Corynebacterium Diphtheriae: The Bacterium Behind Diphtheria

Introduction

Corynebacterium diphtheriae is a Gram-positive bacterium that causes diphtheria, a contagious infection of the nasopharynx or skin. Toxigenic strains of C. diphtheriae secrete a potent exotoxin that can lead to severe complications, including respiratory and heart failure.

Characteristics of C. diphtheriae

Morphology and Metabolism

C. diphtheriae is an anaerobic, non-motile, non-spore-forming, and non-capsulated bacterium. It is pleomorphic, exhibiting a variety of shapes and sizes, including rods, clubs, and beaded forms.

Toxin Production

Toxigenic strains of C. diphtheriae produce a potent exotoxin called diphtheria toxin. This toxin inhibits protein synthesis in host cells, resulting in cell death and tissue damage.

Transmission and Infection

C. diphtheriae is transmitted through respiratory droplets or direct contact with infected individuals. The bacterium colonizes the nasopharynx or skin, where it releases diphtheria toxin. This toxin can cause damage to the respiratory tract, leading to diphtheria.

Symptoms and Complications

Diphtheria typically causes a sore throat, fever, and swollen lymph nodes. In severe cases, the infection can lead to airway obstruction, heart failure, and even death. Diphtheria toxin can also cause damage to the kidneys and nervous system.

Treatment and Prevention

Diphtheria is treated with antibiotics and diphtheria antitoxin. Prevention relies on vaccination with the diphtheria vaccine, which is part of the routine childhood immunization schedule. Adequate sanitation and hygiene measures also help to prevent the spread of C. diphtheriae.