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Mondal AH, Khare K, Saxena P, Debnath P, Mukhopadhyay K, Yadav D. A Review on Colistin Resistance: An Antibiotic of Last Resort. Microorganisms 2024; 12:772. [PMID: 38674716 PMCID: PMC11051878 DOI: 10.3390/microorganisms12040772] [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: 03/17/2024] [Revised: 04/04/2024] [Accepted: 04/08/2024] [Indexed: 04/28/2024] Open
Abstract
Antibiotic resistance has emerged as a significant global public health issue, driven by the rapid adaptation of microorganisms to commonly prescribed antibiotics. Colistin, previously regarded as a last-resort antibiotic for treating infections caused by Gram-negative bacteria, is increasingly becoming resistant due to chromosomal mutations and the acquisition of resistance genes carried by plasmids, particularly the mcr genes. The mobile colistin resistance gene (mcr-1) was first discovered in E. coli from China in 2016. Since that time, studies have reported different variants of mcr genes ranging from mcr-1 to mcr-10, mainly in Enterobacteriaceae from various parts of the world, which is a major concern for public health. The co-presence of colistin-resistant genes with other antibiotic resistance determinants further complicates treatment strategies and underscores the urgent need for enhanced surveillance and antimicrobial stewardship efforts. Therefore, understanding the mechanisms driving colistin resistance and monitoring its global prevalence are essential steps in addressing the growing threat of antimicrobial resistance and preserving the efficacy of existing antibiotics. This review underscores the critical role of colistin as a last-choice antibiotic, elucidates the mechanisms of colistin resistance and the dissemination of resistant genes, explores the global prevalence of mcr genes, and evaluates the current detection methods for colistin-resistant bacteria. The objective is to shed light on these key aspects with strategies for combating the growing threat of resistance to antibiotics.
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Affiliation(s)
- Aftab Hossain Mondal
- Department of Microbiology, Faculty of Allied Health Sciences, Shree Guru Gobind Singh Tricentenary University, Gurugram 122505, Haryana, India; (A.H.M.); (P.D.)
| | - Kriti Khare
- Antimicrobial Research Laboratory, School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India; (K.K.); (P.S.); (K.M.)
| | - Prachika Saxena
- Antimicrobial Research Laboratory, School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India; (K.K.); (P.S.); (K.M.)
| | - Parbati Debnath
- Department of Microbiology, Faculty of Allied Health Sciences, Shree Guru Gobind Singh Tricentenary University, Gurugram 122505, Haryana, India; (A.H.M.); (P.D.)
| | - Kasturi Mukhopadhyay
- Antimicrobial Research Laboratory, School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India; (K.K.); (P.S.); (K.M.)
| | - Dhananjay Yadav
- Department of Life Science, Yeungnam University, Gyeongsan 712-749, Republic of Korea
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2
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Ghosh D, Mangar P, Choudhury A, Kumar A, Saha A, Basu P, Saha D. Characterization of a hemolytic and antibiotic-resistant Pseudomonas aeruginosa strain S3 pathogenic to fish isolated from Mahananda River in India. PLoS One 2024; 19:e0300134. [PMID: 38547304 PMCID: PMC10977779 DOI: 10.1371/journal.pone.0300134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 02/21/2024] [Indexed: 04/02/2024] Open
Abstract
Virulent strain Pseudomonas aeruginosa isolated from Mahananda River exhibited the highest hemolytic activity and virulence factors and was pathogenic to fish as clinical signs of hemorrhagic spots, loss of scales, and fin erosions were found. S3 was cytotoxic to the human liver cell line (WRL-68) in the trypan blue dye exclusion assay. Genotype characterization using whole genome analysis showed that S3 was similar to P. aeruginosa PAO1. The draft genome sequence had an estimated length of 62,69,783 bp, a GC content of 66.3%, and contained 5916 coding sequences. Eight genes across the genome were predicted to be related to hemolysin action. Antibiotic resistance genes such as class C and class D beta-lactamases, fosA, APH, and catB were detected, along with the strong presence of multiple efflux system genes. This study shows that river water is contaminated by pathogenic P. aeruginosa harboring an array of virulence and antibiotic resistance genes which warrants periodic monitoring to prevent disease outbreaks.
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Affiliation(s)
- Dipanwita Ghosh
- Department of Biotechnology, University of North Bengal, Siliguri, West Bengal, India
| | - Preeti Mangar
- Department of Botany, University of North Bengal, Siliguri, West Bengal, India
| | - Abhinandan Choudhury
- Department of Biotechnology, University of North Bengal, Siliguri, West Bengal, India
| | - Anoop Kumar
- Department of Biotechnology, University of North Bengal, Siliguri, West Bengal, India
| | - Aniruddha Saha
- Department of Botany, University of North Bengal, Siliguri, West Bengal, India
| | - Protip Basu
- Department of Botany, Siliguri College, West Bengal, India
| | - Dipanwita Saha
- Department of Biotechnology, University of North Bengal, Siliguri, West Bengal, India
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3
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Poulsen BE, Warrier T, Barkho S, Bagnall J, Romano KP, White T, Yu X, Kawate T, Nguyen PH, Raines K, Ferrara K, Golas A, Fitzgerald M, Boeszoermenyi A, Kaushik V, Serrano-Wu M, Shoresh N, Hung DT. "Multiplexed screen identifies a Pseudomonas aeruginosa -specific small molecule targeting the outer membrane protein OprH and its interaction with LPS". BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.16.585348. [PMID: 38559044 PMCID: PMC10980007 DOI: 10.1101/2024.03.16.585348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The surge of antimicrobial resistance threatens efficacy of current antibiotics, particularly against Pseudomonas aeruginosa , a highly resistant gram-negative pathogen. The asymmetric outer membrane (OM) of P. aeruginosa combined with its array of efflux pumps provide a barrier to xenobiotic accumulation, thus making antibiotic discovery challenging. We adapted PROSPECT 1 , a target-based, whole-cell screening strategy, to discover small molecule probes that kill P. aeruginosa mutants depleted for essential proteins localized at the OM. We identified BRD1401, a small molecule that has specific activity against a P. aeruginosa mutant depleted for the essential lipoprotein, OprL. Genetic and chemical biological studies identified that BRD1401 acts by targeting the OM β-barrel protein OprH to disrupt its interaction with LPS and increase membrane fluidity. Studies with BRD1401 also revealed an interaction between OprL and OprH, directly linking the OM with peptidoglycan. Thus, a whole-cell, multiplexed screen can identify species-specific chemical probes to reveal novel pathogen biology.
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Shideler S, Bookout T, Qasim A, Bowron L, Wu Q, Duan K, Treu R, Reckseidler-Zenteno S, Lewenza S. Biosensor-guided detection of outer membrane-specific antimicrobial activity against Pseudomonas aeruginosa from fungal cultures and medicinal plant extracts. Microbiol Spectr 2023; 11:e0153623. [PMID: 37882578 PMCID: PMC10714926 DOI: 10.1128/spectrum.01536-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 09/18/2023] [Indexed: 10/27/2023] Open
Abstract
IMPORTANCE New approaches are needed to discover novel antimicrobials, particularly antibiotics that target the Gram-negative outer membrane. By exploiting bacterial sensing and responses to outer membrane (OM) damage, we used a biosensor approach consisting of polymyxin resistance gene transcriptional reporters to screen natural products and a small drug library for biosensor activity that indicates damage to the OM. The diverse antimicrobial compounds that cause induction of the polymyxin resistance genes, which correlates with outer membrane damage, suggest that these LPS and surface modifications also function in short-term repair to sublethal exposure and are required against broad membrane stress conditions.
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Affiliation(s)
- Steve Shideler
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Tyson Bookout
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Azka Qasim
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Lauren Bowron
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Qiaolian Wu
- College of Life Sciences, Northwest University, Xian, China
| | - Kangmin Duan
- Department of Oral Biology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Roland Treu
- Faculty of Science and Technology, Athabasca University, Athabasca, Alberta, Canada
| | - Shauna Reckseidler-Zenteno
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
- Faculty of Science and Technology, Athabasca University, Athabasca, Alberta, Canada
| | - Shawn Lewenza
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
- Faculty of Science and Technology, Athabasca University, Athabasca, Alberta, Canada
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5
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Disney-McKeethen S, Seo S, Mehta H, Ghosh K, Shamoo Y. Experimental evolution of Pseudomonas aeruginosa to colistin in spatially confined microdroplets identifies evolutionary trajectories consistent with adaptation in microaerobic lung environments. mBio 2023; 14:e0150623. [PMID: 37847036 PMCID: PMC10746239 DOI: 10.1128/mbio.01506-23] [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: 06/16/2023] [Accepted: 09/08/2023] [Indexed: 10/18/2023] Open
Abstract
Antibiotic resistance is a continuing global health crisis. Identifying the evolutionary trajectories leading to increased antimicrobial resistance can be critical to the discovery of biomarkers for clinical diagnostics and new targets for drug discovery. While the combination of patient data and in vitro experimental evolution has been remarkably successful in extending our understanding of antimicrobial resistance, it can be difficult for in vitro methods to recapitulate the spatial structure and consequent microenvironments that characterize in vivo infection. Notably, in cystic fibrosis (CF) patients, changes to either the PmrA/PmrB or PhoP/PhoQ two-component systems have been identified as critical drivers for high levels of colistin and polymyxin resistance. When using microfluidic emulsions to provide spatially structured, low-competition environments, we found that adaptive mutations to phoQ were more successful than pmrB in increasing colistin resistance. Conversely, mutations to pmrB were readily identified using well-mixed unstructured cultures. We found that oxygen concentration gradients within the microdroplet emulsions favored adaptive changes to the PhoP/PhoQ pathway consistent with microaerobic conditions that can be found in the lungs of CF patients. We also observed mutations linked to hallmark adaptations to the CF lung environment, such as loss of motility and loss of O antigen biosynthesis (wbpL). Mutation to wbpL, in addition to causing loss of O antigen, was additionally shown to confer moderately increased colistin resistance. Taken together, our data suggest that distinct evolutionary trajectories to colistin resistance may be shaped by the microaerobic partitioning and spatial separation imposed within the CF lung.IMPORTANCEAntibiotic resistance remains one of the great challenges confronting public health in the world today. Individuals with compromised immune systems or underlying health conditions are often at an increased for bacterial infections. Patients with cystic fibrosis (CF) produce thick mucus that clogs airways and provides a very favorable environment for infection by bacteria that further decrease lung function and, ultimately, mortality. CF patients are often infected by bacteria such as Pseudomonas aeruginosa early in life and experience a series of chronic infections that, over time, become increasingly difficult to treat due to increased antibiotic resistance. Colistin is a major antibiotic used to treat CF patients. Clinical and laboratory studies have identified PmrA/PmrB and PhoP/PhoQ as responsible for increased resistance to colistin. Both have been identified in CF patient lungs, but why, in some cases, is it one and not the other? In this study, we show that distinct evolutionary trajectories to colistin resistance may be favored by the microaerobic partitioning found within the damaged CF lung.
