1
|
Wang C, Ma Q, Zhang J, Meng N, Xu D. Co-culture of benzalkonium chloride promotes the biofilm formation and decreases the antibiotic susceptibility of a Pseudomonas aeruginosa strain. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2024; 26:858-869. [PMID: 38687259 DOI: 10.1039/d4em00035h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Benzalkonium chloride (BAC) is a disinfectant with broad-spectrum antibacterial properties, yet despite its widespread use and detection in the environment, the effects of BAC exposure on microorganisms remain poorly documented. Herein, the impacts of BAC on a Pseudomonas aeruginosa strain Jade-X were systematically investigated. The results demonstrated that the minimum inhibitory concentration (MIC) of BAC against strain Jade-X was 64 mg L-1. Exposure to BAC concentrations of 8, 16, 32, and 64 mg L-1 significantly augmented biofilm formation by 2.03-, 2.43-, 2.96-, and 2.56-fold respectively. The swimming and twitching abilities, along with the virulence factor production, were inhibited. Consistently, quantitative reverse transcription PCR assays revealed significant downregulation of genes related to flagellate- and pili-mediated motilities (flgD, flgE, pilB, pilQ, and motB), as well as phzA and phzB genes involved in pyocyanin production. The results of disk diffusion and MIC assays demonstrated that BAC decreased the antibiotic susceptibility of ciprofloxacin, levofloxacin, norfloxacin, and tetracycline. Conversely, an opposite trend was observed for polymyxin B and ceftriaxone. Genomic analysis revealed that strain Jade-X harbored eleven resistance-nodulation-cell division efflux pumps, with mexCD-oprJ exhibiting significant upregulation while mexEF-oprN and mexGHI-opmD were downregulated. In addition, the quorum sensing-related regulators LasR and RhlR were also suppressed, implying that BAC might modulate the physiological and biochemical behaviors of strain Jade-X by attenuating the quorum sensing system. This study enhances our understanding of interactions between BAC and P. aeruginosa, providing valuable insights to guide the regulation and rational use of BAC.
Collapse
Affiliation(s)
- Caihong Wang
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
| | - Qiao Ma
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
| | - Jiaxin Zhang
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
| | - Nan Meng
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
| | - Dan Xu
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
| |
Collapse
|
2
|
Zhang J, Ma Q, Wang C, Lu S, Fan S. Biodegradation characteristics and genomic analysis of a newly isolated indole-degrading strain Pseudomonas aeruginosa Jade-X. Int Microbiol 2024; 27:449-457. [PMID: 37490176 DOI: 10.1007/s10123-023-00408-3] [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: 06/10/2023] [Revised: 07/07/2023] [Accepted: 07/18/2023] [Indexed: 07/26/2023]
Abstract
Indole is a typical heterocyclic compound derived from tryptophan widespread in nature. Pseudomonas aeruginosa is one of the most common opportunistic pathogens everywhere in the world. Indole and P. aeruginosa will encounter inevitably; however, the indole transformation process by P. aeruginosa remains unclear. Herein, an indole-degrading strain of P. aeruginosa Jade-X was isolated from activated sludge. Strain Jade-X could degrade 1 mmol/L indole within 48 h with the inoculum size of 1% (v/v). It showed high efficiency in indole degradation under the conditions of 30-42 °C, pH 5.0-9.0, and NaCl concentration less than 2.5%. The complete genome of strain Jade-X was sequenced which was 6508614 bp in length with one chromosome. Bioinformatic analyses showed that strain Jade-X did not contain the indole oxygenase gene. Three cytochrome P450 genes were identified and up-regulated in the indole degradation process by RT-qPCR analysis, while cytochrome P450 inhibitors did not affect the indole degradation process. It suggested that indole oxidation was catalyzed by an unraveled enzyme. An ant gene cluster was identified, among which the anthranilate 1,2-dioxygenase and catechol 1,2-dioxygenase genes were upregulated. An indole-anthranilate-catechol pathway was proposed in indole degradation by strain P. aeruginosa Jade-X. This study enriched our understanding of the indole biodegradation process in P. aeruginosa.
Collapse
Affiliation(s)
- Jiaxin Zhang
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Qiao Ma
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China.
| | - Caihong Wang
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Shuxian Lu
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Shengqiang Fan
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China.
| |
Collapse
|
3
|
Zheng J, Zuo G, Zhou Z, Shi Z, Guo H, Sun Z, Feng Y. Indole inhibited the expression of csrA gene in Escherichia coli. J GEN APPL MICROBIOL 2024; 69:239-248. [PMID: 37423745 DOI: 10.2323/jgam.2023.06.007] [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] [Indexed: 07/11/2023]
Abstract
Indole is a very important signal molecule which plays multiple regulatory roles in many physiological and biochemical processes of bacteria, but up to now, the reasons for its wide range of functions have not been revealed. In this study, we found that indole inhibits the motility, promotes glycogen accumulation and enhances starvation resistance of Escherichia coli. However, the regulatory effects of indole became insignificant while the global csrA gene was mutated. To reveal the regulatory relationship between indole and csrA, we studied the effects of indole on the transcription level of csrA, flhDC, glgCAP and cstA, and also the sensing of the promoters of the genes on indole. It was found that indole inhibited the transcription of csrA, and only the promoter of the csrA gene can sense indole. Namely, indole indirectly regulated the translation level of FlhDC, GlgCAP and CstA. These data indicates that indole regulation is related with the regulation of CsrA, which may throw light on the regulation mechanism research of indole.
Collapse
Affiliation(s)
- Jing Zheng
- School of Life Science, Beijing Institute of Technology
- School of Life Science, Langfang Normal University
| | - Guocai Zuo
- School of Life Science, Langfang Normal University
| | - Zhiguo Zhou
- School of Life Science, Langfang Normal University
| | - Zhenxia Shi
- School of Life Science, Langfang Normal University
| | - Huiying Guo
- School of Life Science, Langfang Normal University
| | - Zemin Sun
- School of Life Science, Beijing Institute of Technology
| | - Yongjun Feng
- School of Life Science, Beijing Institute of Technology
| |
Collapse
|
4
|
Zhang J, Ma Q, Wang C, Meng N. Unraveling the signaling roles of indole in an opportunistic pathogen Pseudomonas aeruginosa strain Jade-X. CHEMOSPHERE 2024; 352:141482. [PMID: 38387666 DOI: 10.1016/j.chemosphere.2024.141482] [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: 08/22/2023] [Revised: 12/29/2023] [Accepted: 02/15/2024] [Indexed: 02/24/2024]
Abstract
Pseudomonas aeruginosa, which can produce several toxins and form biofilm, is listed among the priority pathogens. Indole is a ubiquitous aromatic pollutant and signaling molecule produced by tryptophanase in bacteria. Herein, the impacts of indole on a newly isolated P. aeruginosa strain Jade-X were systematically investigated. Indole (0.5-2.0 mM) enhanced the biofilm production by 1.33-2.31-fold after 24 h incubation at 30 °C. However, the effects indole on biofilm formation were intricate and closely intertwined with factors such as incubation temperature, bacterial growth stage, and indole concentration. The twitching motility was enhanced by 1.15-1.99-fold by indole, potentially facilitating surface exploration and biofilm development. Indole reduced the production of virulence factors (pyocyanin and pyoverdine) as well as altered the surface properties (zeta potential and hydrophobicity). Transcriptional analysis revealed that indole (1.0 mM) significantly downregulated mexGHI-opmD efflux genes (4.73-6.91-fold) and virulence-related genes (pqs, pch, and pvd clusters, and flagella-related genes), while upregulating pili-related genes in strain Jade-X. The quorum sensing related signal regulators, including RhlR, LasR, and MvfR (PqsR), were not altered by indole, while other six transcriptional regulators (AmrZ, BfmR, PchR, QscR, SoxR, and SphR) were significantly affected, implying that indole effects might be regulated in a complex and delicate manner. This study should provide new insights into our understanding of indole signaling roles.
Collapse
Affiliation(s)
- Jiaxin Zhang
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Qiao Ma
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China.
| | - Caihong Wang
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Nan Meng
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
| |
Collapse
|
5
|
Hassan RM, Abd El-Maksoud MS, Ghannam IAY, El-Azzouny AAS, Aboul-Enein MN. Synthetic non-toxic anti-biofilm agents as a strategy in combating bacterial resistance. Eur J Med Chem 2023; 262:115867. [PMID: 37866335 DOI: 10.1016/j.ejmech.2023.115867] [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: 08/11/2023] [Revised: 09/26/2023] [Accepted: 10/09/2023] [Indexed: 10/24/2023]
Abstract
The tremendous increase in the bacterial resistance to the available antibiotics is a serious problem for the treatment of various infections. Biofilm formation in bacteria significantly contributes to the bacterial survival in host cells, and is considered as an crucial factor, responsible for bacterial resistance. The response of the bacterial cells in the biofilm to antibiotics is completely different from that of the free floating planktonic cells of the same strain. The anti-biofilm agents that could inhibit the biofilm production without affecting the bacterial growth, apply less selective pressure over the bacterial strains than the traditional antibiotics; thus the development of bacterial resistance would be of low incidence. Many attempts have been performed to discover novel agents capable of interfering with the bacterial biofilm life cycle, and several compounds have shown promising activities in suppressing the biofilm production or in dispersing mature existing biofilms. This review describes the different chemical classes that have anti-biofilm effects against different Gram-positive and Gram-negative bacteria without affecting the bacterial growth.
Collapse
Affiliation(s)
- Rasha Mohamed Hassan
- Medicinal and Pharmaceutical Chemistry Department, Pharmaceutical and Drug Industries Research Institute, National Research Centre (ID: 60014618), P.O. 12622, Dokki, Giza, Egypt.
| | - Mohamed Samir Abd El-Maksoud
- Medicinal and Pharmaceutical Chemistry Department, Pharmaceutical and Drug Industries Research Institute, National Research Centre (ID: 60014618), P.O. 12622, Dokki, Giza, Egypt
| | - Iman Ahmed Youssef Ghannam
- Chemistry of Natural and Microbial Products Department, Pharmaceutical and Drug Industries Research Institute, National Research Centre, Dokki, Cairo, 12622, Egypt
| | - Aida Abdel-Sattar El-Azzouny
- Medicinal and Pharmaceutical Chemistry Department, Pharmaceutical and Drug Industries Research Institute, National Research Centre (ID: 60014618), P.O. 12622, Dokki, Giza, Egypt
| | - Mohamed Nabil Aboul-Enein
- Medicinal and Pharmaceutical Chemistry Department, Pharmaceutical and Drug Industries Research Institute, National Research Centre (ID: 60014618), P.O. 12622, Dokki, Giza, Egypt.
| |
Collapse
|
6
|
Buch A, Gupta V. Unusual concurrence of P-solubilizing and biocontrol traits under P-limitation in plant-beneficial Pseudomonas aeruginosa P4: insights from in vitro metabolic and gene expression analysis. Arch Microbiol 2023; 205:355. [PMID: 37833514 DOI: 10.1007/s00203-023-03692-9] [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: 07/26/2023] [Revised: 09/19/2023] [Accepted: 09/26/2023] [Indexed: 10/15/2023]
Abstract
Plant-beneficial fluorescent Pseudomonas species with concurrent P-solubilizing and biocontrol traits could have improved rhizospheric survival and efficacy; this rare ability being subject to diverse environmental and endogenous regulations. This study correlates growth patterns, time-course analysis of selected metabolites, non-targeted metabolomics of exometabolites and selected gene expression analysis to elucidate P-limitation-induced physiological shifts enabling co-production of metabolites implied in P-solubilization and biocontrol by P. aeruginosa P4 (P4). P-limited culture supernatants showed enhanced production of selected biocontrol metabolites such as pyocyanin, pyoverdine and pyochelin and IAA while maintaining biomass yield despite reduced growth rate and glucose consumption. Non-targeted exometabolomics further indicated that P-limitation positively impacted pentose phosphate pathway as well as pyruvate, C5-branched dibasic acid and amino acid metabolism. Its correlation with unusually reduced aroC expression and growth phase-dependent changes in the expression of key biosynthetic genes pchA, pchE, pchG, pvdQ and phzM implied a probable regulation of biosynthesis of chorismate-derived secondary metabolites, not neglecting the possibility of multiple factors influencing the gene expression profiles. Similar increase in biocontrol metabolite production was also observed in Artificial Root Exudates (ARE)-grown P4 cultures. While such metabolic flexibility could impart physiological advantage in sustaining P-starvation stress, it manifests as unique coexistence of P-solubilizing and biocontrol abilities.
