Ramila Rodrigues

PhD thesis of Ramila Rodrigues (2012-2015)

Identification of pathways for oxygen detoxification in Campylobacter jejuni (J.M. Cappelier, O. Tresse).

Asbtract:

Campylobacteriosis is the first zoonosis in developed countries with a high prevalence of Campylobacter jejuni. Although described as a strictly microaerobic bacterium, a clinical strain of C. jejuni, called Bf, has been identified as being aerotolerant. The objective of this study was to study the phenotypic properties of Bf to better understand its aerotolerance. Bf has been compared to other strains of C. jejuni for its aerobic and microaerobic growth. The results showed that Bf could multiply aerobically and exhibited a better survival rate in the presence of oxidizing agents. Cells exposed to oxidative stress change their morphology, which has been linked to the modification of mreB expression. Bf also has an aerobic protective effect on other strains of C. jejuni as it has been demonstrated with a better survival rate of NCTC 11168 in the presence of Bf without direct contact. Coupled proteomic, transcriptomic and enzymatic analyzes have made it possible to highlight an important role of the enzymes involved in the detoxification of oxygen with an increased demand for carbon elements and iron homeostasis. Furthermore, virulence tests have shown that Bf is one of the most virulent strains on the uninflamed HT29 line and, unlike other strains, it is the only one that behaves differently on inflamed epithelial cells. This work brings new elements on the adaptive capacities of C. jejuni against harmful oxygen conditions which could explain the survival of C. jejuni along the food processing chain.

Valorisation :

  • Rodrigues, R., A.-L. Pocheron, M. Hernould, H. N., O. Tresse and J.-M. Cappelier 2015. Description of Campylobacter jejuni Bf, an atypical aero-tolerant Gut Pathogens 7(30): 1-12. Ranking du JCR: Q2. https://doi.org/10.1186/s13099-015-0077-x
  • Rodrigues, R. C., N. Haddad, D. Chevret, J.-M. Cappelier and O. Tresse 2016. Comparison of proteomics profiles of Campylobacter jejuni strain Bf under microaerobic and aerobic conditions. Frontiers in Microbiology 7(1596): 1-12. Ranking du JCR: Q1. https://doi.org/10.3389/fmicb.2016.01596.
  • Rodrigues, R. C., A.-L. Pocheron, J.-M. Cappelier, O. Tresse and N. Haddad 2018. An adapted in vitro assay to assess Campylobacter jejuni interaction with intestinal epithelial cells: Taking into stimulation with TNFα. Journal of Microbiological Methods 149: 67-72. Ranking du JCR: Q3. https://doi.org/10.1016/j.mimet.2018.04.020.

Modification date : 21 November 2023 | Publication date : 24 January 2014 | Redactor : AR