Mutator natural Escherichia coli isolates have an unusual virulence phenotype.
Infect Immun
; 69(1): 9-14, 2001 Jan.
Article
en En
| MEDLINE
| ID: mdl-11119483
ABSTRACT
A small percentage of natural Escherichia coli isolates (both commensal and pathogenic) have a mutator phenotype related to defects in methyl-directed mismatch repair (MR) genes. We investigated whether there was a direct link between the mutator phenotype and virulence by (i) studying the relationships between mutation rate and virulence in a mouse model of extraintestinal virulence for 88 commensal and extraintestinal pathogenic E. coli isolates and (ii) comparing the virulence in mice of MR-deficient and MR-proficient strains that were otherwise isogenic. The results provide no support for the hypothesis that the mutator phenotype has a direct role in virulence or is associated with increased virulence. Most of the natural mutator strains studied displayed an unusual virulence phenotype with (i) a lack of correspondence between the number of virulence determinants and pathogenicity in mice and (ii) an intermediate level of virulence. On a large evolutionary scale, the mutator phenotype may help parasites to achieve an intermediate rate of virulence which mathematical models predict to be selected for during long-term parasite-host interactions.
Texto completo:
1
Base de datos:
MEDLINE
Asunto principal:
Disparidad de Par Base
/
Reparación del ADN
/
Escherichia coli
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Infect Immun
Año:
2001
Tipo del documento:
Article
País de afiliación:
Francia