Fimbrial phase variation and systemic E. coli infection studied in the mouse peritonitis model.

Abstract

Mouse peritonitis induced by intraperitoneal injection of a virulent (LD50 4 x 10(5) E. coli 018:K1:H7 strain isolated from neonatal meningitis was studied. These bacteria are capable of producing both type 1 and S fimbriae, binding to mannose or sialic acid containing glycoconjugates, respectively; the production of both fimbrial types is subject to phase variation. A broth culture of the bacteria was fractionated into subpopulations containing either type 1 or S fimbriae or neither (nonfimbriated cells), and each fraction, grown in broth to logarithmic growth phase, was used to infect groups of mice. The type 1 fraction was associated with decreased virulence as the fraction was eliminated rapidly without causing a progressive infection even at 10(6) bacteria/mouse, whereas both S and nonfimbriated cells started rapid multiplication in the peritoneal cavity and spread to the blood. In nonfibriated cells, however, S fimbriae production was induced at the same time so that at 1 h after injection, 60-70% of the bacteria in the peritoneal cavity and in the blood of the mice had S fimbriae. The injected S-fimbriated fraction remained completely S-fimbriated. Rapid induction of S fimbriae also took place in vitro when the nonfimbriated bacteria were grown in mouse serum or peritoneal fluid. Anti-S serum protected the mice from a lethal dose of S-fimbriated bacteria.

• Authors: B Nowicki, J Vuopio-Varkila, P Viljanen, T K Korhonen, P H Mäkelä
• Journal: Microbial pathogenesis (Microb Pathog) Vol. 1 Issue 4 Pg. 335-47 (Aug 1986) ISSN: 0882-4010 [Print] England
• PMID: 2907771 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Topics

• Animals
• Bacterial Adhesion
• Escherichia coli (pathogenicity)
• Escherichia coli Infections (etiology)
• Fimbriae, Bacterial (physiology)
• Mice
• Peritonitis (etiology)
• Phagocytes (microbiology)