Diphtheria
From MicrobeWiki, the student-edited microbiology resource
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.