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Esposito TVF, Blackadar C, Wu L, Rodríguez-Rodríguez C, Haney EF, Pletzer D, Saatchi K, Hancock REW, Häfeli UO. Biodistribution of Native and Nanoformulated Innate Defense Regulator Peptide 1002. Mol Pharm 2024; 21:2751-2766. [PMID: 38693707 DOI: 10.1021/acs.molpharmaceut.3c01169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
Innate defense regulator-1002 (IDR-1002) is a synthetic peptide with promising immunomodulatory and antibiofilm properties. An appreciable body of work exists around its mechanism of action at the cellular and molecular level, along with its efficacy across several infection and inflammation models. However, little is known about its absorption, distribution, and excretion in live organisms. Here, we performed a comprehensive biodistribution assessment with a gallium-67 radiolabeled derivative of IDR-1002 using nuclear tracing techniques. Various dose levels of the radiotracer (2-40 mg/kg) were administered into the blood, peritoneal cavity, and subcutaneous tissue, or instilled into the lungs. The peptide was well tolerated at all subcutaneous and intraperitoneal doses, although higher levels were associated with delayed absorption kinetics and precipitation of the peptide within the tissues. Low intratracheal doses were rapidly absorbed systemically, and small increases in the dose level were lethal. Intravenous doses were rapidly cleared from the blood at lower levels, and upon escalation, were toxic with a high proportion of the dose accumulating within the lung tissue. To improve biocompatibility and prolong its circulation within the blood, IDR-1002 was further formulated onto high molecular weight hyperbranched polyglycerol (HPG) polymers. Constructs prepared at 5:1 and 10:1 peptide-to-polymer ratios were colloidally stable, maintained the biological profile of the peptide payload and helped reduce red blood cell lysis. The 5:1 construct circulated well in the blood, but higher peptide loading was associated with rapid clearance by the reticuloendothelial system. Many peptides face pharmacokinetic and biocompatibility challenges, but formulations such as those with HPG have the potential to overcome these limitations.
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Affiliation(s)
- Tullio V F Esposito
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Colin Blackadar
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Lan Wu
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
- Wuya College of Innovation, Shenyang Pharmaceutical University, Wenhua Road No. 103, Shenyang 110016, China
| | - Cristina Rodríguez-Rodríguez
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
- Department of Physics and Astronomy, Faculty of Science, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Evan F Haney
- Centre for Microbial Disease and Immunity Research, Department of Microbiology and Immunology, Faculty of Science, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
- Asep Medical Holdings, 420 - 730 View Street, Victoria V8W 3Y7, British Columbia, Canada
| | - Daniel Pletzer
- Centre for Microbial Disease and Immunity Research, Department of Microbiology and Immunology, Faculty of Science, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
- Department of Microbiology and Immunology, University of Otago, Dunedin 9054, New Zealand
| | - Katayoun Saatchi
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Robert E W Hancock
- Centre for Microbial Disease and Immunity Research, Department of Microbiology and Immunology, Faculty of Science, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Urs O Häfeli
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 1172, Denmark
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Espíndola-Rodríguez NH, Muñoz-Cázares N, Serralta-Peraza LEDS, Díaz-Nuñez JL, Montoya-Reyes F, García-Contreras R, Díaz-Guerrero M, Rivera-Chávez JA, Gutiérrez J, Sotelo-Barrera M, Castillo-Juárez I. Antivirulence and antipathogenic activity of Mayan herbal remedies against Pseudomonas aeruginosa. JOURNAL OF ETHNOPHARMACOLOGY 2024; 332:118373. [PMID: 38782309 DOI: 10.1016/j.jep.2024.118373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 05/11/2024] [Accepted: 05/19/2024] [Indexed: 05/25/2024]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE The Yucatan Peninsula has a privileged wealth of vascular plants with which various Mayan herbal formulations have been developed. However, studies on their antipathogenic and antivirulence properties are scarce. AIM OF THE STUDY Identify antivirulence properties in Mayan herbal remedies and determine their antipathogenic capacity in burn wounds infected with Pseudomonas aeruginosa. MATERIALS AND METHODS An ethnobotanical study was conducted in Mayan communities in central and southern Quintana Roo, Mexico. Furthermore, the antipathogenic capacity of three Mayan herbal remedies was analyzed using an animal model of thermal damage and P. aeruginosa infection. Antivirulence properties were determined by inhibiting phenotypes regulated by quorum sensing (pyocyanin, biofilm, and swarming) and by the secretion of the ExoU toxin. The chemical composition of the most active herbal remedy was analyzed using molecular network analysis. RESULTS It was found that topical administration of the remedy called "herbal soap" (HS) for eleven days maintained 100% survival of the animals, reduced establishment of the bacteria in the burn and prevented its systemic dispersion. Although no curative effect was recorded on tissue damaged by HS treatment, its herbal composition strongly reduced swarming and ExoU secretion. Through analysis of Molecular Networks, it was possible to carry out a global study of its chemical components, and identify the family of oxindole monoterpenoid alkaloids and carboline and tetrahydropyrididole alkaloids. In addition, flavonols, flavan-3-ols, and quinic acid derivatives were detected. CONCLUSIONS The antipathogenic and antivirulence capacity of ancient Mayan remedies makes them a potential resource for developing new antibacterial therapies to treat burns infected by P. aeruginosa.
