BACTERIAL EXAMINATION OF FAECES 349 



present appears to be of diagnostic value especially in the case of infants and young 

 children. Beautiful preparations may be made by mixing the faeces with water, then 

 centrif uging for one minute. This throws down vegetable debris and crystals. Now 

 decant the supernatant fluid, which holds the bacteria in suspension, and add an 

 equal amount of alcohol. Again centrifuge, decant, and smear out and examine 

 the bacterial sediment. 



Simply taking a small mass of faeces and emulsifying it with a 

 wooden toothpick on a concave slide in 70% alcohol then, after the 

 sediment settles, taking up a loopful with platinum loop from the sur- 

 face and smearing out, gives a very satisfactory smear. Gram's method, 

 with dilute carbol fuchsin counterstaining, gives the best picture. 



The Boas-Oppler bacillus may be found in the stools in this way. Normally, 

 a Gram-stained stool shows a great preponderance of Gram negative bacilli and such 

 a finding in a measure excludes cancer of the stomach. Organisms which are Gram 

 positive as well as the Boas-Oppler bacillus are, i. Lactic acid bacilli these show 

 Gram negative areas in the slender bacilli. 2. A type of bacillus similar in size to the 

 colon bacillus but Gram positive and noncultivable (found in acid stools). 

 3. Bacilli of the B. subtilis type. 



It is very important to examine the fasces for T. B. With children a diagnosis 

 of tuberculosis may be made in this way when the sputum cannot be obtained, 

 the pulmonary secretion being swallowed. The preparation on the concave slide 

 as described above should be stained for T. B. 



To culture for typhoid, dysentery, cholera, or other bacteria, take up the material 

 in a tube of sterile bouillon and smear it out with a swab over a lactose litmus agar 

 plate or an Endo or Conradi-Drigalski plate. Before streaking the plates they should 

 be very dry on the surface. This can be best done by pouring into a plate with a 

 circular piece of filter-paper in the lid and placing in the incubator for one-half hour 

 to dry. The filter-paper absorbs the moisture. Then inoculate the surface of the 

 plate with the faecal material. 



In summer complaints of infants and children the organisms con- 

 cerned are as a rule related to various dysentery strains of bacilli. 

 Kendall in 293 stool examinations found the gas bacillus (B. aerog^ 

 capsul.) in 22 cases. The gas bacillus produces intestinal disorders 

 which are not benefited by lactose but by buttermilk (lactic acid bac- 

 teria). For diagnosis, a loopful of the faeces is emulsified in a tube of 

 sterile milk or litmus milk. The emulsion is heated to 80 C. and held at 

 this temperature for 20 minutes. After incubation for 1 8 to 24 hours, 

 preferably anaerobically, we get (i) a shreddy disruption of the casein, 

 (2) the smell of rancid butter and (3) fully 80% of the casein is dissolved. 

 Smears show short thick Gram positive rods with slightly rounded ends. 

 B. Subtilis is sometimes found but does not give a rancid odor nor the 

 strong disruption of the clot. 



