1
|
Wang X, Chen Q, Pang R, Zhang C, Huang G, Han Z, Su Y. Exposure modes determined the effects of nanomaterials on antibiotic resistance genes: The different roles of oxidative stress and quorum sensing. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 360:124772. [PMID: 39168438 DOI: 10.1016/j.envpol.2024.124772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2024] [Revised: 08/09/2024] [Accepted: 08/17/2024] [Indexed: 08/23/2024]
Abstract
The effects of co-occurrent pollutants on antibiotic resistance genes (ARGs) in wastewater treatment plants (WWTPs) have raised attentions. However, how the different realistic exposure scenarios determining the effects of nanomaterials (NMs) on ARGs, was still unknown. Herein, the effects of NMs on ARGs under two realistic scenarios was investigated by short-term and long-term exposure modes. The presence of NMs with two different exposure modes could both promote the dissemination of ARGs, and the results were dose-, type- and duration-dependent. Compared to short-term exposure, the long-term exposure increased the abundances of ARGs with a greater extent except nano-ZnO. The long-term exposure increased the overall abundances of target ARGs by 2.9%-20.4%, while shot-term exposure caused the 3.4%-10.5% increment. The mechanisms of ARGs fates driven by NMs exposure were further investigated from the levels of microbial community shift, intracellular oxidative stress, and gene abundance. The variations of several potential bacterial hosts did not contribute to the difference in the ARGs transmission with different exposure modes because NMs types played more vital roles in the shift of microbial community compared to the exposure modes. For the short-term exposure, NMs were capable of triggering the QS by upregulating relevant genes, and further activated the production of surfactin and increased membrane permeability, resulting in the facilitation of ARGs transfer. However, NMs under long-term exposure scenario preferentially stimulated oxidative stress by generating more ROS, which then enhanced ARGs dissemination. Therefore, the exposure mode of NMs was one of the pivotal factors determining the ARGs fates by different triggering mechanisms. This study highlighted the importance of exposure scenario of co-occurrent pollutants on ARGs spread, which will benefit the comprehensive understanding of the actual environmental fates of ARGs.
Collapse
Affiliation(s)
- Xueting Wang
- Shanghai Engineering Research Center of Biotransformation on Organic Solid Waste, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China
| | - Qirui Chen
- Shanghai Engineering Research Center of Biotransformation on Organic Solid Waste, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China
| | - Ruirui Pang
- Shanghai Engineering Research Center of Biotransformation on Organic Solid Waste, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China
| | - Congyan Zhang
- Shanghai Engineering Research Center of Biotransformation on Organic Solid Waste, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China
| | - Guangchen Huang
- Shanghai Engineering Research Center of Biotransformation on Organic Solid Waste, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China
| | - Zhibang Han
- Shanghai Engineering Research Center of Biotransformation on Organic Solid Waste, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China
| | - Yinglong Su
- Shanghai Engineering Research Center of Biotransformation on Organic Solid Waste, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China; Engineering Research Center for Nanophotonics & Advanced Instrument, Ministry of Education, East China Normal University, Shanghai, 200241, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
| |
Collapse
|
2
|
Han L, Ren J, Xue Y, Gao J, Fu Q, Shao P, Zhu H, Zhang M, Ding F. Fatty acid synthesis promoted by PA1895-1897 operon delays quorum sensing activation in Pseudomonas aeruginosa. AMB Express 2024; 14:110. [PMID: 39354164 PMCID: PMC11445212 DOI: 10.1186/s13568-024-01758-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Accepted: 08/19/2024] [Indexed: 10/03/2024] Open
Abstract
PA1895-1897 is a quorum sensing (QS) operon regulated by the anti-activator LuxR homologue QscR in Pseudomonas aeruginosa. We aimed to investigate its impact on bacterial metabolism, and whether it contributes to the delayed QS activation. We performed liquid chromatograph-mass spectrometer-based metabolomics using wildtype PAO1, PA1895-1897-knockout mutant, and mutant with pJN105.PA1895-1897 overexpression vector. The impact of metabolites on QS signaling molecule (3OC12-HSL and C4-HSL) concentrations, pyocyanin production, and QS gene (lasR, lasI, rhlR, and rhlI) expression was examined. Metabolomics analysis found that fatty acid biosynthesis had the highest fold enrichment among all metabolic pathways in PA1895-1897-overexpressed mutants. Among these enriched fatty acids, palmitoleic acid and acetic acid were the predominantly abundant ones that significantly affected by PA1895-1897 operon. When different doses of exogenous palmitoleic acid or acetic acid were added to the cultures of PA1895-1897 knockout mutants, their levels of 3OC12-HSL, C4-HSL, and pyocyanin were decreased in a dose-dependent manner. High doses of palmitoleic acid and acetic acid suppressed the mRNA expression of lasR, rhlR, and rhlI. Inhibition of fatty acid biosynthesis increased the production of 3OC12-HSL, C4-HSL, and pyocyanin in PA1895-1897-overexpressed cultures. Our data suggest that fatty acid synthesis is promoted by PA1895-1897 operon, and contributes the delayed expression of QS phenotypes, furthering the understanding about the regulation of bacterial QS activation.
