BACILLUS PARA-PERTUSSIS: A SPECIES RESEMBLING BOTH BACILLUS PERTUSSIS AND BACILLUS BRONCHISEPTICUS BUT IDENTICAL WITH NEITHER

Abstract

In the course of isolating 1,498 Phase I cultures of Bacillus pertussis from diagnostic cough plates, 10 cultures not conforming to Phase I criteria were isolated from 7 whooping cough patients. These cultures were studied as to morphology, cultural and serological characteristics, and certain reactions in animals. Agglutinin absorption tests were done, using antigens prepared from cultures of Bac. p., Bac. b., and 1 of the group of 10 cultures, respectively; and antisera for these respective cultures. Each of the 3 cultures completely removed the agglutinins for itself from each of the 3 anti-sera. Each culture removed the agglutinins for each of the other 2 cultures also from the antiserum produced against itself. However, it only partially absorbed these heterologous agglutinins from the sera produced against the other 2 cultures, respectively. Though closely related antigenically to both Bac. p. and Bac. b., these cultures were not identical with either. The significance of this group of 10 cultures in connection with whooping cough is not yet clear. The name Bacillus para-pertussis is suggested for the organisms descr., pending further investigation upon which to base a reasonable generic terminology.