Amoebae can promote the survival of Francisella species in the aquatic environment

Autor: Aurélie Hennebique, Julien Peyroux, Camille Brunet, Amandine Martin, Thomas Henry, Masa Knezevic, Marina Santic, Sandrine Boisset, Max Maurin
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Emerging Microbes and Infections, Vol 10, Iss 1, Pp 277-290 (2021)
Druh dokumentu: article
ISSN: 22221751
2222-1751
DOI: 10.1080/22221751.2021.1885999
Popis: Francisella tularensis, a tier 1 select agent, is the causative bacterium of tularemia, a zoonosis with a large animal reservoir. However, F. tularensis, like many other Francisella species, is assumed to have an aquatic reservoir. The mechanisms of Francisella species persistence in surface water remain poorly characterized. In this study, we deeply investigated the long-term interactions of the tularemia agent F. tularensis subsp. holarctica, F. novicida or F. philomiragia with amoebae of the Acanthamoeba species. In amoeba plate screening tests, all the Francisella species tested resisted the attack by amoebae. In in vitro infection models, intra-amoebic growth of Francisella varied according to the involved bacterial species and strains, but also the amoeba culture medium used. In co-culture models, the amoebae favoured Francisella survival over 16 days, which was likely dependent on direct contact between bacteria and amoebae for F. novicida and on amoeba-excreted compounds for F. novicida and for F. tularensis. In a spring water co-culture model, amoebae again enhanced F. novicida survival and preserved bacterial morphology. Overall, our results demonstrate that amoebae likely promote Francisella survival in aquatic environments, including the tularemia agent F. tularensis. However, bacteria-amoebae interactions are complex and depend on the Francisella species considered.
Databáze: Directory of Open Access Journals