This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Maier, B. R. Articles by Hentges, D. J. Search for Related Content PubMed PubMed Citation Articles by Maier, B. R. Articles by Hentges, D. J.

 Previous Article  |  Next Article 

Infect Immun. 1972 August; 6(2): 168-173
Copyright © 1972 American Society for Microbiology. All Rights Reserved.

Experimental Shigella Infections in Laboratory Animals I. Antagonism by Human Normal Flora Components in Gnotobiotic Mice ^1,2

^a Department of Microbiology, University of Missouri School of Medicine, Columbia, Missouri 65201

ABSTRACT

Germfree mice were associated with selected species of human intestinal bacteria and then challenged with a streptomycin-resistant Shigella flexneri strain. Antagonism against Shigella was most pronounced in mice associated with Escherichia coli and least pronounced in mice associated with Bacteroides fragilis. A moderate degree of antagonism could be demonstrated in mice associated with either Streptococcus faecalis or Bifidobacterium adolescentis. Shigella persisted in the cecal contents of E. coli-associated mice at very low, stable levels. Shigella populations were reduced to levels below detection in the ceca of mice diassociated with E. coli and Bacteroides. Upon subsequent administration of streptomycin, Bacteroides disappeared from the ceca. The E. coli population was greatly reduced, and Shigella reappeared at very high population levels as an apparent recombinant which resembled E. coli biochemically. A streptomycin-resistant E. coli population subsequently emerged and became dominant in the ceca. Shigella concomitantly declined to levels below detection.

¹ Presented in part at the Annual Meeting of the American Society for Microbiology, Minneapolis, 2-7 May, 1971.

² Taken from a dissertation presented to the Graduate School, University of Missouri, by B. R. Maier in partial fulfillment of requirements for the Ph.D. degree.