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Zhou Q, Hu Y, You Y, Gao Y, Wang X, Qin L. Functional analysis of OmpA and its contribution to pathogenesis of Edwardsiella tarda. Microb Pathog 2024; 193:106760. [PMID: 38914348 DOI: 10.1016/j.micpath.2024.106760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 03/27/2024] [Accepted: 06/21/2024] [Indexed: 06/26/2024]
Abstract
Outer membrane protein A (OmpA), a major component of outer membrane proteins in gram-negative bacteria, is considered to be an important virulence factor in various pathogenic bacteria, but its underlying mechanisms involved in pathogenic process of Edwardsiella tarda has not yet been fully elucidated. E. tarda is an important facultative intracellular pathogen with a broad host range. This bacterium could survive and replicate in macrophages as an escape mechanism from the host defense. To address the functions of OmpA and its potential roles in the pathogenesis of E. tarda, ΔompA mutant strain and ΔompA-C complementary strain were constructed by the allelic exchange method in this study. Here, we demonstrate that the abilities of motility, biofilm formation and adherence to RAW264.7 cells of ΔompA were significantly impaired, although there was no difference in growth between wild-type (WT) strain and ΔompA. Moreover, inactivation of ompA rendered E. tarda more sensitive to oxidative, heat shock and osmotic stress, which simulate the in vivo conditions that E. tarda encounters within the intramacrophage environment. Consist with this observation, ΔompA was also found to be markedly attenuated for growth within macrophages. In addition, compared with the WT strain, ΔompA activated macrophages to release more inflammatory mediators, including tumor necrosis factor alpha (TNF-α), reactive oxygen species (ROS) and nitric oxide (NO). However, flow cytometry analysis revealed that ΔompA induced less apoptosis of RAW264.7 cells as compared with WT strain, characterized by decreased Annexin V binding and the activation of caspase-3. Overall, our findings suggest an importance of OmpA to E. tarda and provide the first comprehensive insight into its functions and potential roles in the pathogenesis of E. tarda, including its effect on interaction with macrophages.
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Affiliation(s)
- Quan Zhou
- School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang, China
| | - Yushuai Hu
- School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang, China
| | - Yicheng You
- School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang, China
| | - Yingli Gao
- School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang, China
| | - Xingqiang Wang
- School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang, China
| | - Lei Qin
- School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang, China.
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2
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Jacob KM, Hernández-Villamizar S, Hammer ND, Reguera G. Mucin-induced surface dispersal of Staphylococcus aureus and Staphylococcus epidermidis via quorum-sensing dependent and independent mechanisms. mBio 2024:e0156224. [PMID: 38953351 DOI: 10.1128/mbio.01562-24] [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: 05/23/2024] [Accepted: 06/04/2024] [Indexed: 07/04/2024] Open
Abstract
Nasopharyngeal carriage of staphylococci spreads potentially pathogenic strains into (peri)oral regions and increases the chance of cross-infections. Some laboratory strains can also move rapidly on hydrated agar surfaces, but the biological relevance of these observations is not clear. Using soft-agar [0.3% (wt/vol)] plate assays, we demonstrate the rapid surface dispersal of (peri)oral isolates of Staphylococcus aureus and Staphylococcus epidermidis and closely related laboratory strains in the presence of mucin glycoproteins. Mucin-induced dispersal was a stepwise process initiated by the passive spreading of the growing colonies followed by their rapid branching (dendrites) from the colony edge. Although most spreading strains used mucin as a growth substrate, dispersal was primarily dependent on the lubricating and hydrating properties of the mucins. Using S. aureus JE2 as a genetically tractable representative, we demonstrate that mucin-induced dendritic dispersal, but not colony spreading, is facilitated by the secretion of surfactant-active phenol-soluble modulins (PSMs) in a process regulated by the agr quorum-sensing system. Furthermore, the dendritic dispersal of S. aureus JE2 colonies was further stimulated in the presence of surfactant-active supernatants recovered from the most robust (peri)oral spreaders of S. aureus and S. epidermidis. These findings suggest complementary roles for lubricating mucins and staphylococcal PSMs in the active dispersal of potentially pathogenic strains from perioral to respiratory mucosae, where gel-forming, hydrating mucins abound. They also highlight the impact that interspecies interactions have on the co-dispersal of S. aureus with other perioral bacteria, heightening the risk of polymicrobial infections and the severity of the clinical outcomes. IMPORTANCE Despite lacking classical motility machinery, nasopharyngeal staphylococci spread rapidly in (peri)oral and respiratory mucosa and cause cross-infections. We describe laboratory conditions for the reproducible study of staphylococcal dispersal on mucosa-like surfaces and the identification of two dispersal stages (colony spreading and dendritic expansion) stimulated by mucin glycoproteins. The mucin type mattered as dispersal required the surfactant activity and hydration provided by some mucin glycoproteins. While colony spreading was a passive mode of dispersal lubricated by the mucins, the more rapid and invasive form of dendritic expansion of Staphylococcus aureus and Staphylococcus epidermidis required additional lubrication by surfactant-active peptides (phenol-soluble modulins) secreted at high cell densities through quorum sensing. These results highlight a hitherto unknown role for gel-forming mucins in the dispersal of staphylococcal strains associated with cross-infections and point at perioral regions as overlooked sources of carriage and infection by staphylococci.
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Affiliation(s)
- Kristin M Jacob
- Department of Microbiology, Genetics and Immunology, Michigan State University, East Lansing, Michigan, USA
| | | | - Neal D Hammer
- Department of Microbiology, Genetics and Immunology, Michigan State University, East Lansing, Michigan, USA
| | - Gemma Reguera
- Department of Microbiology, Genetics and Immunology, Michigan State University, East Lansing, Michigan, USA
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3
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Warrell DL, Zarrella TM, Machalek C, Khare A. Interspecies surfactants serve as public goods enabling surface motility in Pseudomonas aeruginosa. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.03.573969. [PMID: 38260674 PMCID: PMC10802355 DOI: 10.1101/2024.01.03.573969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
In most natural environments, bacteria live in polymicrobial communities where secreted molecules from neighboring species alter bacterial behaviors including motility, but such interactions are understudied. Pseudomonas aeruginosa is a motile opportunistic pathogen that exists in diverse multispecies environments such as the soil and is frequently found in human wound and respiratory tract co-infections with other bacteria including Staphylococcus aureus. Here we show that P. aeruginosa can co-opt secreted surfactants from other species for flagellar-based surface motility. We found that exogenous surfactants from S. aureus, other bacteria, and interkingdom species enabled P. aeruginosa to switch from swarming to an alternative surface spreading motility on semi-solid surfaces and allowed for the emergence of surface motility on hard agar where P. aeruginosa was otherwise unable to move. This motility was distinct from the response of other motile bacteria in the presence of exogenous surfactants. Mutant analysis indicated that this P. aeruginosa motility was similar to a previously described mucin-based motility, 'surfing', albeit with divergent regulation. Thus, our study demonstrates that secreted surfactants from the host as well as neighboring bacterial and interkingdom species act as public goods facilitating P. aeruginosa flagella-mediated surfing-like surface motility, thereby allowing it to access different environmental niches.
