Vibrio splendidus O-antigen structure: a trade-off between virulence to oysters and resistance to grazers.
Environ Microbiol
; 22(10): 4264-4278, 2020 10.
Article
em En
| MEDLINE
| ID: mdl-32219965
ABSTRACT
A major debate in evolutionary biology is whether virulence is maintained as an adaptive trait and/or evolves to non-virulence. In the environment, virulence traits of non-obligatory parasites are subjected to diverse selective pressures and trade-offs. Here, we focus on a population of Vibrio splendidus that displays moderate virulence for oysters. A MARTX (Multifunctional-autoprocessing repeats-in-toxin) and a type-six secretion system (T6SS) were found to be necessary for virulence toward oysters, while a region (wbe) involved in O-antigen synthesis is necessary for resistance to predation against amoebae. Gene inactivation within the wbe region had major consequences on the O-antigen structure, conferring lower immunogenicity, competitive advantage and increased virulence in oyster experimental infections. Therefore, O-antigen structures that favour resistance to environmental predators result in an increased activation of the oyster immune system and a reduced virulence in that host. These trade-offs likely contribute to maintaining O-antigen diversity in the marine environment by favouring genomic plasticity of the wbe region. The results of this study indicate an evolution of V. splendidus towards moderate virulence as a compromise between fitness in the oyster as a host, and resistance to its predators in the environment.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ostreidae
/
Vibrio
/
Antígenos O
/
Sistemas de Secreção Tipo VI
Limite:
Animals
Idioma:
En
Revista:
Environ Microbiol
Assunto da revista:
MICROBIOLOGIA
/
SAUDE AMBIENTAL
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
França