124 STUDY AND IDENTIFICATION OF BACTERIA 



Paratyphoid B. not only gives symptoms resembling a mild typhoid infection, 

 but may show symptoms more like those of meat poisoning or even cholerine. It 

 is more pathogenic for laboratory animals than is B. typhosus. The development of 

 antibodies upon immunizing a man or animal with paratyphoid organisms does not 

 seem to approach that obtained with typhoid. 



Castellani has conducted experiments with typhoid and paratyphoid vaccines 

 and has found that typhoid vaccines give an agglutinating serum of about i to 350 

 titre from the second to fifth week dropping to about i to 100 after three or four 

 months. Paratyphoid A. gives one of about i to 75 for the first month which drops 

 to about i to 60 after four months. Paratyphoid B. gives about one-half the 

 agglutination response that paratyphoid A. does. 



Bacillus Enteritidis (Gartner, 1888). This organism has been fre- 

 quently isolated from cases of gastroenteritis from ingestion of infected 

 meat. 



Meat from healthy animals which has been in contact with that of diseased 

 animals may become infected. The simple act of placing a piece of infected meat 

 on a sound piece may infect the latter. It has been noted that the bacteria, or their 

 toxins, may be distributed unevenly in the meat eaten, so that one person consuming 

 the same meat may be made very ill while others eating this meat may escape 

 infection. Infection of food may occur not only from unclean handling but from the 

 material carried by flies or even from the faeces of mice or rats deposited on 

 foodstuffs. 



This organism is very pathogenic for laboratory animals, producing a haemor- 

 rhagic enteritis and at times a septicaemia. Where meat has been contaminated with 

 Gartner's bacillus toxins may have been produced, and symptoms of poisoning with 

 acute gastroenteritis would occur shortly after ingestion. This is not a true toxin 

 as it does not require a period of incubation before manifesting its toxic action. It 

 is interesting to note that this toxin is not destroyed by the boiling temperature, thus 

 differing from the toxin of the other important meat-poisoning (botulism) bacillus 

 B. botulinus which is rendered innocuous by a temperature of 65 or 7oC. If 

 there is only a little toxin introduced with the contaminated meat, the symptoms 

 will be delayed one or two days. Such organisms have been isolated in pure culture 

 from cases with high fever, marked intestinal derangement, with considerable blood 

 in the rather fluid stools. In two cases studied the disease was at first diagnosed 

 as a severe typhoid infection. Klein thinks the organism of Danysz's virus (to 

 kill rats during plague epidemics) may be identical with B. enter itidis. 



Proteus Vulgaris. This organism is often encountered in plates 

 made from faeces, or sewage contaminated water. 



It is common in decaying meat or cheese, and cases of even fatal poisoning 

 with marked gastrointestinal symptoms and cardiac failure have been reported. 

 At times it is the cause of cystitis. The colonies on agar are moist and unevenly 

 spreading (amoeboid). The bacilli are very motile, long and slender, tend to form 

 filaments and, as a rule, are Gram-negative. It digests blood-serum and is a rapid 

 liquefier of gelatin. In litmus milk it coagulates with a soft clot and an alkaline 



