Which staining is done for the identification of Corynebacterium diphtheria?
To accurately identify C. diphtheriae, a Gram stain is performed to show Gram-positive, highly pleomorphic organisms with no particular arrangement. Special stains like Albert’s stain and Ponder’s stain are used to demonstrate the metachromatic granules formed in the polar regions.
What is the Gram stain of Corynebacterium Diphtheriae?
Corynebacterium diphtheriae is a Gram-positive nonmotile, club-shaped bacillus. Strains growing in tissue, or older cultures in vitro, contain thin spots in their cell walls that allow decolorization during the Gram stain and result in a Gram-variable reaction.
Which color is taken by Corynebacterium Diphtheriae after Gram staining?
Corynebacterium diphtheriae appears green coloured rod shaped bacteria with bluish black metachromatic granules at the poles.
How do you stain Corynebacterium Diphtheriae?
Albert’s method, of staining diphtheria cultures consists of staining a fixed smear for one minute (some laboratories stain for five minutes) with a solution containing toluidine blue and malachite (or methyl) green, washing with water, and applying Albert’s iodine for one minute.
What disease is caused by Corynebacterium?
Diphtheria is a serious infection caused by strains of bacteria called Corynebacterium diphtheriae that make toxin (poison). It can lead to difficulty breathing, heart failure, paralysis, and even death.
What is the role of Corynebacterium?
Species of Corynebacterium have been used in the mass production of various amino acids including glutamic acid, a food additive that is made at a rate of 1.5 million tons/ year. The metabolic pathways of Corynebacterium have been further manipulated to produce lysine and threonine.
What kind of staining does Corynebacterium have?
The group contains a miscellany of species, some of which are assigned to other genera on the basis of chemotaxonomic studies. These small, pleomorphic rods display varying degrees of metachromatic staining; Corynebacterium diphtheriae is outstanding in this regard.
Can a Ponder stain be used to diagnose diphtheria?
Albert, Neisser, or Ponder stain of direct smears shows metachromatic granules (Fig. 27-3). However, diphtheria bacilli may not always be demonstrated in the smears, and also it may be difficult to differentiate the bacilli from those of commensal corynebac-teria frequently found in the throat.
What kind of stain shows gram positive bacilli?
Gram staining of the smear shows Gram-positive bacilli. Albert, Neisser, or Ponder stain of direct smears shows metachromatic granules (Fig. 27-3).
How are metachromatic granules represented in Corynebacterium?
They are gram-positive, catalase -positive, non- spore -forming, non- motile, rod-shaped bacteria that are straight or slightly curved. Metachromatic granules are usually present representing stored phosphate regions.