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Affiliation(s)
- Nadine Heidi Espíndola-Rodríguez
- Laboratorio de Investigación y Aplicación de Fitoquímicos Bioactivos, Posgrado en Botánica, Colegio de Postgraduados, Texcoco, 56230, Mexico.
| | - Naybi Muñoz-Cázares
- Campo Experimental Chetumal, Instituto de Investigaciones Forestales, Agrícolas y Pecuarias, Quintana Roo, 77963, Mexico; Investigadora Posdoctoral CONAHCYT Comisionada al Colegio de Postgraduados-Campus Tabasco, Cárdenas, Tabasco, C. P. 86500, Mexico.
| | | | - José Luis Díaz-Nuñez
- Laboratorio de Investigación y Aplicación de Fitoquímicos Bioactivos, Posgrado en Botánica, Colegio de Postgraduados, Texcoco, 56230, Mexico.
| | - Francisco Montoya-Reyes
- Campo Experimental Chetumal, Instituto de Investigaciones Forestales, Agrícolas y Pecuarias, Quintana Roo, 77963, Mexico.
| | - Rodolfo García-Contreras
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, CDMX, 04510, Mexico.
| | - Miguel Díaz-Guerrero
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, CDMX, 04510, Mexico.
| | - José Alberto Rivera-Chávez
- Departamento de Productos Naturales, Instituto de Química, Universidad Nacional Autónoma de México, CDMX, 04510, Mexico.
| | - Jorge Gutiérrez
- Área de Biología, Departamento de Preparatoria Agrícola, Universidad Autónoma Chapingo, Texcoco, 56230, Mexico.
| | - Mireya Sotelo-Barrera
- Laboratorio de Investigación y Aplicación de Fitoquímicos Bioactivos, Posgrado en Botánica, Colegio de Postgraduados, Texcoco, 56230, Mexico.
| | - Israel Castillo-Juárez
- Laboratorio de Investigación y Aplicación de Fitoquímicos Bioactivos, Posgrado en Botánica, Colegio de Postgraduados, Texcoco, 56230, Mexico; Conahcyt-Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Mineral de la Reforma, Hidalgo, 42184, Mexico.
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3
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Gager C, Flores-Mireles AL. Blunted blades: new CRISPR-derived technologies to dissect microbial multi-drug resistance and biofilm formation. mSphere 2024; 9:e0064223. [PMID: 38511958 PMCID: PMC11036814 DOI: 10.1128/msphere.00642-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024] Open
Abstract
The spread of multi-drug-resistant (MDR) pathogens has rapidly outpaced the development of effective treatments. Diverse resistance mechanisms further limit the effectiveness of our best treatments, including multi-drug regimens and last line-of-defense antimicrobials. Biofilm formation is a powerful component of microbial pathogenesis, providing a scaffold for efficient colonization and shielding against anti-microbials, which further complicates drug resistance studies. Early genetic knockout tools didn't allow the study of essential genes, but clustered regularly interspaced palindromic repeat inference (CRISPRi) technologies have overcome this challenge via genetic silencing. These tools rapidly evolved to meet new demands and exploit native CRISPR systems. Modern tools range from the creation of massive CRISPRi libraries to tunable modulation of gene expression with CRISPR activation (CRISPRa). This review discusses the rapid expansion of CRISPRi/a-based technologies, their use in investigating MDR and biofilm formation, and how this drives further development of a potent tool to comprehensively examine multi-drug resistance.
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Affiliation(s)
- Christopher Gager
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Ana L. Flores-Mireles
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
- W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, Indiana, USA
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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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Al-Rabia MW, Asfour HZ, Alhakamy NA, Abdulaal WH, Ibrahim TS, Abbas HA, Salem IM, Hegazy WAH, Nazeih SI. Thymoquinone is a natural antibiofilm and pathogenicity attenuating agent in Pseudomonas aeruginosa. Front Cell Infect Microbiol 2024; 14:1382289. [PMID: 38638827 PMCID: PMC11024287 DOI: 10.3389/fcimb.2024.1382289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 03/08/2024] [Indexed: 04/20/2024] Open
Abstract
Pseudomonas aeruginosa belongs to the critical pathogens that represent a global public health problem due to their high rate of resistance as listed by WHO. P. aeruginosa can result in many nosocomial infections especially in individuals with compromised immune systems. Attenuating virulence factors by interference with quorum sensing (QS) systems is a promising approach to treat P. aeruginosa-resistant infections. Thymoquinone is a natural compound isolated from Nigella sativa (black seed) essential oil. In this study, the minimum inhibitory concentration of thymoquinone was detected followed by investigating the antibiofilm and antivirulence activities of the subinhibitory concentration of thymoquinone against P. aeruginosa PAO1. The effect of thymoquinone on the expression of QS genes was assessed by quantitative real-time PCR, and the protective effect of thymoquinone against the pathogenesis of PAO1 in mice was detected by the mouse survival test. Thymoquinone significantly inhibited biofilm, pyocyanin, protease activity, and swarming motility. At the molecular level, thymoquinone markedly downregulated QS genes lasI, lasR, rhlI, and rhlR. Moreover, thymoquinone could protect mice from the pathologic effects of P. aeruginosa increasing mouse survival from 20% to 100%. In conclusion, thymoquinone is a promising natural agent that can be used as an adjunct therapeutic agent with antibiotics to attenuate the pathogenicity of P. aeruginosa.
