Optogenetic control of infection signaling cascade of bacteria by an engineered light-responsive protein

ABSTRACTBacterial pathogens operate by tightly controlling the virulence to facilitate invasion and survival in host. Although pathways regulating virulence have been defined in detail and signals modulating these processes are gradually understood, a lack of controlling infection signaling cascades of pathogens when and whereabouts specificity limits deeper investigating of host-pathogen interactions. Here, we employed optogenetics to reengineer the GacS of Pseudomonas aeruginosa, sensor kinase of GacS/GacA TCS regulates the expression of virulence factors by directly mediating several sRNAs. The resultant protein YGS24 displayed significant light-dependent activity of GacS kinases in Pseudomonas aeruginosa. When introduced in Caenorhabditis elegans host systems, YGS24 stimulated the pathogenicity of PAO1 in BHI and of PA14 in SK medium progressively upon blue-light exposure. This optogenetic system provides an accessible way to spatiotemporally control bacterial pathogenicity in defined host even specific tissues to develop new pathogenesis systems, which may in turn expedite development of innovative therapeutics.IMPORTANCEGacS is a signal transduction protein of the global Gac/Rsm regulatory cascade that is of central importance for the regulation of infection and virulence factors in Pseudomonas aeruginosa. Here, we reprogrammed the input signal specificity of GacS by replacing its input sensor domain with a photosensor domain. The resultant fusion protein YGS24 has the ability of perceiving light signal and, in response, regulates the Gac/Rsm signaling cascade. When tested in host models, this optogenetic system enables the light-dependent pathogenicity switch of bacterial cells and correspondingly tunes the susceptibility of Caenorhabditis elegans to P. aeruginosa-mediated killing. We provide a useful optogenetic tool in the area of pathogenic research that has great demands for precise spatiotemporal control of bacterial pathogenicity.

Download Full-text

Cephalosporins target quorum sensing and suppress virulence of Pseudomonas aeruginosa in Caenorhabditis elegans infection model

10.1101/2020.05.15.097790 ◽

2020 ◽

Author(s):

Lokender Kumar ◽

Nathanael Brenner ◽

John Brice ◽

Judith Klein-Seetharaman ◽

Susanta K. Sarkar

Keyword(s):

Pseudomonas Aeruginosa ◽

Caenorhabditis Elegans ◽

Quorum Sensing ◽

Virulence Factors ◽

Biofilm Formation ◽

Host Cells ◽

Infection Model ◽

Host Immune System ◽

Bacterial Cells

ABSTRACTPseudomonas aeruginosa utilizes a chemical social networking system referred to as quorum sensing (QS) to strategically co-ordinate the expression of virulence factors and biofilm formation. Virulence attributes damage the host cells, impair the host immune system, and protect bacterial cells from antibiotic attack. Thus, anti-QS agents may act as novel anti-infective therapeutics to treat P. aeruginosa infections. The present study was performed to evaluate the anti-QS, anti-biofilm, and anti-virulence activity of β-lactam antibiotics (carbapenems and cephalosporins) against P. aeruginosa. The anti-QS activity was quantified using Chromobacterium violaceum CV026 as a QS reporter strain. Our results showed that cephalosporins including cefepime (CP), ceftazidime (CF), and ceftriaxone (CT) exhibited potent anti-QS and anti-virulence activities against P. aeruginosa PAO1. These antibiotics significantly impaired motility phenotypes, decreased pyocyanin production, and reduced the biofilm formation by P. aeruginosa PAO1. In the present study, we studied isogenic QS mutants of PAO1: ΔLasR, ΔRhlR, ΔPqsA, and ΔPqsR and found that the levels of virulence factors of antibiotic-treated PAO1 were comparable to QS mutant strains. Molecular docking predicted high binding affinities of cephalosporins for the ligand-binding pocket of QS receptors (CviR, LasR, and PqsR). In addition, our results showed that the anti-microbial activity of aminoglycosides increased in the presence of sub-inhibitory concentrations (sub-MICs) of CP against P. aeruginosa PAO1. Further, utilizing Caenorhabditis elegans as an animal model for the in vivo anti-virulence effects of antibiotics, cephalosporins showed a significant increase in C. elegans survival by suppressing virulence factor production in P. aeruginosa. Thus, our results indicate that cephalosporins might provide a viable anti-virulence therapy in the treatment of infections caused by multi-drug resistant P. aeruginosa.

