372 A MANUAL OF BACTERIOLOGY 



tidis ; Welbeck in 1880 ; Middlesborough in 1888 ; Mans- 

 field in 1896 ; and Derby in 1902. A small outbreak 

 occurred at Bedford in 1907. 1 These outbreaks are usually 

 caused by varieties of the B. enteritidis having the general 

 characters of the group, which usually do not ferment 

 lactose, and are distinguishable by agglutination reactions 

 and fixation tests, the organism isolated as a rule agglu- 

 tinating well with the patient's serum. 



The B. enteritidis in morphology, motility, and staining 

 reactions resembles the B. typhosus, forms no, or only 

 traces of, indole, and changes neutral red to a fluorescent 

 yellowish colour. Litmus milk after a faint acidity becomes 

 alkaline, and is converted into a thin watery translucent 

 fluid, without coagulation. It does not attack either 

 salicin or glycerin. The fermentation reactions are given 

 in the Table on p. 381. Savage 2 obtained this organism 

 from only one out of fifty-three specimens of human 

 excreta examined. A number of variants were isolated 

 from various materials, some fermenting salicin, some 

 glycerin, and some both these substances (see " Meat," 

 Chap. XXI). 



Swine Fever or Hog Cholera 3 



Swine fever, or hog cholera (to be distinguished from swine 

 erysipelas, which see), is an infective disease of pigs, highly con- 

 tagious, and causing considerable mortality. The duration of the 

 affection is usually three to four weeks ; the animals lie about, 

 their temperature is raised, and they may suffer from cough and 

 frequent respiration, and some lameness in the hind legs. Towards 

 the end mucous diarrhoea is a prominent symptom. Post mortem, 

 the large intestine is found to be ulcerated, the ulcers much 

 resembling the typhoid ulcers of man, and according to Klein, 



1 PuUic Health, vol. xx, 1907-8, p. 310. 



2 Rep. Med. Off. Loc. Gov. Board for 1909-10, p. 446. 



3 See Uhlenhuth, Trans. Fourteenth Internal. Cong, of Hygiene 

 (Berlin, 1907), Bd. iv, p. 50 ; Journ. Roy. Inst. Pub. Health, 1911. 



