Characterization of the mutator phenotype in isolates of P. mirabilis.

Author(s)

Marina Rocha Borges da Fonseca

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2017-02-03

Examining board members

Rodrigo da Silva Galhardo; Rodrigo Tavanelli Hernandes; Carla Taddei de Castro Neves; Beny Spira

• Advisor: Rodrigo da Silva Galhardo

Abstract

Strains with high mutation rates (mutators) were detected in several bacterial genera. The increased mutation rate is related to defects in DNA repair systems. A high incidence of Proteus mirabilis clinical isolates with high mutation frequencies were described previously. The phenomenon was induced in Escherichia coli, when transformed with a plasmid of P. mirabilis. 77 P. mirabilis clinical isolates were tested for the frequency of spontaneous mutants and the presence of a conjugative element found in this species, ICEs SXT/R391, to verify if there is a relation between the element and the mutation frequencies. 9 isolates carry the ICE SXT/R391. The frequency of mutants showed no true mutators among the isolates. 11 isolates show a high frequency of FosR mutants. Considering the high rate of infections by P. mirabilis, it is important to understand the fosfomycin phenomenon, since it is currently used to treat urinary infections. We have seen no relation between a high spontaneous mutation frequency and the presence of ICE SXT/R391 in isolates of P. mirabilis. (AU)

• FAPESP's process: 15/11348-3 - Characterization of mutator phenotypes in Proteus mirabilis isolates
• Grantee: Marina Rocha Borges da Fonseca
• Support Opportunities: Scholarships in Brazil - Master