Citrate not utilized. Sodium oleate severely inhibits growth. Nitrites not produced from nitrates. Urease not produced. Blood agar colonies: 0.7 mm in diameter, smooth, glistening, moderately elevated, entire, transparent, slightly white; later (48 hours) becoming enlarged (1.0 mm in diameter) and white with opaque centers. No hemolysis. Catalase-negative. Aerobic, facultative. Comment : Svenkerud et al. raise the ques- tion whether this species should be placed in Corynebacterinm, Erysipeloihrix or Lis- teria. However, the further cultural and serological studies that have been made of their cultures show that this species is prop- erly placed in the genus Corynebacterinm. Source: Isolated from an erysipelas oc- curring in the transition between the corium and blubber of seals {Phoca groenlandica, P. hispida, Cristophara cristata and Erig- naihus barbatus). 12. Corynebacterinm pseudodiphthe- riticum Lehmann and Neumann, 1896. (Bacillus der pseudodiphtherie, Loeffler, Cent. f. Bakt., 2, 1887, 105; G. von Hof- mann-Wellenhof, Wien. med. Wochenschr., 38, 1888, 65; Lehmann and Neumann, Bakt. Diag., 1 Aufl., 2, 1896, 361.) pseu.do.diph.the.ri'ti.cum. Gr. adj. pseudes false; M.L. fem.n. diphtheria diph- theria; M.L. adj. diphtheriticns diphtheritic; M.L. adj. pseudodiphtheriticus relating to false diphtheria. Common name : Pseudodiphtheria bacillus or Hofmann's bacillus. Excellent historical discussions of this and related organisms are given by Bergey (Comparative Studies upon the Pseudo- diphtheria or Hofmann's Bacillus, the Xerosis Bacillus, and the Loeffler Bacillus. Contrib. from Lab. of Hyg., Univ. of Penn., No. 2, 1898, 19-54) and by Andrewes et al. (Diphtheria. London, 1923, 382-388). Rods, with rounded ends, 0.3 to 0.5 by 0.8 to 1.5 microns, fairly uniform in size, without swollen ends. Not barred but even staining interrupted by transverse, medial unstained septum; granules usually absent. Non-motile. Gram-positive. Gelatin colonies: Small, grayish to cream- colored, smooth, homogeneous, entire. Gelatin stab: Slight surface growth with little growth in stab. No liquefaction. Agar colonies: Opaque, grayish to cream- colored, smooth, homogeneous, entire. Agar slant: Moist, smooth, white to cream-colored, entire growth. Loeffler's blood serum: Same as on agar. Broth: Slightly turbid with slight, grayish sediment. Litmus milk: Unchanged. Potato: Slight, creamy white, smooth, entire growth. Indole not produced. No acid from carbohydrate media. Nitrites produced from nitrates. Hydrolyzes urea (Merkel, Zent. f. Bakt., I Abt., Orig., 147, 1941, 398). Aerobic, facultative. Optimum temperature, 37° C. Not pathogenic. Source : From the oral cavity of 26 out of 45 control cases. Habitat: Normal throats. 13. Corynebacteriuni equi Magnusson, 1923. (Arch. f. wiss. prakt. Tierheilk., 50, 1923, 22.) e'qui. L. noun equus horse; L. gen. noun equi of the horse. Description taken from Dimock and Ed- wards (Kentucky Agr. Exp. Sta. Bull. 333, 1932), Bruner and Edwards (Kentuckj^ Agr. Exp. Sta. Bull. 414, 1941), Merchant (Jour. Bact., SO, 1935, 95) and Brooks and Hucker (Jour. Bact., 48, 1944, 309). Rods variable according to medium. Coc- coid and ellipsoidal cells to rather long, curved and sometimes clubbed forms. The latter are especially apt to occur in liquid media. Non-motile. Gram-positive. Gelatin stab: Good growth. No liquefac- tion. Agar colonies: Usually moist, smooth and glistening, tan to yellow (Brooks and Hucker, ibid., 300) or pink to red chromo- genesis (Merchant, op. cit., 1935, 107). Agar slant: Moist heavy growth which may run down the slant (Dimock and Ed- wards, op. cit., 1932, 322). Broth: Turbid with no pellicle and little sediment (Dimock and Edwards, loc. cit.).
