398 ERYSIPELOTHRIX AND LISTERELLA 



Inoculation of Erysipelothrix into Animals 



Swine. — Loeffler (1886), who first isolated the swine erysipelas bacillus, failed to 

 reproduce the disease in swine with pure cultures, but Schiitz (1886) later succeeded in 

 doing so. Broth cultures injected subcutaneously proved fatal to two pigs, one animal 

 dying in 3, the other in 4 days ; there were typical findings at the necropsy, and the bacilli 

 were recovered in pure culture from the blood and spleen, and from the pleural and peri- 

 toneal exudates. Artificial cultures rapidly lose their virulence for swine. Collins and 

 Goldie (1940) produced polyarthritis by repeated intravenous inoculation of cultures. 

 In addition there was a focal inflammatory polyarteritis, focal necrosis of the liver and 

 myocardium, lymphadenopathy, a monocytosis, and endocarditis, but skin lesions were 

 never found. 



The bacillus is pathogenic for mice, pigeons, and rabbits, but not for guinea-pigs. 



Mice. — 0-001-01 ml. of a 24-hour8' broth culture injected subcutaneously or intra- 

 peritoneally is usually fatal in 2 to 3 days. During life the mice develop conjunctivitis 

 and their lids become glued together with a mucopurulent secretion ; arching of the back 

 is very common, and constipation is usual. Post mortem, the vessels of the skin and 

 subcutaneous tissue are congested, the spleen is enlarged, and the lungs are bright red and 

 oedematous. Bacilli are usually abundant in the blood and viscera ; they are found 

 particularly within the phagocytic cells, in which they appear to multiply (Tenbroeck 1920). 



Pigeons. — O-001-O-l ml. of a 24-hours' broth culture inoculated intramuscularly proves 

 fatal in 3 or 4 days as a rule. Death is often preceded by paralysis of the legs, dyspnoea, 

 and convulsions. Post mortem, there is a black hseraorrhagic mass in the muscle at the 

 site of inoculation ; the spleen is enlarged ; there are often punctiform haemorrhages in 

 the mucosae and viscera ; and there is almost constantly a clear lemon-yellow exudate 

 in the pericardium (Crimi 1914). The bacilli are fairly numerous in the blood and organs. 



Rabbits. — 0-5 ml. of a 24-hours' broth culture inoculated intravenously sometimes 

 proves fatal in 2 to 3 days. A marked oedematous swelling or erysipelatous rash develops 

 in the injected ear, and there is a rise in temperature and a loss in weight. Post mortem, 

 besides the rosy skin lesion, there is congestion of the viscera, and often a clear lemon- 

 yellow pericardial exudate ; there may be large haemorrhages into the lungs. The bacilli are 

 scarce. If the disease is not acutely fatal, a monocytosis occurs, reaching its maximum 

 in 3 to 7 days. In animals dying about this time occasional tiny focal necroses may be 

 found in the liver, and areas of mononuclear cell reaction may be seen in sections of the 

 spleen. Inoculation of the conjunctiva gives rise to conjunctivitis, which often proves 

 fatal. After subcutaneous inoculation death seldom occurs. 



Inoculation of Listerella into Animals 



Fish. — Hettche (1937) and Brunner (1938) have shown that both freshwater and sea 

 fish can be readily infected by feeding or by intraperitoneal inoculation with the bacilli. 

 The organisms are widely distributed iia the tissues and may be recovered after several 

 weeks. They are particularly abundant in the kidneys and are excreted in the urine. 

 The infection appears to be of the covert type, the fish showing no evidence of illness. 



Mice. — Subcutaneous or intraperitoneal inoculation of 100 million living organisms 

 of a highly virulent culture causes death in about 1 to 4 days. During life conjunctivitis 

 sometimes occurs. At post mortem multiple tiny focal necroses are found scattered 

 throughout the liver. The organisms can be readily recovered from the spleen and heart 

 blood. 



Rabbits. — Intravenous inoculation proves fatal in 24 hours or not for several days 

 according to the dose and virulence of the strain. Animals surviving for some time 

 develop a monocytosis, which reaches its maximum in about 3 to 7 days. Post-mortem 

 examination of animals dying after a few days reveals the presence of multiple focal 

 necroses in the liver, and rarely in the spleen and myocardium. Necrosis of the supra- 