Collapse
Affiliation(s)
- Aditi Buch
- Department of Biological Sciences, P D Patel Institute of Applied Sciences, Charotar University of Science and Technology, CHARUSAT Campus, Dist, Anand, Changa, 388 421, Gujarat, India.
| | - Vaishnawi Gupta
- Department of Biological Sciences, P D Patel Institute of Applied Sciences, Charotar University of Science and Technology, CHARUSAT Campus, Dist, Anand, Changa, 388 421, Gujarat, India
| |
Collapse
|
7
|
Cui B, Guo Q, Li X, Song S, Wang M, Wang G, Yan A, Zhou J, Deng Y. A response regulator controls Acinetobacter baumannii virulence by acting as an indole receptor. PNAS NEXUS 2023; 2:pgad274. [PMID: 37649583 PMCID: PMC10465187 DOI: 10.1093/pnasnexus/pgad274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 08/18/2023] [Indexed: 09/01/2023]
Abstract
Indole is an important signal employed by many bacteria to modulate intraspecies signaling and interspecies or interkingdom communication. Our recent study revealed that indole plays a key role in regulating the physiology and virulence of Acinetobacter baumannii. However, it is not clear how A. baumannii perceives and responds to the indole signal in modulating biological functions. Here, we report that indole controls the physiology and virulence of A. baumannii through a previously uncharacterized response regulator designated as AbiR (A1S_1394), which contains a cheY-homologous receiver (REC) domain and a helix-turn-helix (HTH) DNA-binding domain. AbiR controls the same biological functions as the indole signal, and indole-deficient mutant phenotypes were rescued by in trans expression of AbiR. Intriguingly, unlike other response regulators that commonly interact with signal ligands through the REC domain, AbiR binds to indole with a high affinity via an unusual binding region, which is located between its REC and HTH domains. This interaction substantially enhances the activity of AbiR in promoter binding and in modulation of target gene expression. Taken together, our results present a widely conserved regulator that controls bacterial physiology and virulence by sensing the indole signal in a unique mechanism.
Collapse
Affiliation(s)
- Binbin Cui
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Gongchang Road, Guangming District, Shenzhen 518107, China
| | - Quan Guo
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Gongchang Road, Guangming District, Shenzhen 518107, China
| | - Xia Li
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Gongchang Road, Guangming District, Shenzhen 518107, China
| | - Shihao Song
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Gongchang Road, Guangming District, Shenzhen 518107, China
- School of Pharmaceutical Sciences, Hainan University, Renmin Avenue, Meilan District, Haikou 570228, China
| | - Mingfang Wang
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Gongchang Road, Guangming District, Shenzhen 518107, China
| | - Gerun Wang
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Gongchang Road, Guangming District, Shenzhen 518107, China
| | - Aixin Yan
- School of Biological Sciences, The University of Hong Kong, University Road, Pok Fu Lam Estate, Central and Western District, Hong Kong 999077, China
| | - Jianuan Zhou
- Integrative Microbiology Research Center, South China Agricultural University, Wushan Road, Wushan Street, Tianhe District Guangzhou 510642, China
| | - Yinyue Deng
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Gongchang Road, Guangming District, Shenzhen 518107, China
- School of Pharmaceutical Sciences, Hainan University, Renmin Avenue, Meilan District, Haikou 570228, China
| |
Collapse
|
8
|
Jayaraman S, Adhilaxmi Kannan M, Rajendhran N, John GJ, Ramasamy T. Indole-3-acetic acid impacts biofilm formation and virulence production of Pseudomonas aeruginosa. BIOFOULING 2023; 39:800-815. [PMID: 37853689 DOI: 10.1080/08927014.2023.2269537] [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: 01/03/2023] [Accepted: 10/06/2023] [Indexed: 10/20/2023]
Abstract
Bacterial pathogenesis involves complex mechanisms contributing to virulence and persistence of infections. Understanding the multifactorial nature of bacterial infections is crucial for developing effective interventions. The present study investigated the efficacy of indole-3-acetic acid (IAA) against Pseudomonas aeruginosa with various end points including antibacterial activity, minimum inhibitory concentration (MIC), virulence factor production, biofilm inhibition, bacterial cell detachment, and viability assays. Results showed significant biofilm inhibition, bacterial cell detachment, and modest effects on bacterial viability. Microscopic analysis confirmed the disintegrated biofilm matrix, supporting the inhibitory effect of IAA. Additionally, molecular docking studies revealed potential mechanisms of action through active bond interactions between IAA and virulence proteins. These findings highlight IAA as an effective antibiofilm agent against P. aeruginosa.
Collapse
Affiliation(s)
- Sudharshini Jayaraman
- Laboratory of Aquabiotics/Nanoscience, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India
| | - Monika Adhilaxmi Kannan
- Laboratory of Aquabiotics/Nanoscience, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India
| | - Nandhini Rajendhran
- Laboratory of Aquabiotics/Nanoscience, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India
| | - Georrge J John
- Department of Bioinformatics, University of North Bengal, Raja Rammohunpur, West Bengal, India
| | - Thirumurugan Ramasamy
- Laboratory of Aquabiotics/Nanoscience, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India
| |
Collapse
|
9
|
Blachier F. Amino Acid-Derived Bacterial Metabolites in the Colorectal Luminal Fluid: Effects on Microbial Communication, Metabolism, Physiology, and Growth. Microorganisms 2023; 11:1317. [PMID: 37317289 DOI: 10.3390/microorganisms11051317] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/14/2023] [Accepted: 05/15/2023] [Indexed: 06/16/2023] Open
Abstract
Undigested dietary and endogenous proteins, as well as unabsorbed amino acids, can move from the terminal part of the ileum into the large intestine, where they meet a dense microbial population. Exfoliated cells and mucus released from the large intestine epithelium also supply nitrogenous material to this microbial population. The bacteria in the large intestine luminal fluid release amino acids from the available proteins, and amino acids are then used for bacterial protein synthesis, energy production, and in other various catabolic pathways. The resulting metabolic intermediaries and end products can then accumulate in the colorectal fluid, and their concentrations appear to depend on different parameters, including microbiota composition and metabolic activity, substrate availability, and the capacity of absorptive colonocytes to absorb these metabolites. The aim of the present review is to present how amino acid-derived bacterial metabolites can affect microbial communication between both commensal and pathogenic microorganisms, as well as their metabolism, physiology, and growth.
Collapse
Affiliation(s)
- François Blachier
- Université Paris-Saclay, AgroParisTech, INRAe, UMR PNCA, 91120 Palaiseau, France
| |
Collapse
|
10
|
Chunxiao D, Ma F, Wu W, Li S, Yang J, Chen Z, Lian S, Qu Y. Metagenomic analysis reveals indole signaling effect on microbial community in sequencing batch reactors: Quorum sensing inhibition and antibiotic resistance enrichment. ENVIRONMENTAL RESEARCH 2023; 229:115897. [PMID: 37054839 DOI: 10.1016/j.envres.2023.115897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/09/2023] [Accepted: 04/11/2023] [Indexed: 05/05/2023]
Abstract
Indole is an essential signal molecule in microbial studies. However, its ecological role in biological wastewater treatments remains enigmatic. This study explores the links between indole and complex microbial communities using sequencing batch reactors exposed to 0, 15, and 150 mg/L indole concentrations. A concentration of 150 mg/L indole enriched indole degrader Burkholderiales, while pathogens, such as Giardia, Plasmodium, and Besnoitia were inhibited at 15 mg/L indole concentration. At the same time, indole reduced the abundance of predicted genes in the "signaling transduction mechanisms" pathway via the Non-supervised Orthologous Groups distributions analysis. Indole significantly decreased the concentration of homoserine lactones, especially C14-HSL. Furthermore, the quorum-sensing signaling acceptors containing LuxR, the dCACHE domain, and RpfC showed negative distributions with indole and indole oxygenase genes. Signaling acceptors' potential origins were mainly Burkholderiales, Actinobacteria, and Xanthomonadales. Meanwhile, concentrated indole (150 mg/L) increased the total abundance of antibiotic resistance genes by 3.52 folds, especially on aminoglycoside, multidrug, tetracycline, and sulfonamide. Based on Spearman's correlation analysis, the homoserine lactone degradation genes which were significantly impacted by indole negatively correlated with the antibiotic resistance gene abundance. This study brings new insights into the effect of indole signaling on in biological wastewater treatment plants.
Collapse
Affiliation(s)
- Dai Chunxiao
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education) and Dalian POCT Laboratory, School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China
| | - Fang Ma
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
| | - Weize Wu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education) and Dalian POCT Laboratory, School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China
| | - Shuzhen Li
- Aquatic Eco-Health Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
| | - Jing Yang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education) and Dalian POCT Laboratory, School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China
| | - Zhuo Chen
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education) and Dalian POCT Laboratory, School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China
| | - Shengyang Lian
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education) and Dalian POCT Laboratory, School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China
| | - Yuanyuan Qu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education) and Dalian POCT Laboratory, School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China.
| |
Collapse
|
11
|
Regar RK, Singh D, Gaur VK, Thakur RS, Manickam N. Functional genomic analysis of an efficient indole degrading bacteria strain Alcaligenes faecalis IITR89 and its biodegradation characteristics. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:51770-51781. [PMID: 36820967 DOI: 10.1007/s11356-023-25955-0] [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: 10/04/2022] [Accepted: 02/10/2023] [Indexed: 06/18/2023]
Abstract
Indole is a nitrogenous heterocyclic aromatic pollutant often detected in various environments. An efficient indole degrading bacterium strain IITR89 was isolated from River Cauvery, India, and identified as Alcaligenes faecalis subsp. phenolicus. The bacterium was found to degrade ~ 95% of 2.5 mM (293.75 mg/L) of indole within 18 h utilizing it as a sole carbon and energy source. Based on metabolite identification, the metabolic route of indole degradation is indole → (indoxyl) → isatin → (anthranilate) → salicylic acid → (catechol) → (Acetyl-CoA) → and further entering into TCA cycle. Genome sequencing of IITR89 revealed the presence of gene cluster dmpKLMNOP, encoding multicomponent phenol hydroxylase; andAbcd gene cluster, encoding anthranilate 1,2-dioxygenase ferredoxin subunit (andAb), anthranilate 1,2-dioxygenase large subunit (andAc), and anthranilate 1,2-dioxygenase small subunit (andAd); nahG, salicylate hydroxylase; catA, catechol 1,2-dioxygenase; catB, cis, cis-muconate cycloisomerase; and catC, muconolactone D-isomerase which play an active role in indole degradation. The findings strongly support the degradation potential of strain IITR89 and its possible application for indole biodegradation.
Collapse
Affiliation(s)
- Raj Kumar Regar
- Environmental Biotechnology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research, Vishvigyan Bhawan, 31, Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India
- Drug Standardisation Unit, Dr. D.P. Rastogi Central Research Institute for Homoeopathy, Noida, 201301, Uttar Pradesh, India
| | - Deeksha Singh
- Environmental Biotechnology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research, Vishvigyan Bhawan, 31, Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, Uttar Pradesh, India
| | - Vivek Kumar Gaur
- Environmental Biotechnology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research, Vishvigyan Bhawan, 31, Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Korea
| | - Ravindra Singh Thakur
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, Uttar Pradesh, India
- Analytical Chemistry Laboratory, Regulatory Toxicology Group, CSIR-Indian Institute of Toxicology Research, Vishvigyan Bhawan, 31, Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India
| | - Natesan Manickam
- Environmental Biotechnology Laboratory, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research, Vishvigyan Bhawan, 31, Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India.
| |
Collapse
|
12
|
Dou Q, Zhu Y, Li C, Bian Z, Song H, Zhang R, Wang Y, Zhang X, Wang Y. 4F-Indole Enhances the Susceptibility of Pseudomonas aeruginosa to Aminoglycoside Antibiotics. Microbiol Spectr 2023; 11:e0451922. [PMID: 36975825 PMCID: PMC10100892 DOI: 10.1128/spectrum.04519-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 03/06/2023] [Indexed: 03/29/2023] Open
Abstract
Infections caused by multidrug-resistant bacteria are becoming increasingly serious. The aminoglycoside antibiotics have been widely used to treat severe Gram-negative bacterial infections. Here, we reported that a class of small molecules, namely, halogenated indoles, can resensitize Pseudomonas aeruginosa PAO1 to aminoglycoside antibiotics such as gentamicin, kanamycin, tobramycin, amikacin, neomycin, ribosomalin sulfate, and cisomicin. We selected 4F-indole as a representative of halogenated indoles to investigate its mechanism and found that the two-component system (TCS) PmrA/PmrB inhibited the expression of multidrug efflux pump MexXY-OprM, allowing kanamycin to act intracellularly. Moreover, 4F-indole inhibited the biosynthesis of several virulence factors, such as pyocyanin, type III secretion system (T3SS), and type VI secretion system (T6SS) exported effectors, and reduced the swimming and twitching motility by suppressing the expression of flagella and type IV pili. This study suggests that the combination of 4F-indole and kanamycin can be more effective against P. aeruginosa PAO1 and affect its multiple physiological activities, providing a novel insight into the reactivation of aminoglycoside antibiotics. IMPORTANCE Infections caused by Pseudomonas aeruginosa have become a major public health crisis. Its resistance to existing antibiotics causes clinical infections that are hard to cure. In this study, we found that halogenated indoles in combination with aminoglycoside antibiotics could be more effective than antibiotics alone against P. aeruginosa PAO1 and preliminarily revealed the mechanism of the 4F-indole-induced regulatory effect. Moreover, the regulatory effect of 4F-indole on different physiological behaviors of P. aeruginosa PAO1 was analyzed by combined transcriptomics and metabolomics. We explain that 4F-indole has potential as a novel antibiotic adjuvant, thus slowing down the further development of bacterial resistance.
