44 



THE ACTINOMYCETES, Vol. I 



the synthesis of alkaloids and proteins in 

 the plant, as well as in the dissolution of the 

 pectins. Their role in tuber formation and 

 in plant growth in general was suggested. 



The isolation of various organisn:s from 

 diseased plant tubers and other plant tissues 

 has been studied in detail by Peklo, Millard 

 and Burr, and numerous others concerned 

 with the causation of plant diseases by ac- 

 tinomycetes. The earlier work of Arzberger 

 and Peklo on "plant actinomycoses," and 

 the possible role of actinomycetes in the 

 tuberization of species of Myrica, appeared 

 also to have a bearing upon this problem. 



Occurrence of Actinomycetes on and in 

 Animal Bodies 



The etiology of actinomycotic infections 

 in man and in animals is closely bound with 

 the occurrence of specific organisms at the 

 sight of infection. Whether actinomycosis is 

 a result of exogenous infection due to the 

 consumption, by animals, of grasses and 

 foodstuffs containing actinomyces spores and 

 mycelium, or of endogenous infection due to 

 the presence of these spores and mycelium 

 as regular inhabitants of the healthy mouth 

 aroused, in the past, a great deal of discus- 

 sion (Lentze). The history of the causative 

 agent of actinomycosis is closely boimd with 

 the occurrence of actinomycetes at the sight 

 of infection, since considerable difficulty has 

 been experienced in the isolation of the caus- 

 ative agent of the disease and in bringing 

 about experimental infections by these or- 

 ganisms. 



Bollinger demonstrated that the common 

 types of b()\'in(^ actinomycosis are due to an 

 organism named by Plarz in 1877 Actino- 

 myces bovis. Wolff and Israel are credited 

 with the first isolation from maxillary actino- 

 mycosis of cattle of a mic^-oaerophilic strain 

 of A. hnvh, which is now considered as the 

 true etiologic agent of the disease. Api)ar- 

 ently, actinomycosis is an ancient disease. 



since evidences of it have been found in fos- 

 silized animals (Aloodie). 



According to Rosebury and Sonnenwirth, 

 the only actinomycetes indigenous to man 

 are the anaerobic forms which are grouped 

 in a single species ^4 . isracli. They are found 

 in the mouth, pharynx, intestine, and actino- 

 mycotic lesions. They are considered as strict 

 parasites of man and many animals. The sep- 

 aration between the smooth A. bovis found 

 in cattle and rough A. israeli in mtui may not 

 be tenable. 



The further assumption that the etiologic 

 agent A. bovis propagates in the soil and 

 that cattle become infected while grazing 

 upon grass has been another source of error. 

 Emmons pointed out that the true etiologic 

 agent A. bovis has not yet been isolated 

 from a natural habitat outside the animal 

 body. It has been assumed that this organ- 

 ism has both a saprophytic and parasitic 

 existence within the body itself. Emmons 

 obtained pui'e cultures of the microaerophilic 

 Actinomyces from the surface of discolored 

 teeth, from carious teeth, and from tonsilar 

 crypts. When first isolated, these cultures 

 grew more rapidly and the hyphae were 

 coarser than those of the strains isolated 

 from clinical actinomycosis, but upon re- 

 peated subculture, they became similar to 

 .4. bovis in morphology. Lord demonstrated 

 the presence of actinomycetes in the contents 

 of carious teeth and in the crypts of tonsils; 

 he considered the buccal cavity as the source 

 of infection. Further studies of the occur- 

 rence of actinomycetes in the oral cavity 

 have been made by Xa(»slund and by Ludwig 

 and Sullivan. 



Actinomycetes have also been found exten- 

 si\ely in numerous othei' organs and excreta 

 of the human and animal body, such as the 

 fresh ex(;reta of suckling animals (Aloro) and 

 the intestinal canal of hcnilthy animals 

 (Hopffe). Fischer (1915) fovnid actinomy- 

 cetes (»S. albus) to occur abundantly in the 

 caecum, in tlu^ large intestine, in the rumen, 



