Motility, biofilm formation and associated gene expression in Vibrio parahaemolyticus impaired by co‐culture with live Ulva fasciata

Abstract

Aims Vibrio parahaemolyticus is one of the most frequently occurred pathogens in mariculture. This study aimed to explore the mechanism of the impact of Ulva fasciata on the motility and biofilm formation of V. parahaemolyticus. Methods and Results The inhibitory effect of U. fasciata on a V. parahaemolyticus, isolated from clam maricultural sediment, was examined by co‐culture of them. The live U. fasciata significantly inhibited the swimming behaviour, twitching behaviour and biofilm formation of V. parahaemolyticus JF, with inhibition rates range of 2.48%–20.26%, 1.59%–39.18% and 28.3%–94.7% under different nitrate and phosphate levels, respectively. The results of transcriptome sequencing showed that 210 significantly differentially expressed genes (DEGs) were found in strain JF between the presence and absence of U. fasciata, including 90 upregulated genes and 120 downregulated genes. According to GO (Gene Ontology) function enrichment and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis, the downregulated genes of JF were partially enriched in flagella assembly (fliC, fliK, fliG, fliN, fliH, fliI, fliJ and fliA), bacterial chemotaxis (mCP, cheB, cheW and cheY) and biofilm formation (fliA/σ28 and eps), which explained the suppressed motility and biofilm formation of V. parahaemolyticus JF under U. fasciata stress. Conclusions Live U. fasciata significantly impaired the motility and biofilm formation of V. parahaemolyticus, which could occur in niches with either sufficient or inadequate nutrient (nitrate and phosphate) concentrations. The DEGs of V. parahaemolyticus modulated by U. fasciata were enriched mainly in the flagellar assembly, bacterial chemotaxis and biofilm pathways. Significance and Impact of the Study New information on how V. parahaemolyticus respond to U. fasciata regarding motility and adhesion behaviours, and the mechanism of that was firstly explored in this study. The results suggested that the seaweed U. fasciata has promising prospects as an environmentally friendly preventive measure to treat vibriosis in mariculture.

Selected flavonoids exhibit antibiofilm and antibacterial effects against Vibrio by disrupting membrane integrity, virulence and metabolic activities

“…Also, 6-AF and 3,2-DHF suppressed the expressions of fliG, cheZ, and cheY ( Fig. 5 B), which control chemotaxis, flagellar biosynthesis, and clockwise and anticlockwise rotation [ 58 ]. Additionally, 6-AF, 3,2-DHF, and DHMB downregulated tdh, encoding hemolysin production in V. parahaemolyticus , by 3.0-, 3.0-, and 7.2-fold, respectively, and notably downregulated other genes relating to the membrane and effector secretion systems ( Fig.…”

Characterization of biofilm formation by Exiguobacterium strains in response to arsenic exposure

“…3 ), whereas no significant differences were detected in most cases when comparing the patterns between As(V) and As(III). Of the mentioned genes, fliG, which codes for a protein that favors bacterial motility ( 25 ), displayed the lowest induction for all three strains (SH31, SH1S21, and SH31). On the other hand, dnaK , which plays an important role in the folding of proteins necessary for biofilm formation ( 26 ), shows higher expression for the strains SH31 and SH1S21 in response to As(V) than to As(III), which is opposed to what was observed in the SH0S7 strain.…”

Transcriptomic analyses of Vibrio parahaemolyticus under the phenyllactic acid stress

“…Gao et al ( 2018 ) confirmed that the genes flgA , flgC , and flgD were down-regulated in Vibrio anguillarum under starvation stress. Qiao et al ( 2022 ) showed that genes related to flagellar assembly ( fliC , fliK , fliG , fliN , fliH , fliI , fliJ , and fliA ) were significantly enriched when Vp 17802 was co-cultured with Ulva fasciata , showing a trend of down-regulation. Therefore, the flagellar system is an important target for antibacterial substances to exert antibacterial effects.…”