Enterococcus faecalis cytolysin without effect on the intestinal growth of susceptible enterococci in mice.
A murine model was developed to determine whether the Enterococcus faecalis cytolysin, through its bacteriolytic action on gram-positive bacteria, could promote intestinal overgrowth of cytolytic strains. Sets of E. faecalis strains with varying cytolytic production and susceptibility to cytolytic activity were mixed 1:1 and allowed to compete in vitro in broth or in vivo after orogastric administration in mice pretreated with antibiotics. In general, cytolytic strains outgrew, by as much as 2000-fold, competing cytolysin-susceptible or -hypersusceptible strains in vitro. In contrast, no growth advantage was observed in vivo, despite similar transient colonization of the murine intestinal tract by both cytolytic and cytolysin-susceptible strains. These data suggest that cytolysin plays little role in promoting intestinal overgrowth of enterococci through bacteriolytic activity.
Huycke
M M
MM
Medical and Research Services, VA Medical Center, University of Oklahoma Health Sciences Center, Oklahoma City 73104, USA.
Joyce
W A
WA
Gilmore
M S
MS
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D003227:Conjugation, Genetic; D003603:Cytotoxins / Q000235:genetics / Q000502:physiology*; D013293:Enterococcus faecalis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D005260:Female; D005838:Genotype; D007422:Intestines / Q000382:microbiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010641:Phenotype; D010957:Plasmids; D013045:Species Specificity
D000900:Anti-Bacterial Agents; D003603:Cytotoxins