Collapse
Affiliation(s)
- Qin Dou
- College of Marine Life Sciences, and Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Yuxiang Zhu
- College of Marine Life Sciences, and Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Chunhui Li
- College of Marine Life Sciences, and Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Zeran Bian
- College of Marine Life Sciences, and Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Huihui Song
- College of Marine Life Sciences, and Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Ruizhen Zhang
- College of Marine Life Sciences, and Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Yingsong Wang
- College of Marine Life Sciences, and Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Xile Zhang
- College of Marine Life Sciences, and Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Yan Wang
- College of Marine Life Sciences, and Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China
| |
Collapse
|
13
|
Abstract
Phage therapy is challenged by the frequent emergence of bacterial resistance to phages. As an interspecies signaling molecule, indole plays important roles in regulating bacterial behaviors. However, it is unclear whether indole is involved in the phage-bacterium interactions. Here, we report that indole modulated phage resistance of Pseudomonas aeruginosa PAO1. Specifically, we found that the type IV pilus (T4P) acts as an important receptor for P. aeruginosa phages vB_Pae_S1 and vB_Pae_TR, and indole could protect P. aeruginosa against phage infection via decreasing the T4P-mediated phage adsorption. Further investigation demonstrated that indole downregulated the expression of genes pilA, pilB, and pilQ, which are essential for T4P assembly and activity. Indole inhibits phage attacks, but our data suggest that indole functions not through interfering with the AHL-based QS pathway, although las quorum sensing (QS) of P. aeruginosa PAO1 were reported to promote phage infection. Our finding confirms the important roles of indole in virus-host interactions, which will provide important enlightenment in promoting phage therapy for P. aeruginosa infections. IMPORTANCE Our finding is significant with respect to the study of the interactions between phage and host. Although the important roles of indole in bacterial physiology have been revealed, no direct examples of indole participating in phage-host interactions were reported. This study reports that indole could modulate the phage resistance of indole-nonproducing Pseudomonas aeruginosa PAO1 through inhibition of phage adsorption mechanism. Our finding will be significant for guiding phage therapy and fill some gaps in the field of phage-host interactions.
Collapse
|
14
|
Jeong GJ, Khan F, Khan S, Tabassum N, Mehta S, Kim YM. Pseudomonas aeruginosa virulence attenuation by inhibiting siderophore functions. Appl Microbiol Biotechnol 2023; 107:1019-1038. [PMID: 36633626 DOI: 10.1007/s00253-022-12347-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 12/16/2022] [Accepted: 12/20/2022] [Indexed: 01/13/2023]
Abstract
Pseudmonas aeruginosa is a Gram-negative bacterium known to be ubiquitous and recognized as one of the leading causes of infections such as respiratory, urinary tract, burns, cystic fibrosis, and in immunocompromised individuals. Failure of antimicrobial therapy has been documented to be attributable due to the development of various resistance mechanisms, with a proclivity to develop additional resistance mechanisms rapidly. P. aeruginosa virulence attenuation is an alternate technique for disrupting pathogenesis without impacting growth. The iron-scavenging siderophores (pyoverdine and pyochelin) generated by P. aeruginosa have various properties like scavenging iron, biofilm formation, quorum sensing, increasing virulence, and toxicity to the host. As a result, developing an antivirulence strategy, specifically inhibiting the P. aeruginosa siderophore, has been a promising therapeutic option to limit their infection. Several natural, synthetic compounds and nanoparticles have been identified as potent inhibitors of siderophore production/biosynthesis, function, and transport system. The current review discussed pyoverdine and pyochelin's synthesis and transport system in P. aeruginosa. Furthermore, it is also focused on the role of several natural and synthetic compounds in reducing P. aeruginosa virulence by inhibiting siderophore synthesis, function, and transport. The underlying mechanism involved in inhibiting the siderophore by natural and synthetic compounds has also been explained. KEY POINTS: • Pseudomonas aeruginosa is an opportunistic pathogen linked to chronic respiratory, urinary tract, and burns infections, as well as cystic fibrosis and immunocompromised patients. • P. aeruginosa produces two virulent siderophores forms: pyoverdine and pyochelin, which help it to survive in iron-deficient environments. • The inhibition of siderophore production, transport, and activity using natural and synthesized drugs has been described as a potential strategy for controlling P. aeruginosa infection.
Collapse
Affiliation(s)
- Geum-Jae Jeong
- Department of Food Science and Technology, Pukyong National University, Busan, 48513, Republic of Korea
| | - Fazlurrahman Khan
- Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan, 48513, Republic of Korea. .,Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan, 48513, Republic of Korea.
| | - Sohail Khan
- Department of Biotechnology, Jaypee Institute of Information Technology, A-10, Sector-62, Noida, Uttar Pradesh, 201309, India
| | - Nazia Tabassum
- Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan, 48513, Republic of Korea.,Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan, 48513, Republic of Korea
| | - Sonu Mehta
- Anthem Biosciences Private Limited, Bommasandra, Bangalore, Karnataka, 56009, India
| | - Young-Mog Kim
- Department of Food Science and Technology, Pukyong National University, Busan, 48513, Republic of Korea. .,Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan, 48513, Republic of Korea. .,Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan, 48513, Republic of Korea.
| |
Collapse
|
15
|
Gupta MK, Singh R, Rangan L. Phytochemical screening, antibacterial, anti-biofilm and quorum sensing inhibiting activity of Alpinia nigra leaf extract against infectious pathogen Pseudomonas aeruginosa PAO1. Food Control 2023. [DOI: 10.1016/j.foodcont.2022.109327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
16
|
Zhang S, Yang Q, Defoirdt T. Indole analogues decreasing the virulence of Vibrio campbellii towards brine shrimp larvae. Microb Biotechnol 2022; 15:2917-2928. [PMID: 36333944 PMCID: PMC9733641 DOI: 10.1111/1751-7915.14160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 09/20/2022] [Accepted: 10/04/2022] [Indexed: 11/06/2022] Open
Abstract
Indole signalling has been proposed as a potential target for the development of novel virulence inhibitors to control bacterial infections. However, the major structural features of indole analogues that govern antivirulence activity remain unexplored. Therefore, we investigated the impact of 26 indole analogues on indole-regulated virulence phenotypes in Vibrio campbellii and on the virulence of the bacterium in a gnotobiotic brine shrimp model. The results demonstrated that 10 indole analogues significantly increased the fluorescence of indole reporter strain Vibrio cholerae S9149, 21 of them decreased the swimming motility of V. campbellii, and 13 of them significantly decreased the biofilm formation of V. campbellii. Further, we found that 1-methylindole, indene, 2,3-benzofuran, thianaphthene, indole-3-acetonitrile, methyl indole-3-carboxylate, 3-methylindole, and indole-2-carboxaldehyde exhibited a significant protective effect on brine shrimp larvae against V. campbellii infection, resulting in survival rates of challenged brine shrimp above 80%. The highest survival of shrimp larvae (98%) was obtained with indole-3-acetonitrile, even at a relatively low concentration of 20 μM. Importantly, the indole analogues did not affect bacterial growth, both in vitro and in vivo. These results indicate the potential of indole analogues in applications aiming at the protection of shrimp from vibriosis.
Collapse
Affiliation(s)
- Shanshan Zhang
- Center for Microbial Ecology and Technology (CMET)Ghent UniversityGhentBelgium
| | - Qian Yang
- Center for Microbial Ecology and Technology (CMET)Ghent UniversityGhentBelgium
| | - Tom Defoirdt
- Center for Microbial Ecology and Technology (CMET)Ghent UniversityGhentBelgium
| |
Collapse
|
17
|
Zhang S, Yang Q, Defoirdt T. Halogenated Indoles Decrease the Virulence of Vibrio campbellii in a Gnotobiotic Brine Shrimp Model. Microbiol Spectr 2022; 10:e0268922. [PMID: 36154441 PMCID: PMC9602911 DOI: 10.1128/spectrum.02689-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/08/2022] [Indexed: 01/04/2023] Open
Abstract
Indole signaling is viewed as a potential target for antivirulence therapy against antibiotic-resistant pathogens because of its link with the production of virulence factors. This study examined the antimicrobial and antivirulence properties of 44 indoles toward Vibrio campbellii. Based on the results, 17 halogenated indole analogues were selected, as they significantly improved the survival of brine shrimp larvae challenged with V. campbellii. Specifically, 6-bromoindole, 7-bromoindole, 4-fluoroindole, 5-iodoindole, and 7-iodoindole showed a high protective effect, improving the survival of brine shrimp to over 80% even at a low concentration of 10 μM. To explore the impact of selected indole analogues on bacterial virulence phenotypes, swimming motility, biofilm formation, protease activity, and hemolytic activity of V. campbellii were determined. The results showed that all of the 17 selected indole analogues decreased swimming motility at both 10 μM and 100 μM. Most of the indole analogues decreased biofilm formation at a concentration of 100 μM. In contrast, only a slightly decreased protease activity and no effect on hemolytic activity were observed at both concentrations. To our knowledge, this is the first study of the structure-activity relation of halogenated indole analogues with respect to virulence inhibition of a pathogenic bacterium in an in vivo host model system, and the results demonstrate the potential of these compounds in applications aiming at the protection of shrimp from vibriosis, a major disease in aquaculture. IMPORTANCE Bacterial diseases are a major problem in the aquaculture industry. In order to counter this problem, farmers have been using antibiotics, and this has led to the evolution and spread of antibiotic resistance. In order for the aquaculture industry to further grow in a sustainable way, novel and sustainable methods to control diseases are needed. We previously reported that indole signaling is a valid target for the development of novel therapies to control disease caused by Vibrio campbellii and related bacteria, which are among the major bacterial pathogens in aquaculture. In the present study, we identified indole analogues that are more potent in protecting brine shrimp (a model organism for shrimp) from V. campbellii. To our knowledge, this is the first study of the structure-activity relation of halogenated indole analogues with respect to virulence inhibition of a pathogenic bacterium in an in vivo host model system.