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Affiliation(s)
- Delayna L Warrell
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Tiffany M Zarrella
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
- Postdoctoral Research Associate Training Program, National Institute of General Medical Sciences, National Institutes of Health, Bethesda, MD, USA
- Current address: Department of Biology, Georgetown University, Washington, DC, USA
| | - Christopher Machalek
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Anupama Khare
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
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4
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Esnaashari F, Rostamnejad D, Zahmatkesh H, Zamani H. In vitro and in silico assessment of anti-quorum sensing activity of Naproxen against Pseudomonas aeruginosa. World J Microbiol Biotechnol 2023; 39:244. [PMID: 37407806 DOI: 10.1007/s11274-023-03690-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 06/27/2023] [Indexed: 07/07/2023]
Abstract
Serious infections caused by Pseudomonas aeruginosa are usually related to quorum sensing (QS)-dependent virulence factors. Hence, QS inhibition is a promising approach to overcoming P. aeruginosa infections. This study aimed to investigate the effect of naproxen on biofilm formation and QS-related virulence traits of P. aeruginosa. Furthermore, the anti-QS potential of naproxen was evaluated using real-time PCR and molecular docking analysis. Our findings supported the anti-QS activity of naproxen, as evidenced by down-regulation of the lasI and rhlI genes expression as well as the attenuation of bacterial protease, hemolysin, pyocyanin, biofilm, and motility. Additionally, the high binding affinity of naproxen with QS regulatory proteins was determined in the molecular docking simulation. Altogether, these findings suggest that naproxen has a promising potential in inhibiting QS-associated traits of P. aeruginosa.
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Affiliation(s)
- Fatemeh Esnaashari
- Department of Biology, Lahijan Branch, Islamic Azad University, Lahijan, Iran
| | - Dorna Rostamnejad
- Department of Microbiology, Lahijan Branch, Islamic Azad University, Lahijan, Iran
| | - Hossein Zahmatkesh
- Department of Microbiology, Lahijan Branch, Islamic Azad University, Lahijan, Iran
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5
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Wang M, Lian Y, Wang Y, Zhu L. The role and mechanism of quorum sensing on environmental antimicrobial resistance. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 322:121238. [PMID: 36758922 DOI: 10.1016/j.envpol.2023.121238] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 02/03/2023] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
As more environmental contaminants emerging, antibiotics and antibiotic resistance genes (ARGs) have caused a substantial increase of antimicrobial resistance (AMR) in environment. Quorum sensing (QS) is a bacterial cell-to-cell communication process that regulates many traits and gene expression, including ARGs and the related genes that contribute to AMR development. Herein, we summarize the role, physiology, and genetic mechanisms of bacterial QS in AMR development in the environment. First, the effect of QS on AMR is introduced. Next, the role of QS in bacterial physiological behaviors that promote AMR development, including membrane permeability, tactic movement, biofilm formation, persister formation, and small colony variants (SCVs), is systematically analyzed. Furthermore, the regulation of QS on the expression of ARGs, generation of reactive oxygen species (ROS), which affects ARGs formation, and horizontal gene transfer (HGT), which accelerates the transmission of ARGs, are discussed to reveal the molecular mechanism for AMR development. This review provides a reference for a better understanding of AMR evolution and novel insights into AMR prevention.
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Affiliation(s)
- Meizhen Wang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China; Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou, 310012, China
| | - Yulu Lian
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China
| | - Yujie Wang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China
| | - Lin Zhu
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China.
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Shaffique S, Imran M, Wani SH, Khan MA, Kang SM, Adhikari A, Lee IJ. Evaluating the adhesive potential of the newly isolated bacterial strains in research exploitation of plant microbial interaction. FRONTIERS IN PLANT SCIENCE 2022; 13:1004331. [PMID: 36340407 PMCID: PMC9634002 DOI: 10.3389/fpls.2022.1004331] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 10/06/2022] [Indexed: 05/26/2023]
Abstract
Bacterial adhesion potential constitutes the transition of bacteria from the planktonic to the static phase by promoting biofilm formation, which plays a significant role in plant-microbial interaction in the agriculture industry. In present study, the adhesion potential of five soil-borne bacterial strains belonging to different genera was studied. All bacterial strains were capable of forming colonies and biofilms of different levels of firmness on polystyrene. Significant variation was observed in hydrophobicity and motility assays. Among the five bacterial strains (SH-6, SH-8, SH-9, SH-10, and SH-19), SH-19 had a strong hydrophobic force, while SH-10 showed the most hydrophilic property. SH-6 showed great variability in motility; SH-8 had a swimming diffusion diameter of 70 mm, which was three times higher than that of SH-19. In the motility assay, SH-9 and SH-10 showed diffusion diameters of approximately 22 mm and 55 mm, respectively. Furthermore, among the five strains, four are predominately electron donors and one is electron acceptors. Overall, positive correlation was observed among Lewis acid base properties, hydrophobicity, and biofilm forming ability. However, no correlation of motility with bacterial adhesion could be found in present experimental work. Scanning electron microscopy images confirmed the adhesion potential and biofilm ability within extra polymeric substances. Research on the role of adhesion in biofilm formation of bacteria isolated from plants is potentially conducive for developing strategies such as plant-microbial interaction to mitigate the abiotic stress.