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Affiliation(s)
| | - Seokju Seo
- Department of Biosciences, Rice University, Houston , Texas , USA
| | - Heer Mehta
- Department of Biosciences, Rice University, Houston , Texas , USA
| | - Karukriti Ghosh
- Department of Biosciences, Rice University, Houston , Texas , USA
| | - Yousif Shamoo
- Department of Biosciences, Rice University, Houston , Texas , USA
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6
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Lu J, Han M, Yu HH, Bergen PJ, Liu Y, Zhao J, Wickremasinghe H, Jiang X, Hu Y, Du H, Zhu Y, Velkov T. Lipid A Modification and Metabolic Adaptation in Polymyxin-Resistant, New Delhi Metallo-β-Lactamase-Producing Klebsiella pneumoniae. Microbiol Spectr 2023; 11:e0085223. [PMID: 37432123 PMCID: PMC10433984 DOI: 10.1128/spectrum.00852-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 05/12/2023] [Indexed: 07/12/2023] Open
Abstract
Polymyxins are last-line antibiotics employed against multidrug-resistant (MDR) Klebsiella pneumoniae. Worryingly, polymyxin resistance is rapidly on the rise globally. Polymyxins initially target lipid A of lipopolysaccharides (LPSs) in the cell outer membrane (OM), causing disorganization and cell lysis. While most studies focus on how genetic variations confer polymyxin resistance, the mechanisms of membrane remodeling and metabolic changes in polymyxin-resistant strains remain unclear, thus hampering the development of effective therapies to treat severe K. pneumoniae infections. In the present study, lipid A profiling, OM lipidomics, genomics, and metabolomics were integrated to elucidate the global mechanisms of polymyxin resistance and metabolic adaptation in a polymyxin-resistant strain (strain S01R; MIC of >128 mg/L) obtained from K. pneumoniae strain S01, a polymyxin-susceptible (MIC of 2 mg/L), New Delhi metallo-β-lactamase (NDM)-producing MDR clinical isolate. Genomic analysis revealed a novel in-frame deletion at position V258 of PhoQ in S01R, potentially leading to lipid A modification with 4-amino-4-deoxy-l-arabinose (L-Ara4N) despite the absence of polymyxin B. Comparative metabolomic analysis revealed slightly elevated levels of energy production and amino acid metabolism in S01R compared to their levels in S01. Exposure to polymyxin B (4 mg/L for S01 and 512 mg/L for S01R) substantially altered energy, nucleotide, and amino acid metabolism and resulted in greater accumulation of lipids in both strains. Furthermore, the change induced by polymyxin B treatment was dramatic at both 1 and 4 h in S01 but only significant at 4 h in S01R. Overall, profound metabolic adaptation was observed in S01R following polymyxin B treatment. These findings contribute to our understanding of polymyxin resistance mechanisms in problematic NDM-producing K. pneumoniae strains and may facilitate the discovery of novel therapeutic targets. IMPORTANCE Antimicrobial resistance (AMR) is a major threat to global health. The emergence of resistance to the polymyxins that are the last line of defense in so-called Gram-negative "superbugs" has further increased the urgency to develop novel therapies. There are frequent outbreaks of K. pneumoniae infections in hospitals being reported, and polymyxin usage is increasing remarkably. Importantly, the polymyxin-resistant K. pneumoniae strains are imposing more severe consequences to health systems. Using metabolomics, lipid A profiling, and outer membrane lipidomics, our findings reveal (i) changes in the pentose phosphate pathway and amino acid and nucleotide metabolism in a susceptible strain following polymyxin treatment and (ii) how cellular metabolism, lipid A modification, and outer membrane remodeling were altered in K. pneumoniae following the acquisition of polymyxin resistance. Our study provides, for the first time, mechanistic insights into metabolic responses to polymyxin treatment in a multidrug-resistant, NDM-producing K. pneumoniae clinical isolate with acquired polymyxin resistance. Overall, these results will assist in identifying new therapeutic targets to combat and prevent polymyxin resistance.
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Affiliation(s)
- Jing Lu
- Infection Program, Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Meiling Han
- Infection Program, Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Heidi H. Yu
- Infection Program, Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Phillip J. Bergen
- Infection Program, Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Yiyun Liu
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong, China
| | - Jinxin Zhao
- Infection Program, Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Hasini Wickremasinghe
- Infection Program, Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Xukai Jiang
- Infection Program, Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Yang Hu
- Infection Program, Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Haiyan Du
- Infection Program, Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Yan Zhu
- Infection Program, Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Tony Velkov
- Department of Pharmacology, The Faculty of Medicine Nursing and Health Sciences, Monash University, Melbourne, Victoria, Australia
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7
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Mozaheb N, Rasouli P, Kaur M, Van Der Smissen P, Larrouy-Maumus G, Mingeot-Leclercq MP. A Mildly Acidic Environment Alters Pseudomonas aeruginosa Virulence and Causes Remodeling of the Bacterial Surface. Microbiol Spectr 2023; 11:e0483222. [PMID: 37278652 PMCID: PMC10433952 DOI: 10.1128/spectrum.04832-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 05/14/2023] [Indexed: 06/07/2023] Open
Abstract
Pseudomonas aeruginosa is a versatile pathogen that resists environmental stress, such as suboptimal pH. As a result of exposure to environmental stress, P. aeruginosa shows an altered virulence-related phenotype. This study investigated the modifications that P. aeruginosa undertakes at a mildly low pH (pH 5.0) compared with the bacteria grown in a neutral medium (pH 7.2). Results indicated that in a mildly acidic environment, expression of two-component system genes (phoP/phoQ and pmrA/pmrB), lipid A remodeling genes such as arnT and pagP and virulence genes, i.e., pqsE and rhlA, were induced. Moreover, lipid A of the bacteria grown at a mildly low pH is modified by adding 4-amino-arabinose (l-Ara4N). Additionally, the production of virulence factors such as rhamnolipid, alginate, and membrane vesicles is significantly higher in a mildly low-pH environment than in a neutral medium. Interestingly, at a mildly low pH, P. aeruginosa produces a thicker biofilm with higher biofilm biomass. Furthermore, studies on inner membrane viscosity and permeability showed that a mildly low pH causes a decrease in the inner membrane permeability and increases its viscosity. Besides, despite the importance of PhoP, PhoQ, PmrA, and PmrB in Gram-negative bacteria for responding to low pH stress, we observed that the absence of each of these two-component systems does not meaningfully impact the remodeling of the P. aeruginosa envelope. Given that P. aeruginosa is likely to encounter mildly acidic environments during infection in its host, the alterations that the bacterium undertakes under such conditions must be considered in designing antibacterial strategies against P. aeruginosa. IMPORTANCE P. aeruginosa encounters environments with acidic pH when establishing infections in hosts. The bacterium develops an altered phenotype to tolerate a moderate decrease in the environmental pH. At the level of the bacterial envelope, modified lipid A composition and a reduction of the bacterial inner membrane permeability and fluidity are among the changes P. aeruginosa undergoes at a mildly low pH. Also, the bacterium is more likely to form biofilm in a mildly acidic environment. Overall, these alterations in the P. aeruginosa phenotype put obstacles in the way of antibacterial activities. Thus, considering physiological changes in the bacterium at low pH helps design and implement antimicrobial approaches against this hostile microorganism.
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Affiliation(s)
- Negar Mozaheb
- Université catholique de Louvain, Louvain Drug Research Institute, Cellular & Molecular Pharmacology Unit (FACM), Brussels, Belgium
| | - Paria Rasouli
- Université catholique de Louvain, Louvain Drug Research Institute, Cellular & Molecular Pharmacology Unit (FACM), Brussels, Belgium
| | - Mandeep Kaur
- Université catholique de Louvain, Louvain Drug Research Institute, Cellular & Molecular Pharmacology Unit (FACM), Brussels, Belgium
| | - Patrick Van Der Smissen
- Université catholique de Louvain, de Duve Institute, CELL Unit and PICT Platform, Brussels, Belgium
| | - Gerald Larrouy-Maumus
- Imperial College London, Department of Life Sciences, MRC Centre for Molecular Bacteriology and Infection, Faculty of Natural Science, London, United Kingdom
| | - Marie-Paule Mingeot-Leclercq
- Université catholique de Louvain, Louvain Drug Research Institute, Cellular & Molecular Pharmacology Unit (FACM), Brussels, Belgium
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8
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Chandler CE, Hofstaedter CE, Hazen TH, Rasko DA, Ernst RK. Genomic and Functional Characterization of Longitudinal Pseudomonas aeruginosa Isolates from Young Patients with Cystic Fibrosis. Microbiol Spectr 2023; 11:e0155623. [PMID: 37358436 PMCID: PMC10433850 DOI: 10.1128/spectrum.01556-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 06/05/2023] [Indexed: 06/27/2023] Open
Abstract
Individuals with cystic fibrosis (CF) suffer from frequent and recurring microbial airway infections. The Gram-negative bacterium Pseudomonas aeruginosa is one of the most common organisms isolated from CF patient airways. P. aeruginosa establishes chronic infections that persist throughout a patient's lifetime and is a major cause of morbidity and mortality. Throughout the course of infection, P. aeruginosa must evolve and adapt from an initial state of early, transient colonization to chronic colonization of the airways. Here, we examined isolates of P. aeruginosa from children under the age of 3 years old with CF to determine genetic adaptations the bacterium undergoes during this early stage of colonization and infection. These isolates were collected when early aggressive antimicrobial therapy was not the standard of care and therefore highlight strain evolution under limited antibiotic pressure. Examination of specific phenotypic adaptations, such as lipid A palmitoylation, antibiotic resistance, and loss of quorum sensing, did not reveal a clear genetic basis for such changes. Additionally, we demonstrate that the geography of patient origin, within the United States or among other countries, does not appear to significantly influence genetic adaptation. In summary, our results support the long-standing model that patients acquire individual isolates of P. aeruginosa that subsequently become hyperadapted to the patient-specific airway environment. This study provides a multipatient genomic analysis of isolates from young CF patients in the United States and contributes data regarding early colonization and adaptation to the growing body of research about P. aeruginosa evolution in the context of CF airway disease. IMPORTANCE Chronic lung infection with Pseudomonas aeruginosa is of major concern for patients with cystic fibrosis (CF). During infection, P. aeruginosa undergoes genomic and functional adaptation to the hyperinflammatory CF airway, resulting in worsening lung function and pulmonary decline. All studies that describe these adaptations use P. aeruginosa obtained from older children or adults during late chronic lung infection; however, children with CF can be infected with P. aeruginosa as early as 3 months of age. Therefore, it is unclear when these genomic and functional adaptations occur over the course of CF lung infection, as access to P. aeruginosa isolates in children during early infection is limited. Here, we present a unique cohort of CF patients who were identified as being infected with P. aeruginosa at an early age prior to aggressive antibiotic therapy. Furthermore, we performed genomic and functional characterization of these isolates to address whether chronic CF P. aeruginosa phenotypes are present during early infection.