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Affiliation(s)
- Mohammed W. Al-Rabia
- Department of Clinical Microbiology and Immunology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Hani Z. Asfour
- Department of Clinical Microbiology and Immunology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Nabil A. Alhakamy
- Department of Pharmaceutics, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
- Center of Excellence for Drug Research and Pharmaceutical Industries, King Abdulaziz University, Jeddah, Saudi Arabia
- Mohamed Saeed Tamer Chair for Pharmaceutical Industries, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Wesam H. Abdulaal
- Department of Biochemistry, Faculty of Science, Cancer and Mutagenesis Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Tarek S. Ibrahim
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Hisham A. Abbas
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
| | - Ibrahim M. Salem
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Sphinx University, Assiut, Egypt
| | - Wael A. H. Hegazy
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
- Pharmacy Program, Department of Pharmaceutical Sciences, Oman College of Health Sciences, Muscat, Oman
| | - Shaimaa I. Nazeih
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
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Kambouris AR, Brammer JA, Roussey H, Chen C, Cross AS. A combination of burn wound injury and Pseudomonas infection elicits unique gene expression that enhances bacterial pathogenicity. mBio 2023; 14:e0245423. [PMID: 37929965 PMCID: PMC10746159 DOI: 10.1128/mbio.02454-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 10/02/2023] [Indexed: 11/07/2023] Open
Abstract
Burns are a leading cause of morbidity and mortality worldwide with the most common cause of death resulting from sepsis, often from Pseudomonas aeruginosa. We previously reported that a non-lethal flame burn induced an altered host immune response. Using this model, gene expression in both the murine host and P. aeruginosa was measured using a NanoString custom probe panel. We observed differing patterns of gene expression in both host and P. aeruginosa in the skin, blood, liver, and spleen of mice that were burned and/or infected, compared to mice that were neither burned nor infected (i.e., Sham). In mice that were both burned and infected (B/I), we observed changes in gene expression in both the host and P. aeruginosa that were distinct from all other treatment conditions. These data suggest that the combination of the burned state and superimposed infection affects both host and pathogen gene expression to increase infection propensity. Gene transcription significantly changed from 6 to 24 h post-B/I in each tissue. Finally, inhibiting IL-10 signaling or co-administering arginine at the time of P. aeruginosa infection prolonged or restored survival in an otherwise 100% fatal burn and infection model. These findings suggest that disease states such as burns may differentially alter innate immune response gene expression in both a host- and pathogen-specific manner.IMPORTANCEThe interaction between an underlying disease process and a specific pathogen may lead to the unique expression of genes that affect bacterial pathogenesis. These genes may not be observed during infection in the absence of, or with a different underlying process or infection during the underlying process with a different pathogen. To test this hypothesis, we used Nanostring technology to compare gene transcription in a murine-burned wound infected with P. aeruginosa. The Nanostring probeset allowed the simultaneous direct comparison of immune response gene expression in both multiple host tissues and P. aeruginosa in conditions of burn alone, infection alone, and burn with infection. While RNA-Seq is used to discover novel transcripts, NanoString could be a technique to monitor specific changes in transcriptomes between samples and bypass the additional adjustments for multispecies sample processing or the need for the additional steps of alignment and assembly required for RNASeq. Using Nanostring, we identified arginine and IL-10 as important contributors to the lethal outcome of burned mice infected with P. aeruginosa. While other examples of altered gene transcription are in the literature, our study suggests that a more systematic comparison of gene expression in various underlying diseases during infection with specific bacterial pathogens may lead to the identification of unique host-pathogen interactions and result in more precise therapeutic interventions.
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Affiliation(s)
- Adrienne R. Kambouris
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Jerod A. Brammer
- US Army Institute of Surgical Research, Joint Base San Antonio Fort Sam Houston, Houston, Texas, USA
| | - Holly Roussey
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Chixiang Chen
- Division of Biostatistics and Bioinformatics, Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Alan S. Cross
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Evani SJ, Chen P, Karna SR, D'Arpa P, Leung KP. Cerium Nitrate Stiffens In Vitro Skin Models and Reduces Pseudomonas aeruginosa Pathogenicity and Penetration Through Skin Models. Adv Wound Care (New Rochelle) 2023; 12:546-559. [PMID: 36394961 PMCID: PMC10387153 DOI: 10.1089/wound.2022.0026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 11/12/2022] [Indexed: 11/18/2022] Open
Abstract
Objective: Cerium nitrate (CeN) plus silver sulfadiazine (SSD) cream has been used for 40-plus years to manage burns. CeN produces a hardened eschar believed to resist bacterial colonization/infection. To evaluate this potential mechanism, we treated in vitro skin models or Pseudomonas aeruginosa with CeN and measured mechanical properties of the models and bacterial virulence, respectively. Approach: We treated three-dimensional-collagen matrix and ex-vivo-burned porcine skin with CeN and evaluated stiffness and P. aeruginosa penetration. In addition, we treated P. aeruginosa with CeN and evaluated the bacteria's motility, skin model penetration, susceptibility to be phagocytized by the human monocytic cell line THP-1, and ability to stimulate this cell line to produce cytokines. Results: CeN treatment of skin models stiffened them and made them resistant to P. aeruginosa penetration. Inversely, CeN treatment of P. aeruginosa reduced their motility, penetration through skin models (ex-vivo-burned porcine skin), and ability to stimulate cytokine production (tumor necrosis factor-α [TNF-α] and interleukin 8 [IL-8]) by THP-1 cells. In addition, CeN-treated Pseudomonas was more readily phagocytized by THP-1 cells. Finally, P. aeruginosa inoculated on CeN-treated ex-vivo-burned porcine skin was more susceptible to killing by a silver dressing. Innovation: In vitro skin models offer a platform for screening drugs that interfere with bacterial penetration into wounded tissue. Conclusion: CeN treatment reduced P. aeruginosa virulence, altered the mechanical properties of ex-vivo-burned porcine skin and collagen matrix, retarded penetration of P. aeruginosa through the skin models, and resulted in increased vulnerability of P. aeruginosa to killing by antimicrobial wound dressings. These data support the use of CeN in burn management.
