1. Escherichia coli (Migula, 1895) Castellani and Chalmers, 1919. {Bacterium coli commune Escherich, Fortschr. d. Med., 3, 1885, 518; Bacillus escherichii Trevisan, I generi e le specie delle Batteriacee, 1889, 15; Bacillus coli Migula, in Engler and Prantl, Naturlich. Pflanzenfam., 1, la, 1895, 27; Bacterium coli Lehmann and Neumann, Bakt. Diag., 1 Aufl., ^, 1896, 224; Castellani and Chalmers, Man. Trop. Med., 3rd ed., 1919, 941.) co'li. Gr. noun colum or colon the large intestine, colon; L. gen. noun coli of the colon. Rods, usually 0.5 by 1.0 to 3.0 microns, varjing from almost coccoid forms to long rods, occurring singly, in pairs and in short chains. Motile or non-motile; motile strains possess peritrichous flagella. Usually not encapsulated. Non-spore-forming. Gram- negative. Gelatin colonies: Opaque, moist, grayish white, entire. Gelatin stab: Grayish white, spreading, undulate growth. No liquefaction. Agar colonies: Usually white, sometimes yellowish white, entire to undulate, moist, homogeneous. Atypical forms occur fre- quently. Agar slant: Usually white, sometimes yellowish white, moist, glistening, spread- ing growth. Broth: Turbid; heavy, grayish sediment; no pellicle. Litmus milk: Rapid acid production with development of gas; usually coagulated; curd may or may not be broken up; no peptonization of the curd. Litmus may or may not be reduced. Potato: Abundant, grayish to yellowish, spreading growth. Blood agar plates: Different strains vary widely in their action, some being hemoly- tic (Buchgraber and Hilko, Zent. f. Bakt., I Abt., Orig., 133, 1935, 449). Indole usually produced. No hydrogen sulfide produced in peptone iron agar (Levine, Epstein and Vaughn, Amer. Jour. Public Health., 24, 1934, 505; Tittsler and Sandholzer, Amer. Jour. Public Health, 27, 1937, 1240). More sensitive indicators give positive tests for hydrogen sulfide (Hunter and Weiss, Jour. Bact., 35, 1938, 20). Methjd red test positive (Clark and Lubs, Jour. Inf. Dis., 17, 1915, 160); Voges-Pro- skauer test negative (Durham, Jour. Exp. Med., 5, 1901, 373); inverse correlation be- tween methyl red and Voges-Proskauer tests (Levine, Jour. Bact., 1, 1916, 153). Acid and gas from glucose, fructose, galactose, lactose, maltose, arabinose, xylose, rhamnose and mannitol. Sucrose, raffinose, salicin, esculin, dulcitol and glycerol may or may not be fermented. Variable fermentation of sucrose and salicin (Sherman and Wing, Jour. Bact., 33, 1937, 315; Tregoning and Poe, Jour. Bact., 34, 1937, 473). Inulin, pectin and adonitol rarely fermented. Dextrin, starch, glycogen and inositol not fermented. Cellobiose (Jones and Wise, Jour. Bact., 11, 1926, 359) and a-methyl-glucoside (Koser and Saunders, Jour. Bact., 24, 1932, 267) not fermented. See Twort (Proc. Royal Soc. London, 79, 1907, 329) for utilization of unusual gluco- sides, Dozois et al. (Jour. Bact., 30, 1935, 189; and 32, 1936, 499) for utilization of certain sugar alcohols and their anhydrides, and Poe and Klemme (Jour. Biol. Chem., 109, 1935, 43) for utilization of rare sugars. See Winslow, Kligler and Rothberg (Jour. Bact., 4, 1919, 429) for review of literature relative to classification. Gas ratio: Approximately equal volumes of carbon dioxide and hydrogen, ratio 1:1, are produced from glucose (Harden and Walpole, Proc. Roy. Soc, Ser. B, 77, 1905, 399; Rogers, Clark and Davis, Jour. Inf. Dis., 14, 1914, 411). Trimethyleneglycol not produced from glycerol by anaerobic fermentation (Braak, Onderzoekingen over Vergisting van Glyc- erine. Thesis, Delft, 1928, 166; Werkman and Gillen, Jour. Bact., 23, 1932, 167). Citric acid and salts of citric acid not utilized as sole sources of carbon (Koser, Jour. Bact., 8, 1923, 493). Nitrites produced from nitrates. Uric acid not utilized as a sole source of nitrogen (Koser, Jour. Inf. Dis., 23, 1918, 377) ; uracil utilized as a sole source of nitrogen (Mitchell and Levine, Jour. Bact., 35, 1938, 19). Fecal odor produced.