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Affiliation(s)
- Shifa Shaffique
- Department of Applied Biosciences, Kyungpook National University, Daegu, South Korea
| | - Muhammad Imran
- Department of Applied Biosciences, Kyungpook National University, Daegu, South Korea
| | - Shabir Hussain Wani
- Mountain Research for Field Crops Khudwani, Sher-e Kashmir University of Agricultural Sciences and Technology of Kashmir, Srinagar, Jamu and Kashmir, India
| | - Muhamad Aqil Khan
- Department of Applied Biosciences, Kyungpook National University, Daegu, South Korea
| | - Sang-Mo Kang
- Department of Applied Biosciences, Kyungpook National University, Daegu, South Korea
| | - Arjun Adhikari
- Department of Applied Biosciences, Kyungpook National University, Daegu, South Korea
| | - In-Jung Lee
- Department of Applied Biosciences, Kyungpook National University, Daegu, South Korea
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Dostert M, Belanger CR, Pedraz L, Alford MA, Blimkie TM, Falsafi RF, Bains M, Dhillon BK, Haney CH, Lee AH, Hancock REW. BosR: A novel biofilm-specific regulator in Pseudomonas aeruginosa. Front Microbiol 2022; 13:1021021. [PMID: 36312952 PMCID: PMC9611778 DOI: 10.3389/fmicb.2022.1021021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
Biofilms are the most common cause of bacterial infections in humans and notoriously hard to treat due to their ability to withstand antibiotics and host immune defenses. To overcome the current lack of effective antibiofilm therapies and guide future design, the identification of novel biofilm-specific gene targets is crucial. In this regard, transcriptional regulators have been proposed as promising targets for antimicrobial drug design. Therefore, a Transposon insertion sequencing approach was employed to systematically identify regulators phenotypically affecting biofilm growth in Pseudomonas aeruginosa PA14 using the TnSeq analysis tools Bio-TraDIS and TRANSIT. A screen of a pool of 300,000 transposon insertion mutants identified 349 genes involved in biofilm growth on hydroxyapatite, including 47 regulators. Detection of 19 regulatory genes participating in well-established biofilm pathways validated the results. An additional 28 novel prospective biofilm regulators suggested the requirement for multiple one-component transcriptional regulators. Biofilm-defective phenotypes were confirmed for five one-component transcriptional regulators and a protein kinase, which did not affect motility phenotypes. The one-component transcriptional regulator bosR displayed a conserved role in P. aeruginosa biofilm growth since its ortholog in P. aeruginosa strain PAO1 was also required for biofilm growth. Microscopic analysis of a chromosomal deletion mutant of bosR confirmed the role of this regulator in biofilm growth. Overall, our results highlighted that the gene network driving biofilm growth is complex and involves regulators beyond the primarily studied groups of two-component systems and cyclic diguanylate signaling proteins. Furthermore, biofilm-specific regulators, such as bosR, might constitute prospective new drug targets to overcome biofilm infections.
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Affiliation(s)
- Melanie Dostert
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Corrie R. Belanger
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Lucas Pedraz
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Morgan A. Alford
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Travis M. Blimkie
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Reza F. Falsafi
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Manjeet Bains
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Bhavjinder Kaur Dhillon
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Cara H. Haney
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Amy H. Lee
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Robert E. W. Hancock
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
- *Correspondence: Robert E. W. Hancock,
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8
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Effect of samarium oxide nanoparticles on virulence factors and motility of multi-drug resistant Pseudomonas aeruginosa. World J Microbiol Biotechnol 2022; 38:209. [PMID: 36040540 DOI: 10.1007/s11274-022-03384-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 08/09/2022] [Indexed: 10/14/2022]
Abstract
Biofilm formation and quorum sensing (QS) dependent virulence factors are considered the major causes of the emergence of drug resistance, therapeutic failure and development of Pseudomonas aeruginosa infections. This study aimed to investigate the effects of samarium oxide nanoparticles (Sm2O3NPs) on biofilm, virulence factors, and motility of multidrug-resistant P. aeruginosa. Sm2O3NPs were synthesized using curcumin and characterized by Transmission Electron Microscopy, X-ray diffractometer, Field Emission Scanning Electron Microscopy, and Energy-dispersive X-ray spectroscopy. Minimum inhibitory concentration (MIC) was determined using broth microdilution method. The antibiofilm potential of Sm2O3NPs was also evaluated by crystal violet staining and light microscopy examination. Then, the effect of sub-MICs concentrations of Sm2O3NPs on the proteolytic and hemolytic activities of P. aeruginosa was investigated. Finally, the effect of Sm2O3NPs on various types of motility including swarming, swimming, and twitching was studied. Our results showed that Sm2O3NPs significantly inhibited biofilm formation of P. aeruginosa by 49-61%. Additionally, sub-MICs concentrations of Sm2O3NPs effectively decreased virulence factors including pyocyanin (33-55%), protease (24-45%), and hemolytic activity (22-41%). Moreover, swarming, swimming, and twitching motility remarkably was reduced after exposure to the NPs. The findings of this work showed that Sm2O3NPs have a high potential in inhibiting QS-dependent virulence of P. aeruginosa, which could be considered for antibacterial chemotherapy after further characterization.
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Gupta V, Shekhawat SS, Kulshreshtha NM, Gupta AB. A systematic review on chlorine tolerance among bacteria and standardization of their assessment protocol in wastewater. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2022; 86:261-291. [PMID: 35906907 DOI: 10.2166/wst.2022.206] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Though chlorine is a cost-effective disinfectant for water and wastewaters, the bacteria surviving after chlorination pose serious public health and environmental problems. This review critically assesses the mechanism of chlorine disinfection as described by various researchers; factors affecting chlorination efficacy; and the re-growth potential of microbial contaminations in treated wastewater post chlorination to arrive at meaningful doses for ensuring health safety. Literature analysis shows procedural inconsistencies in the assessment of chlorine tolerant bacteria, making it extremely difficult to compare the tolerance characteristics of different reported tolerant bacteria. A comparison of logarithmic reduction after chlorination and the concentration-time values for prominent pathogens led to the generation of a standard protocol for the assessment of chlorine tolerance. The factors that need to be critically monitored include applied chlorine doses, contact time, determination of chlorine demands of the medium, and the consideration of bacterial counts immediately after chlorination and in post chlorinated samples (regrowth). The protocol devised here appropriately assesses the chlorine-tolerant bacteria and urges the scientific community to report the regrowth characteristics as well. This would increase the confidence in data interpretation that can provide a better understanding of chlorine tolerance in bacteria and aid in formulating strategies for effective chlorination.
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Affiliation(s)
- Vinayak Gupta
- Alumnus, Department of Civil and Environmental Engineering, National University of Singapore, Singapore; School of Environment and Society, Tokyo Institute of Technology, Tokyo, Japan
| | - Sandeep Singh Shekhawat
- Department of Civil Engineering, Malaviya National Institute of Technology, Jaipur, India E-mail: ; School of Life and Basic Sciences, SIILAS Campus, Jaipur National University Jaipur, India
| | - Niha Mohan Kulshreshtha
- Department of Civil Engineering, Malaviya National Institute of Technology, Jaipur, India E-mail:
| | - Akhilendra Bhushan Gupta
- Department of Civil Engineering, Malaviya National Institute of Technology, Jaipur, India E-mail:
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Palma V, Gutiérrez MS, Vargas O, Parthasarathy R, Navarrete P. Methods to Evaluate Bacterial Motility and Its Role in Bacterial–Host Interactions. Microorganisms 2022; 10:microorganisms10030563. [PMID: 35336138 PMCID: PMC8953368 DOI: 10.3390/microorganisms10030563] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/02/2022] [Accepted: 02/06/2022] [Indexed: 11/16/2022] Open
Abstract
Bacterial motility is a widespread characteristic that can provide several advantages for the cell, allowing it to move towards more favorable conditions and enabling host-associated processes such as colonization. There are different bacterial motility types, and their expression is highly regulated by the environmental conditions. Because of this, methods for studying motility under realistic experimental conditions are required. A wide variety of approaches have been developed to study bacterial motility. Here, we present the most common techniques and recent advances and discuss their strengths as well as their limitations. We classify them as macroscopic or microscopic and highlight the advantages of three-dimensional imaging in microscopic approaches. Lastly, we discuss methods suited for studying motility in bacterial–host interactions, including the use of the zebrafish model.
