THE TWO-COMPONENT SYSTEM PrrBA FROM Brucella melitensis IS INVOLVED IN OXIDATIVE STRESS RESISTANCE

BENITO P; FERNANDEZ I; SYCZ GABRIELA; GOLDBAUM F; CARRICA M

Mar del Plata

Congreso; SAIB - 51 Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2015

Brucella is the causative agent of the zoonotic disease bruce llosis,which is endemic in many countries around the world. The success of Brucella aspathogen resides in its ability to adapt to the harsh environmental conditionsfound in mammalian hosts, including oxidative and nitrosative stre ss, low pHand low oxygen tension. The two-component system PrrBA from Brucella isinvolved in redox sensing, in the adaptation to low oxygen tension and in the establishmentof a chronic infecti on in mice. We have shown that a prrB mutant strain in B.melitensis is more sensitive to the oxidative stress caused by the reactiveoxygen species O 2 - and H 2 O 2 than the parental strain. Also, we have shown that prrB gene expressionis induced under the presence of O 2 - and H 2 O 2 . Several enzymes have been described in Brucella that participate inthe detoxification of reactive oxygen species, such as: the Cu-Zn and the Mn superoxidedismutases encoded by sodC and sodA genes, respectively; the catalase encodedby katE and the alkyl- hydroperoxide reductase encoded by the ahpCD operon.Performing qRT-PCR assays we have shown that the PrrBA system is involved inthe induction of sodA and ahpC genes under oxidative stress. The resultspresented in this work suggest that the PrrBA two-component system is involvedin coping with the oxidative stress found inside the mammalian hosts during Brucellainfection.