1887

Abstract

Despite the existence of various virulence factors in the genus, enterococcal virulence is still a debated issue. A main consideration is the detection of the same virulence genes in strains isolated from nosocomial or community-acquired infections, and from food products. The goal of this study was to evaluate the roles of two well-characterized enterococcal virulence factors, Fsr and gelatinase, in the potential virulence of food strains. Virulence of unrelated isolates, including dairy strains carrying and operons, was compared in the insect model. dairy strains were able to kill larvae and were as virulent as strain OG1RF, one of the most widely used for virulence studies. In contrast, and strains were avirulent or poorly virulent for . To evaluate the role of and in virulence of dairy strains, both genes were deleted independently in two strains. The Δ and Δ deletion mutants both produced a gelatinase-negative phenotype. Although both mutations significantly attenuated virulence in , the Δ strains were more strongly attenuated. These results agree with previous findings suggesting the involvement of in the control of other cell functions relevant to virulence. Our work demonstrates that the presence of functional , and to a lesser extent , in dairy enterococci should be considered with caution.

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2009-11-01
2019-10-19
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vol. , part 11, pp. 3564 - 3571

In Table 1, page 3565, the phenotype of strain LN68 was given incorrectly: it should be Gel ; not Gel . A corrected version of Table 1 is here(PDF, 98 kb)



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