416 A MANUAL OF BACTERIOLOGY 



to grow on re-inoculation (Chatterjee *). B. typhosus will 

 develop in a slightly acid medium and in media con- 

 taining malachite green, brilliant green and china green 

 dyes and caffeine, which inhibit the growth of B. coli. 



The B. typhosus grows well in milk without curdling 

 and with a slight permanent acidity (Winslow, Kligler 

 and Rothberg state that in a very pure fresh milk after a 

 fortnight there is a reversion to a neutral or faint alkaline 

 reaction). It ferments hexoses, maltose, xylose, mannitol, 

 sorbitol, and dextrin with acid production only, but not 

 lactose, sucrose, arabinose and dulcitol. It is sharply 

 differentiated from other similar organisms by agglutina- 

 tion reactions. 



It is of interest that B. typhosus, in centra-distinction 

 to other members of the group, shows comparatively 

 little variation and forms a singularly homogeneous 

 race. 



Pathogenicity. In cases of typhoid fever in man the 

 Bacillus typhosus is widely distributed in the body, in the 

 various tissues, and in the blood, from which it may be 

 obtained by cultivations made from at least 0-5 c.c. (see 

 " Clinical Diagnosis," p. 430). The bacillus is constantly 

 present in the blood from the commencement of the 

 disease, though not in large numbers, and cultures from 

 the blood in competent hands result in the recovery of the 

 organism in approximately 100 per cent, of the cases ; in 

 the later stages of the disease it is less frequently recovered. 

 In addition to being present in the Peyer's patches, 

 mesenteric glands, and spleen, the B. typhosus has been 

 found in the rose-spots of the eruption, in the sweat, in the 

 sputum and lungs in the pulmonary complications, and 

 in the urine. In the urine it is so frequently present that 

 special disinfection should be practised, more particularly 

 during convalescence, and in some cases it may be so 



i Trans. XlVth Internal. Cong, of Hygiene (Berlin, 1907), Bd. iv, p. 34. 



