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Kroken AR, Gajenthra Kumar N, Yahr TL, Smith BE, Nieto V, Horneman H, Evans DJ, Fleiszig SMJ. Exotoxin S secreted by internalized Pseudomonas aeruginosa delays lytic host cell death. PLoS Pathog 2022; 18:e1010306. [PMID: 35130333 PMCID: PMC8853526 DOI: 10.1371/journal.ppat.1010306] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 02/17/2022] [Accepted: 01/25/2022] [Indexed: 12/22/2022] Open
Abstract
The Pseudomonas aeruginosa toxin ExoS, secreted by the type III secretion system (T3SS), supports intracellular persistence via its ADP-ribosyltransferase (ADPr) activity. For epithelial cells, this involves inhibiting vacuole acidification, promoting vacuolar escape, countering autophagy, and niche construction in the cytoplasm and within plasma membrane blebs. Paradoxically, ExoS and other P. aeruginosa T3SS effectors can also have antiphagocytic and cytotoxic activities. Here, we sought to reconcile these apparently contradictory activities of ExoS by studying the relationships between intracellular persistence and host epithelial cell death. Methods involved quantitative imaging and the use of antibiotics that vary in host cell membrane permeability to selectively kill intracellular and extracellular populations after invasion. Results showed that intracellular P. aeruginosa mutants lacking T3SS effector toxins could kill (permeabilize) cells when extracellular bacteria were eliminated. Surprisingly, wild-type strain PAO1 (encoding ExoS, ExoT and ExoY) caused cell death more slowly, the time extended from 5.2 to 9.5 h for corneal epithelial cells and from 10.2 to 13.0 h for HeLa cells. Use of specific mutants/complementation and controls for initial invasion showed that ExoS ADPr activity delayed cell death. Triggering T3SS expression only after bacteria invaded cells using rhamnose-induction in T3SS mutants rescued the ExoS-dependent intracellular phenotype, showing that injected effectors from extracellular bacteria were not required. The ADPr activity of ExoS was further found to support internalization by countering the antiphagocytic activity of both the ExoS and ExoT RhoGAP domains. Together, these results show two additional roles for ExoS ADPr activity in supporting the intracellular lifestyle of P. aeruginosa; suppression of host cell death to preserve a replicative niche and inhibition of T3SS effector antiphagocytic activities to allow invasion. These findings add to the growing body of evidence that ExoS-encoding (invasive) P. aeruginosa strains can be facultative intracellular pathogens, and that intracellularly secreted T3SS effectors contribute to pathogenesis. While the ADPr domain of the T3SS effector ExoS plays multiple roles in the intracellular lifestyle of P. aeruginosa, ExoS can also be cytotoxic and/or antiphagocytic. Here, we show that when P. aeruginosa enters the cytosol of epithelial cells, cell death is triggered independently of T3SS effector toxins, but ExoS ADPr activity delays this to enable continued intracellular survival and replication. Using rhamnose induction to express the T3SS only after invasion restored this ExoS-dependent phenotype, showing that intracellularly secreted effectors can enable intracellular pathogenesis. ExoS ADPr activity also countered antiphagocytic activity of ExoS and ExoT RhoGAP domains. These results show two additional roles for ExoS ADPr activity in promoting internalization of P. aeruginosa and protecting the intracellular niche, continuing to challenge the notions that P. aeruginosa is exclusively an extracellular pathogen, that it needs to inject T3SS effectors across plasma membranes, and that ExoS is necessarily cytotoxic to host cells.
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Affiliation(s)
- Abby R. Kroken
- School of Optometry, University of California, Berkeley, Berkeley, California, United States of America
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois, United States of America
| | - Naren Gajenthra Kumar
- School of Optometry, University of California, Berkeley, Berkeley, California, United States of America
| | - Timothy L. Yahr
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, United States of America
| | - Benjamin E. Smith
- Vision Science Program, University of California, Berkeley, Berkeley, California, United States of America
| | - Vincent Nieto
- School of Optometry, University of California, Berkeley, Berkeley, California, United States of America
| | - Hart Horneman
- School of Optometry, University of California, Berkeley, Berkeley, California, United States of America
| | - David J. Evans
- School of Optometry, University of California, Berkeley, Berkeley, California, United States of America
- College of Pharmacy, Touro University California, Vallejo, California, United States of America
| | - Suzanne M. J. Fleiszig
- School of Optometry, University of California, Berkeley, Berkeley, California, United States of America
- Vision Science Program, University of California, Berkeley, Berkeley, California, United States of America
- Graduate Groups in Microbiology, and Infectious Diseases & Immunity, University of California, Berkeley, Berkeley, California, United States of America
- * E-mail:
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The Arginine Catabolism-Derived Amino Acid L-ornithine Is a Chemoattractant for Pseudomonas aeruginosa. Microorganisms 2022; 10:microorganisms10020264. [PMID: 35208720 PMCID: PMC8875649 DOI: 10.3390/microorganisms10020264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/05/2022] [Accepted: 01/21/2022] [Indexed: 02/01/2023] Open
Abstract
Pseudomonas aeruginosa is a common, opportunistic bacterial pathogen among patients with cystic fibrosis, asthma, and chronic obstructive pulmonary disease. During the course of these diseases, l-ornithine, a non-proteinogenic amino acid, becomes more abundant. P. aeruginosa is chemotactic towards other proteinogenic amino acids. Here, we evaluated the chemotaxis response of P. aeruginosa towards l-ornithine. Our results show that l-ornithine serves as a chemoattractant for several strains of P. aeruginosa, including clinical isolates, and that the chemoreceptors involved in P. aeruginosa PAO1 are PctA and PctB. It seems likely that P. aeruginosa’s chemotactic response to l-ornithine might be a common feature and thus could potentially contribute to pathogenesis processes during colonization and infection scenarios.
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Arranz San Martín A, Vogel J, Wullich SC, Quax WJ, Fetzner S. Enzyme-Mediated Quenching of the Pseudomonas Quinolone Signal (PQS): A Comparison between Naturally Occurring and Engineered PQS-Cleaving Dioxygenases. Biomolecules 2022; 12:biom12020170. [PMID: 35204671 PMCID: PMC8961568 DOI: 10.3390/biom12020170] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/13/2022] [Accepted: 01/18/2022] [Indexed: 02/06/2023] Open
Abstract
The opportunistic pathogen Pseudomonas aeruginosa employs quorum sensing to govern the production of many virulence factors. Interference with quorum sensing signaling has therefore been put forward as an attractive approach to disarm this pathogen. Here, we analyzed the quorum quenching properties of natural and engineered (2-alkyl-)3-hydroxy-4(1H)-quinolone 2,4-dioxygenases (HQDs) that inactivate the P. aeruginosa signal molecule PQS (Pseudomonas quinolone signal; 2-heptyl-3-hydroxy-4(1H)-quinolone). When added exogenously to P. aeruginosa cultures, all HQDs tested significantly reduced the levels of PQS and other alkylquinolone-type secondary metabolites deriving from the biosynthetic pathway, such as the respiratory inhibitor 2-heptyl-4-hydroxyquinoline N-oxide. HQDs from Nocardia farcinica and Streptomyces bingchenggensis, which combine low KM values for PQS with thermal stability and resilience in the presence of P. aeruginosa exoproducts, respectively, attenuated production of the virulence factors pyocyanin and pyoverdine. A delay in mortality was observed when Galleria mellonella larvae were infected with P. aeruginosa suspensions treated with the S. bingchenggensis HQD or with inhibitors of alkylquinolone biosynthesis. Our data indicate that quenching of PQS signaling has potential as an anti-virulence strategy; however, an efficient anti-virulence therapy against P. aeruginosa likely requires a combination of agents addressing multiple targets.
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Affiliation(s)
- Alba Arranz San Martín
- Institute for Molecular Microbiology and Biotechnology, University of Münster, Corrensstraße 3, 48149 Münster, Germany; (A.A.S.M.); (S.C.W.)
| | - Jan Vogel
- Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands; (J.V.); (W.J.Q.)
| | - Sandra C. Wullich
- Institute for Molecular Microbiology and Biotechnology, University of Münster, Corrensstraße 3, 48149 Münster, Germany; (A.A.S.M.); (S.C.W.)
| | - Wim J. Quax
- Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands; (J.V.); (W.J.Q.)
| | - Susanne Fetzner
- Institute for Molecular Microbiology and Biotechnology, University of Münster, Corrensstraße 3, 48149 Münster, Germany; (A.A.S.M.); (S.C.W.)
- Correspondence: ; Tel.: +49-251-83-39824
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104
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Suppression of lipopolysaccharide-induced corneal opacity by hepatocyte growth factor. Sci Rep 2022; 12:494. [PMID: 35017561 PMCID: PMC8752742 DOI: 10.1038/s41598-021-04418-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 12/22/2021] [Indexed: 12/21/2022] Open
Abstract
Keratitis induced by bacterial toxins, including lipopolysaccharide (LPS), is a major cause of corneal opacity and vision loss. Our previous study demonstrates hepatocyte growth factor (HGF) promotes epithelial wound healing following mechanical corneal injury. Here, we investigated whether HGF has the capacity to suppress infectious inflammatory corneal opacity using a new model of LPS-induced keratitis. Keratitis, induced by two intrastromal injections of LPS on day 1 and 4 in C57BL/6 mice, resulted in significant corneal opacity for up to day 10. Following keratitis induction, corneas were topically treated with 0.1% HGF or PBS thrice daily for 5 days. HGF-treated mice showed a significantly smaller area of corneal opacity compared to PBS-treated mice, thus improving corneal transparency. Moreover, HGF treatment resulted in suppression of α-SMA expression, compared to PBS treatment. HGF-treated corneas showed normalized corneal structure and reduced expression of pro-inflammatory cytokine, demonstrating that HGF restores corneal architecture and immune quiescence in corneas with LPS-induced keratitis. These findings offer novel insight into the potential application of HGF-based therapies for the prevention and treatment of infection-induced corneal opacity.
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105
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Khan S, Shaheen H, Mehmood A, Nasar S, Khan T. Ethnobotanical and antibacterial study of Primula plants traditionally used in the indigenous communities of Western Himalaya, Pakistan. Saudi J Biol Sci 2022; 29:3244-3254. [PMID: 35844385 PMCID: PMC9280169 DOI: 10.1016/j.sjbs.2022.01.048] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 01/11/2022] [Accepted: 01/19/2022] [Indexed: 01/03/2023] Open
Abstract
Background The upper belt of Azad Kashmir is a hilly, mountainous, and remote area where the indigenous communities mainly believe in traditional medicines for the treatment of different ailments. This study aimed to conserve scientifically and culturally important medicinal knowledge of Primula species in Azad Kashmir, Western Himalaya, Pakistan. The additional objective was to evaluate the antibacterial activity of these plants against pathogenic bacteria. Methods The ethnomedicinal data of Primula species was explored by conducting structured interviews with 40 informants of the study area, especially asking about the medicinal uses of Primula species. The indigenously used Primula species were further analyzed for their antibacterial activity against both gram-positive and gram-negative bacteria by using disc diffusion assay supplemented with a more robust minimum inhibitory concentration assay. Results Ethnomedicinal data revealed that indigenous communities living in upper regions of Azad Kashmir use 5 Primula species for the treatment of various disorders. The highly cited disease category was ophthalmic disorders. P. denticulata and P. macrophylla were the most cited plant species with higher use reports such as 104 and 93, respectively. One or more extracts of different parts of Primula species showed a noteworthy antibacterial activity against one or more tested bacteria. Conclusion This study provides novel information regarding several categories of traditional uses and antibacterial activity of Primula species in Azad Kashmir, Western Himalaya. The need for novel and more effective drugs derived from natural products is more important than ever, making future studies on herbal remedies both justified and urgently required.
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Affiliation(s)
- Saima Khan
- Department of Botany, University of Azad Jammu And Kashmir (UAJK), Muzaffarabad 13100, Pakistan
| | - Hamayun Shaheen
- Department of Botany, University of Azad Jammu And Kashmir (UAJK), Muzaffarabad 13100, Pakistan
| | - Ansar Mehmood
- Department of Botany, University of Poonch Rawalakot (UPR), Azad Kashmir 12350, Pakistan
- Corresponding author.
| | - Sidra Nasar
- Department of Botany, University of Azad Jammu And Kashmir (UAJK), Muzaffarabad 13100, Pakistan
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Li N, Shen M, Liu J, Zhang L, Wang H, Xu Y, Cheng J. Multiplexed detection of respiratory pathogens with a portable analyzer in a "raw-sample-in and answer-out" manner. MICROSYSTEMS & NANOENGINEERING 2021; 7:94. [PMID: 34840805 PMCID: PMC8608563 DOI: 10.1038/s41378-021-00321-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 09/10/2021] [Accepted: 10/08/2021] [Indexed: 02/05/2023]
Abstract
Coronavirus disease 2019 (COVID-19) has emerged, rapidly spread and caused significant morbidity and mortality worldwide. There is an urgent public health need for rapid, sensitive, specific, and on-site diagnostic tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In this study, a fully integrated and portable analyzer was developed to detect SARS-CoV-2 from swab samples based on solid-phase nucleic acid extraction and reverse transcription loop-mediated isothermal amplification (RT-LAMP). The swab can be directly inserted into a cassette for multiplexed detection of respiratory pathogens without pre-preparation. The overall detection process, including swab rinsing, magnetic bead-based nucleic acid extraction, and 8-plex real-time RT-LAMP, can be automatically performed in the cassette within 80 min. The functionality of the cassette was validated by detecting the presence of a SARS-CoV-2 pseudovirus and three other respiratory pathogens, i.e., Klebsiella pneumoniae, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia. The limit of detection (LoD) for the SARS-CoV-2 pseudovirus was 2.5 copies/μL with both primer sets (N gene and ORF1ab gene), and the three bacterial species were successfully detected with an LoD of 2.5 colony-forming units (CFU)/μL in 800 μL of swab rinse. Thus, the analyzer developed in this study has the potential to rapidly detect SARS-CoV-2 and other respiratory pathogens on site in a “raw-sample-in and answer-out” manner.
