Diphtheria

From MicrobeWiki, the student-edited microbiology resource
University of Oklahoma Study Abroad Microbiology in Arezzo, Italy[1]

Etiology/Bacteriology

Taxonomy

| Domain = Bacteria | Phylum = Actinobacteria | Class = Actinobacteria | Order = Actinomycetales | Family = Corynebacteriaceae | Genus = Corynebacterium | Species = Diphtheriae

Description

C. diphtheriae infections are the causal agent of diphtheria. Four subspecies are recognized: C. d. mitis, C. d. intermedius, C. d. gravis, and C. d. belfanti. C. diphtheria is known to produce diphtheria toxins. C. diphtheria are Gram-positive, rod-shaped, aerobic, nonmotile, and highly pleumorphic.

Pathogenesis

Virulence factors

Diphtheria toxin

Diphtheria toxin is an exotoxin that prevents protein synthesis through inactivation of eEF2 (eukaryotic elongation factor 2). This is done by ADP-ribosylating the amino acid diphthamide, inhibiting RNA translation.

Mechanism

Adherence

Invasion of the cell

Encountering macrophages

Clinical features

Diagnosis

Treatment

Prevention

Host immune response

References