Is Mycobacterium Gram positive or negative?
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).
Why Mycobacterium is not Gram stain?
Mycobacteria are “Acid Fast” 1. They cannot be stained by the Gram stain because of their high lipid content.
What is IS6110?
IS6110 is an insertion element found exclusively within the members of the Mycobacterium tuberculosis complex (MTBC), and because of this exclusivity, it has become an important diagnostic tool in the identification of MTBC species.
What is the genome size of Mycobacterium tuberculosis?
The M. tuberculosis genome is 4.4 million base pairs long and encodes for approximately 4,000 genes (Cole et al., 1998).
What is Gram-positive vs Gram-negative?
Gram-negative bacteria are surrounded by a thin peptidoglycan cell wall, which itself is surrounded by an outer membrane containing lipopolysaccharide. Gram-positive bacteria lack an outer membrane but are surrounded by layers of peptidoglycan many times thicker than is found in the Gram-negatives.
Is Mycobacterium tuberculosis a closer relative to Gram-positive or Gram-negative bacterial pathogens?
tuberculosis is closer to Gram-positive than to Gram-negative bacteria like Enterobacteria and Neisserias, which are classified as Proteobacteria.
What is the peptidoglycan layer made of?
The peptidoglycan layer in the bacterial cell wall is a crystal lattice structure formed from linear chains of two alternating amino sugars, namely N-acetylglucosamine (GlcNAc or NAGA) and N-acetylmuramic acid (MurNAc or NAMA). The alternating sugars are connected by a β-(1,4)-glycosidic bond.
What Gram stain is Mycobacterium tuberculosis?
tuberculosis belongs to the high G+C Gram-positive bacteria that form a monophyletic group with the low G+C Gram-positive bacteria such as Bacillus subtilis.
What is Spoligotyping technique?
Spoligotyping is a PCR-based method allowing to analyze strain-dependent polymorphisms observed in spacer sequences present within the direct repeat (DR) genomic region of M. tuberculosis complex strains. Spoligotyping provides some important advantages over other genotyping techniques.
Is 6110 a sequence?
Insertion sequence (IS) 6110 is found at multiple sites in the Mycobacterium tuberculosis genome and displays a high degree of polymorphism with respect to copy number and insertion sites. Therefore, IS6110 is considered to be a useful molecular marker for diagnosis and strain typing of M. tuberculosis.
Does Mycobacterium tuberculosis have DNA or RNA?
Mycobacterium tuberculosis contains at least nine small RNA families in its genome. The small RNA (sRNA) families were identified through RNomics – the direct analysis of RNA molecules isolated from cultures of Mycobacterium tuberculosis.
Do Gram positive bacteria have introns?
Many Group I introns have been identified in eukaryotes and bacteria, but none have been found in archaea. Group II introns occur in mitochondrial and chloroplast genomes of fungi and plants and in cyanobacteria, proteobacteria, and Gram-positive bacteria, but not in archaea or in the nuclear DNA of eukaryotes.
How many copies of IS6110 are there in tuberculosis?
Ten to 12 copies are present in various strains of M. tuberculosis, while strains of M. bovis contain only one to three copies. IS6110 was not detected in the DNA of other species of mycobacteria. Restriction endonuclease analysis indicated that the sequence of IS6110 is conserved across strain and species lines.
How is IS6110 used in DNA fingerprinting?
A 123-bp fragment located within IS6110 has been used as a target for a polymerase chain reaction (PCR) assay which specifically identifies DNA from members of the M . tuberculosis complex. The 123-bp fragment is not amplified when DNA from various other species of mycobacteria serve as template for amplification .’
How is the sequence of IS6110 conserved across species lines?
Restriction endonuclease analysis indicated that the sequence of IS6110 is conserved across strain and species lines. Hybridization to the insertion sequence can be used to detect restriction fragment length polymorphism reflecting divergence in the sequence of regions flanking the various copies of IS6110.