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Affiliation(s)
- Victoria Palma
- Laboratory of Microbiology and Probiotics, Institute of Nutrition and Food Technology (INTA), University of Chile, El Líbano 5524, Santiago 7830490, Chile; (V.P.); (M.S.G.); (O.V.)
| | - María Soledad Gutiérrez
- Laboratory of Microbiology and Probiotics, Institute of Nutrition and Food Technology (INTA), University of Chile, El Líbano 5524, Santiago 7830490, Chile; (V.P.); (M.S.G.); (O.V.)
- Millennium Science Initiative Program, Milenium Nucleus in the Biology of the Intestinal Microbiota, National Agency for Research and Development (ANID), Moneda 1375, Santiago 8200000, Chile
| | - Orlando Vargas
- Laboratory of Microbiology and Probiotics, Institute of Nutrition and Food Technology (INTA), University of Chile, El Líbano 5524, Santiago 7830490, Chile; (V.P.); (M.S.G.); (O.V.)
| | - Raghuveer Parthasarathy
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA;
- Department of Physics and Materials Science Institute, University of Oregon, Eugene, OR 97403, USA
| | - Paola Navarrete
- Laboratory of Microbiology and Probiotics, Institute of Nutrition and Food Technology (INTA), University of Chile, El Líbano 5524, Santiago 7830490, Chile; (V.P.); (M.S.G.); (O.V.)
- Millennium Science Initiative Program, Milenium Nucleus in the Biology of the Intestinal Microbiota, National Agency for Research and Development (ANID), Moneda 1375, Santiago 8200000, Chile
- Correspondence:
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11
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Nassar O, Desouky SE, El-Sherbiny GM, Abu-Elghait M. Correlation between phenotypic virulence traits and antibiotic resistance in Pseudomonas aeruginosa clinical isolates. Microb Pathog 2021; 162:105339. [PMID: 34861345 DOI: 10.1016/j.micpath.2021.105339] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 11/25/2021] [Accepted: 11/28/2021] [Indexed: 12/21/2022]
Abstract
Pseudomonas aeruginosa is a ubiquitous pathogen capable of infecting virtually all tissues and its one of the standout amongst the most hazardous microorganisms of high morbidity and mortality rates especially in debilitated patients with few successful antibiotic choices available. This pathogen regulating most virulence traits by that so-called quorum sensing (QS), a cell to cell communication system. the present study was intended to phenotypically evaluate the activity of specific virulence traits (including swarming and swimming motility, protease, pyocyanin, and biofilm production) in Pseudomonas aeruginosa clinical isolates and assess the statistical correlation between these traits and antibiotic resistance. One hundred and thirteen bacterial isolates were obtained from different clinical samples and identified as P. aeruginosa, among them, 73.4% have the ability to forming biofilm with different degrees; 59.2% were able to produce pyocyanin pigment while all isolates having the ability to make swarming and swimming motility and able to produce protease enzyme with different degrees. The isolates that produce the higher levels of the virulence traits were identified by both biochemical using Vitek2 automated system and genetically via 16s rRNA gene analysis. The statistical analysis results indicate that a positive significant correlation was found between biofilm formation and other studied virulence traits except for protease (r = 0.584: 0.324, P < 0.05) while a non-significant correlation was found between biofilm formation and protease activity (r = 0.105, P ˃ 0.05). Swimming and swarming motility have a positive significant correlation with other studied virulence traits (r = 0.613: 0.297, P < 0.05) except for protease. Pyocyanin pigment production have a positive significant correlation with other studied virulence traits (r = 0.33: 0.297, P < 0.05) except for protease. on the other hand, negative significant correlations were found between biofilm formation, swimming; and swarming motility, Pyocyanin pigment production, and the susceptibility of antibiotics (r = -0.512: -0.281, P < 0.05). Detection of such correlations in P. aeruginosa is useful for study the behavior of this pathogen and may be provide a new target for the treatment of MDR infections.
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Affiliation(s)
- Osama Nassar
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, 11884, Cairo, Egypt
| | - Said E Desouky
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, 11884, Cairo, Egypt
| | - Gamal M El-Sherbiny
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, 11884, Cairo, Egypt
| | - Mohammed Abu-Elghait
- Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, 11884, Cairo, Egypt.
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12
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Use of Alternative Gelling Agents Reveals the Role of Rhamnolipids in Pseudomonas aeruginosa Surface Motility. Biomolecules 2021; 11:biom11101468. [PMID: 34680106 PMCID: PMC8533327 DOI: 10.3390/biom11101468] [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] [Received: 07/28/2021] [Revised: 08/30/2021] [Accepted: 09/03/2021] [Indexed: 12/02/2022] Open
Abstract
Pseudomonas aeruginosa is a motile bacterium able to exhibit a social surface behaviour known as swarming motility. Swarming requires the polar flagellum of P. aeruginosa as well as the secretion of wetting agents to ease the spread across the surface. However, our knowledge on swarming is limited to observed phenotypes on agar-solidified media. To study the surface behaviour and the impact of wetting agents of P. aeruginosa on other surfaces, we assessed surface motility capabilities of the prototypical strain PA14 on semi-solid media solidified with alternative gelling agents, gellan gum and carrageenan. We found that, on these alternative surfaces, the characteristic dendritic spreading pattern of P. aeruginosa is drastically altered. One striking feature is the loss of dependence on rhamnolipids to spread effectively on plates solidified with these alternative gelling agents. Indeed, a rhlA-null mutant unable to produce its wetting agents still spreads effectively, albeit in a circular shape on both the gellan gum- and carrageenan-based media. Our data indicate that rhamnolipids do not have such a crucial role in achieving surface colonization of non-agar plates, suggesting a strong dependence on the physical properties of the tested surface. The use of alternative gelling agent provides new means to reveal unknown features of bacterial surface behaviour.