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Affiliation(s)
- Courtney E. Chandler
- Department of Microbial Pathogenesis, University of Maryland—Baltimore, Baltimore, Maryland, USA
| | - Casey E. Hofstaedter
- Department of Microbial Pathogenesis, University of Maryland—Baltimore, Baltimore, Maryland, USA
- Medical Scientist Training Program, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Tracy H. Hazen
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland—Baltimore, Baltimore, Maryland, USA
| | - David A. Rasko
- Department of Microbial Pathogenesis, University of Maryland—Baltimore, Baltimore, Maryland, USA
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland—Baltimore, Baltimore, Maryland, USA
- Center for Pathogen Research, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Robert K. Ernst
- Department of Microbial Pathogenesis, University of Maryland—Baltimore, Baltimore, Maryland, USA
- Center for Pathogen Research, University of Maryland School of Medicine, Baltimore, Maryland, USA
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9
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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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10
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De Gaetano GV, Lentini G, Famà A, Coppolino F, Beninati C. Antimicrobial Resistance: Two-Component Regulatory Systems and Multidrug Efflux Pumps. Antibiotics (Basel) 2023; 12:965. [PMID: 37370284 DOI: 10.3390/antibiotics12060965] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 05/22/2023] [Accepted: 05/24/2023] [Indexed: 06/29/2023] Open
Abstract
The number of multidrug-resistant bacteria is rapidly spreading worldwide. Among the various mechanisms determining resistance to antimicrobial agents, multidrug efflux pumps play a noteworthy role because they export extraneous and noxious substrates from the inside to the outside environment of the bacterial cell contributing to multidrug resistance (MDR) and, consequently, to the failure of anti-infective therapies. The expression of multidrug efflux pumps can be under the control of transcriptional regulators and two-component systems (TCS). TCS are a major mechanism by which microorganisms sense and reply to external and/or intramembrane stimuli by coordinating the expression of genes involved not only in pathogenic pathways but also in antibiotic resistance. In this review, we describe the influence of TCS on multidrug efflux pump expression and activity in some Gram-negative and Gram-positive bacteria. Taking into account the strict correlation between TCS and multidrug efflux pumps, the development of drugs targeting TCS, alone or together with already discovered efflux pump inhibitors, may represent a beneficial strategy to contribute to the fight against growing antibiotic resistance.
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Affiliation(s)
| | - Germana Lentini
- Department of Human Pathology, University of Messina, 98124 Messina, Italy
| | - Agata Famà
- Department of Human Pathology, University of Messina, 98124 Messina, Italy
| | - Francesco Coppolino
- Department of Biomedical, Dental and Imaging Sciences, University of Messina, 98124 Messina, Italy
| | - Concetta Beninati
- Department of Human Pathology, University of Messina, 98124 Messina, Italy
- Scylla Biotech Srl, 98124 Messina, Italy
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11
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Sayed M, Griffin M, Ware C, Ozdemir O, Tekedar HC, Essa M, Karsi A, Lawrence ML, Abdelhamed H. Evaluation of Edwardsiella piscicida basS and basR mutants as vaccine candidates in catfish against edwardsiellosis. JOURNAL OF FISH DISEASES 2022; 45:1817-1829. [PMID: 36053889 DOI: 10.1111/jfd.13703] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 07/26/2022] [Accepted: 07/29/2022] [Indexed: 06/15/2023]
Abstract
Catfish farming is the largest aquaculture industry in the United States and an important economic driver in several southeastern states. Edwardsiella piscicida is a Gram-negative pathogen associated with significant losses in catfish aquaculture. Several Gram-negative bacteria use the BasS/BasR two-component system (TCS) to adapt to environmental changes and the host immune system. Currently, the role of BasS/BasR system in E. piscicida virulence has not been characterized. In the present study, two mutants were constructed by deleting the basS and basR genes in E. piscicida strain C07-087. Both mutant strains were characterized for virulence and immune protection in catfish hosts. The EpΔbasS and EpΔbasR mutants were more sensitive to acidic environments and produced significantly less biofilm than the wild-type. In vivo studies in channel catfish (Ictalurus punctatus) revealed that both EpΔbasS and EpΔbasR were significantly attenuated compared with the parental wild-type (3.57% and 4.17% vs. 49.16% mortalities). Moreover, there was significant protection, 95.2% and 92.3% relative percent survival (RPS), in channel catfish vaccinated with EpΔbasS and EpΔbasR against E. piscicida infection. Protection in channel catfish was associated with a significantly higher level of antibodies and upregulation of immune-related genes (IgM, IL-8 and CD8-α) in channel catfish vaccinated with EpΔbasS and EpΔbasR strains compared with non-vaccinated fish. Hybrid catfish (channel catfish ♀ × blue catfish ♂) challenges demonstrated long-term protection against subsequent challenges with E. piscicida and E. ictaluri. Our findings demonstrate BasS and BasR contribute to acid tolerance and biofilm formation, which may facilitate E. piscicida survival in harsh environments. Further, our results show that EpΔbasS and EpΔbasR mutants were safe and protective in channel catfish fingerlings, although their virulence and efficacy in hybrid catfish warrant further investigation. These data provide information regarding an important mechanism of E. piscicida virulence, and it suggests EpΔbasS and EpΔbasR strains have potential as vaccines against this emergent catfish pathogen.
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Affiliation(s)
- Mohamed Sayed
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Stoneville, Mississippi, USA
- Department of Fish Diseases and Management, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef, Egypt
| | - Matt Griffin
- Thad Cochran National Warmwater Aquaculture Center, Delta Research and Extension Center, Mississippi State University, Stoneville, Mississippi, USA
| | - Cynthia Ware
- Thad Cochran National Warmwater Aquaculture Center, Delta Research and Extension Center, Mississippi State University, Stoneville, Mississippi, USA
| | - Ozan Ozdemir
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Stoneville, Mississippi, USA
| | - Hasan C Tekedar
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Stoneville, Mississippi, USA
| | - Manal Essa
- Department of Fish Diseases and Management, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef, Egypt
| | - Attila Karsi
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Stoneville, Mississippi, USA
| | - Mark L Lawrence
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Stoneville, Mississippi, USA
| | - Hossam Abdelhamed
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Stoneville, Mississippi, USA
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12
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Hasan CM, Pottenger S, Green AE, Cox AA, White JS, Jones T, Winstanley C, Kadioglu A, Wright MH, Neill DR, Fothergill JL. Pseudomonas aeruginosa utilizes the host-derived polyamine spermidine to facilitate antimicrobial tolerance. JCI Insight 2022; 7:158879. [PMID: 36194492 PMCID: PMC9746822 DOI: 10.1172/jci.insight.158879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 09/27/2022] [Indexed: 12/15/2022] Open
Abstract
Pseudomonas aeruginosa undergoes diversification during infection of the cystic fibrosis (CF) lung. Understanding these changes requires model systems that capture the complexity of the CF lung environment. We previously identified loss-of-function mutations in the 2-component regulatory system sensor kinase gene pmrB in P. aeruginosa from CF lung infections and from experimental infection of mice. Here, we demonstrate that, while such mutations lowered in vitro minimum inhibitory concentrations for multiple antimicrobial classes, this was not reflected in increased antibiotic susceptibility in vivo. Loss of PmrB impaired aminoarabinose modification of LPS, increasing the negative charge of the outer membrane and promoting uptake of cationic antimicrobials. However, in vivo, this could be offset by increased membrane binding of other positively charged molecules present in lungs. The polyamine spermidine readily coated the surface of PmrB-deficient P. aeruginosa, reducing susceptibility to antibiotics that rely on charge differences to bind the outer membrane and increasing biofilm formation. Spermidine was elevated in lungs during P. aeruginosa infection in mice and during episodes of antimicrobial treatment in people with CF. These findings highlight the need to study antimicrobial resistance under clinically relevant environmental conditions. Microbial mutations carrying fitness costs in vitro may be advantageous during infection, where host resources can be utilized.
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Affiliation(s)
- Chowdhury M. Hasan
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Sian Pottenger
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Angharad E. Green
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Adrienne A. Cox
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Jack S. White
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Trevor Jones
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Craig Winstanley
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Aras Kadioglu
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Megan H. Wright
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Daniel R. Neill
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Joanne L. Fothergill
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
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13
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Mahamad Maifiah MH, Zhu Y, Tsuji BT, Creek DJ, Velkov T, Li J. Integrated metabolomic and transcriptomic analyses of the synergistic effect of polymyxin-rifampicin combination against Pseudomonas aeruginosa. J Biomed Sci 2022; 29:89. [PMID: 36310165 PMCID: PMC9618192 DOI: 10.1186/s12929-022-00874-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 10/21/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Understanding the mechanism of antimicrobial action is critical for improving antibiotic therapy. For the first time, we integrated correlative metabolomics and transcriptomics of Pseudomonas aeruginosa to elucidate the mechanism of synergistic killing of polymyxin-rifampicin combination. METHODS Liquid chromatography-mass spectrometry and RNA-seq analyses were conducted to identify the significant changes in the metabolome and transcriptome of P. aeruginosa PAO1 after exposure to polymyxin B (1 mg/L) and rifampicin (2 mg/L) alone, or in combination over 24 h. A genome-scale metabolic network was employed for integrative analysis. RESULTS In the first 4-h treatment, polymyxin B monotherapy induced significant lipid perturbations, predominantly to fatty acids and glycerophospholipids, indicating a substantial disorganization of the bacterial outer membrane. Expression of ParRS, a two-component regulatory system involved in polymyxin resistance, was increased by polymyxin B alone. Rifampicin alone caused marginal metabolic perturbations but significantly affected gene expression at 24 h. The combination decreased the gene expression of quorum sensing regulated virulence factors at 1 h (e.g. key genes involved in phenazine biosynthesis, secretion system and biofilm formation); and increased the expression of peptidoglycan biosynthesis genes at 4 h. Notably, the combination caused substantial accumulation of nucleotides and amino acids that last at least 4 h, indicating that bacterial cells were in a state of metabolic arrest. CONCLUSION This study underscores the substantial potential of integrative systems pharmacology to determine mechanisms of synergistic bacterial killing by antibiotic combinations, which will help optimize their use in patients.
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Affiliation(s)
- Mohd Hafidz Mahamad Maifiah
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
- International Institute for Halal Research and Training, International Islamic University Malaysia, 50728, Kuala Lumpur, Malaysia
| | - Yan Zhu
- Infection Program and Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
| | - Brian T Tsuji
- Department of Pharmacy Practice, School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Darren J Creek
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Tony Velkov
- Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Jian Li
- Infection Program and Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia.
