Proteomic analysis of Hfq-regulon in B. pertussis

ALVAREZ HAYES, JIMENA;; SURMANN, KRISTIN; LAMBERTI, YANINA; DEPKE, MAREN; VIDHNU, DHOLPE; BLANCÁ, BRUNO; RUIZ, ESPERANZA; VECEREK, BRANISLAV; SCHMIDT, FRANK; VÖLKER, UWE; RODRIGUEZ, M.EUGENIA

Simposio; 12th International Bordetella Symposium; 2019

Iron starvation is a critical stress a pathogen has to overcome during infection and induces deep changes in bacterial phenotype. In this study we used shotgun proteomics to study Bordetella parapertussis and its iron-starved phenotype. A final number of 1311 proteins were identified and 175 showed significant changes under iron starvation. As expected, a big number of proteins involved in iron acquisition from different sources such as siderophores and heme were found increased in abundance, namely, BrfB, BfrC, BhuR, BhuS, BhuT, exbB, exbD, and the recently described protective antigen AfuA. We also found that the lack of iron induced significant changes in metabolism, triggering a reduction in abundance of enzymes related to the Krebs cycle, amino acids biosynthesis, cythocromes and ribosomal proteins which suggest that B. parapertussis adapts to iron starvation decreasing the production of iron-dependent enzymes probably to redirect iron to more essential pathways. Finally, the abundance of some virulence factors was also altered under iron starvation. Worth to mention is the increased abundance of the main toxin of this pathogen ,adenylate cyclase, and the decreased abundance of, a protein required for the O-antigen biosynthesis which led to a reduced amount of the O-antigen molecule in iron starved Bpp. An observation that deserves further investigation. Additionally, since this is the first proteomic study of B. parapertussis, we also analyzed identified proteins not encoded in the genome of B. pertussis. We found proteins potentially involved in stress tolerance, intracellular survival, pathogenesis, and virulence solely present in B. parapertussis which might help to explain the differences in the pathogenesis of these closely related species and the lack of cross protection of pertussis vaccines against B. parapertussis