920 



ORDER X. MYCOPLASMATALES 



Horse-blood agar: Slight hemolj^sis. 



Rabbit-serum agar: Poor growth. 



Semi -solid media: Growth throughout the 

 medium is neither definitely smooth nor 

 definitely granular. 



Carbohydrates not attacked. 



Methylene blue is slowly reduced. 



Aerobic, facultatively anaerobic. 



Serologicall}^ distinct from the other mem- 

 bers of this genus. 



Pathogenicity: Unknown. 



Comments: Shoetensack (Kitasato Arch. 

 Exp. Med., 11, 1934, 277; also see ibid., 13, 

 1936, 175 and 269) isolated organisms of this 

 genus from the tissues and nasal secretions 

 of dogs suffering from distemper and re- 

 garded these organisms as comprising two 

 distinct types, differing from each other in 

 their cultural characteristics: Asterococcus 

 canis, type I, Shoetensack (Shoetensack, 

 op. cit., 1936, 175; Canomyces 'pulmonis I, 

 Sabin, Bact. Rev., 5, 1941, 57; Canomyces 

 canis I, Sabin, ibid., 334) and Asterococcus 

 canis, type II, Shoetensack (Shoetensack, 

 op. cit., 1936, 175; Canomyces pulmonis II, 

 Sabin, op. cit., 1941, 57; Canomyces canis II, 

 Sabin, ibid., 334). Klieneberger (Jour. Hyg., 

 38, 1938, 458), furthermore, noted that type 

 I differed serologically from type II. Type I 

 apparently produced distemper in dogs on 

 subcutaneous inoculation and was regarded 

 by Shoetensack as the etiological agent of 

 the disease; this organism is not now re- 

 garded as the cause of canine distemper. 

 Shoetensack's organisms were lost and can- 

 not, with certainty, be identified wuth any 

 of the recently established species from 

 dogs. 



Source: Isolated from the vaginae and 

 throats of dogs. 



7. Mycoplasma hyorhinis Switzer, 1955. 

 (Filterable agent of infectious, atrophic 

 rhinitis of swine, Switzer, Jour. Amer. Vet. 

 Med. Assoc, 123, 1953, 45; also see Vet. 

 Med., 48, 1953, 392; Amer. Jour. Vet. Res., 

 16, 1955, 540.) 



hy.o.rhi'nis. Gr. noun hys, hyos a swine; 

 Gr. noun rhis, rhinis nose; M.L. gen. noun 

 hyorhinis of a hog's nose. 



Elementary bodies appear as minute, 

 coccoid rods 0.3 to 0.6 micron in size. Stain 



distinctly blue with Machiavello's stain. 

 Gram-negative. 



Serum agar colonies: 0.01 to 0.1 mm in 

 diameter, smooth, glistening, entire; some 

 of the colonies have a small central eleva- 

 tion; the central portions become granular 

 as the colonies age. 



Carbohydrates not attacked. 



Withstands 56°C. for 30 but not for 60 

 minutes. Remains viable for 2 to 3 weeks 

 at 4°C. and for more than 10 months at 

 -40°C. 



Pathogenicity: Produces an irregular 

 mortality pattern when inoculated into 

 chicken embryos. Heart and liver lesions 

 are produced in the embryos, the outstand- 

 ing lesion being a severe pericarditis which 

 is usually present in those dead after the 

 seventh day postinoculation. When inocu- 

 lated intraperitoneally into pigs 6 weeks or 

 less of age, the organism produces severe 

 fibrinous pericarditis, moderate fibrinous 

 pleuritis and mild peritonitis; from 5 to 20 

 per cent of the inoculated pigs usually de- 

 velop arthritis. Similar lesions produced by 

 this organism occur in swine under field 

 conditions. Not pathogenic for mice or 

 guinea pigs when inoculated intraperi- 

 toneally or for mice on intranasal instilla- 

 tion. Inoculation into the trachea, nasal 

 cavity, infraorbital sinus or conjunctival 

 sac of 10-day-old chickens fails to produce 

 any symptoms. 



Comment: Further studies are needed in 

 order to determine the cultural and physio- 

 logical characteristics of this species. 



Source: Isolated from the nasal cavity 

 of swine with infectious atrophic rhinitis; 

 also found in apparently healthy pigs. 

 Pleuropneumonia-like organisms were also 

 isolated by Carter and McKay (Canad. 

 Jour. Comp. Med., 17, 1953, 413) and by 

 Carter (Canad. Jour. Comp. Med., 18, 1954, 

 246) from the nasal cavities of swine wuth 

 atrophic rhinitis and from the tissues of pigs 

 suffering from an infectious condition (Glas- 

 ser's disease) similar to that reported by 

 Switzer; young pigs inoculated intraperi- 

 toneally with secondarj^ cultures developed 

 typical lesions. 



Habitat: Found in the nasal cavity of 

 swine. The etiological agent of a generalized 



