Chapter XI 



— 171 



Human and Animal Diseases 



ScHABAD (388) considered the existence of another group of micro- 

 organisms which stand midway between the actinomycetes and the 

 tuberculosis group and which are capable of causing infection in man. 

 These were looked upon as atypical actinomycetes, causing diseases 

 similar to actinomycosis. The organisms are acid-fast and produce no 

 swellings. 



As more accurate information accumulated concerning the specific 

 nature of those actinomycetes that are causative agents of disease, and 



Table 44 : Comparative i/wrphological and physiological properties of two common types of 

 ■ pathogenic actinomycetes (80, 312): — 



Actino?nyces A 



Actinomyces B 



Hyphae 



Aerial spores 



Acid-fastness 



Granules in body 



Clubs in body 



Growth on common media 



Oxygen requirement 



Growth at room temperature 



Pigment formation 



Resistance to drying 

 Pathogenicity to animals 



Development outside of 

 infectious area 



Rather long in the body, 

 shorter on artificial me- 

 dia 



Never observed 



Seldom 



Characteristic 



Characteristic 



None or only insignificant 



Preferably anaerobic 



Absent or limited 



Not marked 



Weak 



Subcutaneous injection in 

 cattle sometimes causes 

 limited suppurative 

 swelling. Pathogenic- 

 ity for dogs and guinea- 

 pigs insignificant 



Mouth and other body 

 cavities, such as intes- 

 tinal canal, not in free 

 nature 



Long both in body and on 

 artificial media 



Verv common 



Often 



Common 



Less common 



Very good 



Preferably aerobic 



Excellent 



Reddish or yellow colo- 

 nies 



Very good 



Subcutaneous injection in 

 dogs and guinea-pigs 

 usually produces a local 

 well limited suppura- 

 tive swelling 



In free nature 



as a better knowledge was gained concerning the systematic position of 

 this group of organisms, a clearer understanding of their relation to 

 the various types of infection gradually evolved. Just as Wright and 

 others tried to study the relationship of actinomycetes to disease by 

 considering all the organisms involved as comprising only one type or 

 species, so have others assumed the existence of numerous types of in- 

 fection. 



Erikson and others, for example, believed that even the anaerobic 

 organisms should be divided into two groups, the human and the bovine 

 types. Lentze (257) also came to the conclusion that in human and 

 ar^imal actinomycosis two different, largely anaerobic, gram-positive or- 

 ganisms were concerned : one growing on the surface of the medium in 



