Bottle of diphtheria antitoxin, produced by the Hygienic Laboratory and dated May 8, 1895. Diphtheria is an upper respiratory tract illness caused by Corynebacterium diphtheriae, a facultative anaerobic, gram-positive bacterium. It is characterized by sore throat, low fever, and an adherent membrane (a pseudomembrane) on the tonsils, pharynx, and/or nasal cavity. Diphtheria is a contagious disease spread by direct physical contact or breathing the aerosolized secretions of infected individuals. Historically quite common, diphtheria has largely been eradicated in industrialized nations through widespread vaccination. Diphtheria toxin is produced by Corynebacterium diphtheriae only when infected with a bacteriophage that integrates the toxin-encoding genetic elements into the bacteria.