Collapse
Affiliation(s)
- Shanshan Zhang
- Center for Microbial Ecology and Technology (CMET), Ghent University, Gent, Belgium
| | - Qian Yang
- Center for Microbial Ecology and Technology (CMET), Ghent University, Gent, Belgium
| | - Tom Defoirdt
- Center for Microbial Ecology and Technology (CMET), Ghent University, Gent, Belgium
| |
Collapse
|
18
|
Song S, Wood TK. Manipulating indole symbiont signalling. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:691-696. [PMID: 35667868 DOI: 10.1111/1758-2229.13100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 06/15/2023]
Affiliation(s)
- Sooyeon Song
- Department of Animal Science, Jeonbuk National University, Jeonju-si, Jeollabuk-do, Republic of Korea
- Agricultural Convergence Technology, Jeonbuk National University, Jeonju-si, Jeollabuk-do, Republic of Korea
| | - Thomas K Wood
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA, USA
| |
Collapse
|
19
|
Wang Y, Bian Z, Wang Y. Biofilm formation and inhibition mediated by bacterial quorum sensing. Appl Microbiol Biotechnol 2022; 106:6365-6381. [DOI: 10.1007/s00253-022-12150-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 08/23/2022] [Accepted: 08/24/2022] [Indexed: 11/25/2022]
|
20
|
Cui B, Chen X, Guo Q, Song S, Wang M, Liu J, Deng Y. The Cell-Cell Communication Signal Indole Controls the Physiology and Interspecies Communication of Acinetobacter baumannii. Microbiol Spectr 2022; 10:e0102722. [PMID: 35862954 PMCID: PMC9431217 DOI: 10.1128/spectrum.01027-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 06/16/2022] [Indexed: 11/20/2022] Open
Abstract
Many bacteria utilize quorum sensing (QS) to control group behavior in a cell density-dependent manner. Previous studies have demonstrated that Acinetobacter baumannii employs an N-acyl-L-homoserine lactone (AHL)-based QS system to control biological functions and virulence. Here, we report that indole controls biological functions, virulence and AHL signal production in A. baumannii. The biosynthesis of indole is performed by A1S_3160 (AbiS, Acinetobacter baumannii indole synthase), which is a novel indole synthase annotated as an alpha/beta hydrolase in A. baumannii. Heterologous expression of AbiS in an Escherichia coli indole-deficient mutant also rescued the production of indole by using a distinct biosynthetic pathway from the tryptophanase TnaA, which produces indole directly from tryptophan in E. coli. Moreover, we revealed that indole from A. baumannii reduced the competitive fitness of Pseudomonas aeruginosa by inhibiting its QS systems and type III secretion system (T3SS). As A. baumannii and P. aeruginosa usually coexist in human lungs, our results suggest the crucial roles of indole in both the bacterial physiology and interspecies communication. IMPORTANCE Acinetobacter baumannii is an important human opportunistic pathogen that usually causes high morbidity and mortality. It employs the N-acyl-L-homoserine lactone (AHL)-type quorum sensing (QS) system, AbaI/AbaR, to regulate biological functions and virulence. In this study, we found that A. baumannii utilizes another QS signal, indole, to modulate biological functions and virulence. It was further revealed that indole positively controls the production of AHL signals by regulating abaI expression at the transcriptional levels. Furthermore, indole represses the QS systems and type III secretion system (T3SS) of P. aeruginosa and enhances the competitive ability of A. baumannii. Together, our work describes a QS signaling network where a pathogen uses to control the bacterial physiology and pathogenesis, and the competitive ability in microbial community.
Collapse
Affiliation(s)
- Binbin Cui
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Xiayu Chen
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Quan Guo
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Shihao Song
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Mingfang Wang
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Jingyun Liu
- Department of Stomatology, Zhengzhou Shuqing Medical College, Zhenzhou, China
| | - Yinyue Deng
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| |
Collapse
|
21
|
Deng JJ, Deng D, Wang ZL, Luo XC, Chen HP, Liu SY, Ma XY, Li JZ. Indole metabolism mechanisms in a new, efficient indole-degrading facultative anaerobe isolate Enterococcus hirae GDIAS-5. JOURNAL OF HAZARDOUS MATERIALS 2022; 434:128890. [PMID: 35452978 DOI: 10.1016/j.jhazmat.2022.128890] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 04/04/2022] [Accepted: 04/08/2022] [Indexed: 06/14/2023]
Abstract
Indole is an inter-species and inter-kingdom signaling molecule widespread in the natural world. A large amount of indole in livestock wastes makes it difficult to be degraded, which causes serious malodor. Identifying efficient and eco-friendly ways to eliminate it is an urgent task for the sustainable development of husbandry. While bioconversion is a widely accepted means, the mechanism of indole microbial degradation is little understood, especially under anaerobic conditions. Herein, a new Enterococcus hirae isolate GDIAS-5, effectively degraded 100 mg/L indole within 28 h aerobically or 5 days anaerobically. Three intermediates (oxindole, isatin, and catechol) were identified in indole degradation, and catechol was further degraded by a meta-cleavage catabolic pathway. Two important processes for GDIAS-5 indole utilization were discovered. One is Fe(III) uptake and reduction, which may be a critical process that is coupled with indole oxidation, and the other is the entire pathway directly involved in indole oxidation and metabolism. Furthermore, monooxygenase ycnE responsible for indole oxidation via the indole-oxindole-isatin pathway was identified for the first time. Bioinformatic analyses showed that ycnE from E. hirae formed a phylogenetically separate branch from monooxygenases of other species. These findings provide new targets and strategies for synthetic biological reconstruction of indole-degrading bacteria.
Collapse
Affiliation(s)
- Jun-Jin Deng
- Institute of Animal Science, Guangdong Academy of Agricultural Sciences, State Key Laboratory of Livestock and Poultry Breeding, The Key Laboratory of Animal Nutrition and Feed Science in South China, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Animal Breeding and Nutrition, No. 1 Dafeng Street, Wushan Road, Tianhe District, Guangzhou, Guangdong 510640, China
| | - Dun Deng
- Institute of Animal Science, Guangdong Academy of Agricultural Sciences, State Key Laboratory of Livestock and Poultry Breeding, The Key Laboratory of Animal Nutrition and Feed Science in South China, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Animal Breeding and Nutrition, No. 1 Dafeng Street, Wushan Road, Tianhe District, Guangzhou, Guangdong 510640, China
| | - Zhi-Lin Wang
- Agro-Biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
| | - Xiao-Chun Luo
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Panyu District, Guangzhou, Guangdong 510006, China
| | - Hong-Ping Chen
- Institute of Animal Science, Guangdong Academy of Agricultural Sciences, State Key Laboratory of Livestock and Poultry Breeding, The Key Laboratory of Animal Nutrition and Feed Science in South China, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Animal Breeding and Nutrition, No. 1 Dafeng Street, Wushan Road, Tianhe District, Guangzhou, Guangdong 510640, China
| | - Shu-Yang Liu
- School of Life Sciences and Engineering, Foshan University, Foshan, Guangdong 528225, China
| | - Xian-Yong Ma
- Institute of Animal Science, Guangdong Academy of Agricultural Sciences, State Key Laboratory of Livestock and Poultry Breeding, The Key Laboratory of Animal Nutrition and Feed Science in South China, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Animal Breeding and Nutrition, No. 1 Dafeng Street, Wushan Road, Tianhe District, Guangzhou, Guangdong 510640, China
| | - Jia-Zhou Li
- Institute of Animal Science, Guangdong Academy of Agricultural Sciences, State Key Laboratory of Livestock and Poultry Breeding, The Key Laboratory of Animal Nutrition and Feed Science in South China, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Animal Breeding and Nutrition, No. 1 Dafeng Street, Wushan Road, Tianhe District, Guangzhou, Guangdong 510640, China.
| |
Collapse
|
22
|
Beenker WAG, Hoeksma J, den Hertog J. Gregatins, a Group of Related Fungal Secondary Metabolites, Inhibit Aspects of Quorum Sensing in Gram-Negative Bacteria. Front Microbiol 2022; 13:934235. [PMID: 35865924 PMCID: PMC9296082 DOI: 10.3389/fmicb.2022.934235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 06/02/2022] [Indexed: 12/11/2022] Open
Abstract
Quorum sensing (QS) is a process that regulates gene expression based on cell density. In bacteria, QS facilitates collaboration and controls a large number of pathways, including biofilm formation and virulence factor production, which lead to lower sensitivity to antibiotics and higher toxicity in the host, respectively. Inhibition of QS is a promising strategy to combat bacterial infections. In this study, we tested the potential of secondary metabolites from fungi to inhibit bacterial QS using a library derived from more than ten thousand different fungal strains. We used the reporter bacterium, Chromobacterium violaceum, and identified 39 fungal strains that produced QS inhibitor activity. These strains expressed two QS inhibitors that had been described before and eight QS inhibitors that had not been described before. Further testing for QS inhibitor activity against the opportunistic pathogen Pseudomonas aeruginosa led to the identification of gregatins as an interesting family of compounds with QS inhibitor activity. Although various gregatins inhibited QS in P. aeruginosa, these gregatins did not inhibit virulence factor production and biofilm formation. We conclude that gregatins inhibit some, but not all aspects of QS.
Collapse
Affiliation(s)
- Wouter A. G. Beenker
- Hubrecht Institute-KNAW and University Medical Center Utrecht, Utrecht, Netherlands
| | - Jelmer Hoeksma
- Hubrecht Institute-KNAW and University Medical Center Utrecht, Utrecht, Netherlands
| | - Jeroen den Hertog
- Hubrecht Institute-KNAW and University Medical Center Utrecht, Utrecht, Netherlands
- Institute Biology Leiden, Leiden University, Leiden, Netherlands
- *Correspondence: Jeroen den Hertog
| |
Collapse
|
23
|
Novel indole-mediated potassium ion import system confers a survival advantage to the Xanthomonadaceae family. THE ISME JOURNAL 2022; 16:1717-1729. [PMID: 35319020 DOI: 10.1038/s41396-022-01219-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 03/02/2022] [Accepted: 03/07/2022] [Indexed: 12/30/2022]
Abstract
Interspecific and intraspecific communication systems of microorganisms are involved in the regulation of various stress responses in microbial communities. Although the significance of signaling molecules in the ubiquitous family Xanthomonadaceae has been reported, the role bacterial communications play and their internal mechanisms are largely unknown. Here, we use Lysobacter enzymogenes, a member of Xanthomonadaceae, to identify a novel potassium ion import system, LeKdpXFABC. This import system participates in the indole-mediated interspecies signaling pathway and matters in environmental adaptation. Compared with the previously reported kdpFABC of Escherichia coli, LekdpXFABC contains a novel indispensable gene LekdpX and is directly regulated by the indole-related two-component system QseC/B. QseC autophosphorylation is involved in this process. The operon LekdpXFABC widely exists in Xanthomonadaceae. Moreover, indole promotes antimicrobial product production at the early exponential phase. Further analyses show that indole enhances potassium ion adsorption on the cell surface by upregulating the production of O-antigenic polysaccharides. Finally, we confirm that LeKdpXFABC mediation by indole is subject to the intraspecific signaling molecules DSFs, of which the biosynthesis genes always exist together with LekdpXFABC. Therefore, as a new idea, the signal collaborative strategy of indole and DSFs might ensure the persistent fitness advantage of Xanthomonadaceae in variable environments.
Collapse
|
24
|
Ye X, Li H, Anjum K, Zhong X, Miao S, Zheng G, Liu W, Li L. Dual Role of Indoles Derived From Intestinal Microbiota on Human Health. Front Immunol 2022; 13:903526. [PMID: 35784338 PMCID: PMC9248744 DOI: 10.3389/fimmu.2022.903526] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 05/23/2022] [Indexed: 12/12/2022] Open
Abstract
Endogenous indole and its derivatives (indoles), considered as promising N-substituted heterocyclic compounds, are tryptophan metabolites derived from intestinal microbiota and exhibit a range of biological activities. Recent studies indicate that indoles contribute to maintaining the biological barrier of the human intestine, which exert the anti-inflammatory activities mainly through activating AhR and PXR receptors to affect the immune system’s function, significantly improving intestinal health (inflammatory bowel disease, hemorrhagic colitis, colorectal cancer) and further promote human health (diabetes mellitus, central system inflammation, and vascular regulation). However, the revealed toxic influences cannot be ignored. Indoxyl sulfate, an indole derivative, performs nephrotoxicity and cardiovascular toxicity. We addressed the interaction between indoles and intestinal microbiota and the indoles’ effects on human health as double-edged swords. This review provides scientific bases for the correlation of indoles with diseases moreover highlights several directions for subsequent indoles-related studies.
Collapse
Affiliation(s)
- Xuewei Ye
- State Key Laboratory for Diagnosis and Treatment of Infectious Disease, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, China
- Department of Basic Medical Sciences, Shulan International Medical College, Zhejiang Shuren University, Hangzhou, China
| | - Haiyi Li
- Department of Basic Medical Sciences, Shulan International Medical College, Zhejiang Shuren University, Hangzhou, China
| | - Komal Anjum
- Department of Medicine and pharmacy, Ocean University of China, Qingdao, China
| | - Xinye Zhong
- Department of Basic Medical Sciences, Shulan International Medical College, Zhejiang Shuren University, Hangzhou, China
| | - Shuping Miao
- Department of Basic Medical Sciences, Shulan International Medical College, Zhejiang Shuren University, Hangzhou, China
| | - Guowan Zheng
- Key Laboratory of Endocrine Gland Diseases of Zhejiang Province, Hangzhou, China
- Otolaryngology & Head and Neck Center, Cancer Center, Department of Head and Neck Surgery, Zhejiang Provincial People’s Hospital (Affiliated People’s Hospital, Hangzhou Medical College), Hangzhou, China
| | - Wei Liu
- Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
- *Correspondence: Lanjuan Li, ; Wei Liu,
| | - Lanjuan Li
- State Key Laboratory for Diagnosis and Treatment of Infectious Disease, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, China
- *Correspondence: Lanjuan Li, ; Wei Liu,
| |
Collapse
|
25
|
Abstract
Indole signaling in bacteria plays an important role in antibiotic resistance, persistence, and tolerance. Here, we used the nonlinear optical technique, second-harmonic light scattering (SHS), to examine the influence of exogenous indole on the bacterial uptake of the antimicrobial quaternary ammonium cation (qac), malachite green. The transport rates of the antimicrobial qac across the individual membranes of Escherichia coli and Pseudomonas aeruginosa, as well as liposomes composed of the polar lipid extract of E. coli, were directly measured using time-resolved SHS. Whereas exogenous indole was shown to induce a 2-fold increase in the transport rate of the qac across the cytoplasmic membranes of the wild-type bacteria, it had no influence on a knockout strain of E. coli lacking the tryptophan-specific transport protein (Δmtr). Likewise, indole did not affect the transport rate of the qac diffusing across the liposome membrane. Our findings suggest that indole increases the bacterial uptake of antimicrobials through an interaction with the Mtr permease.
