VARIATIONS IN TYPHOID BACILLI 279 



taining glycerol. He showed that these cases were infected, in all prob- 

 ability from the same typhoid carrier, a woman who served as a milker 

 in a dairy near Munich. This w^oman harbored both typical and atypi- 

 cal bacilli. The B. metatyphi retained the property of producing alkali 

 in glycerol medium for five and one-half years when transplanted on 

 plain nutrient agar. Russowici (1908) reported one case of B. meta- 

 typhi, and Ditthorn and Luerssen (1912) reported two similar cases. 



Jacobsen obtained (1910) a bacillus which he described as B. typhi 

 mutahile from a small epidemic of clinical typhoid fever in an insane 

 asylum in Denmark. It resembled Bad. typhosum in all respects 

 except the following: 



1. It fermented mannitol after fifty hours. 2. Its growth was 

 strongly inhibited on Conradi-Drigalski agar or plain agar which had 

 been autoclaved. 3. Cultures from the plates showing retarded growth 

 did not agglutinate in typhoid immune serum, but cultures of the same 

 strain on media yielding good growth gave typical agglutination with 

 typhoid immune serum and resembled Bad. typhosum in all other 

 respects. B. typhi mutahile gave good specific agglutination five 

 months after its isolation. There was normal growth on the Endo 

 plates which removed the inhibitory action exerted on this strain by 

 other media. 



Fromme (1911) reports a bacillus, the growth of which was retarded 

 on nutrient agar but which grew in ascitic fluid, human blood, guinea 

 pig's blood, rabbit's blood and egg-yolk or on agar to which sodium 

 sulphite had been added. His bacillus differed from Jacobsen's in that 

 it agglutinated with typhoid immune serum from the start. 



The variants of typhoid bacilli — B. metatyphid (Mandelbaum), B. 

 typhi mutahile (Jacobsen) and the xylose non-fermenter of Weiss are 

 unquestionably true Bad. typhosum. 



Twort (1907) after growing a strain of Bad. typhosum for two years 

 in lactose media succeeded in producing a strain that fermented lactose. 

 He also conducted special experiments with a typhoid bacillus which 

 had acquired the power of fermenting dulcitol. When such a culture 

 was plated out on agar, subcultures from single colonies retained the 

 dulcitol splitting powers, although they were still capable of being 

 agglutinated by a typhoid immune serum, thus proving that the fer- 

 mentation was not due to any contaminating microbe. On inoculat- 

 ing the dulcitol-fermenting typhoid culture into a guinea pig, subcul- 

 tures were obtained showing the same reactions and these reactions 

 were also maintained, even when the organism was grown for several 



