262 



THE ACTINOMYCETES, Vol. I 



He considered it to be the most common 

 causative agent of the disease. These aerobic 

 organisms cause specific types of mycetomas. 

 Infections of the hmgs and of the skin are 

 frequently produced. The organisms are 

 culti\'ated much more readily than the ana- 

 erobic types and are pathogenic to labora- 

 torj" animals. .V. farcinica, isolated from 

 cattle, forms a yellowish, wiinkled growth on 

 solid media. A'', caprae, isolated from the 

 lung of a goat, gives a more whitish growth 

 and greater fragmentation of the mycelium. 

 A^. canis, which produces infection in dogs, 

 is similar to A'', caprae. 



Conant and Rosebury described the clin- 

 ical features of nocardiosis as follows: 



"Nocardiosis is a chronic suppurative, purulo- 

 granulomatous disease of the subcutaneous tissues 

 and bones (mj^cetoma) characterized bj' multiple 

 tumefactions and draining sinuses from which 

 granules (yellowish-white, red, or black) are ex- 

 pressed in the pus or found in the tissues; or, a 

 pseudotuberculous infection (systemic) of the 

 lungs and pleura with hematogenous spread 

 throughout the body, especially to the brain and 

 meninges, in which filamentous, bacillar}^ or 

 coccoid, acid-fast forms may be found in the 

 sputum, spinal fluid, or pus from subcutaneous 

 abscesses. 



"Mycetoma of the extremities results in the 

 clinical picture of Madura foot, although other 

 subcutaneous tissues of the body also may become 

 infected. The characteristic lesion with pain, 

 swelling, and sinus formation, and eventual club- 

 bing and marked deformity of the infected member 

 is developed only after months or years. Infection 

 spreads bj' extension through adjacent tissues 

 with bone destruction, multiple abscesses with 

 rupture, and with no systemic reaction unless 

 secondary t)acterial invasion is established. 

 Histological!}', sections of the sinus and abscess 

 walls may show only a chronic inflammatory re- 

 action. Further development of the acute purulent 

 abscess results in a surrounding layer of granula- 

 tion tissue infiltrated with round cells and fat- 

 laden macrophages enclosed by a fibrous capsule. 

 Diagnosis, however, depends on the presence of 

 granules, surroiuided by polymorphonuclear 

 neutrophils, centrally located in the abscesses. 



"Systemic nocardiosis is caused by .V. asteroides 

 and is chiefly pulmonary in origin. Of thirty four 



cases, including two new cases, reviewed by Kirby 

 and McNaught (1946) the lungs were infected in 

 twenty-nine and, of these, eleven had metastases 

 to the brain. Occasionally the presenting symp- 

 toms of headache, nausea and vomiting may indi- 

 cate either brain tumor or brain abscess; or, the 

 symptoms may be those of an infectious meningitis 

 (tuberculous) with minimal or no findings in the 

 lungs. Symptoms referable to a pulmonary infec- 

 tion include general malaise, fever, productive 

 cough with sputum, night sweats, anorexia and 

 loss of weight. Roentgenograms of the lungs 

 usually show a progressive infiltrative proce.ss 

 which may lead to multiple cavity formation. 

 Hematogenous spread results in metastatic lesions 

 throughout the body. Histologically, such lesions 

 may be of a purulent nature, containing centers 

 composed of polymorphonuclear neutrophils and a 

 few mycelial fragments, or such areas maj^ show a 

 more advanced granulomatous reaction leading to 

 granulation tissue, giant cells and scarring." 



Granules are not formed by N. asteroides. 



IVIariat (1957) made a detailed study of 

 the causative agents of chronic subcutaneous 

 lesions, known as mycetomas. Only five 

 species were recognized: 



1 . Nocardia asteroides. An infrequent caus- 

 ati\'e agent of mycetoma. Semi acid-fast or- 

 ganism. Enzymatic reaction reduced or ab- 

 sent; pathogenic to experimental animals. 



2. Nocardia hrasiliensis. Prevalent in 

 Central and South America. Semi acid-fast. 

 High enzymatic potential. Xo agreement on 

 experimental pathogenicity. 



3. Streptomyces madurae. World-wide dis- 

 tribution. Causative agent of mycetoma. 

 Forms large granules, white to reddish white; 

 surroimded by long, club-shaped swellings. 

 Hyphae not acid-fast. Xonpathogenic to ani- 

 mals. 



4. Streptomyces pellctieri. Found largely 

 in .Vfrica. Granules small, numerous, and 

 red, often fragmented. Hyphae not acid-fast. 

 High enzymatic potential, l)ut not patho- 

 genic to animals. 



5. Streptomyces somaliensis. Frequently 

 foimd in Africa. Granules yellowish white. 

 Hyphae not fragmented. High enzymatic po- 

 tential. Xot pathogenic to animals. The nu- 



