630 



Typhoid Fever 



its environment. Levy and Kayser* found it still alive in soil that 

 two weeks previously had been manured with the five months old 

 contents of a privy vault. From privy vaults and from infected 

 soils it may easily find its way into wells and streams. Gartnerf 

 found that it lived long enough to be transported a distance of 140 

 kilbmeters in running water. Jordon, Russell and ZeitJ found it 

 alive and retaining its virulence for five days in natural bodies of 

 water. 



Morphology. — The typhoid bacillus measures about i to 3 m (2 to 

 4 n — Chantemesse, Widal) in length and 0.5 to 0.8 m in breadth 

 (Sternberg). The ends are rounded, and it is exceptional for the 

 bacilli to be united in chains. The size and morphology vary with 

 the nature of the culture-medium and the age of the culture. Thoi- 



Fig. 255. — Bacillus typhosus. 



not and Masselin,§ in describing these morphologic variations, point 

 out that when grown in bouillon the typhoid bacillus is very slender; 

 in milk it is stouter; upon agar-agar and potato it is thick and short; 

 and in old gelatin cultures it forms long filaments. It produces 

 no spores. 



Flagella.^ — ^The organisms are actively motile and are provided 

 with numerous flagella, which arise from all parts of the bacillus 

 (peritricha), and are 10 to 20 in number. They stain well by 

 L6fl3er's method. The movements of the short bacilli are oscillating; 

 those of the longer bacilli, serpentine and undulating. 



Staining. — The organism stains quite well by the ordinary meth- 

 ods, but not by Gram's method. As it gives up its color in the pres- 

 ence of almost any solvent, it is difficult to stain in tissue. 



* "Centralbl. f. Bakt. u. Parasitenk," 1903, xxill, 489. 



t Klinisches Jahrbuch, 1902, 335. 



t "Jour. Infectious Diseases," 1904, I, 641. 



§ "Pr6cis de Microbie," Paris, 1893. 