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14
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Holban AM, Gregoire CM, Gestal MC. Conquering the host: Bordetella spp. and Pseudomonas aeruginosa molecular regulators in lung infection. Front Microbiol 2022; 13:983149. [PMID: 36225372 PMCID: PMC9549215 DOI: 10.3389/fmicb.2022.983149] [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: 06/30/2022] [Accepted: 08/17/2022] [Indexed: 11/27/2022] Open
Abstract
When bacteria sense cues from the host environment, stress responses are activated. Two component systems, sigma factors, small RNAs, ppGpp stringent response, and chaperones start coordinate the expression of virulence factors or immunomodulators to allow bacteria to respond. Although, some of these are well studied, such as the two-component systems, the contribution of other regulators, such as sigma factors or ppGpp, is increasingly gaining attention. Pseudomonas aeruginosa is the gold standard pathogen for studying the molecular mechanisms to sense and respond to environmental cues. Bordetella spp., on the other hand, is a microbial model for studying host-pathogen interactions at the molecular level. These two pathogens have the ability to colonize the lungs of patients with chronic diseases, suggesting that they have the potential to share a niche and interact. However, the molecular networks that facilitate adaptation of Bordetella spp. to cues are unclear. Here, we offer a side-by-side comparison of what is known about these diverse molecular mechanisms that bacteria utilize to counteract host immune responses, while highlighting the relatively unexplored interactions between them.
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Affiliation(s)
- Alina M. Holban
- Research Institute of the University of Bucharest (ICUB), Bucharest, Romania
- Department of Microbiology and Immunology, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Courtney M. Gregoire
- Department of Microbiology and Immunology, Louisiana State University Health Science Center, Shreveport, LA, United States
| | - Monica C. Gestal
- Department of Microbiology and Immunology, Louisiana State University Health Science Center, Shreveport, LA, United States
- *Correspondence: Monica C. Gestal, ;
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15
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Qi L, Liang R, Duan J, Song S, Pan Y, Liu H, Zhu M, Li L. Synergistic antibacterial and anti-biofilm activities of resveratrol and polymyxin B against multidrug-resistant Pseudomonas aeruginosa. J Antibiot (Tokyo) 2022; 75:567-575. [PMID: 35999263 DOI: 10.1038/s41429-022-00555-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Revised: 07/31/2022] [Accepted: 08/02/2022] [Indexed: 11/10/2022]
Abstract
Bacterial infection caused by multidrug-resistant Pseudomonas aeruginosa has become a challenge in clinical practice. Polymyxins are used as the last resort agent for otherwise untreatable Gram-negative bacteria, including multidrug-resistant P.aeruginosa. However, pharmacodynamic (PD) and pharmacokinetic (PK) data on polymyxins suggest that polymyxin monotherapy is unlikely to generate reliably efficacious plasma concentrations. Also, polymyxin resistance has been frequently reported, especially among multidrug-resistant P.aeruginosa, which further limits its clinical use. A strategy for improving the antibacterial activity of polymyxins and preventing the development of polymyxin resistance is to use polymyxins in combination with other agents. In this study, we have demonstrated that resveratrol, a well tolerated compound, has synergistic effects when tested in vitro with polymyxin B on antibacterial and anti-biofilm activities. However, its' systemic use is limited as the required high plasma levels of resveratrol are not achievable. This suggests that it could be a partner for the combination therapy of polymyxin B in the treatment of topical bacterial infection caused by MDR P.aeruginosa.
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Affiliation(s)
- Lin Qi
- Department of Clinical Laboratory, Jinzhou Medical University Graduate Training Base, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, 442000, P. R. China
| | - Rongxin Liang
- Department of Clinical Laboratory, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, 442000, P. R. China
| | - Jingjing Duan
- Department of Clinical Laboratory, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, 442000, P. R. China
| | - Songze Song
- Jinzhou Medical University, Jinzhou, Liaoning, 121001, P. R. China
| | - Yunjun Pan
- Department of Clinical Laboratory, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, 442000, P. R. China
| | - Hui Liu
- Department of Clinical Laboratory, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, 442000, P. R. China
| | - Mingan Zhu
- Department of Clinical Laboratory, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, 442000, P. R. China
| | - Lian Li
- Department of Clinical Laboratory, Jinzhou Medical University Graduate Training Base, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, 442000, P. R. China. .,Department of Clinical Laboratory, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, 442000, P. R. China.
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16
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Lemare M, Puja H, David SR, Mathieu S, Ihiawakrim D, Geoffroy VA, Rigouin C. Engineering siderophore production in Pseudomonas to improve asbestos weathering. Microb Biotechnol 2022; 15:2351-2363. [PMID: 35748120 PMCID: PMC9437886 DOI: 10.1111/1751-7915.14099] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 05/25/2022] [Indexed: 11/01/2022] Open
Abstract
Iron plays a key role in microbial metabolism and bacteria have developed multiple siderophore-driven mechanisms due to its poor bioavailability for organisms in the environment. Iron-bearing minerals generally serve as a nutrient source to sustain bacterial growth after bioweathering. Siderophores are high-affinity ferric iron chelators, of which the biosynthesis is tightly regulated by the presence of iron. Pyoverdine-producing Pseudomonas have shown their ability to extract iron and magnesium from asbestos waste as nutrients. However, such bioweathering is rapidly limited due to repression of the pyoverdine pathway and the low bacterial requirement for iron. We developed a metabolically engineered strain of Pseudomonas aeruginosa for which pyoverdine production was no longer repressed by iron as a proof of concept. We compared siderophore-promoted dissolution of flocking asbestos waste by this optimized strain to that by the wild-type strain. Interestingly, pyoverdine production by the optimized strain was seven times higher in the presence of asbestos waste and the dissolution of magnesium and iron from the chrysotile fibres contained in flocking asbestos waste was significantly enhanced. This innovative mineral weathering process contributes to remove toxic iron from the asbestos fibres and may contribute to the development of an eco-friendly method to manage asbestos waste.
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Affiliation(s)
- Marion Lemare
- Université de Strasbourg, CNRS-UMR7242, BSC, ESBS, 300 Bld Sébastien Brant, 67413, Illkirch, Strasbourg, France
| | - Hélène Puja
- Université de Strasbourg, CNRS-UMR7242, BSC, ESBS, 300 Bld Sébastien Brant, 67413, Illkirch, Strasbourg, France
| | - Sébastien R David
- Université de Strasbourg, CNRS-UMR7242, BSC, ESBS, 300 Bld Sébastien Brant, 67413, Illkirch, Strasbourg, France
| | - Sébastien Mathieu
- Université de Strasbourg, CNRS-UMR7242, BSC, ESBS, 300 Bld Sébastien Brant, 67413, Illkirch, Strasbourg, France
| | - Dris Ihiawakrim
- Université de Strasbourg, CNRS-UMR7504, IPCMS, 23 Rue du Loess, BP, 43, 67034, Strasbourg, France
| | - Valérie A Geoffroy
- Université de Strasbourg, CNRS-UMR7242, BSC, ESBS, 300 Bld Sébastien Brant, 67413, Illkirch, Strasbourg, France
| | - Coraline Rigouin
- Université de Strasbourg, CNRS-UMR7242, BSC, ESBS, 300 Bld Sébastien Brant, 67413, Illkirch, Strasbourg, France
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17
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Targeting the Holy Triangle of Quorum Sensing, Biofilm Formation, and Antibiotic Resistance in Pathogenic Bacteria. Microorganisms 2022; 10:microorganisms10061239. [PMID: 35744757 PMCID: PMC9228545 DOI: 10.3390/microorganisms10061239] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 06/12/2022] [Accepted: 06/14/2022] [Indexed: 12/12/2022] Open
Abstract
Chronic and recurrent bacterial infections are frequently associated with the formation of biofilms on biotic or abiotic materials that are composed of mono- or multi-species cultures of bacteria/fungi embedded in an extracellular matrix produced by the microorganisms. Biofilm formation is, among others, regulated by quorum sensing (QS) which is an interbacterial communication system usually composed of two-component systems (TCSs) of secreted autoinducer compounds that activate signal transduction pathways through interaction with their respective receptors. Embedded in the biofilms, the bacteria are protected from environmental stress stimuli, and they often show reduced responses to antibiotics, making it difficult to eradicate the bacterial infection. Besides reduced penetration of antibiotics through the intricate structure of the biofilms, the sessile biofilm-embedded bacteria show reduced metabolic activity making them intrinsically less sensitive to antibiotics. Moreover, they frequently express elevated levels of efflux pumps that extrude antibiotics, thereby reducing their intracellular levels. Some efflux pumps are involved in the secretion of QS compounds and biofilm-related materials, besides being important for removing toxic substances from the bacteria. Some efflux pump inhibitors (EPIs) have been shown to both prevent biofilm formation and sensitize the bacteria to antibiotics, suggesting a relationship between these processes. Additionally, QS inhibitors or quenchers may affect antibiotic susceptibility. Thus, targeting elements that regulate QS and biofilm formation might be a promising approach to combat antibiotic-resistant biofilm-related bacterial infections.
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18
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Veetilvalappil VV, Manuel A, Aranjani JM, Tawale R, Koteshwara A. Pathogenic arsenal of Pseudomonas aeruginosa: an update on virulence factors. Future Microbiol 2022; 17:465-481. [PMID: 35289684 DOI: 10.2217/fmb-2021-0158] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The emergence of Pseudomonas aeruginosa as a potential threat in persistent infections can be attributed to the plethora of virulence factors expressed by it. This review discusses the various virulence factors that help this pathogen to establish an infection and regulatory systems controlling these virulence factors. Cell-associated virulence factors such as flagella, type IV pili and non-pilus adhesins have been reviewed. Extracellular virulence factors have also been explained. Quorum-sensing systems present in P. aeruginosa play a cardinal role in regulating the expression of virulence factors. The identification of novel virulence factors in hypervirulent strains indicate that the expression of virulence is dynamic and constantly evolving. An understanding of this is critical for the better clinical management of infections.
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Affiliation(s)
- Vimal V Veetilvalappil
- Department of Pharmaceutical Biotechnology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Atulya Manuel
- Central Frozen Semen Production and Training Institute, Bengaluru, Karnataka, 560088, India
| | - Jesil M Aranjani
- Department of Pharmaceutical Biotechnology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Roshan Tawale
- Department of Pharmaceutical Biotechnology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Ananthamurthy Koteshwara
- Department of Pharmaceutical Biotechnology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, 576104, India
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19
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Cell Envelope Stress Response in Pseudomonas aeruginosa. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:147-184. [DOI: 10.1007/978-3-031-08491-1_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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20
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King A, Blackledge MS. Evaluation of small molecule kinase inhibitors as novel antimicrobial and antibiofilm agents. Chem Biol Drug Des 2021; 98:1038-1064. [PMID: 34581492 PMCID: PMC8616828 DOI: 10.1111/cbdd.13962] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 08/24/2021] [Accepted: 09/15/2021] [Indexed: 12/25/2022]
Abstract
Antibiotic resistance is a global and pressing concern. Our current therapeutic arsenal is increasingly limited as bacteria are developing resistance at a rate that far outpaces our ability to create new treatments. Novel approaches to treating and curing bacterial infections are urgently needed. Bacterial kinases have been increasingly explored as novel drug targets and are poised for development into novel therapeutic agents to combat bacterial infections. This review describes several general classes of bacterial kinases that play important roles in bacterial growth, antibiotic resistance, and biofilm formation. General features of these kinase classes are discussed and areas of particular interest for the development of inhibitors will be highlighted. Small molecule kinase inhibitors are described and organized by phenotypic effect, spotlighting particularly interesting inhibitors with novel functions and potential therapeutic benefit. Finally, we provide our perspective on the future of bacterial kinase inhibition as a viable strategy to combat bacterial infections and overcome the pressures of increasing antibiotic resistance.