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Affiliation(s)
- Nan Li
- State Key Laboratory of Membrane Biology, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, 100084 China
| | - Minjie Shen
- State Key Laboratory of Membrane Biology, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, 100084 China
| | - Jiajia Liu
- State Key Laboratory of Membrane Biology, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, 100084 China
| | - Li Zhang
- State Key Laboratory of Membrane Biology, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, 100084 China
| | - Huili Wang
- State Key Laboratory of Membrane Biology, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, 100084 China
| | - Youchun Xu
- State Key Laboratory of Membrane Biology, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, 100084 China.,National Engineering Research Center for Beijing Biochip Technology, Beijing, 102206 China
| | - Jing Cheng
- State Key Laboratory of Membrane Biology, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, 100084 China.,National Engineering Research Center for Beijing Biochip Technology, Beijing, 102206 China.,Center for Precision Medicine, West China Hospital, Sichuan University, Chengdu, 610041 China
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107
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Acquisition of ionic copper by the bacterial outer membrane protein OprC through a novel binding site. PLoS Biol 2021; 19:e3001446. [PMID: 34762655 PMCID: PMC8610252 DOI: 10.1371/journal.pbio.3001446] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 11/23/2021] [Accepted: 10/18/2021] [Indexed: 11/19/2022] Open
Abstract
Copper, while toxic in excess, is an essential micronutrient in all kingdoms of life due to its essential role in the structure and function of many proteins. Proteins mediating ionic copper import have been characterised in detail for eukaryotes, but much less so for prokaryotes. In particular, it is still unclear whether and how gram-negative bacteria acquire ionic copper. Here, we show that Pseudomonas aeruginosa OprC is an outer membrane, TonB-dependent transporter that is conserved in many Proteobacteria and which mediates acquisition of both reduced and oxidised ionic copper via an unprecedented CxxxM-HxM metal binding site. Crystal structures of wild-type and mutant OprC variants with silver and copper suggest that acquisition of Cu(I) occurs via a surface-exposed “methionine track” leading towards the principal metal binding site. Together with whole-cell copper quantitation and quantitative proteomics in a murine lung infection model, our data identify OprC as an abundant component of bacterial copper biology that may enable copper acquisition under a wide range of conditions. How do Gram-negative bacteria acquire copper? This study shows that the outer membrane protein OprC from Pseudomonas aeruginosa is abundant during infection and mediates highly selective acquisition of both copper redox states via an extracellular "methionine track" and an unprecedented near-irreversible binding site.
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108
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Saqr AA, Aldawsari MF, Khafagy ES, Shaldam MA, Hegazy WAH, Abbas HA. A Novel Use of Allopurinol as A Quorum-Sensing Inhibitor in Pseudomonas aeruginosa. Antibiotics (Basel) 2021; 10:antibiotics10111385. [PMID: 34827323 PMCID: PMC8615079 DOI: 10.3390/antibiotics10111385] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/06/2021] [Accepted: 11/09/2021] [Indexed: 12/16/2022] Open
Abstract
Pseudomonas aeruginosa can cause a variety of healthcare-associated infections by its arsenal of virulence factors. Virulence factor production is largely controlled by the cell-to-cell communication system termed quorum sensing (QS). Targeting QS may be a good approach to inhibit the production of virulence factors and attenuate pathogenicity without exerting selective stress on bacterial growth. This will greatly reduce the emergence of resistant mutants. In this work, we investigated the anti-virulence and anti-QS activities of the FDA-approved drug allopurinol against the P. aeruginosa PAO1 strain. Allopurinol at 200 µg/mL (1/10 MIC) significantly decreased the production of the QS-controlled Chromobacterium violaceum CV026 violet pigment violacein and other P. aeruginosa QS-controlled virulence factors phenotypically. Furthermore, allopurinol reduced the infiltration of P. aeruginosa and leucocytes and diminished the congestion in the liver and kidney tissues of infected mice. In silico study showed that allopurinol could compete with the autoinducers on binding to the receptors LasR and RhlR by hydrogen bonding. On the molecular level, qRT-PCR proved that allopurinol showed a significant downregulating effect on all tested QS-encoding genes that regulate virulence factor production. In summary, allopurinol is a promising QS inhibitor that may be useful in the future treatment of P. aeruginosa infection.
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Affiliation(s)
- Ahmed Al Saqr
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-kharj 11942, Saudi Arabia
| | - Mohammed F Aldawsari
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-kharj 11942, Saudi Arabia
| | - El-Sayed Khafagy
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-kharj 11942, Saudi Arabia
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt
| | - Moataz A Shaldam
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Kafrelsheikh University, Kafr El-Sheikh 33511, Egypt
| | - Wael A H Hegazy
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt
| | - Hisham A Abbas
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt
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Zhu X, Feng C, Zhou L, Li Z, Zhang Y, Pan J. Impacts of Ser/Thr Protein Kinase Stk1 on the Proteome, Twitching Motility, and Competitive Advantage in Pseudomonas aeruginosa. Front Microbiol 2021; 12:738690. [PMID: 34733256 PMCID: PMC8560001 DOI: 10.3389/fmicb.2021.738690] [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: 07/09/2021] [Accepted: 08/20/2021] [Indexed: 11/30/2022] Open
Abstract
Pseudomonas aeruginosa is a ubiquitous gram-negative bacterium in the environment and a leading cause of nosocomial infections worldwide. Therefore, it is listed by the WHO as a human pathogen that urgently needs the development of new antibacterial drugs. Recent findings have demonstrated that eukaryote-type Ser/Thr protein kinases play a vital role in regulating various bacterial physiological processes by catalyzing protein phosphorylation. Stk1 has proven to be a Ser/Thr protein kinase in P. aeruginosa. However, the regulatory roles of Stk1 have not yet been revealed. Thus, we constructed a stk1 knockout mutant (∆stk1) from the P. aeruginosa PAO1 strain and employed a Tandem Mass Tag (TMT) labeling-based quantitative proteomic strategy to characterize proteome-wide changes in response to the stk1 knockout. In total, 620 differentially expressed proteins, among which 288 proteins were upregulated and 332 proteins were downregulated, were identified in ∆stk1 compared with P. aeruginosa PAO1. A detailed bioinformatics analysis of these differentially expressed proteins was performed, including GO annotation, protein domain profile, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, subcellular localization and enrichment analysis. Notably, the downregulation of type IV pilus-related proteins and upregulation of T6SS-H1-related proteins were found in the ∆stk1 strain, and the results were corroborated by quantitative PCR at the mRNA level. Further experiments confirmed that the loss of stk1 weakens bacterial twitching motility and promotes a growth competition advantage, which are, respectively, mediated by type IV pilus-related proteins and T6SS-H1-related proteins. These findings contribute to a better understanding of the physiological role of Stk1, and proteomic data will help further investigations of the roles and mechanisms of Stk1 in P. aeruginosa, although the detailed regulation and mechanism of Stk1 still need to be revealed.
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Affiliation(s)
- Xuan Zhu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
| | - Chao Feng
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
| | - Lantian Zhou
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
| | - Zhenzhen Li
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
| | - Yue Zhang
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
| | - Jianyi Pan
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
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Achouri F, Said MB, Wahab MA, Bousselmi L, Corbel S, Schneider R, Ghrabi A. Effect of photocatalysis (TiO 2/UV A) on the inactivation and inhibition of Pseudomonas aeruginosa virulence factors expression. ENVIRONMENTAL TECHNOLOGY 2021; 42:4237-4246. [PMID: 32241229 DOI: 10.1080/09593330.2020.1751729] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
Water disinfection using visible light-active photocatalyst has recently attracted more attention due to its potential to inactivate microbes. In this study, we have investigated the efficiency of photocatalysis (TiO2/UVA) on the inactivation of Pseudomonas aeruginosa and the attenuation of its virulence factors. For this aim, the photocatalytic effects of TiO2/UVA on the cultivability and viability of P. aeruginosa were investigated. Furthermore, during the photocatalysis, the morphology of the bacterial cells was examined by atomic force microscopy (AFM) while the virulence factors were assessed by protease and lipase activities in addition to the mobility and communication of cells. The results revealed that during the photocatalysis the bacterial cells lost their cultivability and viability on agar under the action of the reactive oxygen species generated by the photocatalytic reaction. In addition, AFM observations have shown a damage of the bacterial membrane and a total disruption of the bacterial cells. Moreover, the major virulence factors such as biofilm, lipase and protease expression have been markedly inhibited by TiO2/UVA treatment. In addition, the bacteria lost their ability of communication 'quorum sensing' and mobility with twitching and swarming types after 60 min of photocatalytic treatment. Accordingly, TiO2/UVA is an effective method to reduce P. aeruginosa virulence and to prevent biofilm formation.
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Affiliation(s)
- Faouzi Achouri
- Laboratoire de Traitement des Eaux Usées, Centre de Recherches et des Technologies des Eaux (CERTE), Soliman, Tunisia
- Laboratoire Réactions et Génie des Procédés (LRGP), UMR7274, CNRS, Université de Lorraine, Nancy Cedex, France
- Faculté des Sciences de Bizerte, Université de Carthage, Bizerte, Tunisia
| | - Myriam Ben Said
- Laboratoire de Traitement des Eaux Usées, Centre de Recherches et des Technologies des Eaux (CERTE), Soliman, Tunisia
| | - Mohamed Ali Wahab
- Centre de Recherches et des Technologies des Eaux (CERTE), Laboratoire de Traitement et Valorisation des Rejets Hydriques, Université de Carthage, Soliman, Tunisia
| | - Latifa Bousselmi
- Laboratoire de Traitement des Eaux Usées, Centre de Recherches et des Technologies des Eaux (CERTE), Soliman, Tunisia
| | - Serge Corbel
- Laboratoire Réactions et Génie des Procédés (LRGP), UMR7274, CNRS, Université de Lorraine, Nancy Cedex, France
| | - Raphaël Schneider
- Laboratoire Réactions et Génie des Procédés (LRGP), UMR7274, CNRS, Université de Lorraine, Nancy Cedex, France
| | - Ahmed Ghrabi
- Laboratoire de Traitement des Eaux Usées, Centre de Recherches et des Technologies des Eaux (CERTE), Soliman, Tunisia
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Alleviation of Pseudomonas aeruginosa Infection by Propeptide-Mediated Inhibition of Protease IV. Microbiol Spectr 2021; 9:e0078221. [PMID: 34704789 PMCID: PMC8549743 DOI: 10.1128/spectrum.00782-21] [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] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa, an opportunistic human pathogen, expresses protease IV (PIV) for infection. Since the PIV activity can be inhibited by its propeptide, we tried to alleviate the severity of P. aeruginosa infection using the purified PIV propeptide (PIVpp). The PIVpp treatment of P. aeruginosa could significantly inhibit the PIV activity and reduce the virulence of P. aeruginosa in multiple invertebrate infection models, such as nematodes, brine shrimp, and mealworms. The effectiveness of PIVpp was further confirmed using mouse skin infection and acute/chronic lung infection models. The amount of PIVpp that inhibited the PIV activity of P. aeruginosa by 65% could alleviate the severity of infection significantly in all of the skin and acute/chronic lung infections. In addition, the PIVpp treatment of P. aeruginosa facilitated the healing of the skin wound infections and repressed the growth of P. aeruginosa in the infected lung. The PIVpp itself did not cause the induction of inflammatory cytokines or have any harmful effects on host tissues and did not affect bacterial growth. Taken together, P. aeruginosa infections can be alleviated by PIVpp treatment. IMPORTANCE Pseudomonas aeruginosa is a highly antibiotic-resistant pathogen and is extremely difficult to treat. Instead of using conventional antibiotics, we attempted to alleviate P. aeruginosa infection using factors that P. aeruginosa itself produces naturally. Extracellular proteases are powerful virulence factors and important targets to control the P. aeruginosa infections. Propeptides are originally expressed as part of extracellular proteases, inhibiting their activity until they go out of the cell, preventing them from becoming toxic to the cells themselves. We confirmed, from multiple animal experiments, that treating P. aeruginosa with the purified propeptide can alleviate its infectivity. Propeptides specifically inhibit only their cognate protease without inhibiting other essential proteases of the host. The development of resistance can be avoided because the propeptide-mediated inhibition is an inherent mechanism of P. aeruginosa; hence, it will be difficult for P. aeruginosa to alter this mechanism. Since propeptides do not affect bacterial growth, there is no selective pressure to develop resistant cells.
