How does diphtheria cause paralysis?
Nerve damage. Typical targets are nerves to the throat, where poor nerve conduction may cause difficulty swallowing. Nerves to the arms and legs also may become inflamed, causing muscle weakness. If the diphtheria toxin damages the nerves that help control muscles used in breathing, these muscles may become paralyzed.
What kind of shape we see if Corynebacterium diphtheria is seen through microscope?
Bacteriology. Corynebacterium diphtheriae is a slender, Gram-positive bacillus, usually with one end being wider, thus giving the often-described club-shaped appearance.
How do you test for Corynebacterium diphtheriae?
Doctors usually decide if a person has diphtheria by looking for common signs and symptoms. They can swab the back of the throat or nose and test it for the bacteria that cause diphtheria. A doctor can also take a sample from an open sore or ulcer and try and grow the bacteria.
What are the virulence factors of Corynebacterium diphtheriae?
For Corynebacterium diphtheriae to cause diphtheria, it must produce two virulence factors: diphtherial cord factor and diphtheria toxin. The cord factor allows the bacteria to grow in rope-like lateral aggregates to colonize in the upper respiratory tract.
Which part of the body is affected by diphtheria?
Diphtheria can infect the respiratory tract (parts of the body involved in breathing) and skin. In the respiratory tract, it causes a thick, gray coating to build up in the throat or nose.
What is Diphtheritic paralysis?
Diphtheritic neuropathy is an acute demyelinating polyneuropathy developing three to five weeks after severe diphtheria infection. It is a biphasic illness with initial bulbar and other cranial nerve involvement followed later by motor weakness in extremities and autonomic dysfunction.
What is the shape of Corynebacterium diphtheriae?
C. diphtheriae is a pleomorphic, club-shaped, Gram positive bacillus that is catalase positive, non-motile, non-spore forming, and non-acid fast.
What does Corynebacterium diphtheriae look like?
Bacteriology. Corynebacterium diphtheriae is a slender Gram-positive bacillus, usually with one end being wider, thus giving the often-described club-shaped appearance. On culture, particularly under suboptimal conditions, characteristic bands or granules appear.
Where is Corynebacterium diphtheriae found in the body?
Clinical Manifestations. Corynebacterium diphtheriae infects the nasopharynx or skin. Toxigenic strains secrete a potent exotoxin which may cause diphtheria. The symptoms of diphtheria include pharyngitis, fever, swelling of the neck or area surrounding the skin lesion.
What is the mechanism of action of diphtheria toxin?
Diphtheria toxin kills cells by inhibiting eukaryotic protein synthesis, and its mechanism of action has been extensively characterized. This potent toxin inactivates elongation factor (EF-2) required for protein synthesis (Collier, 1967).
What is the main virulence factor of Corynebacterium diphtheriae the causative agent of diphtheria?
Toxins Diphtheria toxin
Toxins. Diphtheria toxin is the main virulence factor of C. diphtheriae and responsible for the life-threatening symptoms of respiratory diphtheria (Burkovski 2013b).
What does Corynebacterium 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.
Where is Corynebacterium diphtheriae found?
C. diphtheriae is a rod-shaped, Gram-positive, nonspore-forming, and nonmotile bacterium. The disease occurs primarily in tropical regions and underdeveloped countries, but has been known to appear throughout the world.
Can diphtheria cause peripheral neuropathy?
Diphtheritic polyneuropathy (DP) is recognized as one of the most severe complications of diphtheria, caused by exotoxin of Corynebacterium diphtheriae. Among 20,000 cases of diphtheria reported by WHO during 2007–2011, 17,926 (89.6%) cases were from India alone.
What is Diphtheritic membrane?
A false membrane formed on mucous surfaces in diphtheria.
What is the colony morphology of Corynebacterium diphtheriae?
Biotypes of Corynebacterium Diphtheriae
| Properties | Gravis |
|---|---|
| Morphology | – Short Rods – Uniform Staining – Few or no granules – May be pleomorphic |
| Colony on Tellurite Blood Agar | ≥ 2mm, dull greyish black, opaque colonies, daisy head, brittle, like cold margarine. |
| Hemolysis | Variable |
| Glycogen and Starch fermentation | Positive |
Is Corynebacterium diphtheriae motile?
Corynebacterium diphtheria is anaerobic, Gram-positive, non-motile, non-spore-forming, non-capsulated, toxin-producing, pleomorphic coccobacillus, which is usually club-shaped. Based on biochemical properties and colony morphology, it has four biotypes, namely, gravis, mitis, intermedius, and belfanti.