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Casado-García Á, Chichón G, Domínguez C, García-Domínguez M, Heras J, Inés A, López M, Mata E, Pascual V, Sáenz Y. MotilityJ: An open-source tool for the classification and segmentation of bacteria on motility images. Comput Biol Med 2021; 136:104673. [PMID: 34325228 DOI: 10.1016/j.compbiomed.2021.104673] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 07/19/2021] [Accepted: 07/19/2021] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND OBJECTIVES Infectious diseases produced by antimicrobial resistant microorganisms are a major threat to human, and animal health worldwide. This problem is increased by the virulence and spread of these bacteria. Surface motility has been regarded as a pathogenicity element because it is essential for many biological functions, but also for disease spreading; hence, investigations on the motility behaviour of bacteria are crucial to understand chemotaxis, biofilm formation and virulence in general. To identify a motile strain in the laboratory, the bacterial spread area is observed on media solidified with agar. Up to now, the task of measuring bacteria spread was a manual, and, therefore, tedious and time-consuming task. The aim of this work is the development of a set of tools for bacteria segmentation in motility images. METHODS In this work, we address the problem of measuring bacteria spread on motility images by creating an automatic pipeline based on deep learning models. Such a pipeline consists of a classification model to determine whether the bacteria has spread to cover completely the Petri dish, and a segmentation model to determine the spread of those bacteria that do not fully cover the Petri dishes. In order to annotate enough images to train our deep learning models, a semi-automatic annotation procedure is presented. RESULTS The classification model of our pipeline achieved a F1-score of 99.85%, and the segmentation model achieved a Dice coefficient of 95.66%. In addition, the segmentation model produces results that are indistinguishable, and in many cases preferred, from those produced manually by experts. Finally, we facilitate the dissemination of our pipeline with the development of MotilityJ, an open-source and user-friendly application for measuring bacteria spread on motility images. CONCLUSIONS In this work, we have developed an algorithm and trained several models for measuring bacteria spread on motility images. Thanks to this work, the analysis of motility images will be faster and more reliable. The developed tools will help to advance our understanding of the behaviour and virulence of bacteria.
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Affiliation(s)
| | - Gabriela Chichón
- Area de Microbiología Molecular, Centro de Investigación Biomédica de La Rioja (CIBIR), Logroño, Spain
| | - César Domínguez
- Department of Mathematics and Computer Science, University of La Rioja, Spain
| | | | - Jónathan Heras
- Department of Mathematics and Computer Science, University of La Rioja, Spain.
| | - Adrián Inés
- Department of Mathematics and Computer Science, University of La Rioja, Spain
| | - María López
- Area de Microbiología Molecular, Centro de Investigación Biomédica de La Rioja (CIBIR), Logroño, Spain
| | - Eloy Mata
- Department of Mathematics and Computer Science, University of La Rioja, Spain
| | - Vico Pascual
- Department of Mathematics and Computer Science, University of La Rioja, Spain
| | - Yolanda Sáenz
- Area de Microbiología Molecular, Centro de Investigación Biomédica de La Rioja (CIBIR), Logroño, Spain
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Ma TF, Chen YP, Yan P, Fang F, Shen Y, Mao Z, Guo JS, Zhao B, Feng L. Adaptation mechanism of aerobic denitrifier Enterobacter cloacae strain HNR to short-term ZnO nanoparticle stresses. ENVIRONMENTAL RESEARCH 2021; 197:111178. [PMID: 33865818 DOI: 10.1016/j.envres.2021.111178] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/06/2021] [Accepted: 04/08/2021] [Indexed: 06/12/2023]
Abstract
The adaptation mechanism of a wild type (WT) and resistant type (Re) strain of the aerobic denitrifier Enterobacter cloacae strain HNR to short-term ZnO nanoparticle (NP) stresses was investigated. The results showed that Re maintained higher nitrite reductase (NIR) and nitrate reductase (NR) activities and showed lower increment of reactive oxygen species (ROS) than WT, under ZnO NP stresses. The affinity constant (KA) of WT to Zn2+ was 5.06 times that of Re, indicating that Re was more repulsive to Zn2+ released by ZnO NPs. Transcriptomic analysis revealed that the up-regulation of the nitrogen metabolism of Re helped maintain NIR and NR activities, that the enhancement of purine metabolism lowered the intracellular ROS increment, and that the up-regulation of cationic antimicrobial peptide resistance contributed to the lower KA of Re to Zn2+. These findings provided new insights into the adaptation mechanism of aerobic denitrifying bacteria to ZnO NPs.
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Affiliation(s)
- Teng-Fei Ma
- National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing, 400067, China; Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; Environmental Engineering Technology Research Center, Chongqing Academy of Ecological and Environmental Sciences, Chongqing, 401147, China
| | - You-Peng Chen
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China.
| | - Peng Yan
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China
| | - Fang Fang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China
| | - Yu Shen
- National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing, 400067, China; Chongqing South-to-Thais Environmental Protection Technology Research Institute Co., Ltd., Chongqing, 400069, China
| | - Zheng Mao
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China
| | - Jin-Song Guo
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China
| | - Bin Zhao
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China
| | - Li Feng
- Environmental Engineering Technology Research Center, Chongqing Academy of Ecological and Environmental Sciences, Chongqing, 401147, China
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Langendonk RF, Neill DR, Fothergill JL. The Building Blocks of Antimicrobial Resistance in Pseudomonas aeruginosa: Implications for Current Resistance-Breaking Therapies. Front Cell Infect Microbiol 2021; 11:665759. [PMID: 33937104 PMCID: PMC8085337 DOI: 10.3389/fcimb.2021.665759] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 03/29/2021] [Indexed: 12/12/2022] Open
Abstract
P. aeruginosa is classified as a priority one pathogen by the World Health Organisation, and new drugs are urgently needed, due to the emergence of multidrug-resistant (MDR) strains. Antimicrobial-resistant nosocomial pathogens such as P. aeruginosa pose unwavering and increasing threats. Antimicrobial stewardship has been a challenge during the COVID-19 pandemic, with a majority of those hospitalized with SARS-CoV2 infection given antibiotics as a safeguard against secondary bacterial infection. This increased usage, along with increased handling of sanitizers and disinfectants globally, may further accelerate the development and spread of cross-resistance to antibiotics. In addition, P. aeruginosa is the primary causative agent of morbidity and mortality in people with the life-shortening genetic disease cystic fibrosis (CF). Prolonged periods of selective pressure, associated with extended antibiotic treatment and the actions of host immune effectors, results in widespread adaptive and acquired resistance in P. aeruginosa found colonizing the lungs of people with CF. This review discusses the arsenal of resistance mechanisms utilized by P. aeruginosa, how these operate under high-stress environments such as the CF lung and how their interconnectedness can result in resistance to multiple antibiotic classes. Intrinsic, adaptive and acquired resistance mechanisms will be described, with a focus on how each layer of resistance can serve as a building block, contributing to multi-tiered resistance to antimicrobial activity. Recent progress in the development of anti-resistance adjuvant therapies, targeting one or more of these building blocks, should lead to novel strategies for combatting multidrug resistant P. aeruginosa. Anti-resistance adjuvant therapy holds great promise, not least because resistance against such therapeutics is predicted to be rare. The non-bactericidal nature of anti-resistance adjuvants reduce the selective pressures that drive resistance. Anti-resistance adjuvant therapy may also be advantageous in facilitating efficacious use of traditional antimicrobials, through enhanced penetration of the antibiotic into the bacterial cell. Promising anti-resistance adjuvant therapeutics and targets will be described, and key remaining challenges highlighted. As antimicrobial stewardship becomes more challenging in an era of emerging and re-emerging infectious diseases and global conflict, innovation in antibiotic adjuvant therapy can play an important role in extending the shelf-life of our existing antimicrobial therapeutic agents.
