Project description:Hafnia alvei H4 is a bacteria subject to regulation by N-acyl-l-homoserine lactone (AHL)-mediated quorum sensing system and is closely related to the corruption of instant sea cucumber. Studying the effect of Hafnia alvei H4 quorum sensing regulatory genes on AHLs is necessary for the quality and preservation of instant sea cucumber. In this study, the draft genome of H. alvei H4, which comprises a single chromosome of 4,687,151 bp, was sequenced and analyzed and the types of AHLs were analyzed employing thin-layer chromatography (TLC) and LC-MS/MS. Then the wild-type strain of H. alvei H4 and the luxI/R double mutant (ΔluxIR) were compared by transcriptome sequencing (RNA-seq). The results indicate that the incomplete genome sequence revealed the presence of one quorum-sensing (QS) gene set, designated as lasI/expR. Three major AHLs, N-hexanoyl-L-homoserine lactone (C6-HSL), N-butyryl-L-homoserine lactone (C4-HSL), and N-(3-oxo-octanoyl)-L-homoserine lactone (3-oxo-C8-HSL) were found, with C6-HSL being the most abundant. C6-HSL was not detected in the culture of the luxI mutant (ΔluxI) and higher levels of C4-HSL was found in the culture of the luxR mutant (ΔluxR), which suggested that the luxR gene may have a positive effect on C4-HSL production. It was also found that AHL and QS genes are closely related in the absence of luxIR double deletion. The results of this study can further elucidate at the genetic level that luxI and luxR genes are involved in the regulation of AHL.

2019-10-10 | GSE137815 | GEO

Multi-omics analysis revealed the anti-quorum sensing mechanism of theaflavin-3,3´-digallate on Hafnia alvei H4

Project description:Theaflavin-3,3´-digallate (TF3) exhibits anti-quorum sensing (QS) properties against Hafnia alvei H4, a bacterium commonly found in spoiled aquatic products, by interacting with LuxI and reducing AHL concentration. This study investigated the extensive changes in the transcriptional and metabolic profiles of H. alvei H4 induced by TF3 as a QS inhibitor (QSI). The results demonstrated that a subminimal inhibitory concentration of TF3 (31.25 µM) disrupted the QS system of H. alvei H4 by down-regulating the expression of genes involved in QS and decreasing AHL concentrations. The dysfunction of the QS system in H. alvei H4 exacerbated oxidative stress, which in turn altered membrane composition, increased membrane permeability, and disrupted energy metabolism, amino acid metabolism, and nucleotide metabolism, ultimately contributing to the anti-QS effect. Subsequent validation through real-time fluorescence quantitative PCR and enzyme assays corroborated the sequencing results. These findings enhance our understanding of the comprehensive anti-QS effects induced by TF3, which may facilitate its future development and application in ensuring food safety.

2025-08-01 | GSE276235 | GEO

Hafnia alvei strain:UUNT_MP41

Project description:Hafnia alvei strain:UUNT_MP41 Genome sequencing

| PRJNA1185451 | ENA

Hafnia alvei ATCC 13337

Project description:Hafnia alvei ATCC 13337 genome sequencing

| PRJNA59557 | ENA