Role of DNA repair mechanisms in the response of Pseudomonas aeruginosa to the antimicrobials Ciprofloxacin and Ceftazidime.

Author(s)

Letícia Busato Migliorini

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2017-10-17

Examining board members

Rodrigo da Silva Galhardo; Regina Lúcia Baldini; Henrique Ferreira; Rita de Cassia Cafe Ferreira

• Advisor: Rodrigo da Silva Galhardo

Abstract

Pseudomonas aeruginosa is a human pathogen that has worried the scientific community by increasing antimicrobial resistance. The effects caused by the antimicrobial agents may lead to the activation of mutagenic responses that regulate low fidelity polymerases, acting in DNA Transmission Synthesis (TLS). In this work, we evaluated the response of P. aeruginosa to Ceftazidime and Ciprofloxacin. It has been observed that Ceftazidime does not induce the SOS response nor mutagenesis, unlike Ciprofloxacin. We show that the three TLS polymerases are involved in the mutagenesis induced by Ciprofloxacin and hydrogen peroxide. Also, we observed that the loss of any of the polymerases significantly altered the spectrum of spontaneous mutations induced by Ciprofloxacin and that have redundant functions in this mutagenic process. Thus, we have shown that TLS polymerases are important for Ciprofloxacin-induced mutagenesis in P. aeruginosa, and may be implicated in adaptive mutagenesis and consequently bacterial resistance. (AU)

• FAPESP's process: 15/18886-0 - Role of DNA repair mechanisms in the response of Pseudomonas aeruginosa to antimicrobials ciprofloxacin and ceftazidime
• Grantee: Letícia Busato Migliorini
• Support Opportunities: Scholarships in Brazil - Master