BACILLUS ENTERITIDIS 395 



bacillus, while a low dilution is necessary for the typhoid 

 bacillus, then the case is likely to be paratyphoid fever. With 

 regard to the effects of other sera on the paratyphoid bacillus, 

 it may be said that usually a typhoid serum will require to be 

 used in greater concentration to clump this bacillus than is 

 necessary to obtain an effect with the typhoid bacillus itself. 

 Similar effects are observed when the sera of animals immunised 

 against Gaertner's bacillus or the bacillus of psittacosis are used. 

 In all serum tests the essential point is that deductions should 

 only be based on comparative observations of the highest dilu- 

 tions in which a clumping effect is produced with any series of 

 organisms compared. 



While the bacillus paratyphosus originates a disease resembling 

 typhoid fever, it has also been found in the stools of typhoid 

 patients, and mixed infections may thus occur. Both organisms 

 have been observed together in the stools in typhoid carriers, and 

 pure paratyphoid carriers are also stated to occur. A meat- 

 poisoning epidemic attributed to the bacillus paratyphosus has 

 been reported. Besides the septic cases already alluded to, the 

 organism has been isolated from cases of bone abscess, from 

 orchitis, and in Widal's case from a thyroid abscess, and in such 

 cases the history of a previous typhoid-like illness may not be 

 elicited. It has also been found in ordinary faeces, though 

 different observers have obtained different results with regard to 

 its relative frequency. In animal experiments it produces in 

 rabbits and guinea-pigs a fatal illness of a septicaemic type with 

 serous inflammations. 



While, as has been said, paratyphoid B is the organism most 

 often found in Europe, recent observations in India and Sumatra 

 point to paratyphoid A being of relatively frequent occurrence 

 in these countries. The illness associated with its presence lasts 

 from 9 to 14 days and is characterised by headache, pains in the 

 neck and loins, fever, occasionally by diarrhoea and bronchitis 

 and a rash (sometimes morbilliform). Few fatal results have 

 been recorded. The organism is present in the intestine and in 

 the blood. 



Bacillus Enteritidis (Gaertner). In 1888, Gaertner, in 

 investigating a number of cases of gastro-enteritis resulting from 

 eating the flesh of a diseased cow, isolated, from the meat and 

 from the spleen of a man who died, a bacillus closely resem- 

 bling the typhoid bacillus. Since then, in a great number of 

 similar outbreaks, similar bacilli have been found both in the 

 stools and in the organs. The cultural characters are those of 

 the group, except that in some strains the presence of an effect on 



