944 THE PLEjJrOPNEUMONIA GROUP OF ORGANISMS 



(1) segmentation, and (2) the formation of elementary corpuscles within a body 

 surrounded by a limiting meml:)rane. (1) Starting as an elementary corpuscle 

 or granule (Fig. 231a), the organism grows into a small resolvable sphere, which 

 may take on an irregular (b) or even filamentous (c) shape. This then divides 

 into a variable number of segments {d, e), which may or may not separate from 

 each other. (2) Starting in the segments resulting from (16), darkly stained bodies 

 (/), probably consisting of nuclear material (see Klieneberger 1942), appear. These 

 then divide, forming multiple elementary corpuscles within a body surrounded 

 by a limiting membrane {g). Later, each of these corpuscles is liberated, appar- 

 ently surrounded by a small portion of cytoplasm (h). This stage, it may be 

 remarked, recalls to mind the formation of merozoites in the developmental cycle 

 of the malarial parasite. Later still, the cytoplasmic sheath is lost, and the 

 elementary corpuscles remaining {a) are indistinguishable from those from which 

 the original cycle, described in (1), began. 





g 



Fig. 231. — Organism of Pleuropneumonia. 



Diagrammatic representation of developmental cycle according to Klieneberger and Smiles 

 (1942) and Klieneberger (1942). 



1. Proliferation by segmentation. 



2. Proliferation by formation of elementary corpuscles. 



(«) Elementary granule. 



(b) Sphere. 



(c) Small filament. 



{(I) Segments resulting from division of (b). 



(e) Filaments resulting from division of (c). 



(/) Nucleated bodies, 



(g) Multii^le granules within a limiting membrane resulting from division of (/). 



(/i) Liberated granules still surroiuided by cytoplasm. 



Resistance, Metabolism, Biochemical Reactions, and Antigenic Structure.^ 



According to Tang and his colleagues (1935), serum broth cultures may remain 

 viable for 45 days at 37° C, and for 98 days at 0°-5° C. The organisms are bile- 

 soluble, particularly in the filamentous stage, but are very resistant to ultra-violet 

 irradiation and to the photodynamic action of methylene blue (Tang et al. 1936). 

 They ferment glucose, maltose, and dextrin, and to a less extent sucrose, with the 

 production of acid, but not mannitol, lactose, or salicin. Haemoglobin is reduced 

 by freshly isolated strains. Warren (1942) states that growth is prevented by 

 10 per cent. CO2, that a hfemolysin is produced, that methylene blue is decolorized 

 in the presence of lactate, and that the time-potential curve differs from that 

 of the L group of organisms. Little is known of the antigenic structure of this 

 organism, but there is some evidence, based mainly on cross-protection tests, of 

 the existence of more than one immunological type. 