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Affiliation(s)
- Ashley King
- Department of Chemistry, High Point University, One University Parkway, High Point, NC 27268
| | - Meghan S. Blackledge
- Department of Chemistry, High Point University, One University Parkway, High Point, NC 27268
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21
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Genomic and Metabolic Characteristics of the Pathogenicity in Pseudomonas aeruginosa. Int J Mol Sci 2021; 22:ijms222312892. [PMID: 34884697 PMCID: PMC8657582 DOI: 10.3390/ijms222312892] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 11/26/2021] [Accepted: 11/27/2021] [Indexed: 01/22/2023] Open
Abstract
In recent years, the effectiveness of antimicrobials in the treatment of Pseudomonas aeruginosa infections has gradually decreased. This pathogen can be observed in several clinical cases, such as pneumonia, urinary tract infections, sepsis, in immunocompromised hosts, such as neutropenic cancer, burns, and AIDS patients. Furthermore, Pseudomonas aeruginosa causes diseases in both livestock and pets. The highly flexible and versatile genome of P. aeruginosa allows it to have a high rate of pathogenicity. The numerous secreted virulence factors, resulting from its numerous secretion systems, the multi-resistance to different classes of antibiotics, and the ability to produce biofilms are pathogenicity factors that cause numerous problems in the fight against P. aeruginosa infections and that must be better understood for an effective treatment. Infections by P. aeruginosa represent, therefore, a major health problem and, as resistance genes can be disseminated between the microbiotas associated with humans, animals, and the environment, this issue needs be addressed on the basis of an One Health approach. This review intends to bring together and describe in detail the molecular and metabolic pathways in P. aeruginosa's pathogenesis, to contribute for the development of a more targeted therapy against this pathogen.
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22
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Warrier A, Satyamoorthy K, Murali TS. Quorum-sensing regulation of virulence factors in bacterial biofilm. Future Microbiol 2021; 16:1003-1021. [PMID: 34414776 DOI: 10.2217/fmb-2020-0301] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Chronic polymicrobial wound infections are often characterized by the presence of bacterial biofilms. They show considerable structural and functional heterogeneity, which influences the choice of antimicrobial therapy and wound healing dynamics. The hallmarks of biofilm-associated bacterial infections include elevated antibiotic resistance and extreme pathogenicity. Biofilm helps bacteria to evade the host defense mechanisms and persist longer in the host. Quorum-sensing (QS)-mediated cell signaling primarily regulates biofilm formation in chronic infections and plays a major role in eliciting virulence. This review focuses on the QS mechanisms of two major bacterial pathogens, Staphylococcus aureus and Pseudomonas aeruginosa and explains how they interact in the wound microenvironment to regulate biofilm development and virulence. The review also provides an insight into the treatment modalities aimed at eradicating polymicrobial biofilms. This information will help us develop better diagnostic modalities and devise effective treatment regimens to successfully manage and overcome severe life-threatening bacterial infections.
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Affiliation(s)
- Anjali Warrier
- Department of Biotechnology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Kapaettu Satyamoorthy
- Department of Cell & Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Thokur Sreepathy Murali
- Department of Biotechnology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, India.,Manipal Center for Infectious Diseases (MAC ID), Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, Karnataka, India
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23
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Marunga J, Goo E, Kang Y, Hwang I. Mutations in the Two-Component GluS-GluR Regulatory System Confer Resistance to β-Lactam Antibiotics in Burkholderia glumae. Front Microbiol 2021; 12:721444. [PMID: 34381438 PMCID: PMC8350040 DOI: 10.3389/fmicb.2021.721444] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 06/30/2021] [Indexed: 11/17/2022] Open
Abstract
Bacteria have specific signaling systems to overcome selective pressure, such as exposure to antibiotics. The two-component system (TCS) plays an important role in the development of antibiotic resistance. Using the rice pathogen Burkholderia glumae BGR1 as a model organism, we showed that the GluS (BGLU_1G13350) – GluR (BGLU_1G13360) TCS, consisting of a sensor kinase and response regulator, respectively, contributes to β-lactam resistance through a distinct mechanism. Inactivation of gluS or gluR conferred resistance to β-lactam antibiotics in B. glumae, whereas wild-type (WT) B. glumae was susceptible to these antibiotics. In gluS and gluR mutants, the expression of genes encoding metallo-β-lactamases (MBLs) and penicillin-binding proteins (PBPs) was significantly higher than in the WT. GluR-His bound to the putative promoter regions of annotated genes encoding MBL (BGLU_1G21360) and PBPs (BGLU_1G13280 and BGLU_1G04560), functioning as a repressor. These results demonstrate that the potential to attain β-lactam resistance may be genetically concealed in the TCS, in contrast to the widely accepted view of the role of TCS in antibiotic resistance. Our findings provide a new perspective on antibiotic resistance mechanisms, and suggest a different therapeutic approach for successful control of bacterial pathogens.
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Affiliation(s)
- Joan Marunga
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Eunhye Goo
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Yongsung Kang
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Ingyu Hwang
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea.,Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
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24
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Patiño MI, Restrepo LM, Becerra NY, van der Mei HC, van Kooten TG, Sharma PK. Nonviral Expression of LL-37 in a Human Skin Equivalent to Prevent Infection in Skin Wounds. Hum Gene Ther 2021; 32:1147-1157. [PMID: 33980038 DOI: 10.1089/hum.2021.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Inefficient autologous tissue recovery in skin wounds increases the susceptibility of patients to infections caused by multidrug resistant microorganisms, resulting in a high mortality rate. Genetic modification of skin cells has become an important field of study because it could lead to the construction of more functional skin grafts, through the overexpression of antimicrobial peptides that would prevent early contamination and infection with bacteria. In this study, we produce and evaluate human skin equivalents (HSEs) containing transfected human primary fibroblasts and keratinocytes by polyplexes to express the antimicrobial peptide LL-37. The effect of LL-37 on the metabolic activity of normal HSEs was evaluated before the construction of the transfected HSEs, and the antimicrobial efficacy against Pseudomonas aeruginosa and Staphylococcus aureus was evaluated. Subsequently, the levels of LL-37 in the culture supernatants of transfected HSEs, as well as the local expression, were determined. It was found that LL-37 treatment significantly promoted the cellular proliferation of HSEs. Furthermore, HSEs that express elevated levels of LL-37 were shown to possess histological characteristics close to the normal skin and display enhanced antimicrobial activity against S. aureus in vitro. These findings demonstrate that HSEs expressing LL-37 through nonviral modification of skin cells are a promising approach for the prevention of bacterial colonization in wounds.
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Affiliation(s)
- Maria Isabel Patiño
- Tissue Engineering and Cell Therapy Group, Faculty of Medicine, University of Antioquia, Medellín, Colombia.,Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Luz Marina Restrepo
- Tissue Engineering and Cell Therapy Group, Faculty of Medicine, University of Antioquia, Medellín, Colombia
| | - Natalia Yiset Becerra
- Tissue Engineering and Cell Therapy Group, Faculty of Medicine, University of Antioquia, Medellín, Colombia
| | - Henny C van der Mei
- Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Theo G van Kooten
- Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Prashant K Sharma
- Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
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25
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Tan X, Qiao J, Zhou Q, Huang D, Li H, Wang J, Wang X. Identification of a phosphoethanolamine transferase for lipid A modification in Vibrio parahaemolyticus. Food Control 2021. [DOI: 10.1016/j.foodcont.2021.108033] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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26
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Wang T, Sun W, Fan L, Hua C, Wu N, Fan S, Zhang J, Deng X, Yan J. An atlas of the binding specificities of transcription factors in Pseudomonas aeruginosa directs prediction of novel regulators in virulence. eLife 2021; 10:61885. [PMID: 33779544 PMCID: PMC8041468 DOI: 10.7554/elife.61885] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 03/26/2021] [Indexed: 12/14/2022] Open
Abstract
A high-throughput systematic evolution of ligands by exponential enrichment assay was applied to 371 putative TFs in Pseudomonas aeruginosa, which resulted in the robust enrichment of 199 unique sequence motifs describing the binding specificities of 182 TFs. By scanning the genome, we predicted in total 33,709 significant interactions between TFs and their target loci, which were more than 11-fold enriched in the intergenic regions but depleted in the gene body regions. To further explore and delineate the physiological and pathogenic roles of TFs in P. aeruginosa, we constructed regulatory networks for nine major virulence-associated pathways and found that 51 TFs were potentially significantly associated with these virulence pathways, 32 of which had not been characterized before, and some were even involved in multiple pathways. These results will significantly facilitate future studies on transcriptional regulation in P. aeruginosa and other relevant pathogens, and accelerate to discover effective treatment and prevention strategies for the associated infectious diseases.
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Affiliation(s)
- Tingting Wang
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Wenju Sun
- School of Medicine, Northwest University, Xi'an, China
| | - Ligang Fan
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China.,School of Medicine, Northwest University, Xi'an, China
| | - Canfeng Hua
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Nan Wu
- School of Medicine, Northwest University, Xi'an, China
| | - Shaorong Fan
- School of Medicine, Northwest University, Xi'an, China
| | - Jilin Zhang
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Solna, Sweden
| | - Xin Deng
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Jian Yan
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China.,School of Medicine, Northwest University, Xi'an, China
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27
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Yang B, Liu C, Pan X, Fu W, Fan Z, Jin Y, Bai F, Cheng Z, Wu W. Identification of Novel PhoP-PhoQ Regulated Genes That Contribute to Polymyxin B Tolerance in Pseudomonas aeruginosa. Microorganisms 2021; 9:microorganisms9020344. [PMID: 33572426 PMCID: PMC7916210 DOI: 10.3390/microorganisms9020344] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/06/2021] [Accepted: 02/08/2021] [Indexed: 12/14/2022] Open
Abstract
Polymyxin B and E (colistin) are the last resorts to treat multidrug-resistant Gram-negative pathogens. Pseudomonas aeruginosa is intrinsically resistant to a variety of antibiotics. The PhoP-PhoQ two-component regulatory system contributes to the resistance to polymyxins by regulating an arnBCADTEF-pmrE operon that encodes lipopolysaccharide modification enzymes. To identify additional PhoP-regulated genes that contribute to the tolerance to polymyxin B, we performed a chromatin immunoprecipitation sequencing (ChIP-Seq) assay and found novel PhoP binding sites on the chromosome. We further verified that PhoP directly controls the expression of PA14_46900, PA14_50740 and PA14_52340, and the operons of PA14_11970-PA14_11960 and PA14_52350-PA14_52370. Our results demonstrated that mutation of PA14_46900 increased the bacterial binding and susceptibility to polymyxin B. Meanwhile, mutation of PA14_11960 (papP), PA14_11970 (mpl), PA14_50740 (slyB), PA14_52350 (ppgS), and PA14_52370 (ppgH) reduced the bacterial survival rates and increased ethidium bromide influx under polymyxin B or Sodium dodecyl sulfate (SDS) treatment, indicating roles of these genes in maintaining membrane integrity in response to the stresses. By 1-N-phenylnaphthylamine (NPN) and propidium iodide (PI) staining assay, we found that papP and slyB are involved in maintaining outer membrane integrity, and mpl and ppgS-ppgH are involved in maintaining inner membrane integrity. Overall, our results reveal novel PhoP-PhoQ regulated genes that contribute to polymyxin B tolerance.