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Affiliation(s)
- R. Frèdi Langendonk
- Institute of Infection, Veterinary and Ecological Science, University of Liverpool, Liverpool, United Kingdom
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16
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Saeki EK, Yamada AY, de Araujo LA, Anversa L, Garcia DDO, de Souza RLB, Martins HM, Kobayashi RKT, Nakazato G. Subinhibitory Concentrations of Biogenic Silver Nanoparticles Affect Motility and Biofilm Formation in Pseudomonas aeruginosa. Front Cell Infect Microbiol 2021; 11:656984. [PMID: 33869087 PMCID: PMC8047417 DOI: 10.3389/fcimb.2021.656984] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/15/2021] [Indexed: 12/12/2022] Open
Abstract
Biogenic silver nanoparticles (bio-AgNPs) are increasingly recognized as an antibiofilm and antivirulence strategy against P. aeruginosa, a bacterium that causes chronic infections in immunocompromised and cystic fibrosis patients. This study aimed to investigate the effects of subinhibitory concentrations of bio-AgNPs on motility and biofilm formation in P. aeruginosa. Bio-AgNPs were synthesized via reduction of ionic silver catalyzed by cell-free culture filtrate from Fusarium oxysporum. A total of 17 P. aeruginosa isolates and strains were evaluated for swarming, swimming, and twitching motility in the presence and absence (control) of bio-AgNPs, including 10 clinical isolates from patients with and without cystic fibrosis, 5 environmental isolates obtained from the public water supply system, and 2 reference strains (PAO1 and PA14). Isolates were identified by biochemical and molecular methods. Minimum inhibitory concentrations (MICs) were determined by the broth microdilution method. Swarming, swimming, and twitching motility assays were performed in Petri dishes. Biofilm formation capacity was assessed quantitatively by the crystal violet method. MIC values ranged from 15.62 to 62.50 µM. The results showed that subinhibitory concentrations of bio-AgNPs (½ MIC, 7.81-31.25 µM) significantly increased (p < 0.05) swarming, swimming, and twitching motility in 40.0, 40.0, and 46.7% of isolates, respectively. Subinhibitory bio-AgNP treatment enhanced (p < 0.05) biofilm formation capacity in PA14 and a cystic fibrosis isolate (P11). It is concluded that subinhibitory concentrations of bio-AgNPs increased biofilm formation and swarming, swimming, and twitching motility in PA14 and some P. aeruginosa isolates. These virulence factors are directly involved with quorum-sensing systems. Further research should investigate the effects of AgNPs on P. aeruginosa quorum sensing to help elucidate their mechanism of action at subinhibitory concentrations.
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Affiliation(s)
- Erika Kushikawa Saeki
- Regional Laboratory of Presidente Prudente, Adolfo Lutz Institute, Presidente Prudente, Brazil
| | - Amanda Yaeko Yamada
- Regional Laboratory of Presidente Prudente, Adolfo Lutz Institute, Presidente Prudente, Brazil
| | | | - Laís Anversa
- Regional Laboratory of Bauru, Adolfo Lutz Institute, Bauru, Brazil
| | | | | | - Heloísa Moreira Martins
- Laboratory of Basic and Applied Bacteriology, Department of Microbiology, Center of Biological Sciences, State University of Londrina, Londrina, Brazil
| | - Renata Katsuko Takayama Kobayashi
- Laboratory of Basic and Applied Bacteriology, Department of Microbiology, Center of Biological Sciences, State University of Londrina, Londrina, Brazil
| | - Gerson Nakazato
- Laboratory of Basic and Applied Bacteriology, Department of Microbiology, Center of Biological Sciences, State University of Londrina, Londrina, Brazil
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Abedini E, Khodadadi E, Zeinalzadeh E, Moaddab SR, Asgharzadeh M, Mehramouz B, Dao S, Samadi Kafil H. A Comprehensive Study on the Antimicrobial Properties of Resveratrol as an Alternative Therapy. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2021; 2021:8866311. [PMID: 33815561 PMCID: PMC7987421 DOI: 10.1155/2021/8866311] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 02/16/2021] [Accepted: 03/10/2021] [Indexed: 12/15/2022]
Abstract
Resveratrol is a polyphenolic antioxidant whose possible health benefits include anticarcinogenic, antiaging, and antimicrobial properties that have gained significant attention. The compound is well accepted by individuals and has been commonly used as a nutraceutical in recent decades. Its widespread usage makes it essential to study as a single agent as well as in combination with traditional prescription antibiotics as regards to antimicrobial properties. Resveratrol demonstrates the action of antimicrobials against a remarkable bacterial diversity, viruses, and fungus. This report explains resveratrol as an all-natural antimicrobial representative. It may modify the bacterial virulence qualities resulting in decreased toxic substance production, biofilm inhibition, motility reduction, and quorum sensing disturbance. Moreover, in conjunction with standard antibiotics, resveratrol improves aminoglycoside efficacy versus Staphylococcus aureus, while it antagonizes the deadly function of fluoroquinolones against S. aureus and also Escherichia coli. The present study aimed to thoroughly review and study the antimicrobial potency of resveratrol, expected to help researchers pave the way for solving antimicrobial resistance.
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Affiliation(s)
- Ehsan Abedini
- Drug Applied Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ehsaneh Khodadadi
- Drug Applied Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Elham Zeinalzadeh
- Hematology and Oncology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Seyyed Reza Moaddab
- Pharmaceutical Nanotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Asgharzadeh
- Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Bahareh Mehramouz
- Connective Tissue Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Sounkalo Dao
- Faculté de Médecine, de Pharmacie et d'Odonto-Stomatologie (FMPOS), University of Bamako, Bamako, Mali
| | - Hossein Samadi Kafil
- Drug Applied Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
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Capillary bacterial migration on non-nutritive solid surfaces. Arh Hig Rada Toksikol 2020; 71:251-260. [PMID: 33074174 PMCID: PMC7968502 DOI: 10.2478/aiht-2020-71-3436] [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] [Received: 05/01/2020] [Accepted: 08/01/2020] [Indexed: 12/04/2022] Open
Abstract
Here we describe an additional type of bacterial migration in which bacterial cells migrate vertically across a non-nutritive solid surface carried by capillary forces. Unlike standard motility experiments, these were run on a glass slide inserted into a Falcon tube, partly immersed in a nutrient medium and partly exposed to air. Observations revealed that capillary forces initiated upward cell migration when biofilm was formed at the border between liquid and air. The movement was facilitated by the production of extracellular polymeric substances (EPS). This motility differs from earlier described swarming, twitching, gliding, sliding, or surfing, although these types of movements are not excluded. We therefore propose to call it “capillary movement of biofilm”. This phenomenon may be an ecologically important mode of bacterial motility on solid surfaces.
