Page:Bergey's manual of determinative bacteriology.djvu/356

Serological studies support the cultural studies that show that the species of Serratia Bizio sensu stricto belong in the coliform group (Breed and Breed, Cent. f. Bakt., II Abt., 71 , 1927, 435) . These widely distributed red organisms are found growing not only on starchy foods but also on other foods and on such tropical products as dried coconut (copra), latex and even in palm buds undergoing a soft rot. Likewise, Thj0tta and K&ss (Norske Viden- skaps-Akad., Oslo, I Mat.-Naturv. Klasse, No. 5, 1945, 17) have shown that the bacteria which decompose alginates sometimes have all the characteristics of coliform organisms except that they possess the power to attack these substances that resist attack by the common coliform bacteria. Too few students of the coliform group test their cultures to see whether they will produce soft rots (Erwinia carotovora Holland). Still fewer students of coliform bacteria determine the type of flagellation possessed b}' the organisms they study, although it is well known to students of fish diseases (Schaperclaus, Fischkrank- heiten, 2 Aufi., 1941, Braunschweig, 296 pp.) that several motile (polar flagellate) and non- motile species of Pseudomonadaceae are easily mistaken for coliform or paracolon bacteria. Some of these {Aero77ionas punctata Snieszko and other species in the genus Aeromonas Kluyver and van Niel) are common in water as they cause diseases of carp, salmon and other fish as well as diseases of frogs. Borman, Stuart and Wheeler (Jour. Bact., 48, 1944, 351), Kauffmann (op. cit., 1954), Edwards and Ewing (op. cit., 1955) and others have recently suggested rearrangements in the classification of the species that belong in the family Enter obacieriaceae. Only the future can determine which of the views of these authors best expresses the relationships of the bacteria that belong in this family. — The Editors. Key to the tribes of family Enterobacteriaceae. I. Lactose fermented anaerobically, usually within 48 hours, but in one genus (Paracolo- bactrum) the fermentation may be delayed as much as 30 days. A. Prodigiosin not produced. 1. Do not produce protopectinase. Not parasitic on plants. Tribe I. Escherichieae, p. 334. 2. May produce protopectinase. Parasitic on plants, frequently causing soft rots, blights, etc. Tribe II. Erwinieae, p. 349. B. Prodigiosin produced. Tribe III. Serratieae, p. 359. II. Lactose rarely fermented anaerobically. A. Urea decomposed within 48 hours (except by Proteus inconstans). Tribe IV. Proteeae, p. 364. B. Urea not decomposed within 48 hours. Tribe V. Salmonelleae, p. 368. TRIBE I. ESCHERICHIEAE BERGEY, BREED AND MURRAY, 1938. (Preprint, Manual, 5th ed., 1938 (October), vi.) Esch.er.i.chi'e.ae. M.L. fem.n. Escherichia type genus of the tribe; -cae ending to denote a tribe; M.L. fem.pl.n. Escherichieae the Escherichia tribe. Rods that are either motile by means of peritrichous flagella or occasionally non-motile. Gelatin not liquefied except slowly by Aerobacter cloacae and by Paracolobactrum arizonae. Ferment glucose and lactose with the production of acid and visible gas within 24 hours at 37° C. or within 48 hours at 25° to 30° C. Some forms produce acid and gas from lactose slowly, occasionally not at all. Do not produce soft rots of vegetables.