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Fluoroquinolone resistance contributing mechanisms and genotypes of ciprofloxacin- unsusceptible Pseudomonas aeruginosa strains in Iran: emergence of isolates carrying qnr/aac(6)-Ib genes. Int Microbiol 2021; 25:405-415. [PMID: 34709520 DOI: 10.1007/s10123-021-00220-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 10/08/2021] [Accepted: 10/20/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Fluoroquinolones (FQs) including ciprofloxacin (CIP) are key antibiotics for the treatment of Pseudomonas aeruginosa infections, but resistance to FQs is developing as a result of chromosomal mutations or efflux pump effects. Plasmid-mediated quinolone resistance (PMQR) has been recently reported in the Enterobacteriaceae family. This study aimed to investigate the mechanisms of CIP insusceptibility in P. aeruginosa isolates from ICU patients and to characterize their genotypes. METHODS A total of 40 ciprofloxacin unsusceptible (CIP-US) P. aeruginosa isolates from Tehran hospitals were recruited in this study. A broth microdilution assay was performed to find acquired resistance profiles of the isolates. All isolates were screened for target-site mutations (gyrA and parC), PMQR genes, and efflux pumps (mexB, D, Y, and E) expression. Clonality was determined by random amplified polymorphic DNA (RAPD)-PCR, and genotyping was performed on 5 selected isolates by analyzing 7 loci in the existing multilocus sequence typing scheme. RESULTS Thirty-eight out of 40 CIP-US isolates (95%) were categorized as MDR. Seven (17.5%) had gyrA mutation in codons 83, and no mutation was detected in parC; 77.5% of the isolates were positive for PMQR genes. Among PMQR genes, qnrB (30%), qnrC (35%), and qnrD (30%) predominated, while qnrA, qnrS, and aac(6)-Ib genes were harbored by 20.5%, 12.5%, and 15% of the isolates respectively. Efflux pump protein expression was observed in 35% of the isolates. After RAPD-PCR, 19 different genotypes were yielded, and 5 of them were classified into sequence types (STs): 773, 1160, 2011, 2386, and 359. CONCLUSION In this first-time study on P. aeruginosa CIP-US strains from Iranian ICU patients, three main CIP unsusceptibility mechanisms were investigated. A single mutation in one CIP target enzyme could explain high CIP resistance. qnr genes in the isolates can be considered as a CIP-unsusceptibility mechanism among studied isolates. Efflux pumps have more contribution in multidrug resistance than CIP susceptibility. CIP-US isolates of this study have not spread from distinct clonal strains and probably emerged from different sources. STs identified for the first time in this study in Iran should be considered as emerging MDR strains.
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Fitzgerald S, Holland L, Morrin A. An Investigation of Stability and Species and Strain-Level Specificity in Bacterial Volatilomes. Front Microbiol 2021; 12:693075. [PMID: 34721314 PMCID: PMC8549763 DOI: 10.3389/fmicb.2021.693075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 09/23/2021] [Indexed: 12/26/2022] Open
Abstract
Microbial volatilomics is a rapidly growing field of study and has shown great potential for applications in food, farming, and clinical sectors in the future. Due to the varying experimental methods and growth conditions employed in microbial volatilomic studies as well as strain-dependent volatilomic differences, there is limited knowledge regarding the stability of microbial volatilomes. Consequently, cross-study comparisons and validation of results and data can be challenging. In this study, we investigated the stability of the volatilomes of multiple strains of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli across three frequently used nutrient-rich growth media. Volatilomic stability was assessed based on media-, time- and strain-dependent variation across the examined bacterial volatilomes. Strain-level specificity of the observed volatilomes of E. coli and P. aeruginosa strains was further investigated by comparing the emission of selected compounds at varying stages of cell growth. Headspace solid phase microextraction (HS-SPME) sampling coupled with gas chromatography mass spectrometry (GC-MS) was used to analyze the volatilome of each strain. The whole volatilomes of the examined strains demonstrate a high degree of stability across the three examined growth media. At the compound-level, media dependent differences were observed particularly when comparing the volatilomes obtained in glucose-containing brain heart infusion (BHI) and tryptone soy broth (TSB) growth media with the volatilomes obtained in glucose-free Lysogeny broth (LB) media. These glucose-dependent volatilomic differences were primarily seen in the emission of primary metabolites such as alcohols, ketones, and acids. Strain-level differences in the emission of specific compounds in E. coli and P. aeruginosa samples were also observed across the media. These strain-level volatilomic differences were also observed across varying phases of growth of each strain, therefore confirming that these strains had varying core and accessory volatilomes. Our results demonstrate that, at the species-level, the examined bacteria have a core volatilome that exhibits a high-degree of stability across frequently-used growth media. Media-dependent differences in microbial volatilomes offer valuable insights into identifying the cellular origin of individual metabolites. The observed differences in the core and accessory volatilomes of the examined strains illustrate the complexity of microbial volatilomics as a study while also highlighting the need for more strain-level investigations to ultimately elucidate the whole volatilomic capabilities of microbial species in the future.
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Affiliation(s)
- Shane Fitzgerald
- School of Chemical Sciences, National Center for Sensor Research, SFI Insight Centre for Data Analytics, Dublin City University, Dublin, Ireland
| | - Linda Holland
- School of Biotechnology, Dublin City University, Dublin, Ireland
| | - Aoife Morrin
- School of Chemical Sciences, National Center for Sensor Research, SFI Insight Centre for Data Analytics, Dublin City University, Dublin, Ireland
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Moussaoui O, Byadi S, Eddine Hachim M, Sghyar R, Bahsis L, Moslova K, Aboulmouhajir A, Rodi YK, Podlipnik Č, Hadrami EMEL, Chakroune S. Selective synthesis of novel quinolones-amino esters as potential antibacterial and antifungal agents: Experimental, mechanistic study, docking and molecular dynamic simulations. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2021.130652] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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115
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Zhang X, Xia S, Ye Y, Wang H. Opportunistic pathogens exhibit distinct growth dynamics in rainwater and tap water storage systems. WATER RESEARCH 2021; 204:117581. [PMID: 34461496 DOI: 10.1016/j.watres.2021.117581] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 07/09/2021] [Accepted: 08/16/2021] [Indexed: 06/13/2023]
Abstract
Opportunistic pathogens (OPs) are emerging microbial contaminants in engineered water systems, yet their growth potential in rainwater systems has not been evaluated. The purpose of this study was to compare the growth dynamics of bacterial OPs and related genera (Pseudomonas aeruginosa, Legionella spp., L. pneumophila, Mycobacterium spp., and M. avium), two amoebal hosts (Acanthamoeba spp. and Vermamoeba vermiformis), and the fecal indicator Escherichia coli in simulated rainwater and tap water storage systems (SWSSs). Quantitative polymerase chain reaction (q-PCR) analysis of target microorganisms in SWSS influents and effluents demonstrated that P. aeruginosa and Legionella thrived in rainwater, but not in tap water. V. vermiformis proliferated in both rainwater and tap water polyvinyl chloride (PVC) SWSSs, while mycobacteria were largely absent in rainwater SWSSs. Tank materials exerted stronger influence on target microorganisms in rainwater SWSSs relative to tap water SWSSs, with species-specific responses noted in bulk water and biofilm. For instance, P. aeruginosa and V. vermiformis had the highest gene copy numbers in PVC rainwater SWSS effluents and biofilm, while Legionella peaked in stainless steel rainwater SWSS effluents and PVC rainwater SWSS biofilm. These results highlighted the OP contamination risks in rainwater storage systems and provided insights into rainwater system design and operation in terms of OP control.
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Affiliation(s)
- Xiaodong Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Chengtou Water Group Corporation, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Siqing Xia
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
| | - Yinyin Ye
- Department of Civil, Structural and Environmental Engineering, University at Buffalo, Buffalo, New York 14260, USA
| | - Hong Wang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
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Falchi FA, Borlotti G, Ferretti F, Pellegrino G, Raneri M, Schiavoni M, Caselli A, Briani F. Sanguinarine Inhibits the 2-Ketogluconate Pathway of Glucose Utilization in Pseudomonas aeruginosa. Front Microbiol 2021; 12:744458. [PMID: 34566945 PMCID: PMC8461315 DOI: 10.3389/fmicb.2021.744458] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 08/12/2021] [Indexed: 01/13/2023] Open
Abstract
Interfering with the ability of pathogenic bacteria to import glucose may represent a new promising antibacterial strategy, especially for the treatment of infections occurring in diabetic and other hyperglycemic patients. Such patients are particularly susceptible to infections caused by a variety of bacteria, among which opportunistic pathogens like Pseudomonas aeruginosa. In P. aeruginosa, glucose can be directly imported into the cytoplasm or after its periplasmic oxidation into gluconate and 2-ketogluconate (2-KG). We recently demonstrated that a P. aeruginosa mutant lacking the 2-KG transporter KguT is less virulent than its kguT+ parental strain in an insect infection model, pointing to 2-KG branch of glucose utilization as a possible target for anti-Pseudomonas drugs. In this work, we devised an experimental protocol to find specific inhibitors of the 2-KG pathway of P. aeruginosa glucose utilization and applied it to the screening of the Prestwick Chemical Library. By exploiting mutants lacking genes involved in the transport of glucose derivatives in the primary screening and in the secondary assays, we could identify sanguinarine as an inhibitor of 2-KG utilization. We also demonstrated that sanguinarine does not prevent 2-KG formation by gluconate oxidation or its transport, suggesting that either KguD or KguK is the target of sanguinarine in P. Aeruginosa.
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Affiliation(s)
- Federica A Falchi
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Giorgia Borlotti
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | | | | | - Matteo Raneri
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Marco Schiavoni
- Dipartimento di Chimica, Università degli Studi di Milano, Milan, Italy
| | | | - Federica Briani
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
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Fraser-Pitt DJ, Dolan SK, Toledo-Aparicio D, Hunt JG, Smith DW, Lacy-Roberts N, Nupe Hewage PS, Stoyanova TN, Manson E, McClean K, Inglis NF, Mercer DK, O’Neil DA. Cysteamine Inhibits Glycine Utilisation and Disrupts Virulence in Pseudomonas aeruginosa. Front Cell Infect Microbiol 2021; 11:718213. [PMID: 34631600 PMCID: PMC8494450 DOI: 10.3389/fcimb.2021.718213] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/11/2021] [Indexed: 11/13/2022] Open
Abstract
Pseudomonas aeruginosa is a major opportunistic human pathogen which employs a myriad of virulence factors. In people with cystic fibrosis (CF) P. aeruginosa frequently colonises the lungs and becomes a chronic infection that evolves to become less virulent over time, but often adapts to favour persistence in the host with alginate-producing mucoid, slow-growing, and antibiotic resistant phenotypes emerging. Cysteamine is an endogenous aminothiol which has been shown to prevent biofilm formation, reduce phenazine production, and potentiate antibiotic activity against P. aeruginosa, and has been investigated in clinical trials as an adjunct therapy for pulmonary exacerbations of CF. Here we demonstrate (for the first time in a prokaryote) that cysteamine prevents glycine utilisation by P. aeruginosa in common with previously reported activity blocking the glycine cleavage system in human cells. Despite the clear inhibition of glycine metabolism, cysteamine also inhibits hydrogen cyanide (HCN) production by P. aeruginosa, suggesting a direct interference in the regulation of virulence factor synthesis. Cysteamine impaired chemotaxis, lowered pyocyanin, pyoverdine and exopolysaccharide production, and reduced the toxicity of P. aeruginosa secreted factors in a Galleria mellonella infection model. Thus, cysteamine has additional potent anti-virulence properties targeting P. aeruginosa, further supporting its therapeutic potential in CF and other infections.
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Affiliation(s)
| | - Stephen K. Dolan
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | | | | | | | | | - Piumi Sara Nupe Hewage
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, United Kingdom
| | - Teodora N. Stoyanova
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, United Kingdom
| | - Erin Manson
- College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Kevin McClean
- Proteomics Facility Services, Moredun Research Institute, Penicuik, United Kingdom
| | - Neil F. Inglis
- Proteomics Facility Services, Moredun Research Institute, Penicuik, United Kingdom
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Inhibitory Effects of Artificial Sweeteners on Bacterial Quorum Sensing. Int J Mol Sci 2021; 22:ijms22189863. [PMID: 34576027 PMCID: PMC8472786 DOI: 10.3390/ijms22189863] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 09/09/2021] [Accepted: 09/10/2021] [Indexed: 12/19/2022] Open
Abstract
Despite having been tagged as safe and beneficial, recent evidence remains inconclusive regarding the status of artificial sweeteners and their putative effects on gut microbiota. Gut microorganisms are essential for the normal metabolic functions of their host. These microorganisms communicate within their community and regulate group behaviors via a molecular system termed quorum sensing (QS). In the present study, we aimed to study the effects of artificial sweeteners on this bacterial communication system. Using biosensor assays, biophysical protein characterization methods, microscale thermophoresis, swarming motility assays, growth assays, as well as molecular docking, we show that aspartame, sucralose, and saccharin have significant inhibitory actions on the Gram-negative bacteria N-acyl homoserine lactone-based (AHL) communication system. Our studies indicate that these three artificial sweeteners are not bactericidal. Protein-ligand docking and interaction profiling, using LasR as a representative participating receptor for AHL, suggest that the artificial sweeteners bind to the ligand-binding pocket of the protein, possibly interfering with the proper housing of the native ligand and thus impeding protein folding. Our findings suggest that these artificial sweeteners may affect the balance of the gut microbial community via QS-inhibition. We, therefore, infer an effect of these artificial sweeteners on numerous molecular events that are at the core of intestinal microbial function, and by extension on the host metabolism.
