A Study of Rettger's Bacillus and Related Bacteria

Abstract

Few reports of the occurrence of Rettger's bacillus can be found in the literature prior to its isolation by Cope and Kilander. 1 Originally the organism was isolated by Rettger during his studies of diseases of fowl. It was described, named and classified by Hadley, Elkins and Caldwell, 2 by whom it was considered to be a member of the genus Shigella. St. John Brooks and Rhodes 3 studied one strain obtained from Hadley's collection, but aside from noting that it produced indol, they made no mention of its characteristics. The species is assigned to the genus Shigella in Bergey's Manual, Vth Edition, where it was originally placed by Bergey and later by Weldin. 4 Neter 5 in reviewing the genus Shigella called attention to the scanty and contradictory knowledge of this species. Very shortly, Cope and Kilander in the aforementioned paper rediscovered the species in human gastroenteritis. At about the same time, Stuart and coworkers 6 encountered strains called “type 33111” in their study of the paracolon group.

Rustigian and Stuart 7 in the following year suggested the name “Proteus entericus” for these strains. Subsequently these workers 8 secured presumably authentic type strains and demonstrated that the true species name for their “type 33111” and “Proteus entericus” was “rettgeri” They assigned the species to the genus Proteus. Their conclusions, based on the study of 78 strains are embodied in a recent paper by Rustigian and Stuart. 9

Fulton and Curtis 10 previously reported studies of this species, and Felsenfeld and Young have isolated strains in the Chicago area. There do not appear to be other published reports of the occurrence of this organism, although its isolation in New England, Michigan, Illinois and Texas suggests that it is of widespread distribution.

Organisms resembling Rettger's bacillus but not identical with it have been isolated from time to time by most students of enteric bacteriology. Such cultures have the cardinal characteristics of the genus Eberthella. Fourteen species are recognized by Bergey, most of the descriptions being incomplete.