Collapse
Affiliation(s)
- Tong Wu
- Department of Chemistry, Temple University, 1901 N. 13th Street, Philadelphia, Pennsylvania 19122, United States
| | - Michael J. Wilhelm
- Department of Chemistry, Temple University, 1901 N. 13th Street, Philadelphia, Pennsylvania 19122, United States
| | - Yujie Li
- Department of Chemistry, Temple University, 1901 N. 13th Street, Philadelphia, Pennsylvania 19122, United States
| | - Jianqiang Ma
- Department of Chemistry, Temple University, 1901 N. 13th Street, Philadelphia, Pennsylvania 19122, United States
| | - Hai-Lung Dai
- Department of Chemistry, Temple University, 1901 N. 13th Street, Philadelphia, Pennsylvania 19122, United States
| |
Collapse
|
26
|
Ganesan R, Jeong JJ, Kim DJ, Suk KT. Recent Trends of Microbiota-Based Microbial Metabolites Metabolism in Liver Disease. Front Med (Lausanne) 2022; 9:841281. [PMID: 35615096 PMCID: PMC9125096 DOI: 10.3389/fmed.2022.841281] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 04/19/2022] [Indexed: 12/12/2022] Open
Abstract
The gut microbiome and microbial metabolomic influences on liver diseases and their diagnosis, prognosis, and treatment are still controversial. Research studies have provocatively claimed that the gut microbiome, metabolomics understanding, and microbial metabolite screening are key approaches to understanding liver cancer and liver diseases. An advance of logical innovations in metabolomics profiling, the metabolome inclusion, challenges, and the reproducibility of the investigations at every stage are devoted to this domain to link the common molecules across multiple liver diseases, such as fatty liver, hepatitis, and cirrhosis. These molecules are not immediately recognizable because of the huge underlying and synthetic variety present inside the liver cellular metabolome. This review focuses on microenvironmental metabolic stimuli in the gut-liver axis. Microbial small-molecule profiling (i.e., semiquantitative monitoring, metabolic discrimination, target profiling, and untargeted profiling) in biological fluids has been incompletely addressed. Here, we have reviewed the differential expression of the metabolome of short-chain fatty acids (SCFAs), tryptophan, one-carbon metabolism and bile acid, and the gut microbiota effects are summarized and discussed. We further present proof-of-evidence for gut microbiota-based metabolomics that manipulates the host's gut or liver microbes, mechanosensitive metabolite reactions and potential metabolic pathways. We conclude with a forward-looking perspective on future attention to the “dark matter” of the gut microbiota and microbial metabolomics.
Collapse
|
27
|
Chen J, Zhang H, Wang S, Du Y, Wei B, Wu Q, Wang H. Inhibitors of Bacterial Extracellular Vesicles. Front Microbiol 2022; 13:835058. [PMID: 35283837 PMCID: PMC8905621 DOI: 10.3389/fmicb.2022.835058] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 01/25/2022] [Indexed: 01/22/2023] Open
Abstract
Both Gram-positive and Gram-negative bacteria can secrete extracellular vesicles (EVs), which contain numerous active substances. EVs mediate bacterial interactions with their hosts or other microbes. Bacterial EVs play a double-edged role in infections through various mechanisms, including the delivery of virulence factors, modulating immune responses, mediating antibiotic resistance, and inhibiting competitive microbes. The spread of antibiotic resistance continues to represent a difficult clinical challenge. Therefore, the investigation of novel therapeutics is a valuable research endeavor for targeting antibiotic-resistant bacterial infections. As a pathogenic substance of bacteria, bacterial EVs have gained increased attention. Thus, EV inhibitors are expected to function as novel antimicrobial agents. The inhibition of EV production, EV activity, and EV-stimulated inflammation are considered potential pathways. This review primarily introduces compounds that effectively inhibit bacterial EVs and evaluates the prospects of their application.
Collapse
Affiliation(s)
- Jianwei Chen
- College of Pharmaceutical Science and Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou, China.,State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau SAR, China
| | - Hongfang Zhang
- College of Pharmaceutical Science and Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou, China
| | - Siqi Wang
- College of Pharmaceutical Science and Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou, China
| | - Yujie Du
- College of Pharmaceutical Science and Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou, China
| | - Bin Wei
- College of Pharmaceutical Science and Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou, China
| | - Qiang Wu
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau SAR, China
| | - Hong Wang
- College of Pharmaceutical Science and Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou, China.,Key Laboratory of Marine Fishery Resources Exploitment and Utilization of Zhejiang Province, Zhejiang University of Technology, Hangzhou, China
| |
Collapse
|
28
|
Abstract
Gastrointestinal microbes respond to biochemical metabolites that coordinate their behaviors. Here, we demonstrate that bacterial indole functions as a multifactorial mitigator of Klebsiella grimontii and Klebsiella oxytoca pathogenicity. These closely related microbes produce the enterotoxins tilimycin and tilivalline; cytotoxin-producing strains are the causative agent of antibiotic-associated hemorrhagic colitis and have been associated with necrotizing enterocolitis of premature infants. We demonstrate that carbohydrates induce cytotoxin synthesis while concurrently repressing indole biosynthesis. Conversely, indole represses cytotoxin production. In both cases, the alterations stemmed from differential transcription of npsA and npsB, key genes involved in tilimycin biosynthesis. Indole also enhances conversion of tilimycin to tilivalline, an indole analog with reduced cytotoxicity. In this context, we established that tilivalline, but not tilimycin, is a strong agonist of pregnane X receptor (PXR), a master regulator of xenobiotic detoxification and intestinal inflammation. Tilivalline binding upregulated PXR-responsive detoxifying genes and inhibited tubulin-directed toxicity. Bacterial indole, therefore, acts in a multifunctional manner to mitigate cytotoxicity by Klebsiella spp.: suppression of toxin production, enhanced conversion of tilimycin to tilivalline, and activation of PXR. IMPORTANCE The human gut harbors a complex community of microbes, including several species and strains that could be commensals or pathogens depending on context. The specific environmental conditions under which a resident microbe changes its relationship with a host and adopts pathogenic behaviors, in many cases, remain poorly understood. Here, we describe a novel communication network involving the regulation of K. grimontii and K. oxytoca enterotoxicity. Bacterial indole was identified as a central modulator of these colitogenic microbes by suppressing bacterial toxin (tilimycin) synthesis and converting tilimycin to tilivalline while simultaneously activating a host receptor, PXR, as a means of mitigating tissue cytotoxicity. On the other hand, fermentable carbohydrates were found to inhibit indole biosynthesis and enhance toxin production. This integrated network involving microbial, host, and metabolic factors provides a contextual framework to better understand K. oxytoca complex pathogenicity.
Collapse
|
29
|
Raorane CJ, Raj V, Lee JH, Lee J. Antifungal activities of fluoroindoles against the postharvest pathogen Botrytis cinerea: In vitro and in silico approaches. Int J Food Microbiol 2022; 362:109492. [PMID: 34861563 DOI: 10.1016/j.ijfoodmicro.2021.109492] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 11/07/2021] [Accepted: 11/20/2021] [Indexed: 11/29/2022]
Abstract
Botrytis cinerea is a common necrotrophic fungal pathogen, leading cause of gray mold diseases in plants and fruit. Several benzimidazoles are used for controlling B. cinerea-associated infection in fruit and vegetables, but benzimidazoles resistance restricts its further uses. Therefore, it is a need for alternative drugs that control B. cinerea. Indoles are multi-faceted compounds and their structural similarities with antifungal benzimidazoles make them a choice for further investigation. Thus, the main objective of the study was to investigate the antifungal potencies of indoles against B. cinerea and to decipher the molecular mechanism involved. We conducted in vitro antifungal assays, fruit assays, and computational studies of interactions between indoles and fungal microtubule polymerase. Of the 16 halogenated indoles examined, 4-fluoroindole, 5-fluoroindole, and 7-fluoroindole (MIC range 2-5 mg/L) were found to be more potent than the fungicides fluconazole and natamycin. Fluoroindoles inhibited or eradicated B. cinerea infections in tangerines and strawberries. Molecular dynamic simulation and density functional theory showed that these fluoroindoles stably interacted with microtubule polymerase. Quantitative structure-activity relationship analyses of halogenated indoles revealed that the presence of a fluoro group in the indole moiety is essential for anti-Botrytis activity. The plausibility of the underlying antifungal mechanism was confirmed by in vitro tubulin polymerization. Collective outcomes of this study indicates that fluoroindoles could be used as alternative fungicidal agents against B. cinerea.
Collapse
Affiliation(s)
| | - Vinit Raj
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea
| | - Jin-Hyung Lee
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea.
| | - Jintae Lee
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea.
| |
Collapse
|
30
|
The Anticancer Agent 3,3'-Diindolylmethane Inhibits Multispecies Biofilm Formation by Acne-Causing Bacteria and Candida albicans. Microbiol Spectr 2022; 10:e0205621. [PMID: 35107361 PMCID: PMC8809333 DOI: 10.1128/spectrum.02056-21] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The Gram-positive anaerobic bacterium Cutibacterium acnes is a major inhabitant of human skin and has been implicated in acne vulgaris formation and in the formation of multispecies biofilms with other skin-inhabiting organisms like Staphylococcus aureus and Candida albicans. Indoles are widespread in nature (even in human skin) and function as important signaling molecules in diverse prokaryotes and eukaryotes. In the present study, we investigated the antibacterial and antibiofilm activities of 20 indoles against C. acnes. Of the indoles tested, indole-3-carbinol at 0.1 mM significantly inhibited biofilm formation by C. acnes without affecting planktonic cell growth, and the anticancer drug 3,3'-diindolylmethane (DIM) at 0.1 mM (32 μg/mL) also significantly inhibited planktonic cell growth and biofilm formation by C. acnes, whereas the other indoles and indole itself were less effective. Also, DIM at 0.1 mM successfully inhibited multispecies biofilm formation by C. acnes, S. aureus, and C. albicans. Transcriptional analyses showed that DIM inhibited the expressions of several biofilm-related genes in C. acnes, and at 0.05 mM, DIM inhibited hyphal formation and cell aggregation by C. albicans. These results suggest that DIM and other indoles inhibit biofilm formation by C. acnes and have potential use for treating C. acnes associated diseases. IMPORTANCE Since indoles are widespread in nature (even in human skin), we hypothesized that indole and its derivatives might control biofilm formation of acne-causing bacteria (Cutibacterium acnes and Staphylococcus aureus) and fungal Candida albicans. The present study reports for the first time the antibiofilm and antimicrobial activities of several indoles on C. acnes. Of the indoles tested, two anticancer agents, indole-3-carbinol and 3,3'-diindolylmethane found in cruciferous vegetables, significantly inhibited biofilm formation by C. acnes. Furthermore, the most active 3,3'-diindolylmethane successfully inhibited multispecies biofilm formation by C. acnes, S. aureus, and C. albicans. Transcriptional analyses showed that 3,3'-diindolylmethane inhibited the expressions of several biofilm-related genes including lipase, hyaluronate lyase, and virulence-related genes in C. acnes, and 3,3'-diindolylmethane inhibited hyphal formation and cell aggregation by C. albicans. Our findings show that 3,3'-diindolylmethane offers a potential means of controlling acne vulgaris and multispecies biofilm-associated infections due to its antibiofilm and antibiotic properties.