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119
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Petitjean M, Juarez P, Meunier A, Daguindau E, Puja H, Bertrand X, Valot B, Hocquet D. The rise and the fall of a Pseudomonas aeruginosa endemic lineage in a hospital. Microb Genom 2021; 7. [PMID: 34473016 PMCID: PMC8715434 DOI: 10.1099/mgen.0.000629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The biological features that allow a pathogen to survive in the hospital environment are mostly unknown. The extinction of bacterial epidemics in hospitals is mostly attributed to changes in medical practice, including infection control, but the role of bacterial adaptation has never been documented. We analysed a collection of Pseudomonas aeruginosa isolates belonging to the Besançon Epidemic Strain (BES), responsible for a 12year nosocomial outbreak, using a genotype-to-phenotype approach. Bayesian analysis estimated the emergence of the clone in the hospital 5 years before its opening, during the creation of its water distribution network made of copper. BES survived better than the reference strains PAO1 and PA14 in a copper solution due to a genomic island containing 13 metal-resistance genes and was specifically able to proliferate in the ubiquitous amoeba Vermamoeba vermiformis. Mutations affecting amino-acid metabolism, antibiotic resistance, lipopolysaccharide biosynthesis, and regulation were enriched during the spread of BES. Seven distinct regulatory mutations attenuated the overexpression of the genes encoding the efflux pump MexAB-OprM over time. The fitness of BES decreased over time in correlation with its genome size. Overall, the resistance to inhibitors and predators presumably aided the proliferation and propagation of BES in the plumbing system of the hospital. The pathogen further spread among patients via multiple routes of contamination. The decreased prevalence of patients infected by BES mirrored the parallel and convergent genomic evolution and reduction that affected bacterial fitness. Along with infection control measures, this may have participated in the extinction of BES in the hospital setting.
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Affiliation(s)
- Marie Petitjean
- Hygiène Hospitalière, Centre Hospitalier Universitaire, 25030 Besançon, France.,UMR CNRS 6249, Université de Bourgogne Franche-Comté, 25030 Besançon, France
| | - Paulo Juarez
- UMR CNRS 6249, Université de Bourgogne Franche-Comté, 25030 Besançon, France
| | - Alexandre Meunier
- Hygiène Hospitalière, Centre Hospitalier Universitaire, 25030 Besançon, France
| | - Etienne Daguindau
- UMR INSERM 1098, Université de Bourgogne Franche-Comté, 25030 Besançon, France
| | - Hélène Puja
- UMR CNRS 6249, Université de Bourgogne Franche-Comté, 25030 Besançon, France
| | - Xavier Bertrand
- Hygiène Hospitalière, Centre Hospitalier Universitaire, 25030 Besançon, France.,UMR CNRS 6249, Université de Bourgogne Franche-Comté, 25030 Besançon, France
| | - Benoit Valot
- UMR CNRS 6249, Université de Bourgogne Franche-Comté, 25030 Besançon, France.,Bioinformatique et Big Data au Service de la Santé, UFR Science de la Santé, Université de Bourgogne Franche-Comté, 25030 Besançon, France
| | - Didier Hocquet
- Hygiène Hospitalière, Centre Hospitalier Universitaire, 25030 Besançon, France.,UMR CNRS 6249, Université de Bourgogne Franche-Comté, 25030 Besançon, France.,Bioinformatique et Big Data au Service de la Santé, UFR Science de la Santé, Université de Bourgogne Franche-Comté, 25030 Besançon, France.,Centre de Ressources Biologiques - Filière Microbiologique de Besançon, Centre Hospitalier Universitaire, 25030 Besançon, France
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120
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Cation complexation by mucoid Pseudomonas aeruginosa extracellular polysaccharide. PLoS One 2021; 16:e0257026. [PMID: 34473773 PMCID: PMC8412252 DOI: 10.1371/journal.pone.0257026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 08/23/2021] [Indexed: 11/25/2022] Open
Abstract
Mucoid Pseudomonas aeruginosa is a prevalent cystic fibrosis (CF) lung colonizer, producing an extracellular matrix (ECM) composed predominantly of the extracellular polysaccharide (EPS) alginate. The ECM limits antimicrobial penetration and, consequently, CF sufferers are prone to chronic mucoid P. aeruginosa lung infections. Interactions between cations with elevated concentrations in the CF lung and the anionic EPS, enhance the structural rigidity of the biofilm and exacerbates virulence. In this work, two large mucoid P. aeruginosa EPS models, based on β-D-mannuronate (M) and β-D-mannuronate-α-L-guluronate systems (M-G), and encompassing thermodynamically stable acetylation configurations–a structural motif unique to mucoid P. aeruginosa–were created. Using highly accurate first principles calculations, stable coordination environments adopted by the cations have been identified and thermodynamic stability quantified. These models show the weak cross-linking capability of Na+ and Mg2+ ions relative to Ca2+ ions and indicate a preference for cation binding within M-G blocks due to the smaller torsional rearrangements needed to reveal stable binding sites. The geometry of the chelation site influences the stability of the resulting complexes more than electrostatic interactions, and the results show nuanced chemical insight into previous experimental observations.
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121
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Karash S, Nordell R, Ozer EA, Yahr TL. Genome Sequences of Two Pseudomonas aeruginosa Isolates with Defects in Type III Secretion System Gene Expression from a Chronic Ankle Wound Infection. Microbiol Spectr 2021; 9:e0034021. [PMID: 34259549 PMCID: PMC8552725 DOI: 10.1128/spectrum.00340-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 06/23/2021] [Indexed: 11/20/2022] Open
Abstract
Effector proteins translocated into host cells by the Pseudomonas aeruginosa type III secretion system (T3SS) are critical for phagocytic avoidance and systemic spread of the microorganism. The T3SS genes are present in virtually all P. aeruginosa strains. When examined in environmental isolates and clinical specimens, expression of the T3SS genes is the rule. Isolates from the airways of cystic fibrosis (CF) patients are one exception, and these isolates usually carry mutations that disable T3SS gene expression. In this study, we describe two P. aeruginosa isolates, one pigmented brown and one green, from a keratitis-ichthyosis-deafness (KID) syndrome patient with a chronic cutaneous ankle wound. Similar to most isolates from CF, both of the KID isolates were defective for T3SS gene expression. Providing the primary activator of T3SS transcription (exsA) in trans restored T3SS function. Since the exsA sequences were identical to that of a reference strain with active T3SS gene expression, we examined the cAMP-Vfr system, a critical regulator of T3SS gene expression. Vfr is a cAMP-dependent transcription factor that activates exsA expression. Whereas T3SS activity was corrected in the brown isolate by restoring cAMP synthesis, the same was not observed for the green isolate. These findings suggest that distinct mechanisms resulted in loss of T3SS gene expression in the KID isolates. The mutations responsible for the T3SS defects were not clearly evident by comparison of the whole-genome sequences to a reference strain. Our findings suggest that loss of T3SS gene expression may be a trait common to both CF and non-CF chronic infections. IMPORTANCE A common feature of microorganisms that cause chronic infections is a stealthy lifestyle that promotes immune avoidance and host tolerance. During chronic colonization of cystic fibrosis (CF) patients, Pseudomonas aeruginosa acquires numerous adaptations that include reduced expression of some factors, such as motility, O antigen, and the T3SS, and increased expression of other traits, such as biofilm formation. In this study, we report loss of T3SS gene expression in non-CF chronic isolates. This finding suggests that loss of the T3SS may be a common and important trait that contributes to persistence and may open avenues to explore the significance further using non-CF chronic infection models.
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Affiliation(s)
- Sardar Karash
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, USA
| | - Robert Nordell
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, USA
| | - Egon A. Ozer
- Department of Medicine, Northwestern Fienberg School of Medicine, Chicago, Illinois, USA
| | - Timothy L. Yahr
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, USA
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Sartorio MG, Pardue EJ, Feldman MF, Haurat MF. Bacterial Outer Membrane Vesicles: From Discovery to Applications. Annu Rev Microbiol 2021; 75:609-630. [PMID: 34351789 DOI: 10.1146/annurev-micro-052821-031444] [Citation(s) in RCA: 127] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Secretion of cellular components across the plasma membrane is an essential process that enables organisms to interact with their environments. Production of extracellular vesicles in bacteria is a well-documented but poorly understood process. Outer membrane vesicles (OMVs) are produced in gram-negative bacteria by blebbing of the outer membrane. In addition to their roles in pathogenesis, cell-to-cell communication, and stress responses, OMVs play important roles in immunomodulation and the establishment and balance of the gut microbiota. In this review, we discuss the multiple roles of OMVs and the current knowledge of OMV biogenesis. We also discuss the growing and promising biotechnological applications of OMV. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Mariana G Sartorio
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA;
| | - Evan J Pardue
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA;
| | - Mario F Feldman
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA;
| | - M Florencia Haurat
- Laboratory of Bacterial Polysaccharides, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, USA;
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Prevalence of antibiotic-resistant bacterial strains in wastewater streams: molecular characterization and relative abundance. Folia Microbiol (Praha) 2021; 66:1023-1037. [PMID: 34339002 DOI: 10.1007/s12223-021-00902-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 07/19/2021] [Indexed: 10/20/2022]
Abstract
Bacteria from wastewater discharged to the sewerage near three hospitals of Islamabad, Rawalpindi, and Faisalabad were examined for resistance to the most commonly prescribed antibiotics in Pakistan. From the selected sites, a total of 109 isolates from 40 different species were identified based on 16S rRNA gene sequence and phylogeny. The isolates were tested for their resistance to ciprofloxacin, levofloxacin, ofloxacin, amoxicillin, and ampicillin. The results indicated that the isolates were resistant with the highest percentage to ampicillin and the lowest percentage to ciprofloxacin. Among the resistant isolates, 91.7% were found resistant to ampicillin, 83.5% to amoxicillin, 67.0% to ofloxacin, whereas only 27.5% to ciprofloxacin and 21.1% to levofloxacin. Among three sampled locations, the most of resistance was observed in Escherichia and Acinetobacter species. More than 30% isolated microorganisms were found resistant to more than three antibiotics. These findings concluded the presence of predominant microbial population resistant to antibiotics in wastewater channels near hospitals and its surroundings, which requires further investigation regarding their existence and spread in other environmental media having potential community health implications.
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124
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OsaR (PA0056) functions as a repressor of the gene fleQ encoding an important motility regulator in Pseudomonas aeruginosa. J Bacteriol 2021; 203:e0014521. [PMID: 34339300 DOI: 10.1128/jb.00145-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
FleQ plays a crucial role in motility and biofilm formation by regulating flagellar and exopolysaccharide biosynthesis in Pseudomonas aeruginosa. It has been reported that the expression of FleQ is transcriptionally downregulated by the virulence factor regulator Vfr. Herein we demonstrated that a LysR-type transcriptional regulator, OsaR, is also capable of binding to the promoter region of fleQ and repressing its transcription. Through gel shift and DNase I footprinting assays, the OsaR binding site was identified and characterized as a dual LysR-type transcriptional regulator box (AT-N11-AT-N7-A-N11-T). Mutation of the A-T palindromic base pairs in fleQ promoter not only reduced the binding affinity of OsaR in vitro, but also de-repressed fleQ transcription in vivo. The OsaR binding site was found to cover the Vfr binding site; knockout of osaR or vfr separately exhibited no effect on the transcriptional level of fleQ; however, fleQ expression was repressed by overexpression of osaR or vfr. Furthermore, simultaneously deleting both osaR and vfr resulted in an upregulation of fleQ, but it could be complemented by the expression of either of the two repressors. In summary, our work revealed that OsaR and Vfr function as two transcriptional repressors of fleQ that bind to the same region of fleQ but work separately. IMPORTANCE Pseudomonas aeruginosa is a widespread human pathogen, which accounts for serious infections in the hospital, especially for lung infection in cystic fibrosis and chronic obstructive pulmonary disease patients. P. aeruginosa infection is closely associated with its motility and biofilm formation, which are both under the regulation of the important transcription factor FleQ. However, the upstream regulatory mechanisms of fleQ have not been fully elucidated. Therefore, our research identifying a novel regulator of fleQ as well as new regulatory mechanisms controlling its expression will be significant for better understanding the intricate gene regulatory mechanisms related to P. aeruginosa virulence and infection.
