Enterococci Commensalism and Pathogeny

Commensalism and Pathogenesis of Enterococci       Team leader : Pascale SERROR

RESEARCH AXIS AND ONGOING PROJECTS

Fight against pathogenic and multi-resistant bacteria is a major challenge for human and animal health. The gastrointestinal tract is a reservoir for opportunistic pathogens or pathobionts, which benefit from the imbalance or dysbiosis of the microbiota to invade and infect susceptible hosts.

Enterococci, especially Enterococcus faecalis and Enterococcus faecium, ranks among the top five causes of opportunistic infections in humans. They are present at a sub-dominant level in the gastrointestinal microbiota of healthy humans. Thanks to its intrinsic resistance to different classes of antibiotics and its ability to acquire new ones, enterococci proliferate in the intestinal tract of immunocompromised patients treated with antibiotics, and causes nosocomial infections. Enterococcus cecorum is a commensal of avian species that has emerged as a major cause of lameness in poultry, causing significant economic lost and frequent antibiotic treatments.

CPE goal is to understand the molecular, cellular and physiologic mechanisms that allow enterococci to become pathogenic, using E. faecalis and E. cecorum as main model organism.

Our work aims to generate knowledge to develop new prevention, control and diagnostic strategies against multi-resistant pathogens, to ultimately limit the use of antibiotics in human and animal health.

Our research focuses on the identification and characterisation of bacterial, host and environmental determinants involved in the transition from enterococcal commensalism to pathogenesis. They focus on two research lines:

Research line 1 - Analysis of the early stages of infection to identify new antimicrobial strategies Preventing intestinal colonisation by enterococcal isolates and improving their elimination requires to decipher the enterococcal colonisation mechanisms and to understand how the intestinal microbiota acts as a barrier to their colonisation.

Our current projects involve i) studying the mechanisms of the barrier effect of the intestinal microbiota against E. faecalis and E. faecium, ii) isolation of virulent bacteriophages directed against E. cecorum in order to promote resistance to colonisation and iii) the study of new potential targets and active molecules against enterococc

Research line 2- The interaction of E. faecalis with host cells and the consequences for the host. E. faecalis is one of the rare bacteria whose intestinal overgrowth is associated with liver damage upon excessive alcohol consumption. We have recently shown that E. faecalis replicates in hepatocytes. We are studying the mechanisms of infection of hepatocytes by E. faecalis and its pathophysiological consequences. We are also investigating how the rhamnopolysaccharide EPA allows E. faecalis to escape from phagocytosis.

PUBLICATIONS SINCE 2018 

Click here for our publications.

FUNDINGS FROM 2018

Seed Funding OI MICROBES & GS LSH (2023) Université Paris-Saclay

INRAE-Crète (2022-2023)

ANR-BacWall (2021-2024)

SATT-Cooperate (2021-2022)

EcoAntibio2 Caviar (2019-2022)

INRAE-INTEREST (2020-2021)

SATT-Alright (2018-2021)

INRAE-CecoType (2017-2019)

Fellowships

Health and Therapeutic Innovation (HEALTHI)/INRAE (2021-2024)

MNRET/INRAE (2020-2023)

ANSES/INRAE (2018-2022)

Contacts

Pascale Serror

INRAE – Micalis UMR1319, Bat 442

Domaine de Vilvert, 78350 Jouy en Josas

Tel: 33 (0)1 34 65 21 66