How do you identify Mycobacterium smegmatis?
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 Mycobacterium catalase positive?
Mycobacteria are Gram-positive, catalase positive, non-motile, non-spore forming rod-shaped bacteria (0.2–0.6 μm wide and 1.0–10 μm long). The colony morphology of mycobacteria varies with some species growing as rough or smooth colonies.
Does Mycobacterium produce catalase?
Our findings indicate that mycobacterial catalase encoded by katG plays an essential role in the ability of this organism to evade the immune response through the decomposition of hydrogen peroxide that is an essential trigger for MCETs induction (25).
Can Mycobacterium smegmatis be Gram stained?
Mycobacterium smegmatis is a Gram-positive bacteria, characterized by an inner cell membrane and a thick cell wall. Although this bacteria is Gram-positive, it has some unique qualities that are divergent from most Gram-positive bacteria.
What is the arrangement of M smegmatis?
Mycobacterium smegmatis str. MC2 155
| Names | Mycobacterium smegmatis str. MC2 155 |
|---|---|
| Cell arrangement | Singles |
| Sporulation | Nonsporulating |
| Metabolism | NA |
| Energy source | Chemoorganotroph |
Can M smegmatis be used as a real alternative for M. tuberculosis?
smegmatis of lower pathogenicity has been used as a substitute for the highly pathogenic M. tuberculosis in a large number of molecular biological or molecular genetic experiments.
Is M. tuberculosis catalase positive or negative?
Basic Microbiology Mycobacteria are Gram-positive, catalase positive, non-motile, non-spore forming rod-shaped bacteria (0.2–0.6 μm wide and 1.0–10 μm long).
Is Mycobacterium gram negative or Gram-positive?
The phylogenetic position of Mycobacterium tuberculosis relative to other bacteria is controversial. Its cell wall has characteristics of both Gram-positive and Gram-negative bacteria. In the standard reference of bacterial phylogeny based on 16S ribosomal RNA sequence comparison, M.
Does tuberculosis have a flagellum?
The bacterium has neither cilia or flagella, and is therefore non-motile. Its hydrophobic cell wall contains a high concentration of lipids which repels water. Metabolically, M. tuberculosis is obligate aerobic; it requires oxygen to undergo cellular respiration.
Is M smegmatis acid fast bacteria?
The small pink bacilli above are Mycobacterium smegmatis, an acid fast bacteria because they retain the primary dye.
What causes smegmatis?
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.
What does a positive catalase test indicate?
Catalase is an enzyme that splits hydrogen peroxide into water and oxygen and a positive catalase test is indicated by the formation of gas bubbles. Most species of Mycobacteria, except for certain strains of M. tuberculosis complex (some isoniazid-resistant strains) and M. gastri, produce catalase enzyme.
What are the precautions for catalase test?
Precautions of Catalase Test The test organisms should not be taken from blood agar culture. Red Blood cells contain catalase and their presence will give a false positive test. Culture should be 18 to 24 hours old.
How is quality control performed in the workup of catalase?
Quality control is performed by using organisms known to be positive and negative for catalase. Note: If a platinum inoculating loop is used, do not add 3% H2O 2 to the slide before the organism, as the platinum wire in the loop may produce a false-positive result. This is not the case with nichrome wire. FIG. 1. Slide catalase test results.
What does the catalase enzyme do in anaerobes?
The catalase enzyme neutralizes the bactericidal effects of hydrogen peroxide and protects them. Anaerobes generally lack the catalase enzyme. 2H2O2 → 2H2O+ O2 (gas bubbles) Catalase mediates the breakdown of hydrogen peroxide H 2O 2 into oxygen and water.
