Characterization of phenotype variations of luminescent and non-luminescent variants of Vibrio harveyi wild type and quorum sensing mutants

Abstract

Vibrio harveyi, a luminescent Gram-negative motile marine bacterium, is an important pathogen responsible for causing severe diseases in shrimp, finfish and molluscs leading to severe economic losses. Non-luminescent V.harveyi obtained by culturing luminescent strains under static and dark condition were reported to alter the levels of virulence factors and metalloprotease gene and luxR expression when compared to their luminescent variants. Presently, we conducted an in vitro study aiming at the characterization of virulence-related phenotypic traits of the wild-type V.harveyi BB120 strain and its isogenic quorum sensing mutants before and after switching to the non-luminescent status. We measured the production of caseinase, haemolysin and elastase and examined swimming motility and biofilm formation. Our results showed that switching from the bioluminescent to the non-luminescent state changed the phenotypic physiology or behaviour of V.harveyi resulting in alterations in caseinase and haemolytic activities, swimming motility and biofilm formation. The switching capacity was to a large extent independent from the quorum sensing status, in that quorum sensing mutants were equally capable of making the phenotypic switch.

Keywords

luminescent; non-luminescent; phenotype switch; Vibrio harveyi; virulence factor

Published in

Journal of Fish Diseases
2016, Volume: 39, number: 3, pages: 317-327
Publisher: WILEY

UKÄ Subject classification

Fish and Aquacultural Science


Publication identifier

DOI: https://doi.org/10.1111/jfd.12365

Permanent link to this page (URI)

https://res.slu.se/id/publ/100043