Published online by Cambridge University Press: 15 May 2009
Inagglutinable strains of B. typhosus are of considerable interest bacteriologists both from a practical and theoretical aspect. These strains present the usual characteristics of the typhoid bacillus, with exception that they are not agglutinated by anti-typhoid sera, if and such a contingency be overlooked one may fail to recognise that one dealing with a typhoid infection. This feature persists in the subcultures for many months, thus differentiating the inagglutinable strains from the many strains of B. typhosus which agglutinate with difficulty when freshly isolated but which regain their full agglutinability after one or two subcultures. Since their discovery these inagglutinable strains have been investigated on several occasions without any definite agreement as to the condition being arrived at.