What is the classification of Mycobacterium?
This genus includes pathogens known to cause serious diseases in mammals, including tuberculosis (Mycobacterium tuberculosis) and leprosy (Mycobacterium leprae) in humans….
| Mycobacterium | |
|---|---|
| Phylum: | Actinomycetota |
| Order: | Corynebacteriales |
| Family: | Mycobacteriaceae |
| Genus: | Mycobacterium Lehmann & Neumann 1896 |
How do you identify mycobacteria?
Mycobacterial species are usually identified by time-consuming culture methods. Recently, the development of rapid diagnostic tests that use molecular genetic methods, such as PCR amplification, has been reported.
Is Mycobacterium a fungus or bacteria?
fungus bacterium
Mycobacteria are characterized by the possession of very thick, waxy, lipid-rich hydrophobic cell walls. Being hydrophobic, they tend to grow as fungus-like pellicles on liquid culture media: hence the name Mycobacterium – ‘fungus bacterium.
What is genus Mycobacterium?
Mycobacterium, genus of rod-shaped bacteria of the family Mycobacteriaceae (order Actinomycetales), the most important species of which, M. tuberculosis and M. leprae, cause tuberculosis and leprosy, respectively, in humans. M. bovis causes tuberculosis in cattle and in humans.
What is the structure of Mycobacterium?
The cell envelope of Mtb comprises four main layers: (i) the plasma membrane or inner membrane, (ii) the peptidoglycan–arabinogalactan complex (AGP), (iii) an assymetrical outer membrane or ‘mycomembrane’, that is covalently linked to AGP through the mycolic acids, and (iv) the external capsule [22].
What are the characteristics of Mycobacterium?
Mycobacteria are immobile, slow-growing rod-shaped, gram-positive bacteria with high genomic G+C content (61-71%). Due to their special staining characteristics under the microscope, which is mediated by mycolic acid in the cell wall, they are called acid-fast. This is also the reason for the hardiness of mycobacteria.
What are the basis of identifying Mycobacterium species?
For detection of Mycobacterium species, Kasai et al. (19) have determined the gyrB gene sequences of 43 slowly growing strains belonging to 15 species in the genus Mycobacterium and developed a method of PCR and PCR-restriction fragment length polymorphism analysis to differentiate these species.
Does Mycobacterium grow on MacConkey Agar?
Abstract. Recent evaluations of the MacConkey agar test for differentiation of rapidly growing mycobacteria have revealed that certain strains of Mycobacterium fortuitum and M. chelonei that were expected to grow on MacConkey agar failed to do so.
What is the difference between bacteria and mycobacteria?
Mycobacteria have an outer membrane. They do not have capsules, and most do not form endospores. The distinguishing characteristic of all Mycobacterium species is that the cell wall is thicker than in many other bacteria, which is hydrophobic, waxy, and rich in mycolic acids/mycolates.
Why is it called Mycobacterium?
Being hydrophobic, they tend to grow as fungus-like pellicles on liquid culture media: hence the name Mycobacterium – ‘fungus bacterium. ‘ Even the rapidly growing mycobacteria grow slowly in comparison with most other bacteria.
What is the cell morphology for Mycobacterium?
Table 1
| Feature | Mycobacterium | Rhodococcus |
|---|---|---|
| Cell shape | Mainly rods, sometimes branching | Scanty mycelium fragmenting into rods and cocci |
| Cell envelope | Waxy coat | Waxy coat |
| Mycolic acids | 60 – 90 carbon atoms | 32 – 66 carbon atoms |
| Growth rate (time for visible colonies) | 2 – 40 days | 1 – 3 days |
What are the 3 major components of the Mycobacterium cell wall structure?
The essential core cell wall structure is composed of three main components: a cross-linked polymer of peptidoglycan, a highly branched arabinogalactan polysaccharide, and long-chain mycolic acids.