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28
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Lu HF, Wu BK, Huang YW, Lee MZ, Li MF, Ho HJ, Yang HC, Yang TC. PhoPQ two-component regulatory system plays a global regulatory role in antibiotic susceptibility, physiology, stress adaptation, and virulence in Stenotrophomonas maltophilia. BMC Microbiol 2020; 20:312. [PMID: 33054754 PMCID: PMC7559202 DOI: 10.1186/s12866-020-01989-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 09/30/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Stenotrophomonas maltophilia, an opportunistic pathogen, is ubiquitously present in various environments, signifying its high capability of environmental adaptation. Two-component regulatory system (TCS) is a powerful implement to help organisms to survive in different environments. In clinic, treatment of S. maltophilia infection is difficult because it is naturally resistant to many antibiotics, highlighting the necessity to develop novel drugs or adjuvants. Given their critical and extensively regulatory role, TCS system has been proposed as a convincing target for novel drugs or adjuvants. PhoPQ TCS, a highly conserved TCS in several pathogens, plays crucial roles in low-magnesium adaption, polymyxin resistance, and virulence. In this study, we aimed to characterize the role of PhoPQ TCS of S. maltophilia in antibiotic susceptibility, physiology, stress adaptation, and virulence. RESULTS To characterize PhoPQ system, phoP single mutant as well as phoP and phoQ double mutant were constructed. Distinct from most phoPQ systems of other microorganisms, two features were observed during the construction of phoP and phoQ single deletion mutant. Firstly, the phoQ mutant was not successfully obtained. Secondly, the compromised phenotypes of phoP mutant were not reverted by complementing an intact phoP gene, but were partially restored by complementing a phoPQ operon. Thus, wild-type KJ, phoP mutant (KJΔPhoP), phoPQ mutant (KJΔPhoPQ), and complemented strain (KJΔPhoPQ (pPhoPQ)) were used for functional assays, including antibiotic susceptibility, physiology (swimming motility and secreted protease activity), stress adaptation (oxidative, envelope, and iron-depletion stresses), and virulence to Caenorhabditis elegans. KJΔPhoPQ totally lost swimming motility, had enhanced secreted protease activity, increased susceptibility to antibiotics (β-lactam, quinolone, aminoglycoside, macrolide, chloramphenicol, and sulfamethoxazole/ trimethoprim), menadione, H2O2, SDS, and 2,2'-dipyridyl, as well as attenuated virulence to C. elegans. Trans-complementation of KJΔPhoPQ with phoPQ reverted these altered phenotypes to the wild-type levels. CONCLUSIONS Given the critical and global roles of PhoPQ TCS in antibiotic susceptibility, physiology, stress adaptation, and virulence, PhoPQ is a potential target for the design of drugs or adjuvants.
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Affiliation(s)
- Hsu-Feng Lu
- Department of Clinical Pathology, Cheng Hsin General Hospital, Taipei, Taiwan
- Department of Restaurant, Hotel and Institutional Management, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Bo-Kuan Wu
- Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Yi-Wei Huang
- Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Ming-Zhe Lee
- Department of Clinical Pathology, Cheng Hsin General Hospital, Taipei, Taiwan
| | - Ming-Fang Li
- Department of Medical Laboratory Science and Biotechnology, Yuanpei University of Medical Technology, Hsinchu, Taiwan
| | - Hsu-Jung Ho
- Department of Medical Laboratory Science and Biotechnology, Yuanpei University of Medical Technology, Hsinchu, Taiwan
| | - Hung-Chi Yang
- Department of Medical Laboratory Science and Biotechnology, Yuanpei University of Medical Technology, Hsinchu, Taiwan.
| | - Tsuey-Ching Yang
- Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei, Taiwan.
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29
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Yang Q, Pogue JM, Li Z, Nation RL, Kaye KS, Li J. Agents of Last Resort: An Update on Polymyxin Resistance. Infect Dis Clin North Am 2020; 34:723-750. [PMID: 33011049 DOI: 10.1016/j.idc.2020.08.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Polymyxin resistance is a major public health threat, because the polymyxins represent last-line therapeutics for gram-negative pathogens resistant to essentially all other antibiotics. Minimizing any potential emergence and dissemination of polymyxin resistance relies on an improved understanding of mechanisms of and risk factors for polymyxin resistance, infection prevention and stewardship strategies, together with optimization of dosing of polymyxins (eg, combination regimens).
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Affiliation(s)
- Qiwen Yang
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, No.9 Dongdan Santiao, Dongcheng District, Beijing, China.
| | - Jason M Pogue
- Department of Clinical Pharmacy, University of Michigan College of Pharmacy, 428 Church Street, Ann Arbor, MI 48109, USA
| | - Zekun Li
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, No.9 Dongdan Santiao, Dongcheng District, Beijing, China
| | - Roger L Nation
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Victoria 3052, Australia
| | - Keith S Kaye
- Department of Internal Medicine, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, MI 48109, USA
| | - Jian Li
- Laboratory of Antimicrobial Systems Pharmacology, Department of Microbiology, Monash University, Victoria 3800, Australia
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30
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Felgner S, Preusse M, Beutling U, Stahnke S, Pawar V, Rohde M, Brönstrup M, Stradal T, Häussler S. Host-induced spermidine production in motile Pseudomonas aeruginosa triggers phagocytic uptake. eLife 2020; 9:e55744. [PMID: 32960172 PMCID: PMC7538158 DOI: 10.7554/elife.55744] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 09/15/2020] [Indexed: 12/31/2022] Open
Abstract
Exploring the complexity of host-pathogen communication is vital to understand why microbes persist within a host, while others are cleared. Here, we employed a dual-sequencing approach to unravel conversational turn-taking of dynamic host-pathogen communications. We demonstrate that upon hitting a host cell, motile Pseudomonas aeruginosa induce a specific gene expression program. This results in the expression of spermidine on the surface, which specifically activates the PIP3-pathway to induce phagocytic uptake into primary or immortalized murine cells. Non-motile bacteria are more immunogenic due to a lower expression of arnT upon host-cell contact, but do not produce spermidine and are phagocytosed less. We demonstrate that not only the presence of pathogen inherent molecular patterns induces immune responses, but that bacterial motility is linked to a host-cell-induced expression of additional immune modulators. Our results emphasize on the value of integrating microbiological and immunological findings to unravel complex and dynamic host-pathogen interactions.
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Affiliation(s)
- Sebastian Felgner
- Department of Molecular Bacteriology, Helmholtz Centre for Infection ResearchBraunschweigGermany
| | - Matthias Preusse
- Department of Molecular Bacteriology, Helmholtz Centre for Infection ResearchBraunschweigGermany
| | - Ulrike Beutling
- Department of Chemical Biology, Helmholtz Centre for Infection ResearchBraunschweigGermany
| | - Stephanie Stahnke
- Department of Cell Biology, Helmholtz Centre for Infection ResearchBraunschweigGermany
| | - Vinay Pawar
- Department of Molecular Bacteriology, Helmholtz Centre for Infection ResearchBraunschweigGermany
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz Centre for Infection ResearchBraunschweigGermany
| | - Mark Brönstrup
- Department of Chemical Biology, Helmholtz Centre for Infection ResearchBraunschweigGermany
| | - Theresia Stradal
- Department of Cell Biology, Helmholtz Centre for Infection ResearchBraunschweigGermany
| | - Susanne Häussler
- Department of Molecular Bacteriology, Helmholtz Centre for Infection ResearchBraunschweigGermany
- Department of Molecular Bacteriology, TwincoreHannoverGermany
- Department of Clinical Microbiology, RigshospitaletCopenhagenDenmark
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical SchoolHannoverGermany
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31
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Sun H, Pulakat L, Anderson DW. Challenges and New Therapeutic Approaches in the Management of Chronic Wounds. Curr Drug Targets 2020; 21:1264-1275. [PMID: 32576127 DOI: 10.2174/1389450121666200623131200] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 05/10/2020] [Accepted: 05/20/2020] [Indexed: 02/07/2023]
Abstract
Chronic non-healing wounds are estimated to cost the US healthcare $28-$31 billion per year. Diabetic ulcers, arterial and venous ulcers, and pressure ulcers are some of the most common types of chronic wounds. The burden of chronic wounds continues to rise due to the current epidemic of obesity and diabetes and the increase in elderly adults in the population who are more vulnerable to chronic wounds than younger individuals. This patient population is also highly vulnerable to debilitating infections caused by opportunistic and multi-drug resistant pathogens. Reduced microcirculation, decreased availability of cytokines and growth factors that promote wound closure and healing, and infections by multi-drug resistant and biofilm forming microbes are some of the critical factors that contribute to the development of chronic non-healing wounds. This review discusses novel approaches to understand chronic wound pathology and methods to improve chronic wound care, particularly when chronic wounds are infected by multi-drug resistant, biofilm forming microbes.
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Affiliation(s)
- Hongmin Sun
- Division of Cardiovascular Medicine, Department of Medicine, University of Missouri, Columbia, Missouri 65212, United States
| | - Lakshmi Pulakat
- Division of Cardiovascular Medicine, Department of Medicine, University of Missouri, Columbia, Missouri 65212, United States
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32
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Shao X, Xie Y, Zhang Y, Liu J, Ding Y, Wu M, Wang X, Deng X. Novel therapeutic strategies for treating Pseudomonas aeruginosa infection. Expert Opin Drug Discov 2020; 15:1403-1423. [PMID: 32880507 DOI: 10.1080/17460441.2020.1803274] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Persistent infections caused by the superbug Pseudomonas aeruginosa and its resistance to multiple antimicrobial agents are huge threats to patients with cystic fibrosis as well as those with compromised immune systems. Multidrug-resistant P. aeruginosa has posed a major challenge to conventional antibiotics and therapeutic approaches, which show limited efficacy and cause serious side effects. The public demand for new antibiotics is enormous; yet, drug development pipelines have started to run dry with limited targets available for inventing new antibacterial drugs. Consequently, it is important to uncover potential therapeutic targets. AREAS COVERED The authors review the current state of drug development strategies that are promising in terms of the development of novel and potent drugs to treat P. aeruginosa infection. EXPERT OPINION The prevention of P. aeruginosa infection is increasingly challenging. Furthermore, targeting key virulence regulators has great potential for developing novel anti-P. aeruginosa drugs. Additional promising strategies include bacteriophage therapy, immunotherapies, and antimicrobial peptides. Additionally, the authors believe that in the coming years, the overall network of molecular regulatory mechanism of P. aeruginosa virulence will be fully elucidated, which will provide more novel and promising drug targets for treating P. aeruginosa infections.
