.Moin'll()l,o(;^•, ('^■'I'()l,()(;^•, and lii'i; ('\('I,i:s 



81 



witli ago, undergo lysis, otlicis arc subject lo 

 attack l\v sp(M'ific pliagcs. When inoculated 

 into Uvs\\ niediuni, the linei- oi- disintegrated 

 particles gi\-e rise to a noiinal inyceliuni. 

 This suggestive! to sonic in\-estigaloi's (Kober, 

 Monal, Grigorakis) the possibility- of syni- 

 plasni format ioM as a stag(> in the life cycle 

 of the organisms. FurtluM- study did not 

 sul)stantiate this concei)t . 



CI lib Formation 



An iiUeresting morphological i)henonie- 

 nou among certain actinomycetes, deter- 

 mined by the environment, is the formation 

 of clubs. These clubs should not be confused 

 with involution forms. They are the result 

 not of swelling of the hyphal tip, but of the 

 secretion of a sheath of slime around the tips 

 of the hyphae; therefore they are comparable 

 to the capsules of bacteria. The clubs are 

 formed in the animal body by pathogenic 

 organisms like .4. boris. They were also 

 observed bj^ Wright (1905) in cultures grow- 

 ing in the presence of animal serum or whole 

 blood and by Bayne-Jones (1925) in glucose 

 broth. They may be formed in response to 

 the presence of some thermostable substance 

 in animal fluids, or to some other condition 

 such as a reduced oxj'gen tension. They 

 can be readily induced by the addition of 3 

 to 7 per cent of NH4CI, and also in sugar- 

 containing media on aging. These swellings 

 usually have several times the thickness of 

 the normal hyphae. 



In the animal body the clulis are found in 

 groups, each radiating from a mass of my- 

 celium (granules). They give the impression 

 of a star-like arrangement, which is responsi- 

 ble for the name given to the actinomycetes 

 as a whole (Lieske, 1921). 



Motility 



Motility in actinomycetes was reported 

 for .V. askroides l)y Eppinger (1891) and is 

 characteristic of the genus Actinoplanes. 

 iMotile organisms were mentioufnl by Hull- 





Fkure 41. Sclcrotia t'onnation in a .stropto- 

 inycos (Reproduced from: Tliiruinaiachar, M. ,1. 

 Nature 176: 934, 1955). 



man and others. The presence of flagella was 

 never demonstrated, howe\'er, except for 

 Actinoplanes. Topping (1937) and 0rskov 

 (19.38) observed many instances of motility 

 among nocardia-like bacteria from soil. Their 

 strains included acid-fast as well as nonacid- 

 fast forms; they gave both granular and 

 turbid growth in liquid media. 



Jensen examined one of 0rskov's motile 

 strains and found it to agree with A', citrea. 

 It produced a soft, lemon-yellow growth on 

 nutrient agar and a diffuse turbidity in 

 broth. The cells were gram-positive but not 

 acid-fast. Direct microscopic examination 

 showed well-developed initial mycelium with 

 mere traces of aerial hyphae. The mycelial 

 structure persisted for a considerable time 

 below the agar surface, but after 24 to 40 

 hours some of the surface hyphae began to 

 divide into rod-shaped cells that were very 

 strongly motile; this was best seen when a 

 drop of water and a coverslip were placed on 

 top of the agar colonies. In broth cultures, 

 the motility was much less obvious. Stain- 

 ing of the motile cells showed one to four 

 (or more) stout flagella. 



Jensen emphasized that while motility 

 may not be common among the nocardias, its 

 existence is indisputable. He suggested the 

 necessity for an alteration in the definition 