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Torres MR, Slate AJ, Ryder SF, Akram M, Iruzubieta CJC, Whitehead KA. Ionic gold demonstrates antimicrobial activity against Pseudomonas aeruginosa strains due to cellular ultrastructure damage. Arch Microbiol 2021; 203:3015-3024. [PMID: 33782717 PMCID: PMC8289768 DOI: 10.1007/s00203-021-02270-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 02/23/2021] [Accepted: 03/03/2021] [Indexed: 12/24/2022]
Abstract
Due to the ever-increasing rise of antimicrobial resistant (AMR) bacteria, the development of alternative antimicrobial agents is a global priority. The antimicrobial activity of ionic gold was explored against four Pseudomonas aeruginosa strains with different AMR profiles in order to determine the antimicrobial activity of ionic gold and elucidate the mechanisms of action. Disc diffusion assays (zone of inhibition: ZoI) coupled with minimum inhibitory/bactericidal concentrations (MIC/MBC) were conducted to determine the antimicrobial efficacy of ionic gold. Scanning electron microscopy (SEM) was used to visualise morphological changes to the bacterial cell ultrastructure. Strains with increased AMR were slower to grow which is likely a fitness cost due to the enhanced AMR activity. Although greater concentrations of ionic gold were required to promote antimicrobial activity, ionic gold demonstrated similar antimicrobial values against all strains tested. Lowry assay results indicated that protein leakage was apparent following incubation with ionic gold, whilst SEM revealed cellular ultrastructure damage. This study suggests that the application of ionic gold as an alternative antimicrobial is promising, particularly against AMR P. aeruginosa. The antimicrobial activity of ionic gold against P. aeruginosa could potentially be utilised as an alternative therapeutic option in wound management, an approach that could benefit healthcare systems worldwide.
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Affiliation(s)
- Miguel Reyes Torres
- Microbiology at Interfaces, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK
| | - Anthony J Slate
- Microbiology at Interfaces, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK.
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
| | - Steven F Ryder
- Microbiology at Interfaces, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK
| | - Maliha Akram
- Microbiology at Interfaces, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK
| | - Conrado Javier Carrascosa Iruzubieta
- Department of Animal Pathology, Animal Production, and Food Science and Technology, Universidad de Las Palmas de Gran Canarias, Gran Canarias, 35413, Arucas, Spain
| | - Kathryn A Whitehead
- Microbiology at Interfaces, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK.
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Muraca GS, Soler-Arango J, Castro GR, Islan GA, Brelles-Mariño G. Improving ciprofloxacin antimicrobial activity through lipid nanoencapsulation or non-thermal plasma on Pseudomonas aeruginosa biofilms. J Drug Deliv Sci Technol 2021. [DOI: 10.1016/j.jddst.2021.102644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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127
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Ung L, Chodosh J. Foundational concepts in the biology of bacterial keratitis. Exp Eye Res 2021; 209:108647. [PMID: 34097906 PMCID: PMC8595513 DOI: 10.1016/j.exer.2021.108647] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/28/2021] [Accepted: 05/27/2021] [Indexed: 12/12/2022]
Abstract
Bacterial infections of the cornea, or bacterial keratitis (BK), are notorious for causing rapidly fulminant disease and permanent vision loss, even among treated patients. In the last sixty years, dramatic upward trajectories in the frequency of BK have been observed internationally, driven in large part by the commercialization of hydrogel contact lenses in the late 1960s. Despite this worsening burden of disease, current evidence-based therapies for BK - including broad-spectrum topical antibiotics and, if indicated, topical corticosteroids - fail to salvage vision in a substantial proportion of affected patients. Amid growing concerns of rapidly diminishing antibiotic utility, there has been renewed interest in urgently needed novel treatments that may improve clinical outcomes on an individual and public health level. Bridging the translational gap in the care of BK requires the identification of new therapeutic targets and rational treatment design, but neither of these aims can be achieved without understanding the complex biological processes that determine how bacterial corneal infections arise, progress, and resolve. In this chapter, we synthesize the current wealth of human and animal experimental data that now inform our understanding of basic BK pathophysiology, in context with modern concepts in ocular immunology and microbiology. By identifying the key molecular determinants of clinical disease, we explore how novel treatments can be developed and translated into routine patient care.
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Affiliation(s)
- Lawson Ung
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Infectious Disease Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - James Chodosh
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Infectious Disease Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA.
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Moreira NFF, Ribeirinho-Soares S, Viana AT, Graça CAL, Ribeiro ARL, Castelhano N, Egas C, Pereira MFR, Silva AMT, Nunes OC. Rethinking water treatment targets: Bacteria regrowth under unprovable conditions. WATER RESEARCH 2021; 201:117374. [PMID: 34214892 DOI: 10.1016/j.watres.2021.117374] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 06/08/2021] [Accepted: 06/13/2021] [Indexed: 06/13/2023]
Abstract
Ozonation is among the currently used technologies to remove chemical and biological contaminants from secondary treated urban wastewater (UWW). Despite its effectiveness on the abatement of organic micropollutants (OMPs) and disinfection, previous studies have shown that regrow of bacteria may occur upon storage of the ozonated UWW. This reactivation has been attributed to the high content of assimilable organic carbon after treatment. In order to investigate if ozonation by-products are the main biological regrowth drivers in stored ozonated UWW, the ozonation surviving cells were resuspended in sterile bottled mineral water (MW), simulating a pristine oligotrophic environment. After 7 days storage, organisms such as Acinetobacter, Methylobacterium, Cupriavidus, Massilia, Acidovorax and Pseudomonas were dominant in both ozonated UWW and pristine MW, demonstrating that bacterial regrowth is not strictly related to the eventual presence of ozonation by-products, but instead with the ability of the surviving cells to cope with nutrient-poor environments. The resistome of UWW before and after ozonation was analysed by metagenomic techniques. Draft metagenome assembled genomes (dMAGs), recovered from both ozonated UWW and after cell resuspension in MW, harboured genes conferring resistance to diverse antibiotics classes. Some of these antibiotic resistance genes (ARGs) were located in the vicinity of mobile genetic elements, suggesting their potential to be mobilized. Among these, dMAGs affiliated to taxa with high relative abundance in stored water, such as P. aeruginosa and Acinetobacter spp., harboured ARGs conferring resistance to 12 and 4 families of antibiotics, respectively, including those encoding carbapenem hydrolysing oxacillinases. The results herein obtained point out that the design and development of new wastewater treatment technologies should include measures to attenuate the imbalance of the bacterial communities promoted by storage of the final treated wastewater, even when applying processes with high mineralization rates.
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Affiliation(s)
- Nuno F F Moreira
- LSRE-LCM - Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Sara Ribeirinho-Soares
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Ana Teresa Viana
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Cátia A L Graça
- LSRE-LCM - Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Ana Rita L Ribeiro
- LSRE-LCM - Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Nadine Castelhano
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Conceição Egas
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; Next Generation Sequencing Unit, Biocant, BiocantPark, Núcleo 04, Lote 8, 3060-197 Cantanhede, Portugal
| | - M Fernando R Pereira
- LSRE-LCM - Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Adrián M T Silva
- LSRE-LCM - Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Olga C Nunes
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
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Hausmann S, Gonzalez D, Geiser J, Valentini M. The DEAD-box RNA helicase RhlE2 is a global regulator of Pseudomonas aeruginosa lifestyle and pathogenesis. Nucleic Acids Res 2021; 49:6925-6940. [PMID: 34151378 PMCID: PMC8266600 DOI: 10.1093/nar/gkab503] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 05/24/2021] [Accepted: 06/01/2021] [Indexed: 12/13/2022] Open
Abstract
RNA helicases perform essential housekeeping and regulatory functions in all domains of life by binding and unwinding RNA molecules. The bacterial RhlE-like DEAD-box RNA helicases are among the least well studied of these enzymes. They are widespread especially among Proteobacteria, whose genomes often encode multiple homologs. The significance of the expansion and diversification of RhlE-like proteins for bacterial fitness has not yet been established. Here, we study the two RhlE homologs present in the opportunistic pathogen Pseudomonas aeruginosa. We show that, in the course of evolution, RhlE1 and RhlE2 have diverged in their biological functions, molecular partners and RNA-dependent enzymatic activities. Whereas RhlE1 is mainly needed for growth in the cold, RhlE2 also acts as global post-transcriptional regulator, affecting the level of hundreds of cellular transcripts indispensable for both environmental adaptation and virulence. The global impact of RhlE2 is mediated by its unique C-terminal extension, which supports the RNA unwinding activity of the N-terminal domain as well as an RNA-dependent interaction with the RNase E endonuclease and the cellular RNA degradation machinery. Overall, our work reveals how the functional and molecular divergence between two homologous RNA helicases can contribute to bacterial fitness and pathogenesis.
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Affiliation(s)
- Stéphane Hausmann
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Diego Gonzalez
- Laboratory of Microbiology, Institute of Biology, Faculty of Sciences, University of Neuchâtel, Neuchâtel, Switzerland
| | - Johan Geiser
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Martina Valentini
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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130
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Structure-Activity Relationships of the Imidazolium Compounds as Antibacterials of Staphylococcus aureus and Pseudomonas aeruginosa. Int J Mol Sci 2021; 22:ijms22157997. [PMID: 34360764 PMCID: PMC8347611 DOI: 10.3390/ijms22157997] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/09/2021] [Accepted: 07/14/2021] [Indexed: 11/16/2022] Open
Abstract
This paper presents the results of structure-activity relationship (SAR) studies of 140 3,3'-(α,ω-dioxaalkan)bis(1-alkylimidazolium) chlorides. In the SAR analysis, the dominance-based rough set approach (DRSA) was used. For analyzed compounds, minimum inhibitory concentration (MIC) against strains of Staphylococcus aureus and Pseudomonas aeruginosa was determined. In order to perform the SAR analysis, a tabular information system was formed, in which tested compounds were described by means of condition attributes, characterizing the structure (substructure parameters and molecular descriptors) and their surface properties, and a decision attribute, classifying compounds with respect to values of MIC. DRSA allows to induce decision rules from data describing the compounds in terms of condition and decision attributes, and to rank condition attributes with respect to relevance using a Bayesian confirmation measure. Decision rules present the most important relationships between structure and surface properties of the compounds on one hand, and their antibacterial activity on the other hand. They also indicate directions of synthesizing more efficient antibacterial compounds. Moreover, the analysis showed differences in the application of various parameters for Gram-positive and Gram-negative strains, respectively.
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131
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Del Mar Cendra M, Torrents E. Differential adaptability between reference strains and clinical isolates of Pseudomonas aeruginosa into the lung epithelium intracellular lifestyle. Virulence 2021; 11:862-876. [PMID: 32697923 PMCID: PMC7549915 DOI: 10.1080/21505594.2020.1787034] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Intracellular invasion is an advantageous mechanism used by pathogens to evade host defense and antimicrobial therapy. In patients, the intracellular microbial lifestyle can lead to infection persistence and recurrence, thus worsening outcomes. Lung infections caused by Pseudomonas aeruginosa, especially in cystic fibrosis (CF) patients, are often aggravated by intracellular invasion and persistence of the pathogen. Proliferation of the infectious species relies on a continuous deoxyribonucleotide (dNTP) supply, for which the ribonucleotide reductase enzyme (RNR) is the unique provider. The large genome plasticity of P. aeruginosa and its ability to rapidly adapt to different environments are challenges for studying the pathophysiology associated with this type of infection. Using different reference strains and clinical isolates of P. aeruginosa independently combined with alveolar (A549) and bronchial (16HBE14o- and CF-CFBE41o-) epithelial cells, we analyzed host-pathogen interactions and intracellular bacterial persistence with the aim of determining a cell type-directed infection promoted by the P. aeruginosa strains. The oscillations in cellular toxicity and oxygen consumption promoted by the intracellular persistence of the strains were also analyzed among the different infectious lung models. Significantly, we identified class II RNR as the enzyme that supplies dNTPs to intracellular P. aeruginosa. This discovery could contribute to the development of RNR-targeted strategies against the chronicity occurring in this type of lung infection. Overall our study demonstrates that the choice of bacterial strain is critical to properly study the type of infectious process with relevant translational outcomes.
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Affiliation(s)
- Maria Del Mar Cendra
- Bacterial Infections and Antimicrobial Therapies Group, Institute for Bioengineering of Catalonia (IBEC), the Barcelona Institute of Science and Technology , Barcelona, Spain
| | - Eduard Torrents
- Bacterial Infections and Antimicrobial Therapies Group, Institute for Bioengineering of Catalonia (IBEC), the Barcelona Institute of Science and Technology , Barcelona, Spain.,Microbiology Section, Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona , Barcelona, Spain
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132
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Brassard J, Roy J, Lemay AM, Beaulieu MJ, Bernatchez E, Veillette M, Duchaine C, Blanchet MR. Exposure to the Gram-Negative Bacteria Pseudomonas aeruginosa Influences the Lung Dendritic Cell Population Signature by Interfering With CD103 Expression. Front Cell Infect Microbiol 2021; 11:617481. [PMID: 34295830 PMCID: PMC8291145 DOI: 10.3389/fcimb.2021.617481] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 06/15/2021] [Indexed: 11/25/2022] Open
Abstract
Lung dendritic cells (DCs) are divided into two major populations, which include CD103+XCR1+ cDC1s and CD11b+Sirpα+ cDC2s. The maintenance of their relative proportions is dynamic and lung inflammation, such as caused by exposure to lipopolysaccharide (LPS), a component of the outer membrane of Gram-negative bacteria, can have a significant impact on the local cDC signature. Alterations in the lung cDC signature could modify the capacity of the immune system to respond to various pathogens. We consequently aimed to assess the impact of the Gram-negative bacteria Pseudomonas aeruginosa on lung cDC1 and cDC2 populations, and to identify the mechanisms leading to alterations in cDC populations. We observed that exposure to P. aeruginosa decreased the proportions of CD103+XCR1+ cDC1s, while increasing that of CD11b+ DCs. We identified two potential mechanisms involved in this modulation of lung cDC populations. First, we observed an increase in bone marrow pre-DC IRF4 expression suggesting a higher propensity of pre-DCs to differentiate towards the cDC2 lineage. This observation was combined with a reduced capacity of lung XCR1+ DC1s to express CD103. In vitro, we demonstrated that GM-CSF-induced CD103 expression on cDCs depends on GM-CSF receptor internalization and RUNX1 activity. Furthermore, we observed that cDCs stimulation with LPS or P. aeruginosa reduced the proportions of intracellular GM-CSF receptor and decreased RUNX1 mRNA expression. Altogether, these results suggest that alterations in GM-CSF receptor intracellular localization and RUNX1 signaling could be involved in the reduced CD103 expression on cDC1 in response to P. aeruginosa. To verify whether the capacity of cDCs to express CD103 following P. aeruginosa exposure impacts the immune response, WT and Cd103-/- mice were exposed to P. aeruginosa. Lack of CD103 expression led to an increase in the number of neutrophils in the airways, suggesting that lack of CD103 expression on cDC1s could favor the innate immune response to this bacterium.
