Nuevos genes relacionados con el sistema secretor tipo 4 de Edwardsiella tarda

Abstract

SummaryEdwardsiella tarda is a Gram-negative bacterium that causes edwardsiellosis, a disease of fish and mammals including humans and characterized by multiple abscesses. Different strains of E. tarda possess a number of virulence, antibioticresistance, and toxin secretion system-related genes that explain in some extent its capacity to survive within phagocytic cells and to infect a variety of hosts. Previously we introduced a virulent E. tarda strain (ETSJ54) isolated from Japanese flounder (Paralichthys olivaceus) with edwardsiellosis and reported a number of virulence-related genes. In this study we have re-analyzed the sequencing data of ETSJ54 and identified novel type IV secretion system-related genes, most of them were flanked by transposase and plasmid encoding genes. Interestingly, their nucleotide sequence had no identity to those of the genes published in the E. tarda EIB202 genome, a virulent strain isolated from turbot (Scophthalmus maximus) in China. The results suggest differences in gene content between geographically distinct E. tarda strains that may encourage additional E. tarda genome sequencing projects.

Exploring the genetic diversity of Edwardsiella ictaluri in Vietnamese striped catfish (Pangasianodon hypophthalmus) farms over a 20-year period

“…Although its function in E. ictaluri is not presently known, traD/virD4 has been identified as an ATP-ase "coupling protein" functioning in substrate recruitment in other bacterial species (Grohmann et al, 2018). In addition, this gene has also been implicated in F pilus assembly in E. tarda (Verjan-Garcia et al, 2015), thus similar functions may exist in E. ictaluri. Nonetheless, findings from this study suggest a shift in T4SS-driven virulence pathways for E. ictaluri isolates recently recovered from diseased striped catfish in Vietnam.…”