bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/862151

Assigning a role for chemosensory signal transduction in Campylobacter jejuni biofilms using a combined omics approach

Korolik, V.·Tram, G.·Klare, W. P.·Cain, J. A.·Mourad, B.·Cordwell, S. J.·Day, C. J.
View original source ↗Export metadata ↓

Abstract

Biofilms serve as a protective mechanism for bacteria to cope with environmental stress. Whilst ordinarily a fastidious organism, it has been long suggested that C. jejuni is able to utilise this mode of growth as a way to transmit infection from the avian host to humans. Herein, we undertook a combinatorial approach to examine differential expression of C. jejuni genes and protein abundance during biofilm formation. RNA sequencing and proteomics via quantitative liquid chromatography - tandem mass spectrometry (LC-MS/MS) revealed biofilm growth induced a substantial rearrangement of the C. jejuni transcriptome and proteome, with [~]600 genes differentially expressed in biofilms compared to planktonic cells. Biofilm-induced genes / proteins were those involved in iron metabolism and acquisition, cell division, glycan production and attachment, while those repressed were associated with metabolism, amino acid uptake and utilisation, and large tracts of the chemotaxis pathway. We further examined the role of chemotaxis in C. jejuni biofilm formation by assessing the behaviour of isogenic strains with deletions of the cheV and cheW genes. Both {Delta}cheV and {Delta}cheW exhibited a significant decrease in directed motility when compared to wild-type C. jejuni. Both mutants also demonstrated an increase in autoagglutination ability and increased biofilm formation. A subtle difference was also observed between the phenotypes of {Delta}cheV and {Delta}cheW mutants, both in motility and biofilm formation. This suggests roles for the CheV and CheW signal transduction proteins and may present signal transduction as a potential method for modulating C. jejuni biofilm formation. Author summaryCampylobacter jejuni is a gastroenteric bacterium that is responsible for most cases of bacterial food poisoning in the developed world. The organism commonly resides in avian reservoirs and is passed to humans through contaminated poultry and animal products. Ordinarily, C. jejuni requires a strict set of conditions in order to survive and cause infections in humans. Biofilms are a method of bacterial growth that may provide shielding from harsh environments and provide an important link between reservoirs and human hosts. In this study, we have utilised a multi-platform approach to compare gene expression and protein abundance in planktonic C. jejuni cells and those growing as a biofilm. We subsequently focused on the chemosensory system of C. jejuni and demonstrated that signal transduction proteins play a role in biofilm formation. Our work has provided a broad profile of which genes are important to C. jejuni biofilms and that the chemosensory pathway has an influence on biofilm formation.

Source connections

Explore related subjects

microbiologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Korolik, V., Tram, G., Klare, W. P., Cain, J. A., Mourad, B., Cordwell, S. J., Day, C. J.. 2019-12-02. Assigning a role for chemosensory signal transduction in Campylobacter jejuni biofilms using a combined omics approach. https://doi.org/10.1101/862151

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

A conserved cysteine-histidine-glutamate metal site identifies DUF501 (Rv1025), an essential uncharacterised protein family of Mycobacterium tuberculosis, as a candidate metalloenzyme and drug target

A substantial fraction of the Mycobacterium tuberculosis proteome remains functionally uncharacterised. Rv1025, a 155-residue protein carrying the domain of unknown function DUF501 (Pfam PF04417), is essential by transposon mutagenesis and vulnerable by CRISPR interference, an attractive but neglected drug target, yet has never been functionally described. The family (4,370 proteins, no Gene Ontology term, no solved structure) is uncharacterised across all organisms and essential in three Actinobacterial genera. A Foldseek search of the AlphaFold model against complete structural databases finds no significant homolog, indicating a novel fold. The operon eno-divIC-Rv1025-ppx2 is conserved across the Actinobacteria phylum, yet AlphaFold-Multimer finds no direct complex between Rv1025 and its neighbour DivIC. Instead, conservation across 8,700 homologous sequences reveals a near-invariant Cys113-His115-Glu59 cluster forming a pocket. Holo AlphaFold3 predictions with Zn, Fe and Mn confidently place a divalent metal on this triad at 2.25-2.47 A; mutating the triad relocates the metal, and an independent backbone-geometry predictor recovers the same site, confirming specificity. The triad is universal across the family: present in all 1,472 near-complete bacterial sequences of the Pfam alignment, with no non-conservative substitution among the 2,228 sequences examined, a defining feature of bacterial DUF501 rather than a mycobacterial peculiarity. We propose that DUF501 is a metal-binding protein and candidate metalloenzyme, the first functional hypothesis for this family, whose conserved, essential metal pocket is a promising drug target. As the predictions build on a conservation-defined site within a fully computational study, they are supportive rather than proof of metal occupancy and warrant experimental validation.

microbiology↗
bioRxiv2026

Mycoplasmal endosymbionts of Trichomonas vaginalis are associated with reduced risk for Chlamydia trachomatis endometrial infection in asymptomatic, coinfected, women.

Trichomonas vaginalis is a protozoan parasite that causes trichomoniasis, the most common curable non-viral sexually transmitted infection, and Chlamydia trachomatis is a bacterial pathogen that can ascend to the upper genital tract and cause pelvic inflammatory disease, infertility, and ectopic pregnancy. T. vaginalis harbors bacterial endosymbionts, including Candidatus Malacoplasma girerdii, an obligate symbiont, and Metamycoplasma hominis, which can live freely or symbiotically. In a 16S rRNA sequencing study of the cervicovaginal microbiome of women at high risk for chlamydial infection, Ca. M. girerdii abundance was one of 13 features predicting lack of chlamydial spread to the endometrium, despite no direct association between T. vaginalis infection and reduced chlamydial ascension. Investigating the relationship between these microorganisms further, we found that T. vaginalis vaginal abundance correlated positively with chlamydial burden in women whose infection was confined to the cervix, while a nonsignificant inverse relationship was seen in women with endometrial spread. Among participants with high chlamydial burden, Ca. M. girerdii was detected exclusively in women without endometrial infection. Both endosymbionts trended toward more frequent detection, and higher abundance, in coinfected women without endometrial spread, while M. hominis abundance correlated strongly with T. vaginalis burden in this group. These findings suggest that mycoplasmal endosymbionts of T. vaginalis, rather than T. vaginalis itself, are microbial factors limiting chlamydial ascension, and point to a three-way interaction between parasite, endosymbiont, and bacterial pathogen that shapes upper genital tract C. trachomatis infection risk.

microbiology↗
bioRxiv2026

Understanding the physiological alterations of Vibrio cholerae upon exposure to L-ascorbic acid

The scourge of cholera remains a major global public health threat. It affects up to 4 million people worldwide and causes tens of thousands of deaths each year. The disease is experiencing a concerning resurgence in many parts of Africa, the Middle East, and Asia. To effectively tackle cholera and circumvent rising antimicrobial resistance, targeted biological and preventive approaches, complementing traditional rehydration, are urgently needed. In this regard, our group has demonstrated the efficacy of L-ascorbic acid in controlling the growth and pathogenesis of Vibrio cholerae in vitro. The present work further provides a mechanistic elucidation of the L-ascorbic acid-mediated physiological changes in V. cholerae and also bolsters such a non-antibiotic approach to control cholera.

microbiology↗