Does Corynebacterium Diphtheriae grow on blood agar?

Does Corynebacterium Diphtheriae grow on blood agar?

C. diphtheriae grows well on blood agar, but tellurite blood agar (Hoyle’s medium) is recommended as this inhibits other respiratory flora and allows the characteristic colonial morphology of the three biotypes (gravis, intermedius and mitis) to develop.

What type of hemolysis is Corynebacterium Diphtheriae?

CORYNEBACTERIA – CULTIVATION ON BLOOD AGAR on media with blood with a weak beta-hemolysis (C. diphtheriae biotype mitis and gravis) or is nonhemolytic (biotype intermedius).

How can you identify Corynebacterium Diphtheriae?

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.

How does Corynebacterium Diphtheriae become toxigenic?

diphtheriae becomes toxigenic, it must be lysogenized by a specific bacteriophage. The corynebacteriophage carries the structural gene for the toxin (tox). Toxin-producing strains of all biotypes produce an identical diphtheria exotoxin [1].

What does C Diphtheriae cause?

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. CDC recommends vaccines for infants, children, teens, and adults to prevent diphtheria.

Is Corynebacterium diphtheriae acid fast positive or negative?

Corynebacterium spp., members of the family Corynebacteriaceae, are Gram-positive, non-spore- forming, non-motile, aerobic, pleomorphic rods with coccoid or club-shaped appearance that are catalase-positive and non-acid-fast (Boone et al., 2001; Greenwood, 2007).

Is Corynebacterium Gram positive or negative?

Corynebacteria are Gram-positive, club-shaped bacilli, members of the Actinobacteria.

What kind of spores does c.diphtheriae have?

Spores – C. diphtheriae is a Non-sporing Bacterium. Capsule – Corynebacterium diphtheriae is a non-capsulated bacterium. Gram Staining Reaction – C. diphtheriae is a Gram +ve bacterium (but tend to decolorized easily).

How is the toxin expressed in c.diphtheria?

C. diphtheria strains must contain a bacteriophage (beta-phage), acquired by transduction from other C. diphtheria strains, in order to express the toxin. The phage must be Iysogenized following transduction. The toxin expression (fox gene) is regulated by a chromosomally encoded repressor protein (DtxR) when iron is limited.

What are the three biotypes of Corynebacterium diphtheriae?

Corynebacterium diphtheriae is the etiologic agent of human respiratory and cutaneous diphtheria. There are 3 biotypes (mitis, gravis, and intermedius) of C. diphtheriae, each differentiated by hemolysis, colonial morphology, and fermentative reactions.

What are the determinants of the pathogenesis of diphtheria?

The pathogenesis of diphtheria is based upon two primary determinants: (1) the ability of a given strain of C diphtheriae to colonize in the nasopharyngeal cavity and/or on the skin, and (2) its ability to produce diphtheria toxin.