Generation and testing of mutants of Enterococcus faecalis in a mouse peritonitis model.

TitleGeneration and testing of mutants of Enterococcus faecalis in a mouse peritonitis model.
Publication TypeJournal Article
Year of Publication1998
AuthorsSingh, KV, Qin, X, Weinstock, GM, Murray, BE
JournalJ Infect Dis
Volume178
Issue5
Pagination1416-20
Date Published1998 Nov
ISSN0022-1899
KeywordsAnimals, Disease Models, Animal, Enterococcus faecalis, Feces, Female, Gelatinases, Gram-Positive Bacterial Infections, Hemolysin Proteins, Mice, Mutation, Peritonitis, Rats
Abstract

A previously described mouse peritonitis model was used to study derivatives of Enterococcus faecalis strain OG1RF. The addition of sterile rat fecal extracts (SRFE) lowered the LD50 of OG1RF >10-fold. Hemolysin production caused a 35-fold lower LD50 and a much shorter survival, similar to previous results using a peritonitis model without SRFE. A purine (but not a pyrimidine) auxotroph was considerably less lethal than wild type; gelatinase mutants were also attenuated. A suicide vector was generated with an enterococcal selectable marker in order to disrupt a gene encoding an E. faecalis antigen; the resulting mutant was not attenuated despite a slower growth rate. In conclusion, this model allows attenuated mutants to be detected, corroborates prior reports that hemolysin is a virulence factor, and suggests a role for gelatinase in virulence of E. faecalis in mice; the attenuated purine auxotroph may provide a system for developing vectors for in vivo expression systems.

Alternate JournalJ. Infect. Dis.
PubMed ID9780263
Grant ListAI-33516 / AI / NIAID NIH HHS / United States