Collapse
Affiliation(s)
- Lei Han
- Department of Respiratory and Critical Care Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jie Ren
- Department of Respiratory and Critical Care Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yishu Xue
- Department of Respiratory and Critical Care Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jianwei Gao
- Department of Respiratory and Critical Care Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qiang Fu
- Department of Respiratory and Critical Care Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ping Shao
- Department of Respiratory and Critical Care Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hui Zhu
- Department of Respiratory and Critical Care Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Min Zhang
- Department of Respiratory and Critical Care Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Fengming Ding
- Department of Respiratory and Critical Care Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| |
Collapse
|
3
|
Vadakkan K, Sathishkumar K, Mapranathukaran VO, Ngangbam AK, Nongmaithem BD, Hemapriya J, Nair JB. Critical review on plant-derived quorum sensing signaling inhibitors in pseudomonas aeruginosa. Bioorg Chem 2024; 151:107649. [PMID: 39029321 DOI: 10.1016/j.bioorg.2024.107649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2024] [Revised: 06/21/2024] [Accepted: 07/14/2024] [Indexed: 07/21/2024]
Abstract
Pseudomonas aeruginosa, a biofilm-forming organism with complex quorum mechanisms (Las, Rhl, PQS, and IQS), poses an imminent danger to the healthcare sector and renders current treatment options for chemotherapy ineffectual. The pathogen's diverse pathogenicity, antibiotic resistance, and biofilms make it difficult to eradicate it effectively. Quorum sensing, a complex system reliant on cell density, controls P. aeruginosa's pathogenesis. Quorum-sensing genes are key components of P. aeruginosa's pathogenic arsenal, and their expression determines how severe the spread of infection becomes. Over the past ten years, there has been a noticeable increase in the quest for and development of new antimicrobial medications. Quorum sensing may be an effective treatment for infections triggered by bacteria. Introducing quorum-sensing inhibitors as an anti-virulent strategy might be an intriguing therapeutic method that can be effectively employed along with current medications. Amongst the several speculated processes, a unique anti-virulence strategy using anti-quorum sensing and antibiofilm medications for targeting pseudomonal infestations seems to be at the forefront. Due to their noteworthy quorum quenching capabilities, biologically active phytochemicals have become more well-known in the realm of science in this context. Recent research showed how different phytochemical quorum quenching actions affect P. aeruginosa's QS-dependent pathogenicity. This review focuses on the most current data supporting the implementation of plant bio-actives to treat P.aeruginosa-associated diseases, as well as the benefits and future recommendationsof employing them in anti-virulence therapies as a supplementary drug development approach towards conventional antibiotic approaches.
Collapse
Affiliation(s)
- Kayeen Vadakkan
- Department of Biotechnology, St. Mary's College (Autonomous), Thrissur, Kerala 680020, India; Manipur International University, Imphal, Manipur 795140, India.