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Affiliation(s)
- Shankar J. Evani
- Combat Wound Care Group, United States Army Institute of Surgical Research, Fort Sam Houston, Texas, USA
| | - Ping Chen
- Combat Wound Care Group, United States Army Institute of Surgical Research, Fort Sam Houston, Texas, USA
| | - S.L. Rajasekhar Karna
- Combat Wound Care Group, United States Army Institute of Surgical Research, Fort Sam Houston, Texas, USA
| | - Peter D'Arpa
- Combat Wound Care Group, United States Army Institute of Surgical Research, Fort Sam Houston, Texas, USA
| | - Kai P. Leung
- Combat Wound Care Group, United States Army Institute of Surgical Research, Fort Sam Houston, Texas, USA
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Ambreetha S, Singh V. Genetic and environmental determinants of surface adaptations in Pseudomonas aeruginosa. MICROBIOLOGY (READING, ENGLAND) 2023; 169. [PMID: 37276014 DOI: 10.1099/mic.0.001335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Pseudomonas aeruginosa
is a well-studied Gram-negative opportunistic bacterium that thrives in markedly varied environments. It is a nutritionally versatile microbe that can colonize a host as well as exist in the environment. Unicellular, planktonic cells of
P. aeruginosa
can come together to perform a coordinated swarming movement or turn into a sessile, surface-adhered population called biofilm. These collective behaviours produce strikingly different outcomes. While swarming motility rapidly disseminates the bacterial population, biofilm collectively protects the population from environmental stresses such as heat, drought, toxic chemicals, grazing by predators, and attack by host immune cells and antibiotics. The ubiquitous nature of
P. aeruginosa
is likely to be supported by the timely transition between planktonic, swarming and biofilm lifestyles. The social behaviours of this bacteria viz biofilm and swarm modes are controlled by signals from quorum-sensing networks, LasI-LasR, RhlI-RhlR and PQS-MvfR, and several other sensory kinases and response regulators. A combination of environmental and genetic cues regulates the transition of the
P. aeruginosa
population to specific states. The current review is aimed at discussing key factors that promote physiologically distinct transitioning of the
P. aeruginosa
population.
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Affiliation(s)
- Sakthivel Ambreetha
- Department of Developmental Biology and Genetics, Indian Institute of Science, Bengaluru, Karnataka - 560012, India
| | - Varsha Singh
- Department of Developmental Biology and Genetics, Indian Institute of Science, Bengaluru, Karnataka - 560012, India
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Li C, Gan Y, Li Z, Fu M, Li Y, Peng X, Yang Y, Tian GB, Yang YY, Yuan P, Ding X. Neutrophil-inspired photothermo-responsive drug delivery system for targeted treatment of bacterial infection and endotoxins neutralization. Biomater Res 2023; 27:30. [PMID: 37061741 PMCID: PMC10105932 DOI: 10.1186/s40824-023-00372-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 03/26/2023] [Indexed: 04/17/2023] Open
Abstract
BACKGROUND P. aeruginosa, a highly virulent Gram-negative bacterium, can cause severe nosocomial infections, and it has developed resistance against most antibiotics. New therapeutic strategies are urgently needed to treat such bacterial infection and reduce its toxicity caused by endotoxin (lipopolysaccharide, LPS). Neutrophils have been proven to be able to target inflammation site and neutrophil membrane receptors such as Toll-like receptor-4 (TLR4) and CD14, and exhibit specific affinity to LPS. However, antibacterial delivery system based on the unique properties of neutrophils has not been reported. METHODS A neutrophil-inspired antibacterial delivery system for targeted photothermal treatment, stimuli-responsive antibiotic release and endotoxin neutralization is reported in this study. Specifically, the photothermal reagent indocyanine green (ICG) and antibiotic rifampicin (RIF) are co-loaded into poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NP-ICG/RIF), followed by coating with neutrophil membrane to obtain antibacterial delivery system (NM-NP-ICG/RIF). The inflammation targeting properties, synergistic antibacterial activity of photothermal therapy and antibiotic treatment, and endotoxin neutralization have been studied in vitro. A P. aeruginosa-induced murine skin abscess infection model has been used to evaluate the therapeutic efficacy of the NM-NP-ICG/RIF. RESULTS Once irradiated by near-infrared lasers, the heat generated by NP-ICG/RIF triggers the release of RIF and ICG, resulting in a synergistic chemo-photothermal antibacterial effect against P. aeruginosa (~ 99.99% killing efficiency in 5 min). After coating with neutrophil-like cell membrane vesicles (NMVs), the nanoparticles (NM-NP-ICG/RIF) specifically bind to inflammatory vascular endothelial cells in infectious site, endowing the nanoparticles with an infection microenvironment targeting function to enhance retention time. Importantly, it is discovered for the first time that NMVs-coated nanoparticles are able to neutralize endotoxins. The P. aeruginosa murine skin abscess infection model further demonstrates the in vivo therapeutic efficacy of NM-NP-ICG/RIF. CONCLUSION The neutrophil-inspired antibacterial delivery system (NM-NP-ICG/RIF) is capable of targeting infection microenvironment, neutralizing endotoxin, and eradicating bacteria through a synergistic effect of photothermal therapy and antibiotic treatment. This drug delivery system made from FDA-approved compounds provides a promising approach to fighting against hard-to-treat bacterial infections.
