382 ACTINOMYCES 



between the aerobic and anaerobic species is not sufficiently sharp. Instead, she 

 places reliance on pigment formation, and proteolytic action. 



Waksman and Henrici (1943) suggest a classification based primarily on the 

 fragmentation or not of the mycelium. Organisms in which the mycelium breaks 

 up into bacillary or coccoid elements they would place in the family Actinomy- 

 cetacece ; this would comprise two genera — Actinomyces for the anaerobic and 

 Nocardia for the aerobic species. Organisms in which the mycelium does not 

 fragment they would place in a new family Streptomycetacece ; this would com- 

 prise two genera — Streptomyces for those species in which multiplication occurs 

 by conidia in chains from aerial hyphse, and Micromonosjyora for those species in 

 which multiplication occurs by single terminal spores or short sporophores. It 

 will be realized that agreement on the classification of members of the Actinomyces 

 group is still far from being reached. 



A detailed description of some of the more important members is appended, 

 followed by notes on others that are of less importance. These descriptions are 

 based in part on our own observations of relatively few strains. For a differential 

 table see j). 392 (Table 24), and for a general description of different types see 

 Lieske (1921), Naeslund (1925), Setti (1929), and Kosebury (1944). 



Actinomyces bovis Harz 



Isolation. — Described by Bollinger in 1877, named Actinomyces bovis by Harz in 1877 

 and first isolated by Wolff and Israel in 1891. 



Habitat. — Strict parasite found in lesions of actinomycosis in man and cattle. Frequent 

 in human mouth and in salivary calcidi. 



Morphology. — Glycerol agar, 7 days at 37° C. Long and short rods predominate ; long 

 continuous or segmented threads with a straight or curved axis, showing simple 

 or dichotomous branching ; S-shaped or spiral organisms ; coccoid forms. The 

 rods resemble, and are arranged like, certain members of the corynebacteria ; 

 sides parallel or irregular ; ends rounded, clubbed or tapered ; axis straight or 

 curved ; great variation in appearance ; irregular staining is usual ; granular and 

 beaded forms are not uncommon. Non-motile. Non-sporing. Gram-positive. 

 Non-acid-fast. 



Agar Plate. — 7 days at 37° C. anaerobically. Poor growth of round, 0-5-1 mm. in diame- 

 ter, convex, opaque, amorphous colonies with smooth dull surface and entire edge ; 

 greyish-white by transmitted, porcelain white by reflected light ; butyrous or 

 friable consistency ; emulsifiabiUty not diflficult as a rule. 21 days, rather larger, 

 1-1 '5 mm. in diameter, umbonate, with slightly irregular nodular surface and 

 lobate edge ; differentiated into a ghstening raised centre and a dull shelving 

 periphery resembUng a rosette. Colonies may grow into medium. 



Agar Slope. — 7 days at 37° C. anaerobically. Moderate growth of discrete colonies similar 

 to those described. Numerous greyish-white floccular masses of coarsely granular 

 structure in water of condensation ; they are irregular in shape, have an irregular 

 edge, and are opaque. In the condensation water there is also a finely granular 

 turbidity. 



Gelatin Stab. — No growth at 23° C. After 12 days at 37° C, the culture shows, when 

 cooled, a band of growth 4 mm. deep with its upper margin 1 mm. below the sur- 

 face. Growth consists of very fine greyish-white interlacing filaments, looking 

 Uke cotton- wool. No liquefaction. 



Broth. — 5 days at 37° C. anaerobically. Poor to moderate growth ; deposit of compact, 

 white, mulberry-like granules with nodular surface, often adherent to each other ; 

 not disintegrated on shaking. No turbidity ; no surface growth ; no odour. 