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Affiliation(s)
- Julyanne Brassard
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, QC, Canada
| | - Joanny Roy
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, QC, Canada
| | - Anne-Marie Lemay
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, QC, Canada
| | - Marie-Josée Beaulieu
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, QC, Canada
| | - Emilie Bernatchez
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, QC, Canada
| | - Marc Veillette
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, QC, Canada
| | - Caroline Duchaine
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, QC, Canada
| | - Marie-Renée Blanchet
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, QC, Canada
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Carbapenem Resistance Determinants Acquired through Novel Chromosomal Integrations in Extensively Drug-Resistant Pseudomonas aeruginosa. Antimicrob Agents Chemother 2021; 65:e0028921. [PMID: 33941520 PMCID: PMC8373256 DOI: 10.1128/aac.00289-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Two novel blaDIM-1- or blaIMP-1-containing genomic islands (GIs) were discovered by whole-genome sequence analyses in four extensively drug-resistant (XDR) Pseudomonas aeruginosa isolates from inpatients at a tertiary hospital in Ghana. The strains were of sequence type 234 (ST234) and formed a phylogenetic clade together with ST111, which is recognized as a global high-risk clone. Their carbapenem resistance was encoded by two Tn402-type integrons, In1592 (blaDIM-1) and In1595 (blaIMP-1), both carrying complete tni mobilization modules. In1595 was bound by conserved 25-bp inverted repeats (IRs) flanked by 5-bp direct repeats (DRs) associated with target site duplication. The integrons were embedded in two GIs that contained cognate integrases and were distinguished by a lower GC content than the chromosomal average. PAGI-97A (52.659 bp; In1592), which encoded a P4-type site-specific integrase of the tyrosine recombinase family in its 3′ border, was integrated into tRNA-Pro(ggg) and bracketed by a 49-bp perfect DR created by 3′-end target duplication. GIs with the same structural features, but diverse genetic content, were identified in 41/226 completed P. aeruginosa genomes. PAGI-97B (22,636 bp; In1595), which encoded an XerC/D superfamily integrase in its 5′ border, was inserted into the small RNA (sRNA) PrrF1/PrrF2 locus. Specific insertions into this highly conserved locus involved in iron-dependent regulation, all leaving PrrF1 intact, were identified in an additional six phylogenetically unrelated P. aeruginosa genomes. Our molecular analyses unveiled a hospital-associated clonal dissemination of carbapenem-resistant ST234 P. aeruginosa in which the XDR phenotype resulted from novel insertions of two GIs into specific chromosomal sites.
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134
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Wang Y, Cao Q, Cao Q, Gan J, Sun N, Yang CG, Bae T, Wu M, Lan L. Histamine activates HinK to promote the virulence of Pseudomonas aeruginosa. Sci Bull (Beijing) 2021; 66:1101-1118. [PMID: 36654344 DOI: 10.1016/j.scib.2021.01.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/25/2020] [Accepted: 12/28/2020] [Indexed: 01/20/2023]
Abstract
During infections, bacteria stimulate host cells to produce and release histamine, which is a key mediator of vital cellular processes in animals. However, the mechanisms underlying the bacterial cell's ability to sense and respond to histamine are poorly understood. Herein, we show that HinK, a LysR-type transcriptional regulator, is required to evoke responses to histamine in Pseudomonas aeruginosa, an important human pathogen. HinK directly binds to and activates the promoter of genes involved in histamine uptake and metabolism, iron acquisition, and Pseudomonas quinolone signal (PQS) biosynthesis. The transcriptional regulatory activity of HinK is induced when histamine is present, and it occurs when HinK binds with imidazole-4-acetic acid (ImAA), a histamine metabolite whose production in P. aeruginosa depends on the HinK-activated histamine uptake and utilization operon hinDAC-pa0222. Importantly, the inactivation of HinK inhibits diverse pathogenic phenotypes of P. aeruginosa. These results suggest that histamine acts as an interkingdom signal and provide insights into the mechanism used by pathogenic bacteria to exploit host regulatory signals to promote virulence.
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Affiliation(s)
- Yaya Wang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Qiao Cao
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; College of Life Science, Northwest University, Xi'an 710069, China
| | - Qin Cao
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jianhua Gan
- State Key Laboratory of Genetic Engineering, Shanghai Public Health Clinical Center, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Fudan University, Shanghai 201438, China
| | - Ning Sun
- The State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong 999077, China
| | - Cai-Guang Yang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, Beijing 100049, China; School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - Taeok Bae
- Department of Microbiology and Immunology, Indiana University School of Medicine-Northwest, Gary IN 46408, USA
| | - Min Wu
- Department of Biomedical Sciences, University of North Dakota, Grand Forks ND 58203-9037, USA
| | - Lefu Lan
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, Beijing 100049, China; School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China; NMPA Key Laboratory for Testing Technology of Pharmaceutical Microbiology, Shanghai Institute for Food and Drug Control, Shanghai 201203, China.
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Eladawy M, El-Mowafy M, El-Sokkary MMA, Barwa R. Antimicrobial resistance and virulence characteristics in ERIC-PCR typed biofilm forming isolates of P. aeruginosa. Microb Pathog 2021; 158:105042. [PMID: 34119625 DOI: 10.1016/j.micpath.2021.105042] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/22/2021] [Accepted: 06/04/2021] [Indexed: 10/21/2022]
Abstract
Pseudomonas aeruginosa is a serious pathogen particularly in immunocompromised patients. In this work, 103 clinical isolates of P. aeruginosa were collected and classified into weak, moderate, and strong biofilm producers according to their biofilm forming abilities via tissue culture plate method. The antimicrobial resistance and the presence of different virulence genes were investigated via disc diffusion method and polymerase chain reaction respectively. Moreover, ERIC-PCR typing was performed to investigate the genetic diversity among the clinical isolates. No significant correlation was observed between biofilm formation and resistance to each antimicrobial agent. Similar observation was detected concerning the multidrug resistance and biofilm formation. Regarding virulence genes, algD gene was harbored by all isolates (100%). Only pelA and phzM were significantly prevalent in strong biofilm producers. Additionally, the mean virulence score was higher in strong biofilm producers (9.33) than moderate (8.62) and weak (7) biofilm producers. Moreover, there was a significant correlation between the overall virulence score of the isolates and its ability to form biofilm. ERIC-PCR genotyping revealed the presence of 99 different ERIC patterns based on 70% similarity, and the different ERIC patterns were categorized into 8 clusters. 100% similarity indicates the possibility of cross-colonization in P. aeruginosa infections.
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Affiliation(s)
- Mohamed Eladawy
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Egypt
| | - Mohammed El-Mowafy
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Egypt
| | - Mohamed M A El-Sokkary
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Egypt.
| | - Rasha Barwa
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Egypt
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136
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Proteomic analysis of Caenorhabditis elegans against Salmonella Typhi toxic proteins. Genes Immun 2021; 22:75-92. [PMID: 33986511 DOI: 10.1038/s41435-021-00132-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 04/08/2021] [Accepted: 04/26/2021] [Indexed: 02/03/2023]
Abstract
Bacterial effector molecules are crucial infectious agents that can cause pathogenesis. In the present study, the pathogenesis of toxic Salmonella enterica serovar Typhi (S. Typhi) proteins on the model host Caenorhabditis elegans was investigated by exploring the host's regulatory proteins during infection through the quantitative proteomics approach. Extracted host proteins were analyzed using two-dimensional gel electrophoresis (2D-GE) and differentially regulated proteins were identified using MALDI TOF/TOF/MS analysis. Of the 150 regulated proteins identified, 95 were downregulated while 55 were upregulated. The interaction network of regulated proteins was predicted using the STRING tool. Most downregulated proteins were involved in muscle contraction, locomotion, energy hydrolysis, lipid synthesis, serine/threonine kinase activity, oxidoreductase activity, and protein unfolding. Upregulated proteins were involved in oxidative stress pathways. Hence, cellular stress generated by S. Typhi proteins in the model host was determined using lipid peroxidation as well as oxidant and antioxidant assays. In addition, candidate proteins identified via extract analysis were validated by western blotting, and the roles of several crucial molecules were analyzed in vivo using transgenic strains (myo-2 and col-19) and mutant (ogt-1) of C. elegans. To the best of our knowledge, this is the first study to report protein regulation in host C. elegans exposed to toxic S. Typhi proteins. It highlights the significance of p38 MAPK and JNK immune pathways.
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Bhardwaj S, Bhatia S, Singh S, Franco Jr F. Growing emergence of drug-resistant Pseudomonas aeruginosa and attenuation of its virulence using quorum sensing inhibitors: A critical review. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2021; 24:699-719. [PMID: 34630947 PMCID: PMC8487598 DOI: 10.22038/ijbms.2021.49151.11254] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 11/24/2020] [Indexed: 12/25/2022]
Abstract
A perilous increase in the number of bacterial infections has led to developing throngs of antibiotics for increasing the quality and expectancy of life. Pseudomonas aeruginosa is becoming resistant to all known conventional antimicrobial agents thereby posing a deadly threat to the human population. Nowadays, targeting virulence traits of infectious agents is an alternative approach to antimicrobials that is gaining much popularity to fight antimicrobial resistance. Quorum sensing (QS) involves interspecies communication via a chemical signaling pathway. Under this mechanism, cells work in a concerted manner, communicate with each other with the help of signaling molecules called auto-inducers (AI). The virulence of these strains is driven by genes, whose expression is regulated by AI, which in turn acts as transcriptional activators. Moreover, the problem of antibiotic-resistance in case of infections caused by P. aeruginosa becomes more alarming among immune-compromised patients, where the infectious agents easily take over the cellular machinery of the host while hidden in the QS mediated biofilms. Inhibition of the QS circuit of P. aeruginosa by targeting various signaling pathways such as LasR, RhlR, Pqs, and QScR transcriptional proteins will help in blocking downstream signal transducers which could result in reducing the bacterial virulence. The anti-virulence agent does not pose an immediate selective pressure on growing bacterium and thus reduces the pathogenicity without harming the target species. Here, we review exclusively, the growing emergence of multi-drug resistant (MDR) P. aeruginosa and the critical literature survey of QS inhibitors with their potential application of blocking P. aeruginosa infections.
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Affiliation(s)
- Snigdha Bhardwaj
- Department of Pharmaceutical Science, SHALOM Institute of Health and Allied Sciences, Sam Higginbottom University of Agriculture, Technology and Sciences (SHUATS), Naini, Prayagraj, India
| | - Sonam Bhatia
- Department of Pharmaceutical Science, SHALOM Institute of Health and Allied Sciences, Sam Higginbottom University of Agriculture, Technology and Sciences (SHUATS), Naini, Prayagraj, India
| | - Shaminder Singh
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad - 121 001, Haryana, India
| | - Francisco Franco Jr
- Department of Chemistry, De La Salle University, Manila, Metro Manila, Philippines
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Mawla GD, Hall BM, Cárcamo-Oyarce G, Grant RA, Zhang JJ, Kardon JR, Ribbeck K, Sauer RT, Baker TA. ClpP1P2 peptidase activity promotes biofilm formation in Pseudomonas aeruginosa. Mol Microbiol 2021; 115:1094-1109. [PMID: 33231899 PMCID: PMC8141546 DOI: 10.1111/mmi.14649] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 11/15/2020] [Accepted: 11/16/2020] [Indexed: 01/07/2023]
Abstract
Caseinolytic proteases (Clp) are central to bacterial proteolysis and control cellular physiology and stress responses. They are composed of a double-ring compartmentalized peptidase (ClpP) and a AAA+ unfoldase (ClpX or ClpA/ClpC). Unlike many bacteria, the opportunistic pathogen Pseudomonas aeruginosa contains two ClpP homologs: ClpP1 and ClpP2. The specific functions of these homologs, however, are largely elusive. Here, we report that the active form of PaClpP2 is a part of a heteromeric PaClpP17 P27 tetradecamer that is required for proper biofilm development. PaClpP114 and PaClpP17 P27 complexes exhibit distinct peptide cleavage specificities and interact differentially with P. aeruginosa ClpX and ClpA. Crystal structures reveal that PaClpP2 has non-canonical features in its N- and C-terminal regions that explain its poor interaction with unfoldases. However, experiments in vivo indicate that the PaClpP2 peptidase active site uniquely contributes to biofilm development. These data strongly suggest that the specificity of different classes of ClpP peptidase subunits contributes to the biological outcome of proteolysis. This specialized role of PaClpP2 highlights it as an attractive target for developing antimicrobial agents that interfere specifically with late-stage P. aeruginosa development.
