188 Medical Bacteriology. 



BACILLUS ICTEROIDES. Make agar streaks from blood or fragment of liver (where liver is 

 obtained it is best wrapped in cloth and kept in incubator at 38C. for 12 hours before 

 cultures are made to encourage development of the micro-organisms, which are usually 

 only sparingly present in tissue). Keep the cultures at 38C. for 12-16 hours and 

 then at 22C. for same time; the characteristic appearance is a transparent, bluish 

 growth surrounded by an opaque zone. If this is not obtained other cultures must be 

 prepared and a thorough study of the organisms isolated made. 



REFERENCES, v. J. 45; S- 79. See also texts under particular organisms. 



WIDAL REACTION. Directions for collecting samples of blood. " Wash with boiled 

 water the part from which the blood is to be obtained (lobe of ear, end of finger, or toe 

 in infant). Prick deeply the skin with a clean needle." Remove two or three large drops 

 of blood on a clean glass slide, alluminum foil, piece of isinglass or letter paper. 



Allow the blood to dry. Then place in an envelope and send to laboratory and test 

 as follows : 



a. Make a hanging drop preparation from a 24-72 hour old agar, or bouillon, cul- 

 ture of Bacillus typhosus. 



b. If the bacilli are actively motile, remove the cover-glass, add to the culture a 

 small drop of a solution of typhoid blood (diluted from 10-50 times), return the cover- 

 glass to the slide and seal well with vaselin. 



c. Examine with a high dry power (| in. obj.) rather than with the oil immersion. 

 In a typical reaction the motility is almost immediately affected and soon motion 



ceases altogether while the bacilli collect in clumps, i. e. become "agglutinated." 

 REFERENCES, v. J. 45; S. 79. See also texts under particular organism. 



EXERCISE CIX. EXAMINATION OF FAECES. 



The material expelled from the rectum and comprising the substances from the 

 food and the secretions of the alimentary tract come under this head. The number of 

 micro-organisms occuring here is enormous, and comprise a large number of species and 

 among them several pathogenic forms particularly B. typhosus. M. comma, B. tubercu- 

 losis and Amoeba coli. 



BACILLUS TYPHOSUS. This organism occurs in the faeces in the case of typhoid pa- 

 tients, but on account of the large number of other organisms its detection is very diffi- 

 cult The following methods are the most serviceable : 



Parietti's Method. This method consists in adding Parietti's solution (carbolic 

 acid 5 grams: hydrochloric acid 4 grams, and distilled water 100 cc.) to bouillon in 

 the following manner: A number of tubes of bouillon have a varying quantity of the 

 above solution added, e. g, 1 drop to one tube, 2 to another, 3 to another, and so on. 

 These tubes are inoculated with a small quantity, (one or two loops), of the faeces 

 and then placed in the 38 C- incubator. Twenty-four hours later the tube containing 

 the largest amount of Parietti's solution which shows growth probably contains B. coli 

 and B. typhosus if it is present. The organisms may be separated most quickly and 

 easily by the use of the lactose litmus agar plate. The blue colonies should be worked 

 up, and especially tested for its agglutinating power on typhoid blood. Instead of the 

 use of the lactose litmus agar plate, either Eisner's or Hiss' methods may be used. 



