4 BULLETIN 674, U. S. DEPARTMENT OF AGRICULTURE. 



The bipolar staining property of the organism may be demon- 

 strated readily in preparations made from the tissues or body fluids 

 (kidneys, blood, etc.), cultures of the organism usually giving less 

 pronounced results in this respect. 



Attempts have been made during an outbreak of hemorrhagic 

 septicemia among cattle to transfer the disease from affected to 

 healthy animals by means of rubbing saliva from diseased cattle into 

 the mouths of healthy susceptible animals, and by injecting serum 

 from the blood of a diseased yearling beneath the skin of susceptible 

 young cattle, but without success. Many attempts to infect hogs by 

 natural means from diseased cattle also have failed. In one in- 

 stance, however, a colt that fed from the rack with a number of 

 diseased sheep contracted the disease and died. 



The spread of the disease seems to depend nearly as much upon 

 the condition and susceptibility of the animal as upon the contagious 

 nature of the disease, as thin, poorly nourished young stock most 

 frequently become infected and die of septicemia. 



In a number of outbreaks of a disease resembling hemorrhagic 

 septicemia in all its manifestations and anatomical changes an or- 

 ganism which differs in cultural characteristics from the true B. bi- 

 polaris septicus has been recovered. This organism proves to be 

 virulent for experimental animals (rabbits and guinea pigs), pro- 

 ducing in them changes suggestive of hemorrhagic septicemia. In 

 preparations from affected tissue or body fluids the organism stains 

 bipolar, and usually occurs singly or occasionally in pairs. It differs 

 from the true B. bipolaris septicus in that it appears slightly larger, 

 possesses a sluggish motility, and produces gas in sugar media. In 

 its cultural characteristics it corresponds in most instances to bac- 

 teria of the colon group, although some of the characteristics pos- 

 sessed by the paratyphoid B group have been noted. 



Bipolar ovoid bacilli which closely resemble the organism of 

 hemorrhagic septicemia are widely distributed in nature. They 

 have been found in the soil, upon various plants, in stagnant water, 

 and upon the moist nasal membranes of normal calves and hogs. 

 In several instances these harmless organisms have been so increased 

 in virulence by passing through animals that they finally proved to 

 be fatal when injected into pigs, and in those instances the tissue 

 changes, which were found at the autopsy of the pig, were similar 

 to those found in swine that had died from swine plague. 



It is thought by some writers that after the organisms have be- 

 come virulent enough to cause an outbreak among animals, they will 

 later, after that infection has been overcome, return to their ju'evious 

 harmless stage. The increased virulence which is made evident by 

 an attack of several animals of a single species appears to be effective 

 only in animals of that particular species, and the disease does not 