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Affiliation(s)
- Gina D. Mawla
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Branwen M. Hall
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Gerardo Cárcamo-Oyarce
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Robert A. Grant
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Jia Jia Zhang
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Julia R. Kardon
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Katharina Ribbeck
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Robert T. Sauer
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Tania A. Baker
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
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139
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Sun Y, Cao N, Duan C, Wang Q, Ding C, Wang J. Selection of antibiotic resistance genes on biodegradable and non-biodegradable microplastics. JOURNAL OF HAZARDOUS MATERIALS 2021; 409:124979. [PMID: 33421879 DOI: 10.1016/j.jhazmat.2020.124979] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/06/2020] [Accepted: 12/23/2020] [Indexed: 05/18/2023]
Abstract
Growing evidence have demonstrated that microplastics in the marine ecosystem can provide novel substrates for biofilm formation, potentially facilitating the spread of antibiotic resistance. However, the occurrence of antibiotic resistance genes (ARGs) in the biofilm on microplastics has not been fully explored. This study used the metagenomic data of biodegradable and non-biodegradable microplastics staged at a coastal lagoon in the northern Gulf of Mexico to profile the ARGs and their bacterial hosts. The abundance and Shannon diversity of ARGs on biodegradable poly hydroxy alkanoate (PHA) and non-biodegradable polyethylene terephthalate (PET) have no significant differences. Nevertheless, the abundance of multidrug resistance genes on PET (3.05 copies per 16S rRNA) was statistically higher than that on PHA (2.05). Beta diversity showed that the overall pattern of resistome on PHA was significantly distinct with that on PET. Procrustes analysis suggested a good-fit correlation between ARG profiles and bacterial community composition. The host-tracking analysis identified that Pseudomonas was always the major host for glycopeptide and multidrug resistance genes in PET and PHA biofilms, whereas the primary host for macrolide-lincosamide-streptogramin (MLS) changed to Desulfovibrio on PET. This study provided the first metagenomic insights into the ARGs and their hosts on biodegradable and non-biodegradable microplastics, suggesting that both two types of plastics harbor ARGs with preferences.
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Affiliation(s)
- Yuanze Sun
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Na Cao
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Chongxue Duan
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Qian Wang
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
| | - Changfeng Ding
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Jie Wang
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
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Heterogenous Susceptibility to R-Pyocins in Populations of Pseudomonas aeruginosa Sourced from Cystic Fibrosis Lungs. mBio 2021; 12:mBio.00458-21. [PMID: 33947755 PMCID: PMC8262887 DOI: 10.1128/mbio.00458-21] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Bacteriocins are proteinaceous antimicrobials produced by bacteria that are active against other strains of the same species. R-type pyocins are phage tail-like bacteriocins produced by Pseudomonas aeruginosa Due to their antipseudomonal activity, R-pyocins have potential as therapeutics in infection. P. aeruginosa is a Gram-negative opportunistic pathogen and is particularly problematic for individuals with cystic fibrosis (CF). P. aeruginosa organisms from CF lung infections develop increasing resistance to antibiotics, making new treatment approaches essential. P. aeruginosa populations become phenotypically and genotypically diverse during infection; however, little is known of the efficacy of R-pyocins against heterogeneous populations. R-pyocins vary by subtype (R1 to R5), distinguished by binding to different residues on the lipopolysaccharide (LPS). Each type varies in killing spectrum, and each strain produces only one R-type. To evaluate the prevalence of different R-types, we screened P. aeruginosa strains from the International Pseudomonas Consortium Database (IPCD) and from our biobank of CF strains. We found that (i) R1-types were the most prevalent R-type among strains from respiratory sources, (ii) a large number of strains lack R-pyocin genes, and (iii) isolates collected from the same patient have the same R-type. We then assessed the impact of intrastrain diversity on R-pyocin susceptibility and found a heterogenous response to R-pyocins within populations, likely due to differences in the LPS core. Our work reveals that heterogeneous populations of microbes exhibit variable susceptibility to R-pyocins and highlights that there is likely heterogeneity in response to other types of LPS-binding antimicrobials, including phage.IMPORTANCE R-pyocins have potential as alternative therapeutics against Pseudomonas aeruginosa in chronic infection; however, little is known about the efficacy of R-pyocins in heterogeneous bacterial populations. P. aeruginosa is known to become resistant to multiple antibiotics and to evolve phenotypic and genotypic diversity over time; thus, it is particularly difficult to eradicate in chronic cystic fibrosis (CF) lung infections. In this study, we found that P. aeruginosa populations from CF lungs maintain the same R-pyocin genotype but exhibit heterogeneity in susceptibility to R-pyocins from other strains. Our findings suggest there is heterogeneity in response to other types of LPS-binding antimicrobials, such as phage, highlighting the necessity of further studying the potential of LPS-binding antimicrobial particles as alternative therapies in chronic infections.
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141
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Gálvez NMS, Bohmwald K, Pacheco GA, Andrade CA, Carreño LJ, Kalergis AM. Type I Natural Killer T Cells as Key Regulators of the Immune Response to Infectious Diseases. Clin Microbiol Rev 2021; 34:e00232-20. [PMID: 33361143 PMCID: PMC7950362 DOI: 10.1128/cmr.00232-20] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The immune system must work in an orchestrated way to achieve an optimal response upon detection of antigens. The cells comprising the immune response are traditionally divided into two major subsets, innate and adaptive, with particular characteristics for each type. Type I natural killer T (iNKT) cells are defined as innate-like T cells sharing features with both traditional adaptive and innate cells, such as the expression of an invariant T cell receptor (TCR) and several NK receptors. The invariant TCR in iNKT cells interacts with CD1d, a major histocompatibility complex class I (MHC-I)-like molecule. CD1d can bind and present antigens of lipid nature and induce the activation of iNKT cells, leading to the secretion of various cytokines, such as gamma interferon (IFN-γ) and interleukin 4 (IL-4). These cytokines will aid in the activation of other immune cells following stimulation of iNKT cells. Several molecules with the capacity to bind to CD1d have been discovered, including α-galactosylceramide. Likewise, several molecules have been synthesized that are capable of polarizing iNKT cells into different profiles, either pro- or anti-inflammatory. This versatility allows NKT cells to either aid or impair the clearance of pathogens or to even control or increase the symptoms associated with pathogenic infections. Such diverse contributions of NKT cells to infectious diseases are supported by several publications showing either a beneficial or detrimental role of these cells during diseases. In this article, we discuss current data relative to iNKT cells and their features, with an emphasis on their driving role in diseases produced by pathogenic agents in an organ-oriented fashion.
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Affiliation(s)
- Nicolás M S Gálvez
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Karen Bohmwald
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Gaspar A Pacheco
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Catalina A Andrade
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Leandro J Carreño
- Millennium Institute on Immunology and Immunotherapy, Programa de Inmunología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Alexis M Kalergis
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Departamento de Endocrinología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
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142
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Peña JM, Prezioso SM, McFarland KA, Kambara TK, Ramsey KM, Deighan P, Dove SL. Control of a programmed cell death pathway in Pseudomonas aeruginosa by an antiterminator. Nat Commun 2021; 12:1702. [PMID: 33731715 PMCID: PMC7969949 DOI: 10.1038/s41467-021-21941-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 02/19/2021] [Indexed: 01/29/2023] Open
Abstract
In Pseudomonas aeruginosa the alp system encodes a programmed cell death pathway that is switched on in a subset of cells in response to DNA damage and is linked to the virulence of the organism. Here we show that the central regulator of this pathway, AlpA, exerts its effects by acting as an antiterminator rather than a transcription activator. In particular, we present evidence that AlpA positively regulates the alpBCDE cell lysis genes, as well as genes in a second newly identified target locus, by recognizing specific DNA sites within the promoter, then binding RNA polymerase directly and allowing it to bypass intrinsic terminators positioned downstream. AlpA thus functions in a mechanistically unusual manner to control the expression of virulence genes in this opportunistic pathogen.
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Affiliation(s)
- Jennifer M Peña
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Samantha M Prezioso
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Kirsty A McFarland
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Tracy K Kambara
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Kathryn M Ramsey
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.,Departments of Cell and Molecular Biology and Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI, USA
| | | | - Simon L Dove
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
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143
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Morpholinium-based ionic liquids show antimicrobial activity against clinical isolates of Pseudomonas aeruginosa. Res Microbiol 2021; 172:103817. [PMID: 33741516 DOI: 10.1016/j.resmic.2021.103817] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 03/02/2021] [Accepted: 03/04/2021] [Indexed: 11/22/2022]
Abstract
Pseudomonas aeruginosa is a multi-drug resistant (MDR) pathogen. It is classified by WHO as one of the most life-threatening pathogens causing nosocomial infections. Some of its clinical isolates and their subpopulations show high persistence to many antibiotics that are recommended by the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Thus, there is a need for non-traditional classes of antibiotics to fight the increasing threat of MDR P. aeruginosa. Ionic liquids (IL) are one such promising class of novel antibiotics. We selected four strains of P. aeruginosa and studied the growth inhibition and other effects of 12 different ILs. We used the well-characterized P. aeruginosa PAO1 (ATCC 15692) as model strain and compared it to three other isolates from chronic lung infection (LES B58), skin burn infection (UCBPP-PA14) and keratitis infection (39016), respectively. The ILs consisted of either 4,4-didecylmorpholinium [Dec2Mor]+ or 4-decyl-4-ethylmorpholinium [DecEtMor]+ cations combined with different anions. We found that the ILs with 4,4-didecylmorpholinium [Dec2Mor]+ cations most effectively inhibited bacterial growth as well as reduced strain fitness and virulence factor production. Our results indicate that these ILs could be used to treat P. aeruginosa infections.
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144
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Wang L, Peng F, Peng C, Du JR. Gut Microbiota in Tumor Microenvironment: A Critical Regulator in Cancer Initiation and Development as Potential Targets for Chinese Medicine. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2021; 49:609-626. [PMID: 33683187 DOI: 10.1142/s0192415x21500270] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cancer is a disease with a high mortality and disability rate. Cancer consists not only of cancer cells, but also of the surrounding microenvironment and tumor microenvironment (TME) constantly interacting with tumor cells to support tumor development and progression. Over the last decade, accumulating evidence has implicated that microbiota profoundly influences cancer initiation and progression. Most research focuses on gut microbiota, for the gut harbors the largest collection of microorganisms. Gut microbiota includes bacteria, viruses, protozoa, archaea, and fungi in the gastrointestinal tract, affecting DNA damage, host immune response and chronic inflammation in various types of cancer (i.e., colon cancer, gastric cancer and breast cancer). Notably, gut dysbiosis can reshape tumor microenvironment and make it favorable for tumor growth. Recently, accumulating studies have attached the importance of traditional Chinese medicine (TCM) to cancer treatments, and the bioactive natural compounds have been considered as potential drug candidates to suppress cancer initiation and development. Interestingly, more recent studies demonstrate that TCM could potentially prevent and suppress early-stage cancer progression through the regulation of gut microbiota. This review is on the purpose of exhausting the significance of gut microbiota in the tumor microenvironment as potential targets of Chinese medicine.
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Affiliation(s)
- Li Wang
- Department of Pharmacology, Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, P. R. China
| | - Fu Peng
- Department of Pharmacology, Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, P. R. China.,State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, P. R. China
| | - Cheng Peng
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, P. R. China
| | - Jun-Rong Du
- Department of Pharmacology, Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, P. R. China
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145
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Kim S, Jo S, Kim MS, Shin DH. A study of Rose Bengal against a 2-keto-3-deoxy-d- manno-octulosonate cytidylyltransferase as an antibiotic candidate. J Enzyme Inhib Med Chem 2021; 35:1414-1421. [PMID: 32588669 PMCID: PMC7717453 DOI: 10.1080/14756366.2020.1751150] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Frequent occurrences of multi-drug resistance of pathogenic Gram-negative bacteria threaten human beings. The CMP-2-keto-3-deoxy-d-manno-octulosonic acid biosynthesis pathway is one of the new targets for antibiotic design. 2-Keto-3-deoxy-d-manno-octulosonate cytidylyltransferase (KdsB) is the key enzyme in this pathway. KdsB proteins from Burkholderia pseudomallei (Bp), B. thailandensis (Bt), Pseudomonas aeruginosa (Pa), and Chlamydia psittaci (Cp) have been assayed to find inhibitors. Interestingly, Rose Bengal (4,5,6,7-tetrachloro-2′,4′,5′,7′-tetraiodofluorescein) was turned out to be an inhibitor of three KdsBs (BpKdsB, BtKdsB, and PaKdsB) with promising IC50 values and increased thermostability. The inhibitory enzyme kinetics of Rose Bengal revealed that it is competitive with 2-keto-3-deoxy-manno-octulosonic acid (KDO) but non-competitive against cytidine 5′-triphosphate (CTP). Induced-fit docking analysis of PaKdsB revealed that Arg160 and Arg185 together with other interactions in the substrate binding site seemed to play an important role in binding with Rose Bengal. We suggest that Rose Bengal can be used as the scaffold to develop potential antibiotics.
