Iron starvation response of Bordetella parapertussis

OVIEDO, JUAN MARCOS; VALDEZ, HUGO; ALVAREZ HAYES, JIMENA; RODRIGUEZ, MARÍA EUGENIA

Buenos Aires

Simposio; 11th International Bordetella Symposium.; 2016

Objective. The aim of this work was to determine the proteome of Bordetella parapertussis (Bpp) grown under iron limitation. Methods. Bpp was grown in SS media with or without iron. Total proteins were separated with 2D electrophoresis gels (pH 4-7; SDS-PAGE 10%). Differentially expressed proteins were identified with MALDI-TOF. Results. Whole cell lysates of Bpp grown either under iron-starvation or iron-excess conditions were analyzed by two-dimensional (2-D) gel electrophoresis. Image analysis of 2-D maps revealed an average of 550 protein spots and 23 proteins with differential expression that were identified-using MALDI-TOF. Some of the most relevant iron starvation induced proteins are the following. IrpA, a highly conserved iron regulated protein with a potential role in the interaction with the host but also involved in high affinity iron uptake of many bacteria. Fpr, a ferredoxin-NADP reductase, involved in the Fe-S cluster biogenesis and multiple stress responses. NlpA, a metal ABC transporter presumably involved in TLR-2 activation during infection. These two latter proteins were never described in Bordetella spp before. IRP1-1, a putative ABC transporter involved in the transport and metabolism of inorganic ions, like iron. DapD, involved in the biosynthesis of lysine and the precursor diaminopemilate (DAP) necessary for the synthesis of the tracheal cytotoxin involved in the virulence of the bacteria. Peroxidase was also found highly induced under this condition, even higher than in Bordetella pertussis. Conclusion. This first proteomic study showed that iron availability induces changes in Bpp proteome mainly related to stress response, and bacterial-host interaction. Further studies will help to reveal their eventual roles in the pathogen adaptation to the lack of iron and to the infection process