Short answers, pulled from the story.
Diphtheria toxin is produced only by strains of Corynebacterium diphtheriae infected with a specific bacteriophage. The tox gene integrates into the bacterial genome through lysogenic conversion, making these strains tox positive.
Fragment A of the toxin enters the cytoplasm and inhibits protein synthesis by ADP-ribosylating elongation factor EF-2. This modification transfers an ADP-ribose group from NAD+ to a diphthamide residue within the EF-2 protein, stopping translation and causing cell death.
Symptoms of diphtheria begin two to seven days after infection. Patients develop fever above 38 degrees Celsius along with chills, fatigue, sore throat, and hoarseness within this timeframe.
Edwin Klebs identified the bacterium in 1883 and named it the Klebs-Loeffler bacterium. Friedrich Loeffler became the first person to cultivate Corynebacterium diphtheriae in 1884 and fulfilled Koch's postulates using guinea pigs and rabbits.
The Great Race of Mercy delivered diphtheria antitoxin to Nome Alaska in 1925 during an outbreak that killed thousands. This event highlighted the critical need for rapid medical intervention during respiratory epidemics.