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Affiliation(s)
- Chengnan Li
- School of Pharmaceutical Science (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, 518107, PR China
| | - Yingying Gan
- School of Pharmaceutical Science (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, 518107, PR China
| | - Zongshao Li
- School of Pharmaceutical Science (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, 518107, PR China
| | - Mengjing Fu
- School of Pharmaceutical Science (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, 518107, PR China
| | - Yuzhen Li
- School of Pharmaceutical Science (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, 518107, PR China
| | - Xinran Peng
- School of Pharmaceutical Science (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, 518107, PR China
| | - Yongqiang Yang
- Center for Pathogen Research, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Guo-Bao Tian
- Department of Immunology, School of Medicine, Sun Yat-sen University, Shenzhen, 518107, China
| | - Yi Yan Yang
- Bioprocessing Technology Institute (BTI), Agency for Science, Technology and Research (A*STAR), 20 Biopolis Way, Centros #06-01, Singapore, 138668, Republic of Singapore.
| | - Peiyan Yuan
- School of Pharmaceutical Science (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, 518107, PR China.
| | - Xin Ding
- School of Pharmaceutical Science (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, 518107, PR China.
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Li S, Shui Y, Ma J, Yuan Y, Jiang W, Xu C, Wang L, Ren Y, Deng B, Zhang W, Li Z. Antimicrobial activity of CT-K3K7, a modified peptide by lysine substitutions from ctry2459 - A Chaerilus tryznai scorpion venom peptide. Toxicon 2022; 218:88-98. [PMID: 36113685 DOI: 10.1016/j.toxicon.2022.09.004] [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: 07/13/2022] [Revised: 09/04/2022] [Accepted: 09/07/2022] [Indexed: 11/27/2022]
Abstract
Antimicrobial peptides (AMPs) have started to garner more interest as novel antimicrobial agents. The scorpion venom peptide ctry2459 was modified to CT-K3K7 by lysine substitutions at the 3rd and 7th positions to increase the cationic properties. We discovered that the modified peptides CT-K3K7 had improved antibacterial activity, higher thermal stability, as well as lower hemolytic activity. It can kill S. aureus and P. aeruginosa rapidly, and reduce the production of biofilm and live bacterial residues in biofilm in vitro. CT-K3K7 has also been demonstrated to decrease bacterial counts, abscess area, and inflammatory cell infiltration in the mouse subcutaneous abscess models that were duplicated by S. aureus and P. aeruginosa. CT-K3K7 has difficulty in inducing S. aureus and P. aeruginosa to develop drug resistance, which may be related to the bactericidal properties. CT-K3K7 increases cationic properties by lysine substitutions can increase the electrostatic force between the peptides and the bacterial surface, which can lead to an increase in bacterial membrane permeability and DNA binding. In conclusion, the modified peptide CT-K3K7 enhances the antimicrobial activity and can be a novel antimicrobial agent candidate for the treatment of infections by S. aureus and P. aeruginosa.
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Affiliation(s)
- Shasha Li
- School of Basic Medical Sciences, Henan University of Science and Technology, Luoyang, 471003, China
| | - Yingbin Shui
- School of Basic Medical Sciences, Henan University of Science and Technology, Luoyang, 471003, China
| | - Jiayue Ma
- School of Basic Medical Sciences, Henan University of Science and Technology, Luoyang, 471003, China
| | - Yaping Yuan
- School of Basic Medical Sciences, Henan University of Science and Technology, Luoyang, 471003, China
| | - Wenxing Jiang
- School of Basic Medical Sciences, Henan University of Science and Technology, Luoyang, 471003, China
| | - Chenxi Xu
- School of Basic Medical Sciences, Henan University of Science and Technology, Luoyang, 471003, China
| | - Lejing Wang
- School of Basic Medical Sciences, Henan University of Science and Technology, Luoyang, 471003, China
| | - Yongjing Ren
- School of Basic Medical Sciences, Henan University of Science and Technology, Luoyang, 471003, China
| | - Bo Deng
- School of Basic Medical Sciences, Henan University of Science and Technology, Luoyang, 471003, China
| | - Wenlu Zhang
- School of Basic Medical Sciences, Henan University of Science and Technology, Luoyang, 471003, China
| | - Zhongjie Li
- School of Basic Medical Sciences, Henan University of Science and Technology, Luoyang, 471003, China.