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Affiliation(s)
- Xiaolong Shao
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China
| | - Yingpeng Xie
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China
| | - Yingchao Zhang
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China
| | - Jingui Liu
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China
| | - Yiqing Ding
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China
| | - Min Wu
- Department of Biomedical Sciences, University of North Dakota , Grand Forks, North Dakota, USA
| | - Xin Wang
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China
| | - Xin Deng
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China.,Shenzhen Research Institute, City University of Hong Kong , Shenzhen, China
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33
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Vitale A, Pessi G, Urfer M, Locher HH, Zerbe K, Obrecht D, Robinson JA, Eberl L. Identification of Genes Required for Resistance to Peptidomimetic Antibiotics by Transposon Sequencing. Front Microbiol 2020; 11:1681. [PMID: 32793157 PMCID: PMC7390954 DOI: 10.3389/fmicb.2020.01681] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/26/2020] [Indexed: 12/27/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic human pathogen and a leading cause of nosocomial infections. Due to its high intrinsic and adaptive resistance to antibiotics, infections caused by this organism are difficult to treat and new therapeutic options are urgently needed. Novel peptidomimetic antibiotics that target outer membrane (OM) proteins have shown great promise for the treatment of P. aeruginosa infections. Here, we have performed genome-wide mutant fitness profiling using transposon sequencing (Tn-Seq) to identify resistance determinants against the recently described peptidomimetics L27-11, compounds 3 and 4, as well as polymyxin B2 (PMB) and colistin (COL). We identified a set of 13 core genes that affected resistance to all tested antibiotics, many of which encode enzymes involved in the modification of the lipopolysaccharide (LPS) or control their expression. We also identified fitness determinants that are specific for antibiotics with similar structures that may indicate differences in their modes of action. These results provide new insights into resistance mechanisms against these peptide antibiotics, which will be important for future clinical development and efforts to further improve their potency.
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Affiliation(s)
- Alessandra Vitale
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Gabriella Pessi
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | | | | | - Katja Zerbe
- Department of Chemistry, University of Zurich, Zurich, Switzerland
| | | | - John A Robinson
- Department of Chemistry, University of Zurich, Zurich, Switzerland
| | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
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34
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Balaure PC, Grumezescu AM. Recent Advances in Surface Nanoengineering for Biofilm Prevention and Control. Part I: Molecular Basis of Biofilm Recalcitrance. Passive Anti-Biofouling Nanocoatings. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E1230. [PMID: 32599948 PMCID: PMC7353097 DOI: 10.3390/nano10061230] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/19/2020] [Accepted: 06/20/2020] [Indexed: 12/17/2022]
Abstract
Medical device-associated infections are becoming a leading cause of morbidity and mortality worldwide, prompting researchers to find new, more effective ways to control the bacterial colonisation of surfaces and biofilm development. Bacteria in biofilms exhibit a set of "emergent properties", meaning those properties that are not predictable from the study of free-living bacterial cells. The social coordinated behaviour in the biofilm lifestyle involves intricate signaling pathways and molecular mechanisms underlying the gain in resistance and tolerance (recalcitrance) towards antimicrobial agents as compared to free-floating bacteria. Nanotechnology provides powerful tools to disrupt the processes responsible for recalcitrance development in all stages of the biofilm life cycle. The present paper is a state-of-the-art review of the surface nanoengineering strategies currently used to design antibiofilm coatings. The review is structurally organised in two parts according to the targeted biofilm life cycle stages and molecular mechanisms intervening in recalcitrance development. Therefore, in the present first part, we begin with a presentation of the current knowledge of the molecular mechanisms responsible for increased recalcitrance that have to be disrupted. Further, we deal with passive surface nanoengineering strategies that aim to prevent bacterial cells from settling onto a biotic or abiotic surface. Both "fouling-resistant" and "fouling release" strategies are addressed as well as their synergic combination in a single unique nanoplatform.
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Affiliation(s)
- Paul Cătălin Balaure
- “Costin Nenitzescu” Department of Organic Chemistry, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, G. Polizu Street 1-7, 011061 Bucharest, Romania
| | - Alexandru Mihai Grumezescu
- Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, G. Polizu Street 1-7, 011061 Bucharest, Romania
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35
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Hua J, Jia X, Zhang L, Li Y. The Characterization of Two-Component System PmrA/PmrB in Cronobacter sakazakii. Front Microbiol 2020; 11:903. [PMID: 32655500 PMCID: PMC7326031 DOI: 10.3389/fmicb.2020.00903] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 04/16/2020] [Indexed: 01/12/2023] Open
Abstract
Cronobacter sakazakii is an opportunistic Gram-negative pathogen that could cause meningitis and necrotizing enterocolitis. Several Gram-negative bacteria use the PmrA/PmrB system to sense and adapt to environmental change by resistance to cationic antimicrobial peptides of host immune systems. The PmrA/PmrB two-component system regulates several genes to modify LPS structure in the bacterial outer membrane. The role of PmrA/PmrB of C. sakazakii has been studied within the current study. The results suggest that PmrA/PmrB plays a crucial role in modifying LPS structure, cationic antimicrobial peptide susceptibility, cell membrane permeability and hydrophobicity, and invading macrophage.
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Affiliation(s)
- Jingjing Hua
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
| | - Xiangyin Jia
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Liang Zhang
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, China
| | - Yanyan Li
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, China
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36
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Badal D, Jayarani AV, Kollaran MA, Kumar A, Singh V. Pseudomonas aeruginosa biofilm formation on endotracheal tubes requires multiple two-component systems. J Med Microbiol 2020; 69:906-919. [PMID: 32459613 DOI: 10.1099/jmm.0.001199] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Introduction. Indwelling medical devices such as endotracheal tubes (ETTs), urinary catheters, vascular access devices, tracheostomies and feeding tubes are often associated with hospital-acquired infections. Bacterial biofilm formed on the ETTs in intubated patients is a significant risk factor associated with ventilator-associated pneumonia. Pseudomonas aeruginosa is one of the four frequently encountered bacteria responsible for causing pneumonia, and the biofilm formation on ETTs. However, understanding of biofilm formation on ETT and interventions to prevent biofilm remains lagging. The ability to sense and adapt to external cues contributes to their success. Thus, the biofilm formation is likely to be influenced by the two-component systems (TCSs) that are composed of a membrane-associated sensor kinase and an intracellular response regulator.Aim. This study aims to establish an in vitro method to analyse the P. aeruginosa biofilm formation on ETTs, and identify the TCSs that contribute to this process.Methodology. In total, 112 P. aeruginosa PA14 TCS mutants were tested for their ability to form biofilm on ETTs, their effect on quorum sensing (QS) and motility.Results. Out of 112 TCS mutants studied, 56 had altered biofilm biomass on ETTs. Although the biofilm formation on ETTs is QS-dependent, none of the 56 loci controlled quorum signal. Of these, 18 novel TCSs specific to ETT biofilm were identified, namely, AauS, AgtS, ColR, CopS, CprR, NasT, KdpD, ParS, PmrB, PprA, PvrS, RcsC, PA14_11120, PA14_32580, PA14_45880, PA14_49420, PA14_52240, PA14_70790. The set of 56 included the GacS network, TCS proteins involved in fimbriae synthesis, TCS proteins involved in antimicrobial peptide resistance, and surface-sensing. Additionally, several of the TCS-encoding genes involved in biofilm formation on ETTs were found to be linked to flagellum-dependent swimming motility.Conclusions. Our study established an in vitro method for studying P. aeruginosa biofilm formation on the ETT surfaces. We also identified novel ETT-specific TCSs that could serve as targets to prevent biofilm formation on indwelling devices frequently used in clinical settings.
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Affiliation(s)
- Divakar Badal
- Department of Biosystems Sciences and Engineering, Indian Institute of Science, Bangalore, Karnataka, INDIA
| | - Abhijith Vimal Jayarani
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, Karnataka, INDIA
| | - Mohammed Ameen Kollaran
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, Karnataka, INDIA
| | - Aloke Kumar
- Department of Mechanical Engineering, Indian Institute of Science, Bangalore, Karnataka, INDIA.,Department of Biosystems Sciences and Engineering, Indian Institute of Science, Bangalore, Karnataka, INDIA
| | - Varsha Singh
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, Karnataka, INDIA.,Department of Biosystems Sciences and Engineering, Indian Institute of Science, Bangalore, Karnataka, INDIA
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Lo Sciuto A, Cervoni M, Stefanelli R, Mancone C, Imperi F. Effect of lipid A aminoarabinosylation on Pseudomonas aeruginosa colistin resistance and fitness. Int J Antimicrob Agents 2020; 55:105957. [PMID: 32278012 DOI: 10.1016/j.ijantimicag.2020.105957] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 03/10/2020] [Accepted: 03/20/2020] [Indexed: 01/06/2023]
Abstract
Colistin represents the last-line treatment option against many multidrug-resistant Gram-negative pathogens. Several lines of evidence indicate that aminoarabinosylation of the lipid A moiety of lipopolysaccharide (LPS) is an essential step for the development of colistin resistance in Pseudomonas aeruginosa. However, whether it is sufficient to confer resistance in this bacterium remains unclear. The aim of this work was to investigate the specific contribution of lipid A aminoarabinosylation to colistin resistance in P. aeruginosa and evaluate the effect of this resistance mechanism on bacterial fitness. Recombinant strains constitutively expressing the enzymes for lipid A aminoarabinosylation were generated in a small collection of reference and clinical isolates and verified by quantitative reverse transcription polymerase chain reaction (qRT-PCR), lipid A extraction and mass spectrometry. The effect of aminoarabinosylated lipid A on colistin resistance was found to be strain- and culture condition-dependent. Higher levels of resistance were generally obtained in the presence of divalent cations, which appear to be important for aminoarabinosylation-mediated colistin resistance. High colistin resistance was also observed for most strains in human serum and in artificial sputum medium, which should partly mimic growth conditions during infection. The results of growth, biofilm, cell envelope integrity and Galleria mellonella infection assays indicate that lipid A aminoarabinosylation does not cause relevant fitness costs in P. aeruginosa.