Download Full-text

Pseudomonas aeruginosa killing of Caenorhabditis elegans used to identify P. aeruginosa virulence factors

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.96.5.2408 ◽

1999 ◽

Vol 96 (5) ◽

pp. 2408-2413 ◽

Cited By ~ 394

Author(s):

M.-W. Tan ◽

L. G. Rahme ◽

J. A. Sternberg ◽

R. G. Tompkins ◽

F. M. Ausubel

Keyword(s):

Pseudomonas Aeruginosa ◽

Caenorhabditis Elegans ◽

Virulence Factors

Download Full-text

The fucose containing polymer (FCP) rich fraction of Ascophyllum nodosum (L.) Le Jol. protects Caenorhabditis elegans against Pseudomonas aeruginosa by triggering innate immune signaling pathways and suppression of pathogen virulence factors

ALGAE ◽

10.4490/algae.2015.30.2.147 ◽

1970 ◽

Vol 30 (2) ◽

pp. 147-161 ◽

Cited By ~ 6

Keyword(s):

Pseudomonas Aeruginosa ◽

Caenorhabditis Elegans ◽

Signaling Pathways ◽

Virulence Factors ◽

Ascophyllum Nodosum ◽

Innate Immune ◽

Immune Signaling ◽

Pathogen Virulence ◽

Innate Immune Signaling

Download Full-text

Absence of Light Exposure Increases Pathogenicity of Pseudomonas aeruginosa Pneumonia-Associated Clinical Isolates

Biology ◽

10.3390/biology10090837 ◽

2021 ◽

Vol 10 (9) ◽

pp. 837

Author(s):

Cristina S. Mesquita ◽

Artur Ribeiro ◽

Andreia C. Gomes ◽

Pedro M. Santos

Keyword(s):

Pseudomonas Aeruginosa ◽

Light Exposure ◽

Growth Conditions ◽

Phenotypic Characterization ◽

Full Spectrum ◽

Pathogenic Potential ◽

Morphological Alterations ◽

Cellular Processes ◽

Bacterial Pathogenicity ◽

Evaluation Approaches

Pseudomonas aeruginosa can alter its lifestyle in response to changes in environmental conditions. The switch to a pathogenic host-associated lifestyle can be triggered by the luminosity settings, resorting to at least one photoreceptor which senses light and regulates cellular processes. This study aimed to address how light exposure affects the dynamic and adaptability of two P. aeruginosa pneumonia-associated isolates, HB13 and HB15. A phenotypic characterization of two opposing growth conditions, constant illumination and intensity of full-spectrum light and total absence of light, was performed. Given the nature of P. aeruginosa pathogenicity, distinct fractions were characterized, and its inherent pathogenic potential screened by comparing induced morphological alterations and cytotoxicity against human pulmonary epithelial cells (A549 cell line). Growth in the dark promoted some virulence-associated traits (e.g., pigment production, LasA proteolytic activity), which, together with higher cytotoxicity of secreted fractions, supported an increased pathogenic potential in conditions that better mimic the lung microenvironment of P. aeruginosa. These preliminary findings evidenced that light exposure settings may influence the P. aeruginosa pathogenic potential, likely owing to differential production of virulence factors. Thus, this study raised awareness towards the importance in controlling light conditions during bacterial pathogenicity evaluation approaches, to more accurately interpret bacterial responses.

Download Full-text

Sesamin and sesamolin rescues Caenorhabditis elegans from Pseudomonas aeruginosa infection through the attenuation of quorum sensing regulated virulence factors

Microbial Pathogenesis ◽

10.1016/j.micpath.2021.104912 ◽

2021 ◽

Vol 155 ◽

pp. 104912

Author(s):

V.T. Anju ◽

Siddhardha Busi ◽

Sampathkumar Ranganathan ◽

Dinakara Rao Ampasala ◽

Sandeep Kumar ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Caenorhabditis Elegans ◽

Quorum Sensing ◽

Virulence Factors ◽

Pseudomonas Aeruginosa Infection

Download Full-text

Caenorhabditis elegans Senses Bacterial Autoinducers

Applied and Environmental Microbiology ◽

10.1128/aem.00611-06 ◽

2006 ◽

Vol 72 (7) ◽

pp. 5135-5137 ◽

Cited By ~ 78

Author(s):

Elmus Beale ◽

Guigen Li ◽

Man-Wah Tan ◽

Kendra P. Rumbaugh

Keyword(s):

Pseudomonas Aeruginosa ◽

Caenorhabditis Elegans ◽

Quorum Sensing ◽

Virulence Factors ◽

Homoserine Lactones ◽

C Elegans ◽

Acylated Homoserine Lactones

ABSTRACT Pseudomonas aeruginosa uses virulence factors controlled by quorum sensing (QS) to kill Caenorhabditis elegans. Here we show that C. elegans is attracted to the acylated homoserine lactones (AHSLs) that mediate QS in P. aeruginosa. Our data also indicate that C. elegans can distinguish AHSLs and may use them to mediate aversive or attractive learning.