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11
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V F Esposito T, Rodríguez-Rodríguez C, Blackadar C, Haney EF, Pletzer D, E W Hancock R, Saatchi K, Häfeli UO. Biodistribution and Toxicity of Innate Defense Regulator 1018 (IDR-1018). Eur J Pharm Biopharm 2022; 179:11-25. [PMID: 36028151 DOI: 10.1016/j.ejpb.2022.08.004] [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: 05/21/2022] [Revised: 08/03/2022] [Accepted: 08/10/2022] [Indexed: 11/04/2022]
Abstract
Innate defense regulators (IDRs) are synthetic host-defense peptides (HDPs) with broad-spectrum anti-infective properties, including immunomodulatory, anti-biofilm and direct antimicrobial activities. A lack of pharmacokinetic data about these peptides hinders their development and makes it challenging to fully understand how they work in vivo since their mechanism of action is dependent on tissue concentrations of the peptide. Here, we set out to define in detail the pharmacokinetics of a well-characterized IDR molecule, IDR-1018. To make the peptide traceable, it was radiolabeled with the long-lived gamma-emitting isotope gallium-67. After a series of bench-top characterizations, the radiotracer was administered to healthy mice intravenously (IV) or subcutaneously (SQ) at various dose levels (2.5-13 mg/kg). Nuclear imaging and ex-vivo biodistributions were used to quantify organ and tissue uptake of the radiotracer over time. When administered as an IV bolus, the distribution profile of the radiotracer changed as the dose was escalated. At 2.5 mg/kg, the peptide was well-tolerated, poorly circulated in the blood and was cleared predominately by the reticuloendothelial system. Higher doses (7 and 13 mg/kg) as an IV bolus were almost immediately lethal due to respiratory arrest; significant lung uptake of the radiotracer was observed from nuclear scans of these animals, and histological examination found extensive damage to the pulmonary vasculature and alveoli. When administered SQ at a dose of 3 mg/kg, radiolabeled IDR-1018 was rapidly absorbed from the site of injection and predominately cleared renally. Apart from the SQ injection site, no other tissue had a concentration above the minimum inhibitory concentration that would enable this peptide to exert direct antimicrobial effects against most pathogenic bacteria. Tissue concentrations were sufficient however to disrupt microbial biofilms and alter the host immune response. Overall, this study demonstrated that the administration of synthetic IDR peptide in vivo is best suited to local administration which avoids some of the issues associated with peptide toxicity that are observed when administered systemically by IV injection, an issue that will have to be addressed through formulation.
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Affiliation(s)
- Tullio V F Esposito
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada; Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Cristina Rodríguez-Rodríguez
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada; Department of Physics and Astronomy, Faculty of Science, University of British Columbia, Vancouver, Canada
| | - Colin Blackadar
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
| | - Evan F Haney
- Centre for Microbial Disease and Immunity Research, Department of Microbiology and Immunology, Faculty of Science, University of British Columbia, Vancouver, Canada; Asep Medical Holdings, Victoria, BC, Canada
| | - Daniel Pletzer
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.
| | - Robert E W Hancock
- Centre for Microbial Disease and Immunity Research, Department of Microbiology and Immunology, Faculty of Science, University of British Columbia, Vancouver, Canada
| | - Katayoun Saatchi
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
| | - Urs O Häfeli
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada; Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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12
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Ambreetha S, Marimuthu P, Mathee K, Balachandar D. Plant-associated Pseudomonas aeruginosa strains harbour multiple virulence traits critical for human infection. J Med Microbiol 2022; 71. [PMID: 35947528 DOI: 10.1099/jmm.0.001493] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Introduction. Pseudomonas aeruginosa causes fatal infections in immunocompromised individuals and patients with pulmonary disorders.Gap Statement. Agricultural ecosystems are the vast reservoirs of this dreaded pathogen. However, there are limited attempts to analyse the pathogenicity of P. aeruginosa strains associated with edible plants.Aim. This study aims to (i) elucidate the virulence attributes of P. aeruginosa strains isolated from the rhizosphere and endophytic niches of cucumber, tomato, eggplant and chili;and (ii) compare these phenotypes with that of previously characterized clinical isolates.Methodology. Crystal-violet microtitre assay, swarm plate experiment, gravimetric quantification and sheep blood lysis were performed to estimate the biofilm formation, swarming motility, rhamnolipid production and haemolytic activity, respectively, of P. aeruginosa strains. In addition, their pathogenicity was also assessed based on their ability to antagonize plant pathogens (Xanthomonas oryzae, Pythium aphanidermatum, Rhizoctonia solani and Fusarium oxysporum) and kill a select nematode (Caenorhabditis elegans).Results. Nearly 80 % of the plant-associated strains produced rhamnolipid and exhibited at least one type of lytic activity (haemolysis, proteolysis and lipolysis). Almost 50 % of these strains formed significant levels of biofilm and exhibited swarming motility. The agricultural strains showed significantly higher and lower virulence against the bacterial and fungal pathogens, respectively, compared to the clinical strains. In C. elegans, a maximum of 40 and 100% mortality were induced by the agricultural and clinical strains, respectively.Conclusion. This investigation shows that P. aeruginosa in edible plants isolated directly from the farm express virulence and pathogenicity. Furthermore, clinical and agricultural P. aeruginosa strains antagonized the tested fungal phytopathogens, Pythium aphanidermatum, Rhizoctonia solani and Fusarium oxysporum. Thus, we recommend using these fungi as simple eukaryotic model systems to test P. aeruginosa pathogenicity.
