A New Method for the Isolation of Organisms from Faeces and Sputum, with some observations on Haemolytic Streptococci in Faeces obtained by this Method

Abstract

PROFESSOR L. S. DUDGEON, wheni consulting bacteriologist to the Forces in the Balkans during the late war, had tried the effect of drying the stools of suspected dysentery patients on some porous material so as to leave only the Imiucus. In bacillary cases he found that a more abundant growth of dysentery bacilli was obtained from the dried mucus than from the untreated specinen, so that the drying had no harmful effect on the organisms. He used for this purpose unglazed red tiles such as were to be found locally, and suggested that the inethod should be given a more thorough trial with a more satisfactory type of tile made in this country. With this view the following experiments were inade. DUDGEON'S METHOD.A portion of the faeces, about a small teaspoonful, is evenly spread over a porous tile resting on an asbestos mat and allowed to dry for from 30 minutes to two hours, at room tenmperature, according to the amount of water or mucus in the specimen. When the faeces are dried to a stiff paste, this is scraped off and evenly spread on a second tile and allowed to dry for a further one to two hours or until it has become a fine dry powder when scraped off. A quantity of this dry powder is transferred to a plate, and evenly spread over the surface with a glass spreader. If the faeces are liquid, as much as possible should be poured on the first tile short of letting it run over the edge. By using two tiles one after the other, it will be found that however liquid the faeces are, or however much mucus is present, complete drying can be obtained. It is important, in order to get the best results, that the material should be coinpletely dried on the second tile before plating, and when scraped off, be in the form of a sand-like powder, with no trace of stickiness.By this method excellent separation of individual colonies is obtainied over the whole surface of the plate with no tendency to run together so that suspicious colonies can be picked off with ease. It is quick, and since it is equally 1 Thie expenses of this investigation were defrayed by a special grant fiom Mr Louis Oppenheimer to whom I a.m greatly indebted.

The Haemolytic Organisms of Normal Infants' Faeces

“…The stools were dried by Dudgeon's method as detailed by Wordley (1921). A moderately thick layer of faeces was spread on a sterile unglazed porcelain tile and allowed to dry in the air at room temperature under a glass bell jar.…”

“…The heat resistance of the streptococci was examined by the method employed by Wordley (1921). The organism was cultivated in beef broth for 24 hours and the culture was then placed in a water bath at 600 C. for half an hour at the end of which time it was allowed to cool to room temperature for one hour.…”

“…Twentytwo strains were found to be haemolytic streptococci which fermented lactose and salicin, but not mannitol or inulin. Wordley (1921), by using Dudgeon's method was able to isolate streptococci from all the samples of faeces which he examined. He obtained 52 strains of streptococci from the faeces of 19 adult patients suffering from a variety of diseases and 33 normal persons, and found that 13 of these strains were haemolytic on blood agar and that 11 strains also caused haemolysis of human red cells in peptone water cultures.…”

The Bacteriological Examinations of the Faeces in Four Cases of Typhoid Fever, made at frequent intervals for a period of one month

“…The general character of the stool, and its reaction to litmus was noted, a small portion of the stool was then dried by the method devised by Dudgeon and described by Wordley (1921).…”

OnBacillus coliInfections of the Urinary Tract especially in relation to Haemolytic Organisms

“…Reference has already been made (Section I a) to the bacteriological findings of the faeces in 12 cases of colon infection of the urinary tract. The method employed for the examination of the faeces is that introduced by one of us (L. S. D.) and described in detail in our first communication and by Wordley (1921). The dried faeces were spread on agar plates to which whole fresh human blood had been added at 45 to 500 C. and those colonies which were haemolytic by this method were tested in the liquid media for haemolysis.…”