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19
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Alford MA, Baghela A, Yeung ATY, Pletzer D, Hancock REW. NtrBC Regulates Invasiveness and Virulence of Pseudomonas aeruginosa During High-Density Infection. Front Microbiol 2020; 11:773. [PMID: 32431676 PMCID: PMC7214821 DOI: 10.3389/fmicb.2020.00773] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 03/31/2020] [Indexed: 12/21/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that is a major cause of nosocomial and chronic infections contributing to morbidity and mortality in cystic fibrosis patients. One of the reasons for its success as a pathogen is its ability to adapt to a broad range of circumstances. Here, we show the involvement of the general nitrogen regulator NtrBC, which is structurally conserved but functionally diverse across species, in pathogenic and adaptive states of P. aeruginosa. The role of NtrB and NtrC was examined in progressive or chronic infections, which revealed that mutants (ΔntrB, ΔntrC, and ΔntrBC) were reduced in their ability to invade and cause damage in a high-density abscess model in vivo. Progressive infections were established with mutants in the highly virulent PA14 genetic background, whereas chronic infections were established with mutants in the less virulent clinical isolate LESB58 genetic background. Characterization of adaptive lifestyles in vitro confirmed that the double ΔntrBC mutant demonstrated >40% inhibition of biofilm formation, a nearly complete inhibition of swarming motility, and a modest decrease and altered surfing motility colony appearance; with the exception of swarming, single mutants generally had more subtle or no changes. Transcriptional profiles of deletion mutants under swarming conditions were defined using RNA-Seq and unveiled dysregulated expression of hundreds of genes implicated in virulence in PA14 and LESB58 chronic lung infections, as well as carbon and nitrogen metabolism. Thus, transcriptional profiles were validated by testing responsiveness of mutants to several key intermediates of central metabolic pathways. These results indicate that NtrBC is a global regulatory system involved in both pathological and physiological processes relevant to the success of Pseudomonas in high-density infection.
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Affiliation(s)
- Morgan A Alford
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Arjun Baghela
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | | | - Daniel Pletzer
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada.,Department of Microbiology, University of Otago, Dunedin, New Zealand
| | - Robert E W Hancock
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada.,Wellcome Sanger Institute, Hinxton, United Kingdom
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20
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Pletzer D, Sun E, Ritchie C, Wilkinson L, Liu LT, Trimble MJ, Wolfmeier H, Blimkie TM, Hancock REW. Surfing motility is a complex adaptation dependent on the stringent stress response in Pseudomonas aeruginosa LESB58. PLoS Pathog 2020; 16:e1008444. [PMID: 32208458 PMCID: PMC7122816 DOI: 10.1371/journal.ppat.1008444] [Citation(s) in RCA: 14] [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: 10/19/2019] [Revised: 04/03/2020] [Accepted: 02/29/2020] [Indexed: 11/18/2022] Open
Abstract
Cystic fibrosis (CF) is a genetic disease that affects mucin-producing body organs such as the lungs. Characteristic of CF is the production of thick, viscous mucus, containing the glycoprotein mucin, that can lead to progressive airway obstruction. Recently, we demonstrated that the presence of mucin induced a rapid surface adaptation in motile bacteria termed surfing motility, which data presented here indicates is very different from swarming motility. Pseudomonas aeruginosa, the main colonizing pathogen in CF, employs several stress coping mechanisms to survive the highly viscous environment of the CF lung. We used motility-based assays and RNA-Seq to study the stringent stress response in the hypervirulent CF isolate LESB58 (Liverpool Epidemic Strain). Motility experiments revealed that an LESB58 stringent response mutant (ΔrelAΔspoT) was unable to surf. Transcriptional profiling of ΔrelAΔspoT mutant cells from surfing agar plates, when compared to wild-type cells from the surfing edge, revealed 2,584 dysregulated genes. Gene Ontology and KEGG enrichment analysis revealed effects of the stringent response on amino acid, nucleic acid and fatty acid metabolism, TCA cycle and glycolysis, type VI secretion, as well as chemotaxis, cell communication, iron transport, nitrogen metabolic processes and cyclic-di-GMP signalling. Screening of the ordered PA14 transposon library revealed 224 mutants unable to surf and very limited overlap with genes required for swarming. Mutants affecting surfing included two downstream effector genes of the stringent stress response, the copper regulator cueR and the quinolone synthase pqsH. Both the cueR and pqsH cloned genes complemented the surfing deficiency of ΔrelAΔspoT. Our study revealed insights into stringent stress dependency in LESB58 and showed that surfing motility is stringently-controlled via the expression of cueR and pqsH. Downstream factors of the stringent stress response are important to investigate in order to fully understand its ability to colonize and persist in the CF lung.
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Affiliation(s)
- Daniel Pletzer
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- * E-mail: (DP); (REWH)
| | - Evelyn Sun
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Caleb Ritchie
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Lauren Wilkinson
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Leo T. Liu
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Michael J. Trimble
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Heidi Wolfmeier
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Travis M. Blimkie
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Robert E. W. Hancock
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
- * E-mail: (DP); (REWH)
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Riva V, Mapelli F, Syranidou E, Crotti E, Choukrallah R, Kalogerakis N, Borin S. Root Bacteria Recruited by Phragmites australis in Constructed Wetlands Have the Potential to Enhance Azo-Dye Phytodepuration. Microorganisms 2019; 7:E384. [PMID: 31554215 PMCID: PMC6843347 DOI: 10.3390/microorganisms7100384] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 08/30/2019] [Accepted: 09/20/2019] [Indexed: 12/11/2022] Open
Abstract
The microbiome associated with plants used in phytodepuration systems can boost plant growth and services, especially in ecosystems dealing with recalcitrant compounds, hardly removed via traditional wastewater (WW) treatments, such as azo-dyes used in textile industry. In this context, we aimed to study the cultivable microbiome selected by Phragmites australis plants in a Constructed Wetland (CW) in Morocco, in order to obtain candidate inoculants for the phytodepuration of azo-dye contaminated WW. A collection of 152 rhizospheric and endophytic bacteria was established. The strains were phylogenetically identified and characterized for traits of interest in the phytodepuration context. All strains showed Plant Growth Promotion potential in vitro and 67% of them significantly improved the growth of a model plant in vivo compared to the non bacterized control plants. Moreover, most of the isolates were able to grow in presence of several model micropollutants typically found in WW, indicating their potential use in phytodepuration of a wide spectrum of effluents. The six most promising strains of the collection were tested in CW microcosms alone or as consortium: the consortium and two single inocula demonstrated to significantly increase the removal of the model azo-dye Reactive Black 5 compared to the non bacterized controls.
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Affiliation(s)
- Valentina Riva
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, 20133 Milano, Italy.
| | - Francesca Mapelli
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, 20133 Milano, Italy.
| | - Evdokia Syranidou
- School of Environmental Engineering, Technical University of Crete, Polytecneioupolis, 73100 Chania, Greece.
| | - Elena Crotti
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, 20133 Milano, Italy.
| | - Redouane Choukrallah
- Hassan II, Salinity and Plant Nutrition Laboratory, Institut Agronomique et Vétérinaire, 86150 Agadir, Morocco.
| | - Nicolas Kalogerakis
- School of Environmental Engineering, Technical University of Crete, Polytecneioupolis, 73100 Chania, Greece.
| | - Sara Borin
- Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, 20133 Milano, Italy.
