Extraintestinal Pathogenic Eschericia coli (ExPEC) virulence regarding host age and sex La virulencia de Escherichia coli (ExPEC) patogénica intraintestinal en relación a la edad y al sexo del hospedero

DOI: 10.15343/0104-7809.20094392400

Abstract

E. coli is the Gram-negative rod most important cause of bacteremia both in the community and in the hospital environment.
Since the reports on virulence of E. coli isolated from the bloodstream are rare in Brazil, this work aimed to investigate isolates from hospitalized
patients in regard to the frequency of their virulence factors, and phylogeny, as well as their relationship with the sex and age of
the patients. The analysis of phylogenetic relationship was done by PCR, and the search for virulence factors by colony hybridization. Most
of the strains were classified in phylogenetic groups B2 and D. Among 20 virulence traits searched, the most frequent were related to Type
1 fimbriae, yersiniabactin iron acquisition system, and capsule. The most virulent strains were found in the female gender, while age seemed
not to have any connection with the virulence of the isolates. These data suggest that E. coli strains causing bacteremia in female patients
are more virulent than those able to cause the same infection in man. The same is not seen in regard to the age of the patients.