EDWIN O. JORDAN 445 



number of different animal species' may be caused by B. enteritidis, but bovine sources 

 of human-food poisoning seem relatively frequent, milk, beef, or veal being the more 

 commonly reported vehicles of infection. Karsten- considers B. enteritidis to be the 

 usual cause of paratyphoid disease in calves. Another source of human infection with 

 B. enteritidis appears to be accidental contamination of food with the commercial 

 rat viruses which usually contain this organism.' Several recorded outbreaks have 

 been traced to this cause (e.g., Spray).^ 



B. aertrycke is the name now commonly given to an organism with many of the 

 B. schottmiiUeri (B. paratyphosus B) characteristics, but of genuinely specific nature. 

 It is not certain that the bacillus isolated by De Nobele in a food-poisoning outbreak 

 in Aertryck was the exact prototype of the organism now called B. aertrycke, but there 

 is some evidence that favors this presumption. For a time B. aertrycke was definitely 

 identified with B. schottmiiUeri by many German bacteriologists. t On the other hand, 

 English bacteriologists long regarded it as identical with B. suipestifer.^ Schiitze,'' 

 however, showed clearly that a definite serological difference existed between the 

 Aertryck or "mutton" type and the Schottmiiller type. I have elsewhere set forth 

 cogent reasons for regarding B. aertrycke as an independent form culturally and 

 immunologically, although closely related to B. schottmiiUeri.'' 



B. aertrycke, while often found in spontaneous epidemics in laboratory animals, 

 is not a distinct rodent type, as believed by Krumwiede, but is found frequently in 

 infections of many other animal species such as cattle and sheep. ^ It has been reported 

 in a relatively large number of human food poisoning outbreaks.' Savage and White, 

 in their study of one hundred recent outbreaks in Great Britain, record the positive 

 isolation of B. aertrycke in fourteen instances and consider this organism the more or 

 less probable causal agent in thirteen others. In the same series, as stated above, 

 B. enteritidis was isolated but once and suspected in but three other instances. This 

 corresponds with the large number of food poisoning outbreaks due to B. aertrycke 

 that have been reported by various German writers, provided we assume that most 

 of the Paratyphosus B bacilli are of the B. aertrycke type. 



So far as can be determined from the published accounts, the symptoms produced 

 by B. aertrycke and B. enteritidis show no noteworthy divergence. Either organism 

 may cause death; whether any difference in case fatality exists cannot be determined 

 from the meager data available. 



'Jordan, E. O.: J. Inject. Dis., 36, 309. 1925. 



* Karsten: Der Paratyphus der Kalber. Pp. 109. Berlin, 1921. 



3 Spray, R. S.: loc. cil. 



4 Hiibener, E.: loc. cit. 



s Cf., e.g., Bainbridge, F. A., and O'Brien, R. A.: J. Hyg., 11, 68. 1911; Savage, W. G.: Rept. 

 to Loc. Gov. Bd. (N.S.), No. 77. 1913. 



^Schiitze, H.: Lancet, i, 93. 1920. 



7 Jordan, E. O.: op. cit., 33, 567. 1923. ^ Jordan, E. O.: ibid., 36, 309. 1925. 



'From the following outbreaks: Savage, W. G., and Gunson, C. H.: /. Hyg., 8, 601. 1908; 

 Robinson, G. H.: /. Infect. Dis., 16, 448. 1915; McWeeney, E. J.: op. cit., 2, 451. 1916; Delepine, 

 S.: /. Hyg., 3, 68. 1903; "mutton" strain of English writers: Comrie, J. D., and Bird, G. A.: 

 /. Roy. Army M. Corps, 33, 34. 1919; Young, W. A., and Dawson, G. D.: Lancet, 203, 609. 1922; 

 Winslow, C.-E. A., et al.: Am. J. Hyg., 3, 238. 1923; unpublished report to Washington State 

 Board of Health, obtained through Dr. J. C. Geiger; Salthe, O., and Krumwiede, C., Jr.: Am. J. 

 Hyg., 4, 23. 1924. 



