488 Typhoid Fever 



As the isolation of a pure culture of the typhoid bacillus 

 from the spleen is sometimes difficult because the groups of 

 bacilli are scattered throughout the organ, E. Frankel recom- 

 mends that as soon as the organ is removed from the body it 

 be wrapped in cloths wet with a solution of bichlorid of mer- 

 cury and kept for three days in a warm room, in order that 

 a considerable and massive development of the bacilli may 

 take place. 



Cultures of the typhoid bacillus may also be obtained 

 from the blood, and with much more difficulty from the 

 alvine discharges of typhoid patients during the second and 

 third weeks of the disease. 



Numerous methods for facilitating the isolation of the 

 bacillus have been suggested in the hope that they could 

 be practically applied to the diagnosis of the disease. Thus, 

 as numerous saprophytic bacteria are always present in the 

 feces, the resistance of the typhoid bacillus to carbolic acid 

 has been made use of in obtaining the pure culture. To 

 each of several tubes of melted gelatin 0.05 per cent, of 

 carbolic acid is added. This addition is most easily calcu- 

 lated by supposing the average quantity of gelatin contained 

 in a tube to be 10 c.c., when the addition of o.i c.c. of a 5 

 per cent, solution of carbolic acid gives nearly the desired 

 quantity. A minute portion of feces is broken up with a 

 platinum loop and stirred in the tube of melted carbolized 

 gelatin; a drop from this dilution is transferred to the 

 second tube, and a drop from it to a third, and then the 

 contents of each tube are poured upon a sterile plate, into 

 a sterile Petri dish, or rolled, according to Esmarch's sug- 

 gestion, upon its own walls. The carbolic acid prevents 

 the majority of saprophytes from developing without inhibit- 

 ing that of the typhoid bacillus and, unfortunately, Bacillus 

 coli communis. 



Cultivation. Colonies. The deep colonies upon gela- 

 tin plates appear under the microscope of a brownish- 

 yellow colorand spindle shape, and are sharply circumscribed. 

 When superficial, however, they become larger and form a 

 thin, bluish, iridescent layer with notched edges. The 

 superficial colonies are often described as resembling grape- 

 vine leaves in shape. The center of the superficial colonies 

 is the only portion which shows the yellowish-brown color. 

 The gelatin is not liquefied. 



Differentiation. Unfortunately, the appearances of the 



