The Enterococcus faecalis fsrB gene, a key component of the fsr quorum-sensing system, is associated with virulence in the rabbit endophthalmitis model - PubMed (original) (raw)

The Enterococcus faecalis fsrB gene, a key component of the fsr quorum-sensing system, is associated with virulence in the rabbit endophthalmitis model

Eleftherios Mylonakis et al. Infect Immun. 2002 Aug.

Abstract

We used a rabbit endophthalmitis model to explore the role of fsrB, a gene required for the function of the fsr quorum-sensing system of Enterococcus faecalis, in pathogenicity. A nonpolar deletion mutant of fsrB had significantly reduced virulence compared to wild type. Complementation of mutation restored virulence. These data corroborate the role of fsrB in E. faecalis pathogenesis and suggest that the rabbit endophthalmitis model can be used to study the in vivo role of quorum sensing.

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Figures

FIG. 1.

(a) Growth of wild-type E. faecalis strain OG1RF, the nonpolar deletion mutant Δ_fsrB_, and the complemented strain TX5266.01 in vitreo. (b) Retinal function after intraocular infection with E. faecalis OG1RF, the nonpolar deletion mutant Δ_fsrB_ (TX5266), and the complemented strain TX5266.01. Rabbits (n = 12) were injected with ca. 102 CFU, and retinal function was assessed at 12, 24, 36, and 48 h after injection. Percent retinal function was defined as follows: (B-wave amplitude of the infected eye)/(B-wave amplitude of the saline-injected contralateral eye). The P values shown are derived from a two-tailed Student's t test for unequal variances comparing Δ_fsrB_ to OG1RF; there was no statistical difference between the group that received OG1RF and the TX5266.01 group. Error bars represent the standard errors of the means.

FIG. 2.

Thin-section histopathology (representative slides; H-E stain). (A) Infection with E. faecalis OG1RF after 48 h, showing marked vitreal polymorphonuclear infiltrate, cystoid changes in the ganglionic cell layer, decreased nuclear density of inner and outer nuclear layers, mild subretinal polymorphonuclear infiltrate, and overall loss of structural integrity. (B) Infection with the Δ_fsrB_ strain after 48 h, showing mild vitreal polymorphonuclear infiltrate, structure of all retinal layers preserved, and no subretinal inflammatory infiltrate. V, vitreous; R, retina; C, cornea; S, sclera.

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The Enterococcus faecalis fsrB gene, a key component of the fsr quorum-sensing system, is associated with virulence in the rabbit endophthalmitis model - PubMed (original) (raw)