Broth: Moderate turbidity in 24 hours. Pellicle formed. Milk: Acid curd and slow peptonization. Indole not produced. Hydrogen sulfide not produced. Acid from glucose, lactose, sucrose and glycerol. Starch not hydrolyzed. Nitrites not produced from nitrates. Slight growth in 5 per cent salt. Optimum temperature, 31° C. Ma.ximum temperature, between 36° and 40° C. Distinctive character: A strict vascular parasite of the bean. Source: Isolated from wilted bean plants from South Dakota. Habitat: Causes a wilt of beans and re- lated plants. 29. Corynebacterium acnes (Gilchrist, 1901) Eberson, 1918. {Bacillus acnes Gil- christ, Johns Hopkins Hosp. Repts., 9, 1901, 425; Bacillus parvus liguefaciens Jun- gano, Compt. rend. Soc. Biol., Paris, 65, 1908, 618; Eberson, Jour. Inf. Dis., 23, 1918, 10; Corynebacterium liquefaciens Prevot, Ann. Inst. Past., 60, 1938, 304; not Coryne- hacteriiim liquefaciens Andrewes et al.. Diphtheria, London, 1923, 408; not Coryne- bacterium liquefaciens Jensen, Proc. Linn. Soc. New So. Wales, 59, 1934, 49; Propioni- bacterium acnes Douglas and Gunter, Jour. Bact., 52, 1946, 22.) ac'nes. Gr. noun acme a point; incorrectly transliterated as M.L. noun acne acne; M.L. gen. noun acnes of acne. Original description supplemented by material from more recent authors. Rods varying in dimensions, usually 0.4 to 0.5 by 0.8 to 0.9 micron, occasionallj^ slightly club-shaped; under aerobic condi- tions the cells are quite long and are swollen or club-shaped, sometimes possessing what appears to be rudimentary branching (Douglas and Gunter, ibid., 17 and 18). Show alternate bands of stained and unstained material. Non-motile. Gram-positive. Aerobic growth in culture media is very feeble; anaerobic growth is excellent. Best growth occurs in shake cultures with soft, slightly acid, glucose agar. Gelatin: Liquefaction (Douglas and Gunter, ibid., 19). Agar colonies: Circular, 1.5 to 4.0 mm in diameter, raised, smooth, glistening, entire, slightly pink, later becoming a pale salmon- pink (Douglas and Gunter, ibid., 18). Agar slant: Very small, circular, trans- parent colonies which may later become rose-colored. Loeffler's blood serum: Small, grayish colonies which may later become rose-col- ored. Broth: Clear. Litmus milk: Soft coagulum. Potato: No growth in aerobic cultures, but pink streak in anaerobic cultures. Indole may or may not be produced (Douglas and Gunter, ibid., 19). Indole produced (Seeliger, personal communica- tion, 1955). Acid from glucose, sucrose (slight), malt- ose, mannitol and inulin (Eberson, op. cit., 1918, 23). Produces propionic acid; lactic acid not fermented (Douglas and Gunter, op. cit., 1946, 22). Nitrites produced from nitrates. Anaerobic to aerotolerant. Catalase-positive. Optimum temperature, between 35° and 37° C. Blood agar: Beta hemolj-sis (Douglas and Gunter, ibid., 19). Pathogenic for mice, giving rise to char- acteristic lesions (Eberson, op, cit., 1918, 23). Serology: See Linzenmeier (Ann. Inst. Past., 87, 1954, 572). Comments: Even before 1901 several authors reported finding bacteria in acne pustules which were evidently diphtheroid in nature. Unna (Monatshefte f. prakt. Derm., 13, 1891, 232) found an organism in acne pustules for which he gave the name Flaschenbacillus. Hodara (Monatshefte f. prakt. Derm., 18, 1894, 586) reported the presence of two types of bacteria in acne lesions, the second of which he called Fla- schenkugelbacillus. Sabouraud (Ann. Inst. Past., 11, 1897, 134) gave a more accurate description of these diphtheroids which he reported to need an acid medium for growth; he called this bacterium "bacille de s^borrh^e grasse". Relationship to Corynebacterium lique- faciens: Seeliger (Arch. f. Hyg. u. Bakt.,
