Mutator phenotype confers advantage in Escherichia coli chronic urinary tract infection pathogenesis

Area of Science:

• Microbiology
• Bacterial Pathogenesis
• Genetics

Background:

• The mutator phenotype, associated with elevated mutation rates, is hypothesized to increase bacterial virulence.
• Epidemiological data indicate a high prevalence of mutator strains in Escherichia coli urinary tract infection (UTI) isolates.
• Experimental evidence directly linking the mutator phenotype to enhanced virulence has been limited.

Purpose of the Study:

• To investigate whether the mutator phenotype confers a selective advantage during urinary tract infections.
• To experimentally validate the association between increased mutation rates and virulence in Escherichia coli.

Main Methods:

• Utilized the uropathogenic Escherichia coli strain CFT073 and its isogenic mutS- mutant (a mutator strain).
• Assessed the in vitro selection of the mutator strain in urine.
• Evaluated the in vivo selection of the mutator strain during the late stages of a mouse model of urinary tract infection.

Main Results:

• The mutator strain demonstrated a selective advantage in vitro when cultured in urine.
• In a mouse model of urinary tract infection, the mutator strain was also selected during the late stages of infection.
• These findings provide experimental evidence supporting the role of the mutator phenotype in pathogenesis.

Conclusions:

• The mutator phenotype can confer a selective advantage under specific conditions, such as urinary tract infections.
• This study provides experimental evidence for the link between the mutator phenotype and enhanced pathogenesis in Escherichia coli.
• The findings highlight the importance of genetic instability in bacterial virulence strategies.