926 



ORDER X. MYCOPLASMATALES 



15. Mycoplasma laidlawii (Sabin, 1941) 

 Freundt, 1955. (Types A and B, Laidlaw and 

 Elford, Proc. Roy. Soc. London, B, 120, 

 1936, 292; Sapromyces laidlawi AB, Sabin, 

 Bact. Rev., 5, 1941, 59; Freundt, Internat. 

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

 73; also see Edward, Internat. Bull, of Bact. 

 Nomen. and Taxon., 5, 1955, 91.) 



laid.law'i.i. M.L. gen. noun laidlawii of 

 Laidlaw; named for P. Laidlaw, one of the 

 bacteriologists who first isolated this spe- 

 cies. 



Relatively stable mycelioid structure with 

 filaments of moderate length (10 to 30 mi- 

 crons) (0rskov, Zent. f. Bakt., I Abt., Orig., 

 IJtl, 1938, 229; also see Acta Path, et Micro- 

 biol. Scand., 19, 1942, 586; Freundt, un- 

 published observation) . Elementary bodies, 

 but no filaments, have been demonstrated 

 in electron micrographs by Ruska and 

 Poppe (Ztschr. f. Hyg., 127, 1947, 201) and 

 by Kandler and Kandler (Arch. f. Mikro- 

 h\o\., 21, 1954, 178 and 202). Gram-negative. 



Serum is not required for growth. 



Horse-serum agar: Neither film nor spots 

 are produced. 



Horse-blood agar: Alpha hemolysis. 



Semi-solid media: Fluffy growth near the 

 surface. 



Broth: Strong opalescence. 



Hydrogen sulfide is not produced. 



Acid from glucose, fructose, maltose, 

 starch, glycogen and dextrin; acid may or 

 may not be produced from galactose. No 

 acid from mannose, lactose, sucrose, xylose, 

 salicin, glycerol, mannitol or dulcitol. 



Nitrites not produced from nitrates. 



Ammonia is not produced. 



Methylene blue is rapidly reduced. 



Sodium tellurite is slowly reduced. 



Aerobic; poor growth under anaerobic 

 conditions. 



Optimum temperature, about 30°C. 

 Growth between 22° and 37°C. 



Laidlaw and Elford {op. cit., 1936, 292) 

 recognized three serological types by agglu- 

 tination tests: A, B and C. A and C are 

 quite distinct antigenically, and B is more 

 closely related to A than to C. 



Comments: Various strains, which are 

 similar to the A and B strains of Laidlaw 

 and Elford culturally, phj-siologically, sero- 

 logically and with respect to their habitats, 

 have been described in the literature, viz. 

 Seiffert's Strains (Seiffert, Zent. f. Bakt., 

 I Abt., Orig., 139, 1937, 337; also see ibid., 

 140, 1937, 168; Klieneberger, Jour. Hyg., 40, 

 1940, 204; and Kandler and Kandler, Zent. 

 f. Bakt., II Abt., 108, 1955, 383) and S 

 Strains (Edward, Jour. Gen. Microbiol., 

 4, 1950, 4). The C strains of Laidlaw and 

 Elford are regarded by Sabin {op. cit., 1941, 

 59) as belonging to a separate species, 

 Sapromyces laidlawi C. The C strain has been 

 lost and has not been compared culturally 

 or physiologically by appropriate methods 

 with the A and B strains for which reason 

 it has not been included in Mycoplasma 

 laidlawii Freundt. 



Source: Isolated from sewage (Laidlaw 

 and Elford). Seiffert obtained his strains 

 from manure, humus and soil, and Edward 

 secured his as a contaminant of cultures 

 from the genital tract of cattle. 



Habitat: Apparently frequently found as 

 saprophytes in sewage, manure, humus and 

 soil. 



ADDENDUM TO CLASS II. SCHIZOMYCETES VON NAEGELI. 

 BACTERIA SITVIBIOTIC OR PARASITIC IN PROTOZOA. 



In studying various species of Protozoa, protozoologists have occasionally found them to 

 be infected with organisms living either on the surface of the protozoan cells or more fre- 

 quently intracellularly. Many of the intracellular microorganisms cause diseases that may 

 destroy the host organisms. 



These intracellular parasites of Protozoa are of the size of ordinary bacteria. Some have 

 the morphology of cocci, and these have sometimes been placed in a special genus, Carijo- 

 cocciis Dangeard, near the genus Micrococcus Cohn, while one species has been placed in 

 Micrococcus. In a similar way other species have been placed in Cladothrix Cohn {Sphaero- 

 tilis Ktitzing) or in Myxococcus Thaxter. Some spirally shaped cells have been assigned to a 

 special genus placed near Vibrio and Spirillum. Still others of these bacteria form spores 