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Affiliation(s)
- Sakthivel Ambreetha
- Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India.,Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida, USA
| | - Ponnusamy Marimuthu
- Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India
| | - Kalai Mathee
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida, USA.,Biomolecular Sciences Institute, Florida International University, Miami, Florida, USA
| | - Dananjeyan Balachandar
- Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India
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13
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Knocking down Pseudomonas aeruginosa virulence by oral hypoglycemic metformin nano emulsion. World J Microbiol Biotechnol 2022; 38:119. [PMID: 35644864 PMCID: PMC9148876 DOI: 10.1007/s11274-022-03302-8] [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: 03/22/2022] [Accepted: 05/05/2022] [Indexed: 11/18/2022]
Abstract
Long-term antibiotic treatment results in the spread of multi-drug resistance in Pseudomonas aeruginosa that complicates treatment. Anti-virulence agents can be viewed as alternative options that cripple virulence factors of the bacteria to facilitate their elimination by the host immunity. The use of nanoparticles in the inhibition of P. aeruginosa virulence factors is a promising strategy. This study aims to study the effect of metformin (MET), metformin nano emulsions (MET-NEs), silver metformin nano emulsions (Ag-MET-NEs) and silver nanoparticles (AgNPs) on P. aeruginosa virulence factors’ expression. The phenotypic results showed that MET-NEs had the highest virulence inhibitory activity. However, concerning RT-PCR results, all tested agents significantly decreased the expression of quorum sensing regulatory genes of P. aeruginosa; lasR, lasI, pqsA, fliC, exoS and pslA, with Ag-MET-NEs being the most potent one, however, it failed to protect mice from P. aeruginosa pathogenesis. MET-NEs showed the highest protective activity against pseudomonal infection in vivo. Our findings support the promising use of nano formulations particularly Ag-MET-NEs as an alternative against multidrug resistant pseudomonal infections via inhibition of virulence factors and quorum sensing gene expression.
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14
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Surveying a Swarm: Experimental Techniques to Establish and Examine Bacterial Collective Motion. Appl Environ Microbiol 2021; 88:e0185321. [PMID: 34878816 DOI: 10.1128/aem.01853-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The survival and successful spread of many bacterial species hinges on their mode of motility. One of the most distinct of these is swarming, a collective form of motility where a dense consortium of bacteria employ flagella to propel themselves across a solid surface. Surface environments pose unique challenges, derived from higher surface friction/tension and insufficient hydration. Bacteria have adapted by deploying an array of mechanisms to overcome these challenges. Beyond allowing bacteria to colonize new terrain in the absence of bulk liquid, swarming also bestows faster speeds and enhanced antibiotic resistance to the collective. These crucial attributes contribute to the dissemination, and in some cases pathogenicity, of an array of bacteria. This mini-review highlights; 1) aspects of swarming motility that differentiates it from other methods of bacterial locomotion. 2) Facilitatory mechanisms deployed by diverse bacteria to overcome different surface challenges. 3) The (often difficult) approaches required to cultivate genuine swarmers. 4) The methods available to observe and assess the various facets of this collective motion, as well as the features exhibited by the population as a whole.
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15
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Alford MA, Baquir B, An A, Choi KYG, Hancock REW. NtrBC Selectively Regulates Host-Pathogen Interactions, Virulence, and Ciprofloxacin Susceptibility of Pseudomonas aeruginosa. Front Cell Infect Microbiol 2021; 11:694789. [PMID: 34249781 PMCID: PMC8264665 DOI: 10.3389/fcimb.2021.694789] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 06/03/2021] [Indexed: 12/11/2022] Open
Abstract
Pseudomonas aeruginosa is a metabolically versatile opportunistic pathogen capable of infecting distinct niches of the human body, including skin wounds and the lungs of cystic fibrosis patients. Eradication of P. aeruginosa infection is becoming increasingly difficult due to the numerous resistance mechanisms it employs. Adaptive resistance is characterized by a transient state of decreased susceptibility to antibiotic therapy that is distinct from acquired or intrinsic resistance, can be triggered by various environmental stimuli and reverted by removal of the stimulus. Further, adaptive resistance is intrinsically linked to lifestyles such as swarming motility and biofilm formation, both of which are important in infections and lead to multi-drug adaptive resistance. Here, we demonstrated that NtrBC, the master of nitrogen control, had a selective role in host colonization and a substantial role in determining intrinsic resistance to ciprofloxacin. P. aeruginosa mutant strains (ΔntrB, ΔntrC and ΔntrBC) colonized the skin but not the respiratory tract of mice as well as WT and, unlike WT, could be reduced or eradicated from the skin by ciprofloxacin. We hypothesized that nutrient availability contributed to these phenomena and found that susceptibility to ciprofloxacin was impacted by nitrogen source in laboratory media. P. aeruginosa ΔntrB, ΔntrC and ΔntrBC also exhibited distinct host interactions, including modestly increased cytotoxicity toward human bronchial epithelial cells, reduced virulence factor production and 10-fold increased uptake by macrophages. These data might explain why NtrBC mutants were less adept at colonizing the upper respiratory tract of mice. Thus, NtrBC represents a link between nitrogen metabolism, adaptation and virulence of the pathogen P. aeruginosa, and could represent a target for eradication of recalcitrant infections in situ.
