FAMILY I. MYCOPLASMATACEAE 



921 



infection in swine involving the serous mem- 

 branes of the thoracic and abdominal cav- 

 ity. The relationship of this organism to 

 atrophic rhinitis seems to require further 

 study. 



8. Mycoplasma pulmonis (Sabin, 1941) 

 Freundt, 1955. (L3 , Klieneberger and Steab- 

 ben, Jour. Hj^g., 37, 1937, 143; Murimyces 

 -pulmonis Sabin, Bact. Rev., 5, 1941, 57; 

 Freundt, Internat. Bull, of Bact. Nomen. 

 and Taxon., 5, 1955, 73; also see Edward, 

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

 5, 1955, 91.) 



pul.mo'nis. L. noun pulmo the lung; L. 

 gen. noun pulmonis of the lung. 



Unstable, sparsely branched mj^celioid 

 structure with very short, almost bacillary 

 filaments which usually measure 2 to 5 mi- 

 crons in length (0rskov, Acta Path, et Mi- 

 crobiol. Scand., 19, 1942, 575; Freundt, un- 

 published observation). Elementary bodies 

 and short rods have been demonstrated in 

 electron micrographs by Klieneberger- 

 Nobel and Cuckow (Jour. Gen. Microbiol., 

 12, 1955, 95). Gram-negative. 



Horse-serum agar: A film and spots are 

 produced. Central spot of the colonies is 

 less marked than those of most of the other 

 species in this genus; rough surface. 



Horse-blood agar: Alpha hemolysis. 



Rabbit-serum agar: Poor growth. 



Semi-solid media: Granular growth, pref- 

 erably near the surface. 



Broth: Granular growth. 



Acid from glucose, mannose, maltose, 

 glycogen, dextrin and starch. No acid from 

 fructose, galactose, sucrose, lactose, salicin, 

 mannitol or dulcitol. 



Methylene blue is slowly reduced. 



Aerobic; very poor growth under an- 

 aerobic conditions. 



Serologically different from Mycoplasma 

 arthritidis Freundt. 



Pathogenicitj-: Produces suppuration in 

 mice when injected along with agar. Not 

 pathogenic for rats in artificial infection. 

 Sometimes found in young rats without 

 definite lung lesions, while in older rats a 

 close connection has been demonstrated 

 between the presence of this organism and 

 bronchiectatic pulmonary disease; however, 



the etiological significance of this organism 

 to this condition seems obscure. Experi- 

 ments reported by Klieneberger-Nobel and 

 Cheng (Jour. Path, and Bact., 70, 1955, 245) 

 suggest that the role of this organism may 

 be that of a secondary invader. 



Comment : The isolation of closelj^ related 

 organisms from mice with infectious catarrh 

 has been reported by Edward (Jour. Gen. 

 Microbiol., 10, 1954, 27). 



Source: Isolated from the lungs of labora- 

 tory rats, most of which had bronchiectasis 

 although some were without lesions; also 

 isolated from a wild rat. 



Habitat: From the normal and diseased 

 lungs of rats so far as definitely known. 



9. Mycoplasma arthritidis (Sabin, 

 1941) Freundt, 1955. (L4 , Klieneberger, 

 Jour. Hyg., 38, 1938, 458; Murimyces arthri- 

 tidis Sabin, Bact. Rev., 5, 1941, 57; Pleuro- 

 pneumonia arthritidis 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.) 



ar.thri'ti.dis. Gr. noun arthritis gout, 

 arthritis; M.L. gen. noun arthritidis of ar- 

 thritis. 



Unstable to relatively stable mycelioid 

 structure; filaments vary from short, almost 

 bacillary forms (usually 2 to 5 microns in 

 length) to moderately long structures (10 

 to 30 microns) (Preston, Jour. Inf. Dis., 

 70, 1942, 180; Freundt, unpublished obser- 

 vation). Gram-negative. 



Horse-serum agar: Neither film nor spots 

 are produced. 



Horse-blood agar: Alpha hemolysis. 



Rabbit-serum agar: Good growth. 



Semi-solid media: Fluffy growth through- 

 out. 



Broth: Slight, uniform opalescence. 



Carbohj'drates not attacked. 



Methylene blue is slowly reduced. 



Aerobic, facultatively anaerobic. 



Serologically distinct from Mycoplasma 

 pulmonis Freundt. 



Pathogenicity: When injected together 

 with agar intravenously or into the pads of 

 rats and mice, the organism appears to have 



