Generation and Testing of Mutants of Enterococcus faecalis in a Mouse Peritonitis Model
KV Singh, X Qin, GM Weinstock… - The Journal of infectious …, 1998 - academic.oup.com
KV Singh, X Qin, GM Weinstock, BE Murray
The Journal of infectious diseases, 1998•academic.oup.comA 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 …
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 …
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.
Oxford University Press