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Affiliation(s)
- Morgan A Alford
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Beverlie Baquir
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Andy An
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Ka-Yee G Choi
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Robert E W Hancock
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
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16
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Wilkinson LV, Alford MA, Coleman SR, Wu BC, Lee AHY, Blimkie TM, Bains M, Falsafi R, Pletzer D, Hancock REW. Peptide 1018 inhibits swarming and influences Anr-regulated gene expression downstream of the stringent stress response in Pseudomonas aeruginosa. PLoS One 2021; 16:e0250977. [PMID: 33930077 PMCID: PMC8087004 DOI: 10.1371/journal.pone.0250977] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 04/16/2021] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa is a ubiquitous opportunistic pathogen that causes considerable human morbidity and mortality, particularly in nosocomial infections and individuals with cystic fibrosis. P. aeruginosa can adapt to surface growth by undergoing swarming motility, a rapid multicellular movement that occurs on viscous soft surfaces with amino acids as a nitrogen source. Here we tested the small synthetic host defense peptide, innate defense regulator 1018, and found that it inhibited swarming motility at concentrations as low as 0.75 μg/ml, well below the MIC for strain PA14 planktonic cells (64 μg/ml). A screen of the PA14 transposon insertion mutant library revealed 29 mutants that were more tolerant to peptide 1018 during swarming, five of which demonstrated significantly greater swarming than the WT in the presence of peptide. Transcriptional analysis (RNA-Seq) of cells that were inoculated on swarming plates containing 1.0 μg/ml peptide revealed differential expression of 1,190 genes compared to cells swarming on plates without peptide. Furthermore, 1018 treatment distinctly altered the gene expression profile of cells when compared to that untreated cells in the centre of the swarm colonies. Peptide-treated cells exhibited changes in the expression of genes implicated in the stringent stress response including those regulated by anr, which is involved in anaerobic adaptation, indicative of a mechanism by which 1018 might inhibit swarming motility. Overall, this study illustrates potential mechanisms by which peptide 1018 inhibits swarming surface motility, an important bacterial adaptation associated with antibiotic resistance, virulence, and dissemination of P. aeruginosa.
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Affiliation(s)
- Lauren V. Wilkinson
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Morgan A. Alford
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Shannon R. Coleman
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Bing C. Wu
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Amy H. Y. Lee
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, Canada
| | - Travis M. Blimkie
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Manjeet Bains
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Reza Falsafi
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - 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
| | - Robert E. W. Hancock
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
- * E-mail:
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17
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Maisetta G, Piras AM, Motta V, Braccini S, Mazzantini D, Chiellini F, Zambito Y, Esin S, Batoni G. Antivirulence Properties of a Low-Molecular-Weight Quaternized Chitosan Derivative against Pseudomonas aeruginosa. Microorganisms 2021; 9:912. [PMID: 33923269 PMCID: PMC8145479 DOI: 10.3390/microorganisms9050912] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 04/20/2021] [Accepted: 04/21/2021] [Indexed: 01/21/2023] Open
Abstract
The co-occurrence of increasing rates of resistance to current antibiotics and the paucity of novel antibiotics pose major challenges for the treatment of bacterial infections. In this scenario, treatments targeting bacterial virulence have gained considerable interest as they are expected to exert a weaker selection for resistance than conventional antibiotics. In a previous study, we demonstrated that a low-molecular-weight quaternized chitosan derivative, named QAL, displays antibiofilm activity against the major pathogen Pseudomonas aeruginosa at subinhibitory concentrations. The aim of this study was to investigate whether QAL was able to inhibit the production of relevant virulence factors of P. aeruginosa. When tested in vitro at subinhibiting concentrations (0.31-0.62 mg/mL), QAL markedly reduced the production of pyocyanin, pyoverdin, proteases, and LasA, as well as inhibited the swarming motility of three out of four P. aeruginosa strains tested. Furthermore, quantitative reverse transcription PCR (qRT-PCR) analyses demonstrated that expression of lasI and rhlI, two QS-related genes, was highly downregulated in a representative P. aeruginosa strain. Confocal scanning laser microscopy analysis suggested that FITC-labelled QAL accumulates intracellularly following incubation with P. aeruginosa. In contrast, the reduced production of virulence factors was not evidenced when QAL was used as the main polymeric component of polyelectrolyte-based nanoparticles. Additionally, combination of sub-MIC concentrations of QAL and tobramycin significantly reduced biofilm formation of P. aeruginosa, likely due to a synergistic activity towards planktonic bacteria. Overall, the results obtained demonstrated an antivirulence activity of QAL, possibly due to polymer intracellular localization and QS-inhibition, and its ability to inhibit P. aeruginosa growth synergizing with tobramycin.
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Affiliation(s)
- Giuseppantonio Maisetta
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy; (V.M.); (D.M.); (S.E.); (G.B.)
| | - Anna Maria Piras
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy; (A.M.P.); (Y.Z.)
| | - Vincenzo Motta
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy; (V.M.); (D.M.); (S.E.); (G.B.)
| | - Simona Braccini
- Department of Chemistry and Industrial Chemistry, University of Pisa, UdR INSTM PISA, 56124 Pisa, Italy; (S.B.); (F.C.)
| | - Diletta Mazzantini
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy; (V.M.); (D.M.); (S.E.); (G.B.)
| | - Federica Chiellini
- Department of Chemistry and Industrial Chemistry, University of Pisa, UdR INSTM PISA, 56124 Pisa, Italy; (S.B.); (F.C.)
| | - Ylenia Zambito
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy; (A.M.P.); (Y.Z.)
- Interdepartmental Research Centre “Nutraceuticals and Food for Health”, University of Pisa, 56100 Pisa, Italy
| | - Semih Esin
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy; (V.M.); (D.M.); (S.E.); (G.B.)
| | - Giovanna Batoni
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy; (V.M.); (D.M.); (S.E.); (G.B.)
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