CAUSATION OI' AM MA I, DISEASES 



253 



Hujwitl ohtaiiu'd I'lom limn;iii ;icl iiiomycosis 

 pure cultures of the inijiciohic orn'Miiisni, the 

 true causal i\(' aticul of the disease; its 

 iii'owth on glycerol a^ar I'escniMed that of 

 the tubercle hacilhis. 



In 1891, WoUT and Isiael reported on a 

 comprehensive iu\-estij;ation of the morphol- 

 ogy and jiathogenicity of the organism caus- 

 ing actinomycosis. Tiiey considered the mi- 

 croaerophilic actinomyees to he the only 

 causative agent of tiie iuimaii and l)o\iiie 

 forms of the distvise. It may l)e of interest 

 to ([Uote h(M'(> the r(>sults on the cultix'ation 

 of tlu> organism as reported by them ('I'r. 

 l)y Wright ) : 



"It ^row l)est uiiiltM' aiia('n)l)ic coiKlitioiis and 

 did not grow at room tem])eratvire. On llic surface 

 of anaerobic agar slant cultures on the tliirtl, 

 fourth and fifth da.\' numerous minute isolated 

 dew-drop-like colonies appeared, the largest pin 

 head in size. These gradually became larger and 

 formed ball-like, irregularly rounded elevated 

 nodules varying in size up to that of a millet seed, 

 exceptionally attaining the size of a lentil or 

 larger. As a rule the colonies did not become 

 confluent, and an apparently homogeneous layer 

 of growth was seen to be made up of separate 

 nodules if examined with a lens. In some instances 

 the colonies presented a prominent center with a 

 lobulated margin and appeared as rosettes. A 

 characteristic of the colonies was that they sent 

 into the agar root -like projections. In aerobic agar 

 slant cultures no growth or a slow and very feeble 

 growth was obtained. In stab cultures the growth 

 was sometimes limited to the lower portion of the 

 line of inoculation or was more vigorous there. In 

 bouillon, after three to five days, growth appeared 

 as small white flakes, partly floating and partly 

 collected at the bottom of the tube. Growth oc- 

 curred in bouillon under aerobic conditions, but 

 was better under anaerobic conditions. The micro- 

 organism in smear preparations from agar cultures 

 appeared chiefly as short homogeneous, usually 

 straight, but also comma-like or bowed rods, whose 

 length and breadth varied. In many cultures 

 short-clump rods predominated, and in others 

 longer, thicker, or thinner individuals were more 

 numerous. The ends of the rods often showed olive 

 or ball-like swellings. In egg cultures growth oc- 

 curred in the form of white opaque graimles, the 

 largest about the size of a pin head. Microscop- 

 ically the growth was characterized by the de- 



't''- 



■ i^'- -rp 4 ; 



t--:^ 



>, v 



Figure 98. Stained dental scum (Reproduced 

 from: Ndeslund, C. Acta Patliol. Micrcjljioi. 

 Scand. 2: 140, 1925). 



velopment of long filamentous forms forming a 

 network. The longer filaments were arranged more 

 or less radially, were straight or wavy or spiral and 

 sometimes branched. Cultures on potato or in 

 milk are not mentioned. Some twenty guinea-pigs 

 and rabbits were inoculated, most of them in the 

 peritoneal cavity with pieces of agar culture. 

 Eighteen animals were killed after four to seven- 

 teen weeks, and four were still alive seven to nine 

 months after the inoculation. Seventeen rabbits 

 and one guinea-pig showed at the autopsy tumor 

 growths mostly in the peritoneal cavity and in one 

 instance in the spleen. In the four animals still 

 living tumors were to be felt in the abdominal 

 wall. The tumors in the peritoneal cavity were 

 millet seed to phmi size, and were situated partly 

 on the abdominal wall and partly on the intestines, 

 the omentum, and mesentery, and in the liver or 

 in adhesions. Frequently small millet-seed-sized 

 tumors were situated in the neighborhood of the 

 larger tumors. While the surface of the small 

 tumors was always smooth, the surface of the 

 larger tumors showed small hemispherical promi- 

 nences, giving them the appearance of conglomer- 

 ates of smaller tumors. On section the larger 

 tumors presented a tough capsule from which 

 anastomosing septa extended inward enclosing 

 cheesj^ masses. Microscopical examination of the 

 tumors showed in all cases but one the presence of 

 typical actinomyees colonies, in most cases with 

 typical clubs. The general histological appearance 

 of the tumors was like that of actinomycotic 

 tissue." 



