scholarly journals Effects of Calcium and Signal Sensing Systems on Azorhizobium caulinodans Biofilm Formation and Host Colonization

2020 ◽  
Vol 11 ◽  
Author(s):  
Xiaolin Liu ◽  
Kaiye Zhang ◽  
Yanan Liu ◽  
Desheng Zou ◽  
Dandan Wang ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Azorhizobium Caulinodans ◽  
Host Colonization ◽  
Sensing Systems

scholarly journals Sugar-mediated regulation of a c-di-GMP phosphodiesterase in Vibrio cholerae

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Kyoo Heo ◽  
Young-Ha Park ◽  
Kyung-Ah Lee ◽  
Joonwon Kim ◽  
Hyeong-In Ham ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Biofilm Formation ◽  
Carbon Sources ◽  
Phosphotransferase System ◽  
Host Colonization ◽  
Host Immune Responses ◽  
Gut Colonization ◽  
Host Diet ◽  
Underlying Mechanisms ◽  
Cyclic Dinucleotide

AbstractBiofilm formation protects bacteria from stresses including antibiotics and host immune responses. Carbon sources can modulate biofilm formation and host colonization in Vibrio cholerae, but the underlying mechanisms remain unclear. Here, we show that EIIAGlc, a component of the phosphoenolpyruvate (PEP):carbohydrate phosphotransferase system (PTS), regulates the intracellular concentration of the cyclic dinucleotide c-di-GMP, and thus biofilm formation. The availability of preferred sugars such as glucose affects EIIAGlc phosphorylation state, which in turn modulates the interaction of EIIAGlc with a c-di-GMP phosphodiesterase (hereafter referred to as PdeS). In a Drosophila model of V. cholerae infection, sugars in the host diet regulate gut colonization in a manner dependent on the PdeS-EIIAGlc interaction. Our results shed light into the mechanisms by which some nutrients regulate biofilm formation and host colonization.

scholarly journals Temporal Quorum-Sensing Induction Regulates Vibrio cholerae Biofilm Architecture

2006 ◽  
Vol 75 (1) ◽  
pp. 122-126 ◽  
Author(s):  
Zhi Liu ◽  
Fiona R. Stirling ◽  
Jun Zhu
Keyword(s):  
Quorum Sensing ◽  
Vibrio Cholerae ◽  
Biofilm Formation ◽  
High Cell Density ◽  
Intestinal Colonization ◽  
Signal Molecule ◽  
Biofilm Thickness ◽  
Sensing Systems ◽  
Biofilm Detachment ◽  
Biofilm Architecture

ABSTRACT Vibrio cholerae, the pathogen that causes cholera, also survives in aqueous reservoirs, probably in the form of biofilms. Quorum sensing negatively regulates V. cholerae biofilm formation through HapR, whose expression is induced at a high cell density. In this study, we show that the concentration of the quorum-sensing signal molecule CAI-1 is higher in biofilms than in planktonic cultures. By measuring hapR expression and activity, we found that the induction of quorum sensing in biofilm-associated cells occurs earlier. We further demonstrate that the timing of hapR expression is crucial for biofilm thickness, biofilm detachment rates, and intestinal colonization efficiency. These results suggest that V. cholerae is able to regulate its biofilm architecture by temporal induction of quorum-sensing systems.

scholarly journals Quorum-Sensing Systems in the Plant Growth-Promoting Bacterium Paraburkholderia phytofirmans PsJN Exhibit Cross-Regulation and Are Involved in Biofilm Formation

2017 ◽  
Vol 30 (7) ◽  
pp. 557-565 ◽  
Author(s):  
Ana Zúñiga ◽  
Raúl A. Donoso ◽  
Daniela Ruiz ◽  
Gonzalo A. Ruz ◽  
Bernardo González
Keyword(s):  
Quorum Sensing ◽  
Biofilm Formation ◽  
Type Strain ◽  
Wild Type Strain ◽  
Homoserine Lactone ◽  
Wild Type ◽  
Transcript Levels ◽  
Sensing Systems ◽  
Plant Growth Promoting ◽  
Growth Promoting

Quorum-sensing systems play important roles in host colonization and host establishment of Burkholderiales species. Beneficial Paraburkholderia species share a conserved quorum-sensing (QS) system, designated BraI/R, that controls different phenotypes. In this context, the plant growth-promoting bacterium Paraburkholderia phytofirmans PsJN possesses two different homoserine lactone QS systems BpI.1/R.1 and BpI.2/R.2 (BraI/R-like QS system). The BpI.1/R.1 QS system was previously reported to be important to colonize and produce beneficial effects in Arabidopsis thaliana plants. Here, we analyzed the temporal variations of the QS gene transcript levels in the wild-type strain colonizing plant roots. The gene expression patterns showed relevant differences in both QS systems compared with the wild-type strain in the unplanted control treatment. The gene expression data were used to reconstruct a regulatory network model of QS systems in P. phytofirmans PsJN, using a Boolean network model. Also, we examined the phenotypic traits and transcript levels of genes involved in QS systems, using P. phytofirmans mutants in homoserine lactone synthases genes. We observed that the BpI.1/R.1 QS system regulates biofilm formation production in strain PsJN and this phenotype was associated with the lower expression of a specific extracytoplasmic function sigma factor ecf26.1 gene (implicated in biofilm formation) in the bpI.1 mutant strain.

