The Goulstonian Lectures on the Typhoid Bacillus and Typhoid Fever: Delivered before the Royal College of Physicians of London
Authors: P. Horton-Smith
Journal: BMJ (1900)

Introductory portion of the first lecture consisted nistorical account of the differentiation effected by liam Jenner between typhoid fever and typhus fever, recognition of the typhoid bacilli by Eberth.The then proceeded to discuss the methods which should be ployed in identifying the typhoid bacillus.He laid especial stress on the serum test when performed in dilutions least I in I,ooo, but pointed out that positive results obtained with lower dilutions could not be relied upon.He then ceeded to ask:] Are we justified in saying that a bacillus which is slightly sensitive to a strong typhoid serum is therefore the typhoid bacillus,' even though in all other respects may resemble the latterP In other words, are all typhoid bacilli agglutinated by a given serum to an exactly equal tent?In the opinion of most observers this is the case, Van de Velde,1 from observations on twenty different typhoid stocks, found very considerable variations in the clumping power.The following observations also show thatusing i8-hour broth cultures, as is now the usual practice, marked variations in the clumping power manifested by different typhoid bacilli dole exist.ln these experiments typhoid serums of differenttyphoid clumping power were tested against the laboratory standard typhoid bacillus, and also against typhoid isolated from stools, urine, mesenteric glands, and spleen- bacilli which, be it remembered, were found to resemble typhoid bacillus in all respects both morphologically and turally.As a result it was found that their clumping differed most materially, some refusing to clump at all, agglutinating with ease.If broth cultures be used, typhoid bacilli often markedly among themselves in the ease with which affected by the typhoid agglutinins.With cultures media, however, the case is different.Thus it is not mon to find that while a broth culture of a given bacillus cannot be agglutinated at all, the agar culture same bacillus may be easily and rapidly clumped by the serum which failed with the broth culture.This extraordinary difference I have noticed in the case of six typhoid bacilli, iso- lated from different patients (and in a seventh case result was obtained on using a gelatine culture), so not really be rare.It is possible, too, that it should associated with a fact observed by Kraus,2 who showed broth cultures of the typhoid bacillus be incubated days, and be then filtered, the filtrate gave rise, tion of typhoid serum, to a precipitate closely resembling appearance that produced by agglutinated micro-organisms.The reaction was specific, and only occurred when serum was added.It may be that the constituent bacillary body, on which the agglutinins act, and which seems normally to pass into the surrounding liquid, some cases diffuse much more easily, and even after four hours be no longer present in the bacilli themselves.We should thus have an easy explanation of the absence the reaction in the broth-grown bacilli, and its presence those obtained from solid :media.Be this as it may, obvious moral to be drawn from the fact is that in testing agglutinable qualities of a suspected bacillus, cultures solid media should always be used, and especially agar cultures.So far, too, though myl experiments are not enough for me to speak with certainty, I have not more than slight differences in agglutinable capacity different typhoid bacilli, provided agar cultures Pfeifer's Test.-Should, however, a bacillus be which culturally or morphologically resembles bacillus in all respects, and which yet agglutinates or not at all, then one further test must be applied to itnamely, Pfeiffer's test.This consists in injecting peritoneum of a guinea-pig a lo-times fatal dose of the bacillus in question, together with a very small quantity (o.ooi c.cm. may be quite sufficient) of typhoid serum a highly-immunised animal.If the bacillus in question be the typhoid bacillus, then while a control animal injected only with the bacillus will die this animal will recover, the bacilli being converted first into granular masses (Pfeiffer's phenomenon) and then gradually disappearing under the in- fluence of the lysogenic properties of the serum.serum, however, is specific, and can therefore only protect, in minute doses, against the corresponding micro-organism.If, therefore, the bacillus in question be not the typhoid bacillus, but some variety of bacillus coli, the animal will infallibly die like the control animal.This test is of the highest