Collapse
|
31
|
Dai C, Ma F, Ma Q, Yang J, Li Y, Yang B, Qu Y. Investigation of indole biodegradation by Cupriavidus sp. strain IDO with emphases on downstream biotransformation and indigo production. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:8369-8381. [PMID: 34490563 DOI: 10.1007/s11356-021-14444-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 05/12/2021] [Indexed: 06/13/2023]
Abstract
Indole, as a typical N-heterocyclic aromatic pollutant, poses risks to living things; however, indole-biotransformation mechanisms remain under-discussed, especially those related to its downstream biotransformation. Here, we systematically investigated the characteristics of indole degradation by strain Cupriavidus sp. IDO. We found that Cupriavidus sp. IDO could utilize 25 to 150 mg/L indole within 40 h and identified three intermediates (2-oxindole, indigo, and isatin). Additionally, integrated genomics and proteomics analysis of the indole biotransformation mechanism in strain IDO revealed 317 proteins showing significant changes (262 upregulated and 55 downregulated) in the presence of indole. Among these, three clusters containing indole oxidoreductase, CoA-thioester ligase, and gentisate 1,2-oxidoreductase were identified as potentially responsible for upstream and downstream indole metabolism. Moreover, HPLC-MS and -omics analysis offered insight into the indole-degradation pathway in strain IDO. Furthermore, the indole oxidoreductase IndAB, which initiates indole degradation, was heterologously expressed in Escherichia coli BL21(DE3). Optimization by the response surface methodology resulted in a maximal production of 135.0 mg/L indigo by the recombination strains in tryptophan medium. This work enriches our understanding of the indole-biodegradation process and provides new insights into multiple indole-degradation pathways in natural environments.
Collapse
Affiliation(s)
- Chunxiao Dai
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China
| | - Fang Ma
- State Key Lab of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, China.
| | - Qiao Ma
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Dalian, 116026, China
| | - Jing Yang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China
| | - Yan Li
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China
| | - Bingyu Yang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China
| | - Yuanyuan Qu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China.
| |
Collapse
|
32
|
Abstract
Looking back fondly on the first 15 years of Microbial Biotechnology, a trend is emerging that biotechnology is moving from studies that focus on whole-cell populations, where heterogeneity exists even during robust growth, to those with an emphasis on single cells. This instils optimism that insights will be made into myriad aspects of bacterial growth in communities.
Collapse
Affiliation(s)
- Thomas K. Wood
- Department of Chemical EngineeringPennsylvania State UniversityUniversity ParkPennsylvania16802‐4400USA
| |
Collapse
|
33
|
Zhang J, Gao M, Gao W, Yang P, Meng F, Liu Q, Chang H. Functional silver nanoparticles as broad-spectrum antimicrobial agents. NEW J CHEM 2022. [DOI: 10.1039/d2nj02769k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Drug resistance has become a serious global concern, therefore, developing a new antibacterial agent which could fight drug-resistant bacteria without generation of resistance is urgent. Herein, we synthesize indoles functionalized...
Collapse
|
34
|
Zhang P, Mao D, Gao H, Zheng L, Chen Z, Gao Y, Duan Y, Guo J, Luo Y, Ren H. Colonization of gut microbiota by plasmid-carrying bacteria is facilitated by evolutionary adaptation to antibiotic treatment. THE ISME JOURNAL 2021; 16:1284-1293. [PMID: 34903849 PMCID: PMC9038720 DOI: 10.1038/s41396-021-01171-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 11/25/2021] [Accepted: 12/02/2021] [Indexed: 12/27/2022]
Abstract
Multidrug-resistant plasmid-carrying bacteria are of particular clinical concern as they could transfer antibiotic resistance genes to other bacterial species. However, little is known whether evolutionary adaptation of plasmid-carrying bacteria after long-term antibiotic exposure could affect their subsequent colonization of the human gut. Herein, we combined a long-term evolutionary model based on Escherichia coli K-12 MG1655 and the multidrug-resistant plasmid RP4 with in vivo colonization experiments in mice. We found that the evolutionary adaptation of plasmid-carrying bacteria to antibiotic exposure facilitated colonization of the murine gut and subsequent plasmid transfer to gut bacteria. The evolved plasmid-carrying bacteria exhibited phenotypic alterations, including multidrug resistance, enhanced bacterial growth and biofilm formation capability and decreased plasmid fitness cost, which might be jointly caused by chromosomal mutations (SNPs in rpoC, proQ, and hcaT) and transcriptional modifications. The upregulated transcriptional genes, e.g., type 1 fimbrial-protein pilus (fimA and fimH) and the surface adhesin gene (flu) were likely responsible for the enhanced biofilm-forming capacity. The gene tnaA that encodes a tryptophanase-catalyzing indole formation was transcriptionally upregulated, and increased indole products participated in facilitating the maximum population density of the evolved strains. Furthermore, several chromosomal genes encoding efflux pumps (acriflavine resistance proteins A and B (acrA, acrB), outer-membrane protein (tolC), multidrug-resistance protein (mdtM), and macrolide export proteins A and B (macA, macB)) were transcriptionally upregulated, while most plasmid-harboring genes (conjugal transfer protein (traF) and (trbB), replication protein gene (trfA), beta-lactamase TEM precursor (blaTEM), aminoglycoside 3'-phosphotransferase (aphA) and tetracycline resistance protein A (tetA)) were downregulated. Collectively, these findings demonstrated that evolutionary adaptation of plasmid-carrying bacteria in an antibiotic-influenced environment facilitated colonization of the murine gut by the bacteria and plasmids.
Collapse
Affiliation(s)
- Peng Zhang
- College of Environmental Sciences and Engineering, Nankai University, Tianjin, 300350, China.,State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210046, China
| | - Daqing Mao
- School of Medicine, Nankai University, Tianjin, 300071, China.
| | - Huihui Gao
- School of Medicine, Nankai University, Tianjin, 300071, China
| | - Liyang Zheng
- School of Medicine, Nankai University, Tianjin, 300071, China
| | - Zeyou Chen
- College of Environmental Sciences and Engineering, Nankai University, Tianjin, 300350, China
| | - Yuting Gao
- College of Environmental Sciences and Engineering, Nankai University, Tianjin, 300350, China
| | - Yitao Duan
- College of Environmental Sciences and Engineering, Nankai University, Tianjin, 300350, China
| | - Jianhua Guo
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St. Lucia, Brisbane, QLD, 4072, Australia.
| | - Yi Luo
- College of Environmental Sciences and Engineering, Nankai University, Tianjin, 300350, China. .,State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210046, China.
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210046, China
| |
Collapse
|
35
|
Dai Z, Wu Z, Zhu W, Wu G. Amino Acids in Microbial Metabolism and Function. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1354:127-143. [PMID: 34807440 DOI: 10.1007/978-3-030-85686-1_7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Amino acids (AAs) not only serve as building blocks for protein synthesis in microorganisms but also play important roles in their metabolism, survival, inter-species crosstalk, and virulence. Different AAs have their distinct functions in microbes of the digestive tract and this in turn has important impacts on host nutrition and physiology. Deconjugation and re-conjugation of glycine- or taurine- conjugated bile acids in the process of their enterohepatic recycling is a good example of the bacterial adaptation to harsh gut niches, inter-kingdom cross-talk with AA metabolism, and cell signaling as the critical control point. It is also a big challenge for scientists to modulate the homeostasis of the pools of AAs and their metabolites in the digestive tract with the aim to improve nutrition and regulate AA metabolism related to anti-virulence reactions. Diversity of the metabolic pathways of AAs and their multi-functions in modulating bacterial growth and survival in the digestive tract should be taken into consideration in recommending nutrient requirements for animals. Thus, the concept of functional amino acids can guide not only microbiological studies but also nutritional and physiological investigations. Cutting edge discoveries in this research area will help to better understand the mechanisms responsible for host-microbe interactions and develop new strategies for improving the nutrition, health, and well-being of both animals and humans.
Collapse
Affiliation(s)
- Zhaolai Dai
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China.
| | - Zhenlong Wu
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China
| | - Weiyun Zhu
- National Center for International Research On Animal Gut Nutrition, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Guoyao Wu
- Department of Animal Science, Texas A&M University, College Station, 77843, TX, USA
| |
Collapse
|
36
|
Gut microbiome and metabolic response in non-alcoholic fatty liver disease. Clin Chim Acta 2021; 523:304-314. [PMID: 34666025 DOI: 10.1016/j.cca.2021.10.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 09/19/2021] [Accepted: 10/13/2021] [Indexed: 12/12/2022]
Abstract
Fatty liver disease (FLD) is one of the largest burdens to human health worldwide and is associated with gut microbiome and metabolite stability. Engineered liver tissues have shown promise in restoring liver functions in non-alcoholic FLD (NAFLD), hepatitis and cirrhosis. Fatty liver, largely noted in obesity and hepatic cancer, is highly fatal and has led to a global increase in death rates. It is associated with complex metabolic reprogramming too. A standard approach to therapy in the newly diagnosed setting includes surgery or identification of biomarkers/ metabolites for therapeutic purposes, which ultimately focus on improvement of liver health in patients. As such there are no standard procedures for patient care, but depending on the severity, systemic therapy with either genomic, proteomic or metabolomic profiling form potential options. Better comparisons and study of underlying mechanisms in gut microbiome-based metabolic functions in obesity are urgently required. Today, an emerging field, focusing on metabolomic approaches and metabolic phenotyping, involved in high-throughput identification of metabolome in obesity and gut disorders, is involved in biomarker and metabolite identification. There are supporting technologies and approaches in NAFLD that throw light on the metabolites and gut microbiome, and also on the understanding of the risk factors of obesity along with liver cancer metabolic reaction networks. We discuss the current state of NAFLD metabolites, gut micro-environmental changes, and the further challenges in digital metabolomics profiling. Innovative clinical trial designs, with biomarker-enrichment strategies that are required to improve the outcome of NAFLD in patients are also discussed.
Collapse
|
37
|
Bishai JD, Palm NW. Small Molecule Metabolites at the Host-Microbiota Interface. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2021; 207:1725-1733. [PMID: 34544815 PMCID: PMC8500551 DOI: 10.4049/jimmunol.2100528] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 07/09/2021] [Indexed: 01/15/2023]
Abstract
The trillions of bacteria that constitutively colonize the human gut collectively generate thousands of unique small molecules. These microbial metabolites can accumulate both locally and systemically and potentially influence nearly all aspects of mammalian biology, including immunity, metabolism, and even mood and behavior. In this review, we briefly summarize recent work identifying bioactive microbiota metabolites, the means through which they are synthesized, and their effects on host physiology. Rather than offering an exhaustive list of all known bioactive microbial small molecules, we select a few examples from each key class of metabolites to illustrate the diverse impacts of microbiota-derived compounds on the host. In addition, we attempt to address the microbial logic behind specific biotransformations. Finally, we outline current and emerging strategies for identifying previously undiscovered bioactive microbiota metabolites that may shape human health and disease.
Collapse
Affiliation(s)
- Jason D Bishai
- Department of Microbial Pathogenesis, Yale School of Medicine, Yale University, New Haven, CT; and
| | - Noah W Palm
- Department of Immunobiology, Yale School of Medicine, Yale University, New Haven, CT
| |
Collapse
|
38
|
Bejarano A, Perazzolli M, Pertot I, Puopolo G. The Perception of Rhizosphere Bacterial Communication Signals Leads to Transcriptome Reprogramming in Lysobacter capsici AZ78, a Plant Beneficial Bacterium. Front Microbiol 2021; 12:725403. [PMID: 34489914 PMCID: PMC8416617 DOI: 10.3389/fmicb.2021.725403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 07/21/2021] [Indexed: 12/13/2022] Open
Abstract
The rhizosphere is a dynamic region governed by complex microbial interactions where diffusible communication signals produced by bacteria continuously shape the gene expression patterns of individual species and regulate fundamental traits for adaptation to the rhizosphere environment. Lysobacter spp. are common bacterial inhabitants of the rhizosphere and have been frequently associated with soil disease suppressiveness. However, little is known about their ecology and how diffusible communication signals might affect their behavior in the rhizosphere. To shed light on the aspects determining rhizosphere competence and functioning of Lysobacter spp., we carried out a functional and transcriptome analysis on the plant beneficial bacterium Lysobacter capsici AZ78 (AZ78) grown in the presence of the most common diffusible communication signals released by rhizosphere bacteria. Mining the genome of AZ78 and other Lysobacter spp. showed that Lysobacter spp. share genes involved in the production and perception of diffusible signal factors, indole, diffusible factors, and N-acyl-homoserine lactones. Most of the tested diffusible communication signals (i.e., indole and glyoxylic acid) influenced the ability of AZ78 to inhibit the growth of the phytopathogenic oomycete Pythium ultimum and the Gram-positive bacterium Rhodococcus fascians. Moreover, RNA-Seq analysis revealed that nearly 21% of all genes in AZ78 genome were modulated by diffusible communication signals. 13-Methyltetradecanoic acid, glyoxylic acid, and 2,3-butanedione positively influenced the expression of genes related to type IV pilus, which might enable AZ78 to rapidly colonize the rhizosphere. Moreover, glyoxylic acid and 2,3-butanedione downregulated tRNA genes, possibly as a result of the elicitation of biological stress responses. On its behalf, indole downregulated genes related to type IV pilus and the heat-stable antifungal factor, which might result in impairment of twitching motility and antibiotic production in AZ78. These results show that diffusible communication signals may affect the ecology of Lysobacter spp. in the rhizosphere and suggest that diffusible communication signals might be used to foster rhizosphere colonization and functioning of plant beneficial bacteria belonging to the genus Lysobacter.
