Transfer of pheromone-inducible plasmids between Enterococcus faecalis in the Syrian hamster gastrointestinal tract.
Pheromone-responsive plasmids are common to Enterococcus faecalis, transfer at high frequency in vitro, and carry cytolysin and other gene products implicated in the pathogenesis of enterococcal infection. A Syrian hamster model of enterococcal intestinal overgrowth was used to test for transfer of three isogenic plasmids differing in conjugative and cytolytic phenotypes. Transconjugants were found in 8 (44%) of 18 and 6 (35%) of 17 hamsters given donor strains containing cytolytic (pAM714) and noncytolytic (pAM771) pheromone-responsive plasmids. Of the 14 hamsters from which transconjugants were isolated from stool, 9 (64%) had transconjugants 1 day after donor strain inoculation. The frequency of transfer (mean +/- SD) for pAM714 and pAM771 was 1.4 +/- 2.2 x 10(-1) and 2.9 +/- 4.2 x 10(-2) transconjugants/donor, respectively (P > .20). Transconjugants were not recovered from hamsters receiving a cytolytic, nonconjugative plasmid (pAM930; transfer frequency < 2 x 10(-5) transconjugants/donor). Pheromone-responsive plasmid transfer between E. faecalis strains occurs at high frequency in the gastrointestinal tract of hamsters and may be one means by which enterococcal resistance and virulence factors disseminate.
Huycke
M M
MM
Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City.
Gilmore
M S
MS
Jett
B D
BD
Booth
J L
JL
D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003227:Conjugation, Genetic; D006224:Cricetinae; D003433:Crosses, Genetic; D004064:Digestive System / Q000382:microbiology*; D004352:Drug Resistance, Microbial; D013293:Enterococcus faecalis / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D004917:Erythromycin / Q000494:pharmacology; D005243:Feces / Q000382:microbiology; D005838:Genotype; D008297:Male; D008647:Mesocricetus; D008969:Molecular Sequence Data; D010641:Phenotype; D010675:Pheromones / Q000502:physiology*; D010957:Plasmids; D000198:Spectinomycin / Q000494:pharmacology; D013307:Streptomycin / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D010675:Pheromones; D004917:Erythromycin; D000198:Spectinomycin; D013307:Streptomycin