Role of phase variation of type 1 fimbriae in a uropathogenic Escherichia coli cystitis isolate during urinary tract infection - PubMed (original) (raw)

Role of phase variation of type 1 fimbriae in a uropathogenic Escherichia coli cystitis isolate during urinary tract infection

Jennifer A Snyder et al. Infect Immun. 2006 Feb.

Abstract

Type 1 fimbrial phase-locked mutants of uropathogenic Escherichia coli cystitis isolate F11 were used to assess the role of the invertible element during urinary tract infection. Compared to the wild type, the phase-locked off mutant was attenuated, and constitutive production of type 1 fimbriae by the phase-locked on mutant did not provide a competitive advantage.

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Figures

FIG. 1.

Genotypic characterization of the invertible element. The invertible element was amplified by PCR and digested with SnaBI. Asymmetric cutting demonstrated the phase of the invertible element in wild-type strain F11 and mutants that are phase-locked on or off (A). Strains were cultured in vitro in Luria broth (B) or transurethrally inoculated into mice, whose urine was collected at 48 h postinoculation and used for PCR (C).

FIG. 2.

Independent inoculations with F11 and phase-locked mutants in the murine model of UTI. Mice were transurethrally inoculated individually with wild-type E. coli strain F11, F11-ON, or F11-OFF. Urine (A and D), bladder (B and E), and kidney (C and F) samples were quantitatively cultured at various times postinoculation. Each symbol represents one sample from a mouse. Colonization data were compared for F11 and F11-ON (A to C), and for F11 and F11-OFF (D to F). Values at the lower limit of detection (1 × 102 CFU) are spread out for ease of viewing. Median values for the times are connected by a solid line (F11) or a dashed line (phase-locked mutant), but the lines do not imply that there is a continuous function. Data for F11 colonization are shown in relation to each phase-locked mutant for ease of comparison.

FIG. 3.

Coinoculations with F11 and each phase-locked mutant in the murine model of UTI. Mice were transurethrally coinoculated with a bacterial suspension containing E. coli wild-type strain F11 and F11-ON at a 1:1 ratio (A to C) or E. coli F11 and F11-OFF at a 1:1 ratio (D to F). Urine (A and D), bladder (B and E), and kidney (C and F) samples were quantitatively cultured at various times postinoculation. Each sample from individual mice yielded a value for the wild-type strain and the phase-locked mutant. Values at or below the lower limit of detection (1 × 102 CFU) are spread out for ease of viewing. Note that a urine sample could not be obtained from four mice at 4 h postinoculation; thus n = 4 at this time (D). Median values for the times are connected by a solid line (F11) or a dashed line (phase-locked mutant), but the lines do not imply that there is a continuous function.

FIG. 4.

Coinoculations with F11 and F11-rif in the murine model of UTI. Mice were transurethrally coinoculated with a bacterial suspension containing E. coli wild-type strain F11 and F11-rif (a rifampin-resistant mutant) at a 1:1 ratio. Urine (A), bladder (B), and kidney (C) samples were quantitatively cultured at various times postinoculation. The number of CFU of F11 was determined by subtracting the number of CFU of the rifampin-resistant mutant from the total number of CFU on medium lacking antibiotic. Median values for the times are connected by a solid line (F11) or a dashed line (F11-rif), but the lines do not imply that there is a continuous function.

References

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Role of phase variation of type 1 fimbriae in a uropathogenic Escherichia coli cystitis isolate during urinary tract infection - PubMed (original) (raw)