CHAPTER IV 
DISEASES CAUSED BY BACTERIA 
GENUS BACTERIUM 
General discussion of the genus bacterium. The genus Bacterium 
includes all rod-shaped, non-motile bacteria. The absence of: 
motility appears to be a logical, natural and sufficient reason to place 
these organisms in a genus by themselves. The only objection, that 
can reasonably be urged against it, from the pathologist’ spoint of 
view, is the changing of the generic name of a number of important 
pathogenic bacteria, such as those of anthrax, glanders, tuberculosis 
and others, from Bacillus to Bacterium.* This, however, is not 
serious but should be gladly welcomed if it enables us to-bring into 
groups for study diseases that are etiologically more closely related. 
It is for that reason that this classification is adopted. The further 
subdivision of the non-motile, rod-shaped bacteria into several genera, 
as found in more recent classifications, suggests the desirability of a 
more restricted grouping of diseases for study and comparison than 
the genera of their etiological organisms provide. In order to group 
the diseases due to closely related bacteria, Ligniéres introduced the 
term Pasteurelloses to include the diseases in different species of 
animals caused by bacteria represented by the bacterium of fowl 
cholera. Trevisan gave the generic name Pasteurella to this group 
of organisms. Hueppe designated them under the heading of 
Bacillus septicemiae hemorrhagice. He seems to have taken for his 
type the bacterium of Schweineseuche. 
Ligniérest grouped the diseases caused by the Pasteurella Trev. 
according to the animals affected. Thus, fowl cholera, rabbit 
septicaemia and swine plague are designated as the Pasteurelloses of 
birds, Pasteurelloses of rabbits, and Pasteurelloses of swine. He 
carries this classification to include all the diseases in all species of 
*It is important not to confuse the genus bacterium as revived by Migula with the 
same genus of early writers who characterized it as composed of non-spore bearing, 
rod-shaped organisms. 
fLicnikres. Contribution aI’ étude et a la classification des septicemies hem- 
orrhagiques les “Pasteurelloses.” Ann. del’ Instit. Pasteur, Vol. XV (1901), p. 734. 
AT 
