Chapter XI _179_ Human and Animal Diseases 



clubs in the tissues depcndina upon a balance between the host and 

 the parasite. 



The mouth is commonly looked upon as the source of infection of 

 maxillary actinomycosis (519). The contents of the mouth and tonsils 

 were reported (266) capable of causing actinomycosis in experimental 

 animals; this led to the conclusion that A. hovis is often present in oral 

 cavities, where it may exist as a saprophyte. In spite of his emphasis 

 upon the specificity of A. hovis as the major agent of actinomycosis, 

 Emmons suggested the possibility that there are also atypical strains 

 which are found in certain lesions, in sputum, in carious teeth, and in 

 tonsils. 



In 47 per cent of tonsils examined, the presence of filaments of an 

 actinomyces was demonstrated (107). Microaerophile cultures were 

 obtained in 23 per cent of the cases, the organism corresponding to A. 

 hovis. The conclusion was reached that this organism exists as a 

 saprophyte in the granules sometimes formed in the crypts of the tonsils. 

 Upon discharge into the oral and digestive cavities it may invade more 

 susceptible tissues and give rise to true actinomycosis. In addition to 

 the mouth organs (jaw, tongue) actinomycosis may also affect the 

 abdominal organs, usually the appendix, the lungs, and in the cow, the 

 udder (110). 



Anaerobic strains of actinomyces were isolated by Lord and Tre- 

 VETT (267) from the contents of carious teeth. After isolation, how- 

 ever these strains grew aerobically. The work of Naeslund on the 

 presence of the anaerobic form in the normal mouth has already been 

 mentioned. To this must also be added the observation of Magnus 

 concerning the occurrence of anaerobic actinomycetes in the pharynx 

 and nasopharynx. 



RosEBURY also considered the mouth and throat as the natural 

 habitat of the pathogenic A. hoins. This organism was looked upon as 

 comprising an obligate parasite. Sharp differentiation was made be- 

 tween the parasitic "lumpy jaw" and the saprophvtic actinomvcetes, as 

 brought out in Table 3. The "mycetomas" were included among the 

 saprophvtic tvpes. 



RosEBURY isolated 15 strains of A. hovis; 4 of these were obtained 

 from cervicofacial actinomycosis and II from gingival scrapings taken 

 under oral pathological conditions in the absence of actinomycosis. 

 Streaked plates of brain heart infusion agar were used for isolation pur- 

 poses. Optimum conditions for continued growth of these organisms 

 were provided by anaerobiosis in the presence of 5 per cent carbon 

 dioxide. Some strains were capable of making limited growth, how- 

 ever, in air. Considerable variation was observed in oxygen tolerance 

 among the different strains, at different times. Pure cultures were 

 maintained by cultivation under anaerobic conditions with carbon di- 

 oxide and by alternate transfer through different culture media. 



Of 45 animals inoculated by different routes, experimental acti- 



