Explore the recorded discovery and history of Corynebacterium diphtheriae, with source links and stated limits.
CDC describes diphtheria as any illness caused by a toxin produced by some strains of C. diphtheriae, and toxin production depends on a bacteriophage carrying the tox gene. Respiratory diphtheria is the most serious form, where a thick grey pseudomembrane of dead tissue can build up in the nose and throat; skin infection is a separate presentation. People can carry the organism without becoming ill and still pass it on. Throat illness resembling diphtheria was described in antiquity, long before the bacterium was observed in 1883.
CDC records that the bacterium was first observed by Edwin Klebs in 1883. Illness resembling diphtheria had been described much earlier, which CDC traces to Hippocrates in the 5th century BCE.
CDC records that Friedrich Löffler cultivated the organism in 1884, the year after it was first observed. Cultivation is a separate milestone from observation.
LPSN records Bacillus diphtheriae Kruse 1886 as the basonym for this species.
LPSN records the current name as (Kruse 1886) Lehmann and Neumann 1896, published in their bacteriology atlas and placed on the Approved Lists of 1980, with type strain ATCC 27010 / NCTC 11397.
CDC states that diphtheria toxoid was developed in the 1920s and was incorporated into routine vaccination with tetanus and pertussis components in the 1940s. This event is dated to the start of that decade because the source gives a decade rather than a year.
These references do not establish the first person ever infected. Discovery, naming and isolation milestones do not date biological origin or a patient zero.
Source check: 2026-09-19. Educational content; independent scientific review remains pending.