Collapse
Affiliation(s)
- Ana Bejarano
- Center of Agriculture, Food, Environment, University of Trento, San Michele all'Adige, Italy.,Department of Sustainable Agro-Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Michele Perazzolli
- Center of Agriculture, Food, Environment, University of Trento, San Michele all'Adige, Italy.,Department of Sustainable Agro-Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Ilaria Pertot
- Center of Agriculture, Food, Environment, University of Trento, San Michele all'Adige, Italy.,Department of Sustainable Agro-Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Gerardo Puopolo
- Center of Agriculture, Food, Environment, University of Trento, San Michele all'Adige, Italy.,Department of Sustainable Agro-Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| |
Collapse
|
39
|
Le Guern R, Stabler S, Gosset P, Pichavant M, Grandjean T, Faure E, Karaca Y, Faure K, Kipnis E, Dessein R. Colonization resistance against multi-drug-resistant bacteria: a narrative review. J Hosp Infect 2021; 118:48-58. [PMID: 34492304 DOI: 10.1016/j.jhin.2021.09.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 09/01/2021] [Accepted: 09/01/2021] [Indexed: 12/15/2022]
Abstract
Colonization resistance by gut microbiota is a fundamental phenomenon in infection prevention and control. Hospitalized patients may be exposed to multi-drug-resistant bacteria when hand hygiene compliance among healthcare workers is not adequate. An additional layer of defence is provided by the healthy gut microbiota, which helps clear the exogenous bacteria and acts as a safety net when hand hygiene procedures are not followed. This narrative review focuses on the role of the gut microbiota in colonization resistance against multi-drug-resistant bacteria, and its implications for infection control. The review discusses the underlying mechanisms of colonization resistance (direct or indirect), the concept of resilience of the gut microbiota, the link between the antimicrobial spectrum and gut dysbiosis, and possible therapeutic strategies. Antimicrobial stewardship is crucial to maximize the effects of colonization resistance. Avoiding unnecessary antimicrobial therapy, shortening the antimicrobial duration as much as possible, and favouring antibiotics with low anti-anaerobe activity may decrease the acquisition and expansion of multi-drug-resistant bacteria. Even after antimicrobial therapy, the resilience of the gut microbiota often occurs spontaneously. Spontaneous resilience explains the existence of a window of opportunity for colonization of multi-drug-resistant bacteria during or just after antimicrobial therapy. Strategies favouring resilience of the gut microbiota, such as high-fibre diets or precision probiotics, should be evaluated.
Collapse
Affiliation(s)
- R Le Guern
- Univ. Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, Centre for Infection and Immunity of Lille, Lille, France; Laboratoire de Bactériologie-Hygiène, CHU Lille, Lille, France.
| | - S Stabler
- Univ. Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, Centre for Infection and Immunity of Lille, Lille, France; Service de Maladies Infectieuses, CHU Lille, Lille, France
| | - P Gosset
- Univ. Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, Centre for Infection and Immunity of Lille, Lille, France
| | - M Pichavant
- Univ. Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, Centre for Infection and Immunity of Lille, Lille, France
| | - T Grandjean
- Univ. Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, Centre for Infection and Immunity of Lille, Lille, France
| | - E Faure
- Univ. Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, Centre for Infection and Immunity of Lille, Lille, France; Service de Maladies Infectieuses, CHU Lille, Lille, France
| | - Y Karaca
- Univ. Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, Centre for Infection and Immunity of Lille, Lille, France
| | - K Faure
- Univ. Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, Centre for Infection and Immunity of Lille, Lille, France; Service de Maladies Infectieuses, CHU Lille, Lille, France
| | - E Kipnis
- Univ. Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, Centre for Infection and Immunity of Lille, Lille, France; Service de Réanimation Chirurgicale, CHU Lille, Lille, France
| | - R Dessein
- Univ. Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, Centre for Infection and Immunity of Lille, Lille, France; Laboratoire de Bactériologie-Hygiène, CHU Lille, Lille, France
| |
Collapse
|
40
|
Zhang S, Yang Q, Defoirdt T. Indole decreases the virulence of pathogenic vibrios belonging to the Harveyi clade. J Appl Microbiol 2021; 132:167-176. [PMID: 34297464 DOI: 10.1111/jam.15227] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/28/2021] [Accepted: 07/16/2021] [Indexed: 11/29/2022]
Abstract
AIM Indole is a signaling molecule secreted by over 85 species of bacteria, including several Vibrio species, and it has been reported to affect different bacterial phenotypes such as biofilm formation, motility, and virulence. In this study, we aimed at investigating the inter-strain variability of the effect of indole in 12 different strains belonging to the Harveyi clade of vibrios. METHODS AND RESULTS Indole reduced the virulence of all strains towards gnotobiotic brine shrimp larvae. The survival rate of brine shrimp larvae challenged with vibrios pretreated with indole was increased by 1.3-fold to 1.8-fold. Additionally, indole significantly decreased the biofilm formation in all of the strains, decreased the swimming motility in eight of the strains, and decreased swarming motility in five of the strains. When cultured in the presence of exogenous indole, the mRNA level of the pirA and pirB toxin genes were down-regulated to 65% and 46%, and to 62% and 55% in the AHPND-causing strains Vibrio parahaemolyticus M0904 and Vibrio campbellii S01, respectively. CONCLUSIONS These data indicate that indole has a significant impact on the virulence of different strains belonging to the Harveyi clade of vibrios. SIGNIFICANCE AND IMPACT OF THE STUDY Our results suggest that indole signaling is a valid target for the development of novel therapeutics in order to control infections caused by Harveyi clade vibrios in aquaculture.
Collapse
Affiliation(s)
- Shanshan Zhang
- Center for Microbial Ecology and Technology (CMET), Ghent University, Gent, Belgium
| | - Qian Yang
- Center for Microbial Ecology and Technology (CMET), Ghent University, Gent, Belgium
| | - Tom Defoirdt
- Center for Microbial Ecology and Technology (CMET), Ghent University, Gent, Belgium
| |
Collapse
|
41
|
Abstract
Microbially produced indole metabolites serve as a diverse family of interspecies and interkingdom signaling molecules in the context of human health, crop production, and antibiotic resistance. We mined the protein database for sensors of indole metabolites and developed a biosensor for indole-3-aldehyde (I3A). Microbially produced I3A has been associated with reducing inflammation in diseases such as ulcerative colitis by stimulating the aryl hydrocarbon receptor pathway. We engineered an E. coli strain embedded with a single plasmid carrying a chimeric two-component system that detects I3A. Our I3A receptor characterization confirmed binding site residues that contribute to the sensor's I3A detection range of 0.1-10 μM. This new I3A biosensor opens the door to sensing indole metabolites produced at various host-microbe interfaces and provides new parts for synthetic biology applications.
Collapse
Affiliation(s)
- Jiefei Wang
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Chao Zhang
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - W. Seth Childers
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States
| |
Collapse
|
42
|
Grifka-Walk HM, Jenkins BR, Kominsky DJ. Amino Acid Trp: The Far Out Impacts of Host and Commensal Tryptophan Metabolism. Front Immunol 2021; 12:653208. [PMID: 34149693 PMCID: PMC8213022 DOI: 10.3389/fimmu.2021.653208] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 05/11/2021] [Indexed: 12/12/2022] Open
Abstract
Tryptophan (Trp) is an essential amino acid primarily derived from the diet for use by the host for protein synthesis. The intestinal tract is lined with cells, both host and microbial, that uptake and metabolize Trp to also generate important signaling molecules. Serotonin (5-HT), kynurenine and its downstream metabolites, and to a lesser extent other neurotransmitters are generated by the host to signal onto host receptors and elicit physiological effects. 5-HT production by neurons in the CNS regulates sleep, mood, and appetite; 5-HT production in the intestinal tract by enterochromaffin cells regulates gastric motility and inflammation in the periphery. Kynurenine can signal onto the aryl hydrocarbon receptor (AHR) to elicit pleiotropic responses from several cell types including epithelial and immune cells, or can be further metabolized into bioactive molecules to influence neurodegenerative disease. There is a remarkable amount of cross-talk with the microbiome with regard to tryptophan metabolites as well. The gut microbiome can regulate the production of host tryptophan metabolites and can use dietary or recycled trp to generate bioactive metabolites themselves. Trp derivatives like indole are able to signal onto xenobiotic receptors, including AHR, to elicit tolerogenic effects. Here, we review studies that demonstrate that tryptophan represents a key intra-kingdom signaling molecule.
Collapse
Affiliation(s)
- Heather M Grifka-Walk
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Brittany R Jenkins
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Douglas J Kominsky
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| |
Collapse
|
43
|
Yu J, Jia M, Feng Y. The cytidine repressor regulates the survival of Pantoea agglomerans YS19 under oxidative stress and sulfur starvation conditions. J GEN APPL MICROBIOL 2021; 67:59-66. [PMID: 33518552 DOI: 10.2323/jgam.2020.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Pantoea agglomerans YS19 is a dominant endophytic bacterium isolated from rice, which is capable of promoting host plant growth by nitrogen-fixing and phytohormone secreting. We previously found that the cytidine repressor (CytR) protein conducts the regulation of indole signal in YS19. Here, we compared the whole-cell protein of the wild type YS19 and the ΔcytR mutant and subsequently identified one differential protein as alkyl hydroperoxide reductase subunit C related to oxidative stress and sulfur starvation tolerance. It was tested that cytR had a positive effect on the survival of YS19 under the oxidative stress and sulfur starvation conditions and this effect was inhibited by indole. To further understand the functional mode of indole in this regulation, we cloned the cytR promoter region (PcytR) of YS19 and tested the effect of indole on PcytR using gfp as a reporter gene. It was found that PcytR can sense indole and significantly inhibit the expression of the downstream gene. This study provided a deeper understanding of the multiple function of cytR and expanded a new research direction of how indole participates in gene regulation.
Collapse
Affiliation(s)
- Jiajia Yu
- School of Life Science, Beijing Institute of Technology
| | - Mengqi Jia
- School of Life Science, Beijing Institute of Technology
| | - Yongjun Feng
- School of Life Science, Beijing Institute of Technology
| |
Collapse
|
44
|
Abstract
Antimicrobial resistance is a serious medical threat, particularly given the decreasing rate of discovery of new treatments. Although attempts to find new treatments continue, it has become clear that merely discovering new antimicrobials, even if they are new classes, will be insufficient. It is essential that new strategies be aggressively pursued. Toward that end, the search for treatments that can mitigate bacterial virulence and tilt the balance of host-pathogen interactions in favor of the host has become increasingly popular. In this review, we will discuss recent progress in this field, with a special focus on synthetic small molecule antivirulents that have been identified from high-throughput screens and on treatments that are effective against the opportunistic human pathogen Pseudomonas aeruginosa.