| | - Kuppusamy Sathishkumar
- Center for Global Health Research, Saveetha Medical College and Hospitals, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Thandalam, Chennai, Tamil Nadu 602105, India
| | | | | | | | - Janarthanam Hemapriya
- Department of Microbiology, DKM College for Women, Vellore, Tamil Nadu 632001, India
| | - Jyotsna B Nair
- Department of Biotechnology, JDT Islam College of Arts and Science, Vellimadukunnu, Kozhikode, Kerala 673012, India
| |
Collapse
|
4
|
Çevikbaş H, Ulusoy S, Kaya Kinaytürk N. Exploring rose absolute and phenylethyl alcohol as novel quorum sensing inhibitors in Pseudomonas aeruginosa and Chromobacterium violaceum. Sci Rep 2024; 14:15666. [PMID: 38977845 PMCID: PMC11231148 DOI: 10.1038/s41598-024-66888-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Accepted: 07/05/2024] [Indexed: 07/10/2024] Open
Abstract
Inter-cellular signaling, referred to as quorum sensing (QS), regulates the production of virulence factors in numerous gram-negative bacteria, such as the human pathogens Pseudomonas aeruginosa and Chromobacterium violaceum. QS inhibition may provide an opportunity for the treatment of bacterial infections. This represents the initial study to examine the antibiofilm and antivirulence capabilities of rose absolute and its primary component, phenylethyl alcohol. QS inhibition was assessed by examining extracellular exopolysaccharide synthesis, biofilm development, and swarming motility in P. aeruginosa PAO1, along with violacein production in C. violaceum ATCC 12472. Molecular docking analysis was conducted to explore the mechanism by which PEA inhibits QS. Our results indicate that rose absolute and PEA caused decrease in EPS production (60.5-33.5%), swarming motility (94.7-64.5%), and biofilm formation (98.53-55.5%) in the human pathogen P. aeruginosa PAO1. Violacein production decreased by 98.1% and 62.5% with an absolute (0.5 v/v %) and PEA (2 mM). Moreover, the molecular docking analysis revealed a promising competitive interaction between PEA and AHLs. Consequently, this study offers valuable insights into the potential of rose absolute and PEA as inhibitors of QS in P. aeruginosa and C. violaceum.
Collapse
Affiliation(s)
- Halime Çevikbaş
- Faculty of Engineering and Natural Sciences, Biology Department, Süleyman Demirel University, Isparta, 32260, Turkey
| | - Seyhan Ulusoy
- Faculty of Engineering and Natural Sciences, Biology Department, Süleyman Demirel University, Isparta, 32260, Turkey.
| | - Neslihan Kaya Kinaytürk
- Faculty of Arts and Science, Nanoscience and Nanotechnology Department, Mehmet Akif Ersoy University, Burdur, 15100, Turkey
| |
Collapse
|
5
|
Ammazzalorso A, Granese A, De Filippis B. Recent trends and challenges to overcome Pseudomonas aeruginosa infections. Expert Opin Ther Pat 2024; 34:493-509. [PMID: 38683024 DOI: 10.1080/13543776.2024.2348602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 04/24/2024] [Indexed: 05/01/2024]
Abstract
INTRODUCTION Pseudomonas aeruginosa (PA) is a Gram-negative bacterium that can cause a wide range of severe infections in immunocompromised patients. The most difficult challenge is due to its ability to rapidly develop multi drug-resistance. New strategies are urgently required to improve the outcome of patients with PA infections. The present patent review highlights the new molecules acting on different targets involved in the antibiotic resistance. AREA COVERED This review offers an insight into new potential PA treatment disclosed in patent literature. From a broad search of documents claiming new PA inhibitors, we selected and summarized molecules that showed in vitro and in vivo activity against PA spp. in the period 2020 and 2023. We collected the search results basing on the targets explored. EXPERT OPINION This review examined the main patented compounds published in the last three years, with regard to the structural novelty and the identification of innovative targets. The main areas of antibiotic resistance have been explored. The compounds are structurally unrelated to earlier antibiotics, characterized by a medium-high molecular weight and the presence of heterocycle rings. Peptides and antibodies have also been reported as potential alternatives to chemical treatment, hereby expanding the therapeutic possibilities in this field.
Collapse
Affiliation(s)
| | - Arianna Granese
- Department of Drug Chemistry and Technology, "Sapienza" University of Rome, Rome, Italy
| | | |
Collapse
|
6
|
Vadakkan K, Sathishkumar K, Kuttiyachan Urumbil S, Ponnenkunnathu Govindankutty S, Kumar Ngangbam A, Devi Nongmaithem B. A review of chemical signaling mechanisms underlying quorum sensing and its inhibition in Staphylococcus aureus. Bioorg Chem 2024; 148:107465. [PMID: 38761705 DOI: 10.1016/j.bioorg.2024.107465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 04/29/2024] [Accepted: 05/14/2024] [Indexed: 05/20/2024]
Abstract
Staphylococcus aureus is a significant bacterium responsible for multiple infections and is a primary cause of fatalities among patients in hospital environments. The advent of pathogenic bacteria such as methicillin-resistant S. aureus revealed the shortcomings of employing antibiotics to treat bacterial infectious diseases. Quorum sensing enhances S. aureus's survivability through signaling processes. Targeting the key components of quorum sensing has drawn much interest nowadays as a promising strategy for combating infections caused by bacteria. Concentrating on the accessory gene regulator quorum-sensing mechanism is the most commonly suggested anti-virulence approach for S.aureus. Quorum quenching is a common strategy for controlling illnesses triggered by microorganisms since it reduces the pathogenicity of bacteria and improves bacterial biofilm susceptibility to antibiotics, thus providing an intriguing prospect for drug discovery. Quorum sensing inhibition reduces selective stresses and constrains the emergence of antibiotic resistance while limiting bacterial pathogenicity. This review examines the quorum sensing mechanisms involved in S. aureus, quorum sensing targets and gene regulation, environmental factors affecting quorum sensing, quorum sensing inhibition, natural products as quorum sensing inhibitory agents and novel therapeutical strategies to target quorum sensing in S. aureus as drug developing technique to augment conventional antibiotic approaches.
