Citrobacter and some Serratia species.

Is E. coli indole positive or negative?

positive
Indole production is often used to differentiate E. coli from other indole-negative enteric bacteria because 96% of E coli are indole positive, whereas many enterobacterial species are negative in the indole reaction.

What does a positive indole test mean?

The presence of indole when a microbe is grown in a medium rich in tryptophan demonstrates that an organism has the capacity to degrade tryptophan.

Why do bacteria produce indole?

Indole is known as a metabolite of amino acid tryptophan, which, however, has recently been proved to participate in various aspects of bacterial life including virulence induction, cell cycle regulation, acid resistance, and especially, signaling biofilm formation.

How can you differentiate between Enterobacter aerogenes and Klebsiella pneumoniae?

can be differentiate based on sensitivity patterns. Most Klebsiella strains are susceptible to cephalothin, and all are sensitive to colistin. Enterobacter strains were resistant to cephalothin but susceptible to colistin.

Is Klebsiella pneumoniae Gram positive or negative?

Gram-negative bacteria
Klebsiella [kleb−see−ell−uh] is a type of Gram-negative bacteria that can cause different types of healthcare-associated infections, including pneumonia, bloodstream infections, wound or surgical site infections, and meningitis.