Journal of Hygiene

Research Article

The Phases of Haemophilus pertussis

P. H. Lesliea1 and A. D. Gardnera1

a1 (From the Sir William Dunn School of Pathology, Oxford.)

Haemophilus pertussis is a uniform species, without fixed varieties or “types.”

After isolation from the human subject it tends to pass through a series of antigenically distinct phases, of which the first two are toxic to guinea-pigs, whereas the last two are relatively harmless. The former probably correspond to the smooth, the latter to the rough phase of other bacteria.

The phase-changes are, up to a point, reversible.

Experiments on guinea-pigs have produced some evidence that the toxic Phase I is the best and perhaps the only antigen for the production of active immunity in guinea-pigs.

(Received February 13 1931)