Collapse
|
45
|
Amer MA, Wasfi R, Attia AS, Ramadan MA. Indole Derivatives Obtained from Egyptian Enterobacter sp. Soil Isolates Exhibit Antivirulence Activities against Uropathogenic Proteus mirabilis. Antibiotics (Basel) 2021; 10:363. [PMID: 33805493 PMCID: PMC8065651 DOI: 10.3390/antibiotics10040363] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 03/24/2021] [Accepted: 03/26/2021] [Indexed: 11/05/2022] Open
Abstract
Proteus mirabilis is a frequent cause of catheter associated urinary tract infections (CAUTIs). Several virulence factors contribute to its pathogenesis, but swarming motility, biofilm formation, and urease activity are considered the hallmarks. The increased prevalence in antibiotic resistance among uropathogens is alarming and requires searching for new treatment alternatives. With this in mind, our study aims to investigate antivirulence activity of indole derivatives against multidrug resistant P. mirabilis isolates. Ethyl acetate (EtOAc) extracts from Enterobacter sp. (rhizobacterium), isolated from Egyptian soil samples were tested for their ability to antagonize the virulence capacity and biofilm activity of P. mirabilis uropathogens. Extracts of two Enterobacter sp. isolates (coded Zch127 and Cbg70) showed the highest antivirulence activities against P. mirabilis. The two promising rhizobacteria Zch127 and Cbg70 were isolated from soil surrounding: Cucurbita pepo (Zucchini) and Brassica oleracea var. capitata L. (Cabbage), respectively. Sub-minimum inhibitory concentrations (Sub-MICs) of the two extracts showed potent antibiofilm activity with significant biofilm reduction of ten P. mirabilis clinical isolates (p-value < 0.05) in a dose-dependent manner. Interestingly, the Zch127 extract showed anti-urease, anti-swarming and anti-swimming activity against the tested strains. Indole derivatives identified represented key components of indole pyruvate, indole acetamide pathways; involved in the synthesis of indole acetic acid. Additional compounds for indole acetonitrile pathway were detected in the Zch127 extract which showed higher antivirulence activity. Accordingly, the findings of the current study model the feasibility of using these extracts as promising antivirulence agent against the P. mirabilis uropathogens and as potential therapy for treatment of urinary tract infections (UTIs).
Collapse
Affiliation(s)
- Mai A. Amer
- Department of Microbiology and Immunology, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA), Giza 12451, Egypt; (M.A.A.); (R.W.)
| | - Reham Wasfi
- Department of Microbiology and Immunology, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA), Giza 12451, Egypt; (M.A.A.); (R.W.)
| | - Ahmed S. Attia
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt;
- Department of Microbiology and Immunology, School of Pharmacy, Newgiza University, Giza 11341, Egypt
| | - Mohamed A. Ramadan
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt;
| |
Collapse
|
46
|
Song S, Wood TK. The Primary Physiological Roles of Autoinducer 2 in Escherichia coli Are Chemotaxis and Biofilm Formation. Microorganisms 2021; 9:microorganisms9020386. [PMID: 33672862 PMCID: PMC7918475 DOI: 10.3390/microorganisms9020386] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/10/2021] [Accepted: 02/12/2021] [Indexed: 12/15/2022] Open
Abstract
Autoinducer 2 (AI-2) is a ubiquitous metabolite but, instead of acting as a "universal signal," relatively few phenotypes have been associated with it, and many scientists believe AI-2 is often a metabolic byproduct rather than a signal. Here, the aim is to present evidence that AI-2 influences both biofilm formation and motility (swarming and chemotaxis), using Escherichia coli as the model system, to establish AI-2 as a true signal with an important physiological role in this bacterium. In addition, AI-2 signaling is compared to the other primary signal of E. coli, indole, and it is shown that they have opposite effects on biofilm formation and virulence.
Collapse
Affiliation(s)
- Sooyeon Song
- Department of Animal Science, Jeonbuk National University, Jeonju-si 54896, Jeollabuk-do, Korea;
| | - Thomas K. Wood
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA 16802-7000, USA
- Correspondence:
| |
Collapse
|
47
|
Lopes SP, Jorge P, Sousa AM, Pereira MO. Discerning the role of polymicrobial biofilms in the ascent, prevalence, and extent of heteroresistance in clinical practice. Crit Rev Microbiol 2021; 47:162-191. [PMID: 33527850 DOI: 10.1080/1040841x.2020.1863329] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Antimicrobial therapy is facing a worrisome and underappreciated challenge, the phenomenon of heteroresistance (HR). HR has been gradually documented in clinically relevant pathogens (e.g. Pseudomonas aeruginosa, Staphylococcus aureus, Burkholderia spp., Acinetobacter baumannii, Klebsiella pneumoniae, Candida spp.) towards several drugs and is believed to complicate the clinical picture of chronic infections. This type of infections are typically mediated by polymicrobial biofilms, wherein microorganisms inherently display a wide range of physiological states, distinct metabolic pathways, diverging refractory levels of stress responses, and a complex network of chemical signals exchange. This review aims to provide an overview on the relevance, prevalence, and implications of HR in clinical settings. Firstly, related terminologies (e.g. resistance, tolerance, persistence), sometimes misunderstood and overlapped, were clarified. Factors generating misleading HR definitions were also uncovered. Secondly, the recent HR incidences reported in clinically relevant pathogens towards different antimicrobials were annotated. The potential mechanisms underlying such occurrences were further elucidated. Finally, the link between HR and biofilms was discussed. The focus was to recognize the presence of heterogeneous levels of resistance within most biofilms, as well as the relevance of polymicrobial biofilms in chronic infectious diseases and their role in resistance spreading. These topics were subject of a critical appraisal, gaining insights into the ascending clinical implications of HR in antimicrobial resistance spreading, which could ultimately help designing effective therapeutic options.
Collapse
Affiliation(s)
- Susana Patrícia Lopes
- CEB - Centre of Biological Engineering, LIBRO - Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Braga, Portugal
| | - Paula Jorge
- CEB - Centre of Biological Engineering, LIBRO - Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Braga, Portugal
| | - Ana Margarida Sousa
- CEB - Centre of Biological Engineering, LIBRO - Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Braga, Portugal
| | - Maria Olívia Pereira
- CEB - Centre of Biological Engineering, LIBRO - Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Braga, Portugal
| |
Collapse
|
48
|
Han JT, Li DY, Zhang MY, Yu XQ, Jia XX, Xu H, Yan X, Jia WJ, Niu S, Kempher ML, Tao X, He YX. EmhR is an indole-sensing transcriptional regulator responsible for the indole-induced antibiotic tolerance in Pseudomonas fluorescens. Environ Microbiol 2020; 23:2054-2069. [PMID: 33314494 DOI: 10.1111/1462-2920.15354] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 12/10/2020] [Indexed: 11/29/2022]
Abstract
Indole is well known as an interspecies signalling molecule to modulate bacterial physiology; however, it is not clear how the indole signal is perceived and responded to by plant growth promoting rhizobacteria (PGPR) in the rhizosphere. Here, we demonstrated that indole enhanced the antibiotic tolerance of Pseudomonas fluorescens 2P24, a PGPR well known for its biocontrol capacity. Proteomic analysis revealed that indole influenced the expression of multiple genes including the emhABC operon encoding a major multidrug efflux pump. The expression of emhABC was regulated by a TetR-family transcription factor EmhR, which was demonstrated to be an indole-responsive regulator. Molecular dynamics simulation showed that indole allosterically affected the distance between the two DNA-recognizing helices within the EmhR dimer, leading to diminished EmhR-DNA interaction. It was further revealed the EmhR ortholog in Pseudomonas syringae was also responsible for indole-induced antibiotic tolerance, suggesting this EmhR-dependent, indole-induced antibiotic tolerance is likely to be conserved among Pseudomonas species. Taken together, our results elucidated the molecular mechanism of indole-induced antibiotic tolerance in Pseudomonas species and had important implications on how rhizobacteria sense and respond to indole in the rhizosphere.
Collapse
Affiliation(s)
- Jian-Ting Han
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Di-Yin Li
- Institute of Urology, Lanzhou University Second Hospital, Key Laboratory of Urological Diseases in Gansu Province, Gansu Nephro-Urological Clinical Center, Lanzhou, China
| | - Meng-Yuan Zhang
- School of Pharmacy, Lanzhou University, Lanzhou, 730000, China
| | - Xiao-Quan Yu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Xiang-Xue Jia
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Hang Xu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Xu Yan
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Wen-Juan Jia
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Shaomin Niu
- Institute of Urology, Lanzhou University Second Hospital, Key Laboratory of Urological Diseases in Gansu Province, Gansu Nephro-Urological Clinical Center, Lanzhou, China
| | - Megan L Kempher
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, and School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, Ok, USA
| | - Xuanyu Tao
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, and School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, Ok, USA
| | - Yong-Xing He
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| |
Collapse
|
49
|
Koga N, Hosomi T, Zwama M, Jirayupat C, Yanagida T, Nishino K, Yamasaki S. Identification of Genetic Variants via Bacterial Respiration Gas Analysis. Front Microbiol 2020; 11:581571. [PMID: 33304330 PMCID: PMC7701088 DOI: 10.3389/fmicb.2020.581571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 10/27/2020] [Indexed: 11/13/2022] Open
Abstract
Indole is a signal molecule derived from the conversion of tryptophan, and it is present in bacterial respiratory gas. Besides influencing bacterial growth, indole exhibits effects on human health, including a positive effect on inflammation and protection against pathogens. However, a high fecal indole concentration (FIC) can suggest an unbalanced gut flora or the presence of certain pathogens. To analyze the indole produced by bacteria, its collection and detection is required. Traditional methods usually require centrifugation of liquid bacterial culture medium and subsequent extraction of indole from the medium or partial purification of indole from fecal samples (e.g., by distillation or extraction). In this study, we demonstrate the possibility of identifying gas contents directly from bacteria, and we distinguish the difference in species and their genetics without the need to centrifuge or extract. Using an absorbent sheet placed above a liquid culture, we were able to collect gas content directly from bacteria. Gas chromatography-mass spectrometry (GC-MS) was used for the analysis. The GC-MS results showed a clear peak attributed to indole for wild-type Escherichia coli cells (MG1655 and MC4100 strains), whereas the indole peak was absent in the chromatograms of cells where proteins, part of the indole production pathway from tryptophan (TnaA and TnaB), were not expressed (by using tnaAB-deleted cells). The indole observed was measured to be present in a low nmol-range. This method can distinguish whether the bacterial genome contains the tnaAB gene or not and can be used to collect gas compounds from bacterial cultures quickly and easily. This method is useful for other goals and future research, such as for measurements in restrooms, for food-handling facilities, and for various applications in medical settings.
Collapse
Affiliation(s)
- Naoki Koga
- School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
| | - Takuro Hosomi
- Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Martijn Zwama
- Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | | | - Takeshi Yanagida
- Graduate School of Engineering, The University of Tokyo, Tokyo, Japan.,Institute for Materials Chemistry and Engineering, Kyushu University, Fukuoka, Japan
| | - Kunihiko Nishino
- School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.,Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Seiji Yamasaki
- School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.,Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan.,Institute for Advanced Co-Creation Studies, Osaka University, Osaka, Japan
| |
Collapse
|
50
|
Sethupathy S, Sathiyamoorthi E, Kim YG, Lee JH, Lee J. Antibiofilm and Antivirulence Properties of Indoles Against Serratia marcescens. Front Microbiol 2020; 11:584812. [PMID: 33193228 PMCID: PMC7662412 DOI: 10.3389/fmicb.2020.584812] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 09/30/2020] [Indexed: 12/11/2022] Open
Abstract
Indole and its derivatives have been shown to interfere with the quorum sensing (QS) systems of a wide range of bacterial pathogens. While indole has been previously shown to inhibit QS in Serratia marcescens, the effects of various indole derivatives on QS, biofilm formation, and virulence of S. marcescens remain unexplored. Hence, in the present study, we investigated the effects of 51 indole derivatives on S. marcescens biofilm formation, QS, and virulence factor production. The results obtained revealed that several indole derivatives (3-indoleacetonitrile, 5-fluoroindole, 6-fluoroindole, 7-fluoroindole, 7-methylindole, 7-nitroindole, 5-iodoindole, 5-fluoro-2-methylindole, 2-methylindole-3-carboxaldehyde, and 5-methylindole) dose-dependently interfered with quorum sensing (QS) and suppressed prodigiosin production, biofilm formation, swimming motility, and swarming motility. Further assays showed 6-fluoroindole and 7-methylindole suppressed fimbria-mediated yeast agglutination, extracellular polymeric substance production, and secretions of virulence factors (e.g., proteases and lipases). QS assays on Chromobacterium violaceum CV026 confirmed that indole derivatives interfered with QS. The current results demonstrate the antibiofilm and antivirulence properties of indole derivatives and their potentials in applications targeting S. marcescens virulence.
Collapse
Affiliation(s)
| | | | - Yong-Guy Kim
- School of Chemical Engineering, Yeungnam University, Gyeongsan, South Korea
| | - Jin-Hyung Lee
- School of Chemical Engineering, Yeungnam University, Gyeongsan, South Korea
| | - Jintae Lee
- School of Chemical Engineering, Yeungnam University, Gyeongsan, South Korea
| |
Collapse
|