922 



ORDER X. MYCOPLASMATALES 



a predilection for the joints. Subcutaneous 

 injection produces diffuse abscesses. Intra- 

 cerebral inoculation causes encephalitis in 

 mice but usually no cerebral symptoms in 

 rats. Intranasal instillation causes pneu- 

 monia in mice. Non-pathogenic for mon- 

 keys, rabbits or guinea pigs. 



Comments : The description of this species 

 is based on a strain isolated by Preston 

 (Jour. Inf. Dis., 70, 1942, 180) from infected 

 joints of rats. Preston's organism is gener- 

 ally believed to be identical with Kliene- 

 berger's L4 , although it was not typed sero- 

 logically. Moreover, L4 is identical with the 

 pyogenic virus of Woglom and Warren 

 (Jour. Exp. Med., 68, 1938, 513), with L7 of 

 Findlay, MacKenzie, MacCallum and 

 Klieneberger (Lancet, 237, 1939, 7) and 

 probably also with the organisms isolated 

 by Beeuwkes and Collier (Jour. Inf. Dis., 

 70, 1942, 1). 



Source: Isolated from the submaxillary 

 gland of a laboratory rat with eye, ear and 

 lung infections (Klieneberger, op. cit., 1938, 

 458) ; also isolated from a contaminated 

 transmissible sarcoma (Klieneberger, Jour. 

 Hyg., 39, 1939, 260) and from outbreaks of 

 spontaneous polyarthritis in laboratory rats 

 (Findlay et al., op. cit., 1939, 7; Preston, op. 

 cit., 1942, 180). 



Habitat : From various infected lesions of 

 rats so far as known. 



10. Mycoplasma neurolyticum (Sabin, 

 1941) Freundt, 1955. (A filterable, transmis- 

 sible agent with "neurolytic" properties, 

 Sabin, Science, 88, 1938, 189; also see ibid., 

 575; L5 , Findlay, MacKenzie, MacCallum 

 and Klieneberger, Lancet, 235, 1938, 1511; 

 Musculomyces neurolyticus, type A, Sabin, 

 Bact. Rev., 5, 1941, 24 and 57; Pleuropneu- 

 monia cerehri-muris Tulasne and Brisou, 

 Ann. Inst. Past., 88, 1955, 238; Freundt, 

 Internat. Bull, of Bact. Nomen. and Taxon., 

 5, 1955, 73; also see Edward, Internat. 

 Bull, of Bact. Nomen. and Taxon., 5, 1955, 

 91.) 



neu.ro.ly'ti.cum. Or. noun neuron nerve; 

 Gr. adj. lyticus able to loose; M.L. adj. 

 neurolyticus nerve-destroying. 



Unstable to relatively stable mycelioid 

 structure, the filaments varying from short, 

 almost bacillary forms (usually 2 to 5 mi- 



crons in length) to moderately long sturc- 

 tures (10 to 30 microns) (Freundt, unpub- 

 lished observation). Gram -negative. 



Horse-serum agar: Neither film nor spots 

 are produced. 



Horse-blood agar: Alpha hemolysis. 



Rabbit-serum agar: Poor growth. 



Semi -solid media: Smooth or granular 

 growth, preferably near the surface. 



Broth: Generalized opalescence. 



Acid from glucose, mannose, maltose, 

 dextrin, glycogen and starch. No acid from 

 fructose, galactose, sucrose, lactose, salicin, 

 mannitol or dulcitol. 



Methylene blue is slowly reduced. 



Aerobic; poor growth under anaerobic 

 conditions. 



A thermolabile exotoxin, which causes 

 acute necrosis of the posterior pole of the 

 cerebellum in mice, is produced in vivo and 

 in vitro by the American strains. 



Serologically distinct from the other mem- 

 bers of this genus. The American and Eng- 

 lish strains of this species appear to be sero- 

 logically and immunologically identical. 



Pathogenicity: American strains of this 

 organism produce "rolling disease" and 

 other nervous symptoms in young mice after 

 intracerebral, intraabdominal or intrathora- 

 cal injection; older mice sometimes develop 

 a transient, non-destructive polyarthritis 

 after intravenous injection. The English 

 strains are less virulent, and "rolling dis- 

 ease" develops only if the organisms are 

 injected together with agar or a neurotropic 

 virus. Other animals, with the exception of 

 the field-vole, are not susceptible. 



Source: Isolated from the brain of mice 

 that had developed "rolling disease" dur- 

 ing the course of intracerebral passage of 

 various agents: Toxoplasma (Sabin, op. cit., 

 1938, 189 and 575), lymphocytic choriomen- 

 ingitis and probably also yellow fever virus 

 (Findlay et al., op. cit., 1938, 1511). Later 

 isolated on a few occasions from the brain 

 of normal mice and almost regularly from 

 the conjunctiva and nasal mucosa of car- 

 riers, and from pneumonic foci of mouse 

 lungs after nasal instillation of various ma- 

 terials (Sabin, Science, 90, 1939, 18; also see 

 op. cit., 1941, 24; Sabin and Johnson, Proc. 

 Soc. Exp. Biol, and Med., U, 1940, 569, and 

 Sullivan and Dienes, ibid., 41, 1939, 620). 