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Affiliation(s)
- Suwon Kim
- Graduate School of Pharmaceutical Sciences, Ewha Woman's University, Seoul, Republic of Korea
| | - Seri Jo
- Graduate School of Pharmaceutical Sciences, Ewha Woman's University, Seoul, Republic of Korea
| | - Mi-Sun Kim
- Graduate School of Pharmaceutical Sciences, Ewha Woman's University, Seoul, Republic of Korea
| | - Dong Hae Shin
- Graduate School of Pharmaceutical Sciences, Ewha Woman's University, Seoul, Republic of Korea
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146
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Establishment and Evaluation of a Core Genome Multilocus Sequence Typing Scheme for Whole-Genome Sequence-Based Typing of Pseudomonas aeruginosa. J Clin Microbiol 2021; 59:JCM.01987-20. [PMID: 33328175 DOI: 10.1128/jcm.01987-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 12/07/2020] [Indexed: 01/04/2023] Open
Abstract
The environmental bacterium Pseudomonas aeruginosa, particularly multidrug-resistant clones, is often associated with nosocomial infections and outbreaks. Today, core genome multilocus sequence typing (cgMLST) is frequently applied to delineate sporadic cases from nosocomial transmissions. However, until recently, no cgMLST scheme for a standardized typing of P. aeruginosa was available. To establish a novel cgMLST scheme for P. aeruginosa, we initially determined the breadth of the P. aeruginosa population based on MLST data with a Bayesian approach (BAPS). Using genomic data of representative isolates for the whole population and all 12 serogroups, we extracted target genes and further refined them using a random data set of 1,000 P. aeruginosa genomes. Subsequently, we investigated reproducibility and discriminatory ability with repeatedly sequenced isolates and isolates from well-defined outbreak scenarios, respectively, and compared clustering applying two recently published cgMLST schemes. BAPS generated seven P. aeruginosa groups. To cover these and all serogroups, 15 reference strains were used to determine genes common in all strains. After refinement with the data set of 1,000 genomes, the cgMLST scheme consisted of 3,867 target genes, which are representative of the P. aeruginosa population and highly reproducible using biological replicates. We finally evaluated the scheme by reanalyzing two published outbreaks where the authors used single-nucleotide polymorphism (SNP) typing. In both cases, cgMLST was concordant with the previous SNP results and the results of the two other cgMLST schemes. In conclusion, the highly reproducible novel P. aeruginosa cgMLST scheme facilitates outbreak investigations due to the publicly available cgMLST nomenclature.
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147
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Shang D, Han X, Du W, Kou Z, Jiang F. Trp-Containing Antibacterial Peptides Impair Quorum Sensing and Biofilm Development in Multidrug-Resistant Pseudomonas aeruginosa and Exhibit Synergistic Effects With Antibiotics. Front Microbiol 2021; 12:611009. [PMID: 33643239 PMCID: PMC7906020 DOI: 10.3389/fmicb.2021.611009] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 01/20/2021] [Indexed: 12/12/2022] Open
Abstract
Pseudomonas aeruginosa uses quorum sensing (QS) to control virulence, biofilm formation and antibiotic efflux pump expression. The development of effective small molecules targeting the QS system and biofilm formation represents a novel attractive strategy. In this present study, the effects of a series of Trp-containing peptides on the QS-regulated virulence and biofilm development of multidrug-resistant P. aeruginosa, as well as their synergistic antibacterial activity with three classes of traditional chemical antibiotics were investigated. The results showed that Trp-containing peptides at low concentrations reduced the production of QS-regulated virulence factors by downregulating the gene expression of both the las and rhl systems in the strain MRPA0108. Biofilm formation was inhibited in a concentration-dependent manner, which was associated with extracellular polysaccharide production inhibition by downregulating pelA, algD, and pslA transcription. These changes correlated with alterations in the extracellular production of pseudomonal virulence factors and swarming motility. In addition, the combination of Trp-containing peptides at low concentration with the antibiotics ceftazidime and piperacillin provided synergistic effects. Notably, L11W and L12W showed the highest synergy with ceftazidime and piperacillin. A mechanistic study demonstrated that the Trp-containing peptides, especially L12W, significantly decreased β-lactamase activity and expression of efflux pump genes OprM, MexX, and MexA, resulting in a reduction in antibiotic efflux from MRPA0108 cells and thus increasing the antibacterial activity of these antibiotics against MRPA0108.
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Affiliation(s)
- Dejing Shang
- School of Life Sciences, Liaoning Normal University, Dalian, China
- Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, China
| | - Xue Han
- School of Life Sciences, Liaoning Normal University, Dalian, China
| | - Wanying Du
- School of Life Sciences, Liaoning Normal University, Dalian, China
| | - Zhiru Kou
- School of Life Sciences, Liaoning Normal University, Dalian, China
| | - Fengquan Jiang
- Clinical Laboratory Department of the First Affiliated Hospital, Dalian Medical University, Dalian, China
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148
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Brandel A, Aigal S, Lagies S, Schlimpert M, Meléndez AV, Xu M, Lehmann A, Hummel D, Fisch D, Madl J, Eierhoff T, Kammerer B, Römer W. The Gb3-enriched CD59/flotillin plasma membrane domain regulates host cell invasion by Pseudomonas aeruginosa. Cell Mol Life Sci 2021; 78:3637-3656. [PMID: 33555391 PMCID: PMC8038999 DOI: 10.1007/s00018-021-03766-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 12/22/2020] [Accepted: 01/15/2021] [Indexed: 12/11/2022]
Abstract
The opportunistic pathogen Pseudomonas aeruginosa has gained precedence over the years due to its ability to develop resistance to existing antibiotics, thereby necessitating alternative strategies to understand and combat the bacterium. Our previous work identified the interaction between the bacterial lectin LecA and its host cell glycosphingolipid receptor globotriaosylceramide (Gb3) as a crucial step for the engulfment of P. aeruginosa via the lipid zipper mechanism. In this study, we define the LecA-associated host cell membrane domain by pull-down and mass spectrometry analysis. We unraveled a predilection of LecA for binding to saturated, long fatty acyl chain-containing Gb3 species in the extracellular membrane leaflet and an induction of dynamic phosphatidylinositol (3,4,5)-trisphosphate (PIP3) clusters at the intracellular leaflet co-localizing with sites of LecA binding. We found flotillins and the GPI-anchored protein CD59 not only to be an integral part of the LecA-interacting membrane domain, but also majorly influencing bacterial invasion as depletion of either of these host cell proteins resulted in about 50% reduced invasiveness of the P. aeruginosa strain PAO1. In summary, we report that the LecA-Gb3 interaction at the extracellular leaflet induces the formation of a plasma membrane domain enriched in saturated Gb3 species, CD59, PIP3 and flotillin thereby facilitating efficient uptake of PAO1.
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Affiliation(s)
- Annette Brandel
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- CIBSS, Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
| | - Sahaja Aigal
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | - Simon Lagies
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- Center for Biological Systems Analysis, University of Freiburg, Habsburgerstraße 49, 79104, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstraße 19a, 79104, Freiburg, Germany
| | - Manuel Schlimpert
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- Center for Biological Systems Analysis, University of Freiburg, Habsburgerstraße 49, 79104, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstraße 19a, 79104, Freiburg, Germany
| | - Ana Valeria Meléndez
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- CIBSS, Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstraße 19a, 79104, Freiburg, Germany
| | - Maokai Xu
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- CIBSS, Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
| | - Anika Lehmann
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- CIBSS, Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
| | - Daniel Hummel
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Department of Biochemistry, University of Geneva, 30 Quai Ernest-Ansermet, 1211, Geneva, Switzerland
| | - Daniel Fisch
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
- Department of Infectious Disease, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, SW7 2AZ, UK
| | - Josef Madl
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen, and Faculty of Medicine, University of Freiburg, Elsässer Straße 2q, 79110, Freiburg, Germany
| | - Thorsten Eierhoff
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Clinic for Vascular and Endovascular Surgery, University Hospital Münster, Albert Schweitzer Campus 1, 48149, Münster, Germany
| | - Bernd Kammerer
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany
- Center for Biological Systems Analysis, University of Freiburg, Habsburgerstraße 49, 79104, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstraße 19a, 79104, Freiburg, Germany
| | - Winfried Römer
- Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104, Freiburg, Germany.
- BIOSS, Centre for Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany.
- CIBSS, Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestraße 18, 79104, Freiburg, Germany.
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstraße 19a, 79104, Freiburg, Germany.
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149
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A Novel N4-Like Bacteriophage Isolated from a Wastewater Source in South India with Activity against Several Multidrug-Resistant Clinical Pseudomonas aeruginosa Isolates. mSphere 2021; 6:6/1/e01215-20. [PMID: 33441405 PMCID: PMC7845610 DOI: 10.1128/msphere.01215-20] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In India, multidrug resistance determinants are much more abundant in community-associated bacterial pathogens due to the improper treatment of domestic and industrial effluents. In particular, a high bacterial load of the opportunistic pathogen P. aeruginosa in sewage and water bodies in India is well documented. Multidrug-resistant community-acquired infections caused by the opportunistic human pathogen Pseudomonas aeruginosa are increasingly reported in India and other locations globally. Since this organism is ubiquitous in the environment, samples such as sewage and wastewater are rich reservoirs of P. aeruginosa bacteriophages. In this study, we report the isolation and characterization of a novel P. aeruginosa N4-like lytic bacteriophage, vB_Pae_AM.P2 (AM.P2), from wastewater in Kerala, India. AM.P2 is a double-stranded DNA podovirus that efficiently lyses the model strain, PAO1, at a multiplicity of infection as low as 0.1 phage per bacterium and resistance frequency of 6.59 × 10−4. Synergy in bactericidal activity was observed between AM.P2 and subinhibitory concentrations of the antibiotic ciprofloxacin. Genome sequencing of AM.P2 revealed features similar to those of the N4-like P. aeruginosa phages LUZ7 and KPP21. As judged by two independent assay methods, spot tests and growth inhibition, AM.P2 successfully inhibited the growth of almost 30% of strains from a contemporary collection of multidrug-resistant P. aeruginosa clinical isolates from South India. Thus, AM.P2 may represent an intriguing candidate for inclusion in bacteriophage cocktails developed for various applications, including water decontamination and clinical bacteriophage therapy. IMPORTANCE In India, multidrug resistance determinants are much more abundant in community-associated bacterial pathogens due to the improper treatment of domestic and industrial effluents. In particular, a high bacterial load of the opportunistic pathogen P. aeruginosa in sewage and water bodies in India is well documented. The isolation and characterization of bacteriophages that could target emerging P. aeruginosa strains, representing possible epicenters for community-acquired infections, could serve as a useful alternative tool for various applications, such as phage therapy and environmental treatment. Continuing to supplement the repertoire of broad-spectrum bacteriophages is an essential tool in confronting this problem.
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150
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Zhang J, Liang X, Zhang S, Song Z, Wang C, Xu Y. Maipomycin A, a Novel Natural Compound With Promising Anti-biofilm Activity Against Gram-Negative Pathogenic Bacteria. Front Microbiol 2021; 11:598024. [PMID: 33510721 PMCID: PMC7835661 DOI: 10.3389/fmicb.2020.598024] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 12/15/2020] [Indexed: 01/01/2023] Open
Abstract
Pathogenic bacterial biofilms play an important role in recurrent nosocomial and medical device-related infections. Once occurred, the complex structure of the biofilm promotes the development of antibiotic resistance and becomes extremely difficult to eradicate. Here we describe a novel and effective anti-biofilm compound maipomycin A (MaiA), which was isolated from the metabolites of a rare actinomycete strain Kibdelosporangium phytohabitans XY-R10. Its structure was deduced from analyses of spectral data and confirmed by single-crystal X-ray crystallography. This natural product demonstrated a broad spectrum of anti-biofilm activities against Gram-negative bacteria. Interestingly, the addition of Fe(II) or Fe(III) ions could block the biofilm inhibition activity of MaiA because it is an iron chelator. However, not all iron chelators showed biofilm inhibition activity, suggesting that MaiA prevents biofilm formation through a specific yet currently undefined pathway. Furthermore, MaiA acts as a synergist to enhance colistin efficacy against Acinetobacter baumannii. Our results indicate that MaiA may potentially serve as an effective antibiofilm agent to prevent Gram-negative biofilm formation in future clinical applications.
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Affiliation(s)
- Junliang Zhang
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China.,Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, China
| | - Xiaoyan Liang
- Key Laboratory of Marine Drugs, Ministry of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China.,Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Shiling Zhang
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
| | - Zhiman Song
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
| | - Changyun Wang
- Key Laboratory of Marine Drugs, Ministry of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China.,Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Ying Xu
- Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
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