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22
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Dong N, Wang C, Zhang T, Zhang L, Xue C, Feng X, Bi C, Shan A. Bioactivity and Bactericidal Mechanism of Histidine-Rich β-Hairpin Peptide Against Gram-Negative Bacteria. Int J Mol Sci 2019; 20:ijms20163954. [PMID: 31416220 PMCID: PMC6718988 DOI: 10.3390/ijms20163954] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 08/06/2019] [Accepted: 08/13/2019] [Indexed: 02/07/2023] Open
Abstract
Antibacterial peptides (APMs) are a new type of antibacterial substance. The relationship between their structure and function remains indistinct; in particular, there is a lack of a definitive and fixed template for designing new antimicrobial peptides. Previous studies have shown that porcine Protegrin-1 (PG-1) exhibits considerable antimicrobial activity and cytotoxicity. In this study, to reduce cytotoxicity and increase cell selectivity, we designed histidine-rich peptides based on the sequence template RR(XY)2XDPGX(YX)2RR-NH2, where X represents I, W, V, and F. The results showed that the peptides form more β-hairpin structures in a lipid-rich environment that mimics cell membranes. Among them, the antimicrobial peptide HV2 showed strong antibacterial activity against Gram-negative strains and almost no toxicity to normal cells. The results of our analysis of its antibacterial mechanism showed that peptide HV2 acts on the bacterial cell membrane to increase its permeability, resulting in cell membrane disruption and death. Furthermore, peptide HV2 inhibited bacterial movement in a concentration-dependent manner and had a more robust anti-inflammatory effect by inhibiting the production of TNF-α. In summary, peptide HV2 exhibits high bactericidal activity and cell selectivity, making it a promising candidate for future use as an antibiotic.
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Affiliation(s)
- Na Dong
- Laboratory of Molecular Nutrition and Immunity. The Institute of Animal Nutrition, Northeast Agricultural University, Harbin 150030, China
| | - Chensi Wang
- Laboratory of Molecular Nutrition and Immunity. The Institute of Animal Nutrition, Northeast Agricultural University, Harbin 150030, China
| | - Tingting Zhang
- Laboratory of Molecular Nutrition and Immunity. The Institute of Animal Nutrition, Northeast Agricultural University, Harbin 150030, China
| | - Lei Zhang
- Laboratory of Molecular Nutrition and Immunity. The Institute of Animal Nutrition, Northeast Agricultural University, Harbin 150030, China
| | - Chenyu Xue
- Laboratory of Molecular Nutrition and Immunity. The Institute of Animal Nutrition, Northeast Agricultural University, Harbin 150030, China
| | - Xinjun Feng
- Laboratory of Molecular Nutrition and Immunity. The Institute of Animal Nutrition, Northeast Agricultural University, Harbin 150030, China
| | - Chongpeng Bi
- Laboratory of Molecular Nutrition and Immunity. The Institute of Animal Nutrition, Northeast Agricultural University, Harbin 150030, China
| | - Anshan Shan
- Laboratory of Molecular Nutrition and Immunity. The Institute of Animal Nutrition, Northeast Agricultural University, Harbin 150030, China.
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Istiaq A, Shuvo MSR, Rahman KMJ, Siddique MA, Hossain MA, Sultana M. Adaptation of metal and antibiotic resistant traits in novel β-Proteobacterium Achromobacter xylosoxidans BHW-15. PeerJ 2019; 7:e6537. [PMID: 30886770 PMCID: PMC6421061 DOI: 10.7717/peerj.6537] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 01/29/2019] [Indexed: 12/22/2022] Open
Abstract
Chromosomal co-existence of metal and antibiotic resistance genes in bacteria offers a new perspective to the bacterial resistance proliferation in contaminated environment. In this study, an arsenotrophic bacterium Achromobacter xylosoxidans BHW-15, isolated from Arsenic (As) contaminated tubewell water in the Bogra district of Bangladesh, was analyzed using high throughput Ion Torrent Personal Genome Machine (PGM) complete genome sequencing scheme to reveal its adaptive potentiality. The assembled draft genome of A. xylosoxidans BHW-15 was 6.3 Mbp containing 5,782 functional genes, 1,845 pseudo genes, and three incomplete phage signature regions. Comparative genome study suggested the bacterium to be a novel strain of A. xylosoxidans showing significant dissimilarity with other relevant strains in metal resistance gene islands. A total of 35 metal resistance genes along with arsenite-oxidizing aioSXBA, arsenate reducing arsRCDAB, and mercury resistance merRTPADE operonic gene cluster and 20 broad range antibiotic resistance genes including β-lactams, aminoglycosides, and multiple multidrug resistance (MDR) efflux gene complex with a tripartite system OM-IM-MFP were found co-existed within the genome. Genomic synteny analysis with reported arsenotrophic bacteria revealed the characteristic genetic organization of ars and mer operonic genes, rarely described in β-Proteobacteria. A transposon Tn21 and mobile element protein genes were also detected to the end of mer (mercury) operonic genes, possibly a carrier for the gene transposition. In vitro antibiotic susceptibility assay showed a broad range of resistance against antibiotics belonging to β-lactams, aminoglycosides, cephalosporins (1st, 2nd, and 3rd generations), monobactams and even macrolides, some of the resistome determinants were predicted during in silico analysis. KEGG functional orthology analysis revealed the potential of the bacterium to utilize multiple carbon sources including one carbon pool by folate, innate defense mechanism against multiple stress conditions, motility, a proper developed cell signaling and processing unit and secondary metabolism-combination of all exhibiting a robust feature of the cell in multiple stressed conditions. The complete genome of the strain BHW-15 stands as a genetic basis for the evolutionary adaptation of metal and the antibiotic coexistence phenomenon in an aquatic environment.
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Affiliation(s)
- Arif Istiaq
- Department of Microbiology, University of Dhaka, Dhaka, Bangladesh.,Department of Microbiology, Noakhali Science and Technology University, Noakhali, Bangladesh
| | - Md Sadikur Rahman Shuvo
- Department of Microbiology, University of Dhaka, Dhaka, Bangladesh.,Department of Microbiology, Noakhali Science and Technology University, Noakhali, Bangladesh
| | | | | | - M Anwar Hossain
- Department of Microbiology, University of Dhaka, Dhaka, Bangladesh
| | - Munawar Sultana
- Department of Microbiology, University of Dhaka, Dhaka, Bangladesh
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York A. Surf’s up! Nat Rev Microbiol 2018; 16:658-659. [DOI: 10.1038/s41579-018-0093-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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