Species-specific FITC conjugated antiserum can be prepared for each of the five species of Actinomyces and for Arachnia propionica. These serums can be used for rapid and specific identification of pure or mixed cultures of the bacteria and for identification of organisms seen in direct smears of clinical material or in tissue sections. Two serotypes each of A bovis, A odontolyticus, A israelii, A viscosus, and A propionica have been established, and A naeslundii has been tentatively divided into four serotypes.

A comparative study of 64 strains of Actinomyces israelii was done with the use of techniques standardized by the Subgroup on Taxonomy of the Microaerophilic Actinomycetes. Emphasis was placed on the range of variation to assist recognition of clinical isolates and aid in differentiation from Actinomyces-like organisms. None of the strains was positive for catalase or indole, or in the Voges-Proskauer test; 90% were methyl red-positive and 62% were nitrate-positive. Acid was produced from: glucose (100%), xylose (100%), salicin (98%), raffinose (95%), lactose (89%), cellobiose (83%), mannose (78%), arabinose (76%), inositol (58%), mannitol (48%), starch (31 %), glycogen (0%), glycerol (O%), and rhamnose (0%). A. israeli can be identified by the fluorescent-antibody method, but there is no single morphological or biochemical characteristic which can be used for its identification. By both fluorescent-antibody and gel-diffusion techniques, the serological classification of A. israelii group D with serotypes 1 and 2 was verified. Eleven serotype 2 strains were compared morphologically, biochemically, and serologically with 53 serotype 1 strains. All but two of the serotype 2 strains produced viscous growth in broth and none fermented arabinose. tests. 873

There are two theories regarding the source of infection in actinomycosis. The exogenous theory introduced by Bostroem (1891) was based upon the fact that he observed awns of grass or gram' in the actinomycotic lesions of man and cattle. This theory has been propagated and enlarged upon by numerous authors but has gained support mainly from clinical observations.The endogenous theory did not receive recognition until relatively recent times, although supporting evidence can be found throughout the literature on actinomycosis. Lord (1910) noticed the occasional presence of organisms in sputum having the morphology of actinomycetes. By means of smears and sections, he also demonstrated actinomycetes in the contents of 16 carious teeth. Naeslund (1925) cultivated anaerobic actinomycetes from the oral cavity and stated that these organisms were nearly identical culturally with the anaerobic forms cultivated from cases of actinomycosis. Naeslund (1931) was unsuccessful in his attempt to produce experimental actinomycosis in animals with strains of anaerobic actinomycetes isolated from the oral cavity. Emmons (1935) cultivated anaerobic strains of actinomycetes from the oral cavity which resembled both culturally and morphologically the typical Actinomyces bovis. 1938 he cultured tonsils and obtained several strains of actinomycetes. These tonsillar strains were avirulent for guinea pigs. Lord and Trevett (1936) isolated 4 strains of anaerobic actino-I Summary of a thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at

Catalase-positive actinomycetes which closely resemble the "hamster organism" described by Howell have been isolated from dental calculus and other human sources. These cultures could not be distinguished from the hamster strains on the basis of morphology, oxygen requirements, biochemical reactions, or cell wall composition. These human isolates have been classified with the hamster strains as Actinomyces viscosus. The strains from hamster and human sources fell into two serotypes. Serotype 1 contains the hamster strains plus one strain of unknown origin, whereas serotype 2 contains all of the human strains.

The predominant gram-positive bacteria in 47 fecal specimens from 10 healthy men were studied by microscopic and cultural counts, by the characterization and tentative identification of isolates, and by the use of fluorescein isothiocyanate (FITC)-conjugated globulins prepared using some of the isolates. Grampositive bacteria averaged 101o.5140 (SD/g (wet weight) of feces with significant variation from host to host. Characterization of 865 isolates, all strict anaerobes and carbohydrate fermenters, showed 12 to 39 distinguishable strainas from each