268 BACTERIA IN OTHER FOODS 



Meat-poisoning appears to depend not upon the number of 

 bacteria present in the meat, but upon the particular species and 

 their products. As we have already stated, a long incubation period 

 generally indicates poisoning by bacteria, and a short incubation 

 period poisoning by products (ptomaines, toxins, etc.). In 1888, 

 Gaertner of Jena investigated an outbreak of disease affecting 58 

 persons who had eaten uncooked meat. One of the unfortunate 

 victims died, and from his body, as well as from the meat, Gaertner 

 isolated a bacillus which he called the B. enteritidis, an organism 

 allied to the coli group. This was practically the starting-point of 

 accurate bacteriological investigation into this group of epidemics 

 (Jleischvergiftung, Ger. ; and irUoxications alimentaires, Fr.). Since 

 that period, the B. hotulinus of Ermengem, and certain putrefactive 

 bacteria, have been held responsible for causing such illnesses. 

 More than twenty different species of bacteria have been isolated 

 from tinned meats and hams. As is pointed out elsewhere in the 

 present volume, there is evidence that the infectious properties which 

 food acquires frequently in summer, and which give rise to the 

 ordinary type of epidemic diarrhoea, are due to bacilli belonging to 

 the colon group, of which the B. coli communis of Escherisch and the 

 B. enteritidis of Gaertner are the two extreme types. According to 

 DeMpine, the varieties of those bacilli which are the most important 

 sources of infection are those which resemble the bacillus of Gaertner, 

 and which, therefore, produce no permanent acidity, coagulation, or 

 distinct smell when grown in milk. Very few infectious samples of 

 milk give a distinct acid reaction, so that absence of acidity in milk 

 is not, as generally believed, an index of safety. It is probable that 

 the most dangerous kind of faecal infection is that produced by matter 

 containing bacilli resembling Gaertner's bacillus. Such an infection 

 is probably connected with the existence of an infectious diarrhceal 

 disease liable to occur in the lower animals as well as in man. 



It is certain that bacilli presenting the characters of the ordinary 

 B. coli communis are seldom capable of producing such a rapid 

 infection as that produced by the B. enteritidis, or by closely-allied 

 bacilli, such as the B. enteritidis JDerhiensis. 



The last-named organism is a member of the Gaertner group 

 isolated by DeMpine from pork pies, the consumption of which 

 caused the Derby illness in 1902. He considered the presence of 

 this bacillus in the pork pies was due to faecal pollution of the 

 meat before it was cooked, and that the central parts of the pies 

 were not thoroughly cooked.* It frequently happens in these cases 



* Report on Outbreak of Pood-Poisoning in Derby, 1902 (Howarlh and Del^pine). 

 In this reference, and in Brit. Med. Jour., 1898, ii.' pp. 1456-58 and 1797-1801, and 

 ibid., 1899, vol. ii. , pp. 791, 1367, will be found many particulars with regard to 

 meat-poisoning, its symptoms, prevention, investigation, etc. 



