BACILLUS ENTERITIDIS OF KLEIN 
49 
than in a control culture, though it is usually still typical. If the milk was com- 
pletely oxygenated by this process it is probable that an atypical culture would result. 
To return, I think it has been shown that bacillus enteritidis sporogenes is, 
as Hewlett thought, a ubiquitous organism ; that enteritidis spores of normal viru- 
lence contaminate food which is eaten with impunity. The wide distribution 
of the bacillus was unknown when it was first called a ' diarrhoeal ' * organism. I 
admit it is possible that under certain unknown conditions bacillus enteritidis sporo- 
genes may be pathogenic on the human intestine ; but so may any other bacillus. 
Referring to the frequency of enteritidis spores in milk consumed without toxic effect, 
Klein suggests that ' much may depend on the strain of bacillus enteritidis which 
obtains entrance into the milk,' also on certain atmospheric 'chemical or other' 
conditions. 
The diarrhoea epidemic at St. Bartholomews in 1895 ' appeared referable' to 
the presence of enteritidis spores in certain milk. But there is no definite proof that 
the spores were present in this toxic milk, for no specimen of it was available for 
examination. It is true that enteritidis spores were detected in a sample obtained 
three days after the epidemic from one farm, which had supplied the hospital on the 
day of the outbreak with only about nine per cent, of the total milk consumed. 
The second epidemic was also attributed to milk, which unfortunately does 
not appear to have been submitted to any chemical or bacteriological examination 
beyond the isolation from it of a particular ' ubiquitous' microbe. 
Rice pudding was the incriminated diet in the third epidemic. Dr. Andrewes 
states that, on microscopical examination of the pudding, not only was an enteritidis-like 
bacillus detected, but also other organisms, namely, ' cocci and small bacilli resembling 
lactic acid bacillus.' Bacillus enteritidis was isolated in a non-sporing condition from 
the pudding ; yet no further investigation was made into the ' nature ' of the other 
organisms. f 
But, even if the enteritidis in the rice pudding was ' the direct cause of the 
disease,' from what ingredient was it derived, from the rice, from the sugar, or from 
the milk ? And how can sanitary authorities hope to prevent epidemics of diarrhoea 
due to a bacillus which, though frequently present in 'quite innocent substances' and 
eaten with impunity, is occasionally exceedingly pathogenic ? 
The third main reason for associating enteritidis with diarrhoea appears to be 
its pathogenicity to rodents as guinea-pigs. But even if cultures of a micro- 
organism grown in favourable conditions are pathogenic when inoculated under the 
skin of a guinea-pig, why should that organism necessarily, or even probably, be 
pathogenic to the intestine of man ? Guinea-pigs fed on cultures of enteritidis are 
not attacked with diarrhoea, which is truly fortunate considering the bran and oatmeal 
they eat frequently contain enteritidis spores of normal virulence. 
* Medical Officer's Report, Local Government Board, 1895-96, p. 204. 
t Lancet, January 1899, p. 9. 
E 