Collapse
Affiliation(s)
- Kayeen Vadakkan
- Department of Biotechnology, St. Mary's College (Autonomous), Thrissur, Kerala 680020, India; Manipur International University, Imphal, Manipur 795140, India.
| | - Kuppusamy Sathishkumar
- Center for Global Health Research, Saveetha Medical College and Hospitals, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Thandalam, Chennai, Tamil Nadu 602105, India
| | | | | | | | | |
Collapse
|
7
|
Orlandi VT, Bolognese F, Chiodaroli L, Armenia I, Caruso E, Malacarne MC. Antibiofilm Activity of Combretum micranthum G. Don Catechin-Sugar Phytocomplex on Pseudomonas aeruginosa. Molecules 2024; 29:2091. [PMID: 38731582 PMCID: PMC11085770 DOI: 10.3390/molecules29092091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/24/2024] [Accepted: 04/29/2024] [Indexed: 05/13/2024] Open
Abstract
Clinicians often have to face infections caused by microorganisms that are difficult to eradicate due to their resistance and/or tolerance to antimicrobials. Among these pathogens, Pseudomonas aeruginosa causes chronic infections due to its ability to form biofilms on medical devices, skin wounds, ulcers and the lungs of patients with Cystic Fibrosis. In this scenario, the plant world represents an important reservoir of natural compounds with antimicrobial and/or antibiofilm properties. In this study, an extract from the leaves of Combretum micranthum G. Don, named Cm4-p, which was previously investigated for its antimicrobial activities, was assayed for its capacity to inhibit biofilm formation and/or to eradicate formed biofilms. The model strain P. aeruginosa PAO1 and its isogenic biofilm hyperproducer derivative B13 were treated with Cm4-p. Preliminary IR, UV-vis, NMR, and mass spectrometry analyses showed that the extract was mainly composed of catechins bearing different sugar moieties. The phytocomplex (3 g/L) inhibited the biofilm formation of both the PAO1 and B13 strains in a significant manner. In light of the obtained results, Cm4-p deserves deeper investigations of its potential in the antimicrobial field.
Collapse
Affiliation(s)
- Viviana Teresa Orlandi
- Department of Biotechnology and Life Sciences (DBSV), University of Insubria, Via J.H. Dunant 3, 21100 Varese, Italy; (F.B.); (L.C.); (I.A.); (E.C.); (M.C.M.)
| | | | | | | | | | | |
Collapse
|
8
|
Talaat R, Abu El-Naga MN, El-Bialy HAA, El-Fouly MZ, Abouzeid MA. Quenching of quorum sensing in multi-drug resistant Pseudomonas aeruginosa: insights on halo-bacterial metabolites and gamma irradiation as channels inhibitors. Ann Clin Microbiol Antimicrob 2024; 23:31. [PMID: 38600513 PMCID: PMC11007959 DOI: 10.1186/s12941-024-00684-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 03/03/2024] [Indexed: 04/12/2024] Open
Abstract
BACKGROUND Anti-virulence therapy is a promising strategy to treat multi-drug resistant (MDR) pathogens. Pseudomonas aeruginosa is a potent opportunistic pathogen because of an array of virulence factors that are regulated by quorum sensing systems. METHODS The virulence features of four multi-drug resistant P. aeruginosa strains were investigated upon exposure to the sub-lethal dose of gamma rays (1 kGy), and sub-inhibitory concentrations of bioactive metabolites recovered from local halophilic strains in comparison to control. Then, the gene expression of AHL-mediated quorum sensing systems (las/rhl) was quantitatively determined in treated and untreated groups by real-time PCR. RESULTS The bioactive metabolites recovered from halophilic strains previously isolated from saline ecosystems were identified as Halomonas cupida (Halo-Rt1), H. elongate (Halo-Rt2), Vigibacillus natechei (Halo-Rt3), Sediminibacillus terrae (Halo-Rt4) and H. almeriensis (Halo-Rt5). Results revealed that both gamma irradiation and bioactive metabolites significantly reduced the virulence factors of the tested MDR strains. The bioactive metabolites showed a maximum efficiency for inhibiting biofilm formation and rhamnolipids production whereas the gamma irradiation succeeded in decreasing other virulence factors to lower levels in comparison to control. Quantitative-PCR results showed that AHL-mediated quorum sensing systems (las/rhl) in P. aeruginosa strains were downregulated