Download Full-text

Pyoverdine-Mediated Killing of Caenorhabditis elegans by Pseudomonas syringae MB03 and the Role of Iron in Its Pathogenicity

International Journal of Molecular Sciences ◽

10.3390/ijms21062198 ◽

2020 ◽

Vol 21 (6) ◽

pp. 2198

Author(s):

Anum Bashir ◽

Tian Tian ◽

Xun Yu ◽

Cui Meng ◽

Muhammad Ali ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Pseudomonas Syringae ◽

Virulence Factors ◽

Bacterial Cells ◽

Phytopathogenic Bacterium ◽

C Elegans ◽

Recombination System ◽

Peptide Synthetase ◽

Nematocidal Activity

The pathogenicity of the common phytopathogenic bacterium Pseudomonas syringae toward Caenorhabditis elegans has been recently demonstrated. However, the major virulence factors involved in this interaction remain unknown. In this study, we investigated the nematocidal activity of P. syringae against C. elegans under iron-sufficient/limited conditions, primarily focusing on the role of the ferric chelator pyoverdine in a P. syringae–C. elegans liquid-based pathogenicity model. Prediction-based analysis of pyoverdine-encoding genes in the genome of the wild-type P. syringae strain MB03 revealed that the genes are located in one large cluster. Two non-ribosomal peptide synthetase genes (pvdD and pvdJ) were disrupted via a Rec/TE recombination system, resulting in mutant strains with abrogated pyoverdine production and attenuated virulence against C. elegans. When used alone, pure pyoverdine also showed nematocidal activity. The role of iron used alone or with pyoverdine was further investigated in mutant and MB03-based bioassays. The results indicated that pyoverdine in P. syringae MB03 is a robust virulence factor that promotes the killing of C. elegans. We speculate that pyoverdine functions as a virulence determinant by capturing environmentally available iron for host bacterial cells, by limiting its availability for C. elegans worms, and by regulating and/or activating other intracellular virulence factors that ultimately kills C. elegans worms.

Download Full-text

Vitamin E and K1 as anti-quorum sensing agents against Pseudomonas aeruginosa: A new insight

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01342-20 ◽

2021 ◽

Author(s):

Sadaf Soltani ◽

Bibi Sedigheh Fazly Bazzaz ◽

Farzin Hadizadeh ◽

Fatemeh Roodbari ◽

Vahid Soheili

Keyword(s):

Pseudomonas Aeruginosa ◽

Vitamin E ◽

Quorum Sensing ◽

Human Life ◽

Resistant Bacteria ◽

Bacterial Cells ◽

Chemical Structures ◽

Bacterial Pathogenicity ◽

Drug Resistant Bacteria ◽

Insight Into

Today, anti-virulence compounds which attenuate bacterial pathogenicity and have no interference with bacterial viability or growth are introduced as next generation of antibacterial agents. However, the development of such compounds that can be used by humans is restricted by various factors, including the need for extensive economic investments, the inability of many molecules to penetrate the membrane of Gram-negative bacteria, or unfavorable pharmacological properties and cytotoxicity. Here, we take a new and different insight into two frequent supplements, vitamin E and K1, as anti-quorum sensing agents against Pseudomonas aeruginosa; one of the hazardous pathogens to human life responsible for several diseases. Both vitamins showed significant anti-biofilm activity (62% and 40.3% reduction by vitamin E and K1, respectively) and the expression of virulence factors including pyocyanin, pyoverdine, and protease was significantly inhibited, especially in the presence of vitamin E. Co-treatment of constructed biofilms with these vitamins plus tobramycin significantly reduced the number of bacterial cells sheltered inside the impermeable matrix (71.6% and 69% by a combination of tobramycin and vitamin E or K1, respectively). The in silico studies besides the similarities of chemical structures, reinforce the possibility that both vitamins act through inhibition of the PqsR protein. This is the first report about the anti-virulent and anti-pathogenic activity of vitamin E and K1 against P. aeruginosa and confirms their potential for further research against other multi-drug resistant bacteria.

Download Full-text