scholarly journals Two quorum sensing systems control biofilm formation and virulence in members of theBurkholderia cepaciacomplex

Virulence ◽  
2013 ◽  
Vol 4 (5) ◽  
pp. 400-409 ◽  
Author(s):  
Angela Suppiger ◽  
Nadine Schmid ◽  
Claudio Aguilar ◽  
Gabriella Pessi ◽  
Leo Eberl
Keyword(s):  
Quorum Sensing ◽  
Biofilm Formation ◽  
Sensing Systems ◽  
Systems Control

scholarly journals Inhibition of Quorum Sensing in Pseudomonas aeruginosa by N-Acyl Cyclopentylamides

2007 ◽  
Vol 73 (10) ◽  
pp. 3183-3188 ◽  
Author(s):  
Takenori Ishida ◽  
Tsukasa Ikeda ◽  
Noboru Takiguchi ◽  
Akio Kuroda ◽  
Hisao Ohtake ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Homoserine Lactone ◽  
Ring Structure ◽  
Response Regulators ◽  
Maximal Inhibition ◽  
Sensing Systems ◽  
Reporter Assays

ABSTRACT N-Octanoyl cyclopentylamide (C8-CPA) was found to moderately inhibit quorum sensing in Pseudomonas aeruginosa PAO1. To obtain more powerful inhibitors, a series of structural analogs of C8-CPA were synthesized and examined for their ability to inhibit quorum sensing in P. aeruginosa PAO1. The lasB-lacZ and rhlA-lacZ reporter assays revealed that the chain length and the ring structure were critical for C8-CPA analogs to inhibit quorum sensing. N-Decanoyl cyclopentylamide (C10-CPA) was found to be the strongest inhibitor, and its concentrations required for half-maximal inhibition for lasB-lacZ and rhlA-lacZ expression were 80 and 90 μM, respectively. C10-CPA also inhibited production of virulence factors, including elastase, pyocyanin, and rhamnolipid, and biofilm formation without affecting growth of P. aeruginosa PAO1. C10-CPA inhibited induction of both lasI-lacZ by N-(3-oxododecanoyl)-l-homoserine lactone (PAI1) and rhlA-lacZ by N-butanoyl-l-homoserine lactone (PAI2) in the lasI rhlI mutant of P. aeruginosa PAO1, indicating that C10-CPA interferes with the las and rhl quorum-sensing systems via inhibiting interaction between their response regulators (LasR and RhlR) and autoinducers.

scholarly journals LuxR-Type Regulator AclR1 of Azorhizobium caulinodans Regulates Cyclic di-GMP and Numerous Phenotypes in Free-Living and Symbiotic States

2020 ◽  
Vol 33 (3) ◽  
pp. 528-538
Author(s):  
Wei Liu ◽  
Yan Li ◽  
Xue Bai ◽  
Haiguang Wu ◽  
Lanxing Bian ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Host Plants ◽  
Biological Processes ◽  
Azorhizobium Caulinodans ◽  
Free Living ◽  
A Genome ◽  
Living State ◽  
And Control ◽  
Functional Mechanisms ◽  
Azorhizobium Caulinodans Ors571

LuxR-type regulators play important roles in transcriptional regulation in bacteria and control various biological processes. A genome sequence analysis showed the existence of seven LuxR-type regulators in Azorhizobium caulinodans ORS571, an important nitrogen-fixing bacterium in both its free-living state and in symbiosis with its host, Sesbania rostrata. However, the functional mechanisms of these regulators remain unclear. In this study, we identified a LuxR-type regulator that contains a cheY-homologous receiver (REC) domain in its N terminus and designated it AclR1. Interestingly, phylogenetic analysis revealed that AclR1 exhibited relatively close evolutionary relationships with MalT/GerE/FixJ/NarL family proteins. Functional analysis of an aclR1 deletion mutant (ΔaclR1) in the free-living state showed that AclR1 positively regulated cell motility and flocculation but negatively regulated exopolysaccharide production, biofilm formation, and second messenger cyclic diguanylate (c-di-GMP)-related gene expression. In the symbiotic state, the ΔaclR1 mutant was defective in competitive colonization and nodulation on host plants. These results suggested that AclR1 could provide bacteria with the ability to compete effectively for symbiotic nodulation. Overall, our results show that the REC-LuxR-type regulator AclR1 regulates numerous phenotypes both in the free-living state and during host plant symbiosis.

Sign in / Sign up

Export Citation Format

Share Document