either by halo-bacterial metabolites or gamma irradiation in all treatments except the upregulation of both lasI internal gene and rhlR intact gene in P. aeruginosa NCR-RT3 and both rhlI internal gene and rhlR intact gene in P. aeruginosa U3 by nearly two folds or more upon exposure to gamma irradiation. The most potent result was observed in the expression of lasI internal gene that was downregulated by more than ninety folds in P. aeruginosa NCR-RT2 after treatment with metabolites of S. terrae (Halo-Rt4). Analyzing metabolites recovered from H. cupida (Halo-Rt1) and H. elongate (Halo-Rt2) using LC-ESI-MS/MS revealed many chemical compounds that have quorum quenching properties including glabrol, 5,8-dimethoxyquinoline-2-carbaldehyde, linoleoyl ethanolamide, agelasine, penigequinolones derivatives, berberine, tetracosanoic acid, and liquidambaric lactone in the former halophile and phloretin, lycoctonine, fucoxanthin, and crassicauline A in the latter one. CONCLUSION QS inhibitors can significantly reduce the pathogenicity of MDR P. aeruginosa strains; and thus can be an effective and successful strategy for treating antibiotic resistant traits.
Collapse
Affiliation(s)
- Reham Talaat
- Radiation Microbiology Department, National Center for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA), Cairo, Egypt
| | - Mohamed N Abu El-Naga
- Radiation Microbiology Department, National Center for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA), Cairo, Egypt
| | - Heba Abd Alla El-Bialy
- Radiation Microbiology Department, National Center for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA), Cairo, Egypt.
| | - Mohie Z El-Fouly
- Radiation Microbiology Department, National Center for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA), Cairo, Egypt
| | - Mohamed A Abouzeid
- Microbiology Department, Faculty of Science, Ain Shams University, Cairo, Egypt
- Faculty of Science, Galala University, Suez, Egypt
| |
Collapse
|
9
|
Venkatramanan M, Nalini E. Regulation of virulence in Chromobacterium violaceum and strategies to combat it. Front Microbiol 2024; 15:1303595. [PMID: 38328423 PMCID: PMC10847564 DOI: 10.3389/fmicb.2024.1303595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 01/08/2024] [Indexed: 02/09/2024] Open
Abstract
Chromobacterium is a rod-shaped, Gram-negative, facultatively anaerobic bacteria with a cosmopolitan distribution. Just about 160 Chromobacterium violaceum incidents have been reported globally, but then once infected, it has the ability to cause deadly septicemia, and infections in the lungs, liver, brain, spleen, and lymphatic systems that might lead to death. C. violaceum produces and utilizes violacein to kill bacteria that compete with it in an ecological niche. Violacein is a hydrophobic bisindole that is delivered through an efficient transport route termed outer membrane vesicles (OMVs) through the aqueous environment. OMVs are small, spherical segments detached from the outer membrane of Gram-negative bacteria. C. violaceum OMV secretions are controlled by a mechanism called the quorum sensing system CviI/CviR, which enables cell-to-cell communication between them and regulation of various virulence factors such as biofilm formation, and violacein biosynthesis. Another virulence factor bacterial type 3 secretion system (T3SS) is divided into two types: Cpi-1 and Cpi-2. Cpi-1's needle and rod effector proteins are perhaps recognized by NAIP receptors in humans and mice, activating the NLRC4 inflammasome cascade, effectively clearing spleen infections via pyroptosis, and cytotoxicity mediated by IL-18-driven Natural killer (NK) cells in the liver. In this paper, we attempt to interrelate quorum-controlled biofilm formation, violacein production, violacein delivery by OMVs and T3SS effector protein production and host mediated immunological effects against the Cpi1 of T3SS. We suggest a research path with natural bioactive molecule like palmitic acid that can act as an anti-quorum agent by reducing the expression of virulence factors as well as an immunomodulatory agent that can augment innate immune defense by hyperactivation of NLRC4 inflammasome hence dramatically purge C. violaceum infections.
Collapse
|