The isolation of an X-dependent strain of haemophilus from otitis media identified as H. haemoglobinophilus (canis).

The growth factor requirements, together with the serological results, would seem to justify the view that strain M.G., isolated from a child, M.G., with otitis media, in pure culture has to be regarded as H. haemoglobinophilus (canis). It is interesting to note that two out of the three strains of H. haemoglobinophilus (canis) available in this laboratory agglutinate to a titre of 1:80 with the serum produced against H. aphrophilus, the only other X-dependent haemophilus we had used for the preparation of antiserum.