Why is Mycobacterium smegmatis important?

Mycobacterium smegmatis is so important because it is fast growing and non-pathogenic compared to these species. There are many similarities between Mycobacterium smegmatis and the much more virulent obligate pathogens that are Mycobacteria.

Which of the following biochemical tests detect Mycobacterium tuberculosis?

catalase test
A semiquantitative catalase test is used for the identification of Mycobacteria.

What does Mycobacterium smegmatis cause?

Newton and Weiss are correct that Mycobacterium smegmatis can cause human infection, particularly in a lipid- rich environment such as aspiration pneumonitis associated with achalasia. M. smegmatis, one of the rapid-growing mycobacteria, is an environmental species. It is similar to and has been confused with M.

What does Mycobacterium smegmatis look like?

Mycobacterium smegmatis is an acid-fast bacterial species in the phylum Actinobacteria and the genus Mycobacterium. It is 3.0 to 5.0 µm long with a bacillus shape and can be stained by Ziehl–Neelsen method and the auramine-rhodamine fluorescent method.

Is M Phlei acid-fast positive or negative?

Mycobacterium phlei is a species of acid-fast bacteria in the genus Mycobacterium. It is characterized as one of the fast-growing mycobacteria. M. phlei has only occasionally been isolated in human infections, and patients infected with M.

Is tuberculosis catalase positive or negative?

tuberculosis and other tubercle bacilli. Catalase converts hydrogen peroxide to water and oxygen, generating oxygen bubbles in a liquid solution. Virtually all mycobacteria except certain isoniazid-resistant tubercle bacilli are catalase-positive.

Why is the indole test important for Enterobacteria?

Indole production test is important in the identification of Enterobacteria. Most strains of E. coli, P. vulgaris, P. rettgeri, M. morgani and Providencia species break down the amino acid tryptophan with the release of indole.

Which is the correct procedure for the indole test?

Procedure of Indole Test 1 Take a sterilized test tubes containing 4 ml of tryptophan broth. 2 Inoculate the tube aseptically by taking the growth from 18 to 24 hrs culture. 3 Incubate the tube at 37°C for 24-28 hours. 4 Add 0.5 ml of Kovac’s reagent to the broth culture. 5 Observe for the presence or absence of ring.

How to differentiate indole positive from indole negative?

To differentiate Proteus mirabilis (indole negative) from all other Proteus species (indole positive). To differentiate Klebssiella pneumoniae (indole negative) from Klebsiella oxytoca (indole positive). To differentiate Citrobacter freundii (indole negative) from Citrobacter koseri (indole positive).

How is indole generated from tryptophan hydrolysis?

Tryptophan is an amino acid that can undergo deamination and hydrolysis by bacteria that express tryptophanase enzyme. Indole is generated by reductive deamination from tryptophan via the intermediate molecule indolepyruvic acid.