%0 Journal Article %J J Infect Dis %D 1998 %T Generation and testing of mutants of Enterococcus faecalis in a mouse peritonitis model. %A Singh, K V %A Xiang Qin %A Weinstock, G M %A Murray, B E %K Animals %K Disease Models, Animal %K Enterococcus faecalis %K Feces %K Female %K Gelatinases %K Gram-Positive Bacterial Infections %K Hemolysin Proteins %K Mice %K Mutation %K Peritonitis %K Rats %X

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.

%B J Infect Dis %V 178 %P 1416-20 %8 1998 Nov %G eng %N 5 %1 https://www.ncbi.nlm.nih.gov/pubmed/9780263?dopt=Abstract %R 10.1086/314453