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Affiliation(s)
| | | | - Roberta Stefanelli
- Department of Science, Roma Tre University, Rome, Italy; Department of Biology and Biotechnology Charles Darwin, Sapienza University of Rome, Laboratory affiliated to Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Rome, Italy
| | - Carmine Mancone
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
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The Efflux Pump MexXY/OprM Contributes to the Tolerance and Acquired Resistance of Pseudomonas aeruginosa to Colistin. Antimicrob Agents Chemother 2020; 64:AAC.02033-19. [PMID: 31964794 DOI: 10.1128/aac.02033-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 01/13/2020] [Indexed: 12/29/2022] Open
Abstract
The intrinsic resistance of Pseudomonas aeruginosa to polymyxins in part relies on the addition of 4-amino-4-deoxy-l-arabinose (Ara4N) molecules to the lipid A of lipopolysaccharide (LPS), through induction of operon arnBCADTEF-ugd (arn) expression. As demonstrated previously, at least three two-component regulatory systems (PmrAB, ParRS, and CprRS) are able to upregulate this operon when bacteria are exposed to colistin. In the present study, gene deletion experiments with the bioluminescent strain PAO1::lux showed that ParRS is a key element in the tolerance of P. aeruginosa to this last-resort antibiotic (i.e., resistance to early drug killing). Other loci of the ParR regulon, such as those encoding the efflux proteins MexXY (mexXY), the polyamine biosynthetic pathway PA4773-PA4774-PA4775, and Ara4N LPS modification process (arnBCADTEF-ugd), also contribute to the bacterial tolerance in an intricate way with ParRS. Furthermore, we found that both stable upregulation of the arn operon and drug-induced ParRS-dependent overexpression of the mexXY genes accounted for the elevated resistance of pmrB mutants to colistin. Deletion of the mexXY genes in a constitutively activated ParR mutant of PAO1 was associated with significantly increased expression of the genes arnA, PA4773, and pmrA in the absence of colistin exposure, thereby highlighting a functional link between the MexXY/OprM pump, the PA4773-PA4774-PA4775 pathway, and Ara4N-based modification of LPS. The role played by MexXY/OprM in the adaptation of P. aeruginosa to polymyxins opens new perspectives for restoring the susceptibility of resistant mutants through the use of efflux inhibitors.
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Dean SN, Milton ME, Cavanagh J, van Hoek ML. Francisella novicida Two-Component System Response Regulator BfpR Modulates iglC Gene Expression, Antimicrobial Peptide Resistance, and Biofilm Production. Front Cell Infect Microbiol 2020; 10:82. [PMID: 32232010 PMCID: PMC7082314 DOI: 10.3389/fcimb.2020.00082] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 02/18/2020] [Indexed: 12/20/2022] Open
Abstract
Response regulators are a critical part of the two-component system of gene expression regulation in bacteria, transferring a signal from a sensor kinase into DNA binding activity resulting in alteration of gene expression. In this study, we investigated a previously uncharacterized response regulator in Francisella novicida, FTN_1452 that we have named BfpR (Biofilm-regulating Francisella protein Regulator, FTN_1452). In contrast to another Francisella response regulator, QseB/PmrA, BfpR appears to be a negative regulator of biofilm production, and also a positive regulator of antimicrobial peptide resistance in this bacterium. The protein was crystallized and X-ray crystallography studies produced a 1.8 Å structure of the BfpR N-terminal receiver domain revealing interesting insight into its potential interaction with the sensor kinase. Structural analysis of BfpR places it in the OmpR/PhoP family of bacterial response regulators along with WalR and ResD. Proteomic and transcriptomic analyses suggest that BfpR overexpression affects expression of the critical Francisella virulence factor iglC, as well as other proteins in the bacterium. We demonstrate that mutation of bfpR is associated with an antimicrobial peptide resistance phenotype, a phenotype also associated with other response regulators, for the human cathelicidin peptide LL-37 and a sheep antimicrobial peptide SMAP-29. F. novicida with mutated bfpR replicated better than WT in intracellular infection assays in human-derived macrophages suggesting that the down-regulation of iglC expression in bfpR mutant may enable this intracellular replication to occur. Response regulators have been shown to play important roles in the regulation of bacterial biofilm production. We demonstrate that F. novicida biofilm formation was highly increased in the bfpR mutant, corresponding to altered glycogen synthesis. Waxworm infection experiments suggest a role of BfpR as a negative modulator of iglC expression with de-repression by Mg2+. In this study, we find that the response regulator BfpR may be a negative regulator of biofilm formation, and a positive regulator of antimicrobial peptide resistance in F. novicida.
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Affiliation(s)
- Scott N Dean
- National Center for Biodefense and Infectious Diseases, and School of Systems Biology, George Mason University, Manassas, VA, United States
| | - Morgan E Milton
- Department of Biochemistry and Molecular Biology, The Brody School of Medicine, East Carolina University, Greenville, NC, United States
| | - John Cavanagh
- Department of Biochemistry and Molecular Biology, The Brody School of Medicine, East Carolina University, Greenville, NC, United States
| | - Monique L van Hoek
- National Center for Biodefense and Infectious Diseases, and School of Systems Biology, George Mason University, Manassas, VA, United States
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Hong J, Jiang H, Hu J, Wang L, Liu R. Transcriptome Analysis Reveals the Resistance Mechanism of Pseudomonas aeruginosa to Tachyplesin I. Infect Drug Resist 2020; 13:155-169. [PMID: 32021330 PMCID: PMC6970625 DOI: 10.2147/idr.s226687] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 12/17/2019] [Indexed: 12/11/2022] Open
Abstract
Background Tachyplesin I is a cationic antimicrobial peptide with a typical cyclic antiparallel β-sheet structure. We previously demonstrated that long-term continuous exposure to increased concentration of tachyplesin I can induce resistant Gram-negative bacteria. However, no significant information is available about the resistance mechanism of Pseudomonas aeruginosa (P. aeruginosa) to tachyplesin I. Materials and Methods In this study, the global gene expression profiling of P. aeruginosa strain PA-99 and P. aeruginosa CGMCC1.2620 (PA1.2620) was conducted using transcriptome sequencing. For this purpose, outer membrane permeability and outer membrane proteins (OMPs) were further analyzed. Results Transcriptome sequencing detected 672 upregulated and 787 downregulated genes, covering Clusters of Orthologous Groups (COGs) of P. aeruginosa strain PA-99 compared with PA1.2620. Totally, 749 differentially expressed genes (DEGs) were assigned to 98 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and among them, a two-component regulatory system, a beta-lactam resistance system, etc. were involved in some known genes resistant to drugs. Additionally, we further attempted to indicate whether the resistance mechanism of P. aeruginosa to tachyplesin I was associated with the changes of outer membrane permeability and OMPs. Conclusion Our results indicated that P. aeruginosa resistant to tachyplesin I was mainly related to reduced entry of tachyplesin I into the bacterial cell due to overexpression of efflux pump, in addition to a decrease of outer membrane permeability. Our findings were also validated by pathway enrichment analysis and quantitative reverse transcription polymerase chain reaction (RT-qPCR). This study may provide a promising guidance for understanding the resistance mechanism of P. aeruginosa to tachyplesin I.
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Affiliation(s)
- Jun Hong
- College of Life Science and Engineering, Henan University of Urban Construction, Ping Dingshan 467036, People's Republic of China.,Henan Province Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan, Henan 467036, People's Republic of China
| | - Honghao Jiang
- College of Life Science and Engineering, Henan University of Urban Construction, Ping Dingshan 467036, People's Republic of China
| | - Jianye Hu
- College of Life Science and Engineering, Henan University of Urban Construction, Ping Dingshan 467036, People's Republic of China
| | - Lianzhe Wang
- College of Life Science and Engineering, Henan University of Urban Construction, Ping Dingshan 467036, People's Republic of China
| | - Ruifang Liu
- College of Life Science and Engineering, Henan University of Urban Construction, Ping Dingshan 467036, People's Republic of China
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Yu L, Zhang J, Fu Y, Zhao Y, Wang Y, Zhao J, Guo Y, Li C, Zhang X. Synergetic Effects of Combined Treatment of Colistin With Meropenem or Amikacin on Carbapenem-Resistant Klebsiella pneumoniae in vitro. Front Cell Infect Microbiol 2019; 9:422. [PMID: 31921701 PMCID: PMC6916149 DOI: 10.3389/fcimb.2019.00422] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 11/28/2019] [Indexed: 11/13/2022] Open
Abstract
The purpose of this study was to investigate the synergistic and bactericidal effects of combinations of colistin with meropenem or amikacin in vitro and provide laboratory data needed for development of therapeutic strategies for the treatment of carbapenem-resistant Klebsiella pneumoniae (CRKP) infection. We found that minimum inhibitory concentration (MIC) of colistin, meropenem and amikacin were 2~32, 4~256, and 1~16384 μg/ml, respectively. The minimum bactericidal concentration of the antibiotics was either 1× or 2×MIC. Treatments of 6 CRKP isolates at 1 μg/ml colistin completely killed 2 of them and suppressed 4 others growth. 4 CRKP isolates at 16 μg/ml meropenem or amikacin completely killed and suppressed 2 others growth. 2 CRKP isolates showed synergic effects in all colistin combination and 3 CRKP isolates showed synergic effects in part of colistin combination. Our data suggest that colistin in combination with either meropenem or amikacin could be a valid therapeutic option against colistin-resistant CRKP isolates. Moreover, the combination of colistin-amikacin is less expensive to treat CRKP infections in Eastern Heilongjiang Province.
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Affiliation(s)
- Lan Yu
- Department of Microbiology, Yongchuan Hospital of Chongqing Medical University, Chongqing, China.,Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| | - Jisheng Zhang
- Department of Microbiology, Yongchuan Hospital of Chongqing Medical University, Chongqing, China.,Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| | - Yanjun Fu
- Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| | - Yongxin Zhao
- Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| | - Yong Wang
- Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| | - Jing Zhao
- Department of Scientific Research Section, Jiamusi University School of Clinical Medicine, Jiamusi, China
| | - Yuhang Guo
- Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
| | - Chunjiang Li
- Department of Pathogenic Biology, Jiamusi University School of Basic Medicine, Jiamusi, China
| | - Xiaoli Zhang
- Department of Microbiology, Yongchuan Hospital of Chongqing Medical University, Chongqing, China.,Department of Microbiology, The First Affiliated Hospital of Jiamusi University, Jiamusi, China
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42
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Abdi M, Mirkalantari S, Amirmozafari N. Bacterial resistance to antimicrobial peptides. J Pept Sci 2019; 25:e3210. [DOI: 10.1002/psc.3210] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/04/2019] [Accepted: 07/21/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Milad Abdi
- Student Research Committee, Faculty of MedicineIran University of Medical Sciences Tehran Iran
- Department of Microbiology, Faculty of MedicineIran University of Medical Sciences Tehran Iran
| | - Shiva Mirkalantari
- Department of Microbiology, Faculty of MedicineIran University of Medical Sciences Tehran Iran
| | - Nour Amirmozafari
- Department of Microbiology, Faculty of MedicineIran University of Medical Sciences Tehran Iran
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Lin YW, Han ML, Zhao J, Zhu Y, Rao G, Forrest A, Song J, Kaye KS, Hertzog P, Purcell A, Creek D, Zhou QT, Velkov T, Li J. Synergistic Combination of Polymyxin B and Enrofloxacin Induced Metabolic Perturbations in Extensive Drug-Resistant Pseudomonas aeruginosa. Front Pharmacol 2019; 10:1146. [PMID: 31632279 PMCID: PMC6785843 DOI: 10.3389/fphar.2019.01146] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 09/04/2019] [Indexed: 11/30/2022] Open
Abstract
Polymyxins are used as a last-resort class of antibiotics against multidrug-resistant (MDR) Gram-negative Pseudomonas aeruginosa. As polymyxin monotherapy is associated with potential development of resistance, combination therapy is highly recommended. This study investigated the mechanism underlying the synergistic killing of polymyxin B and enrofloxacin against extensive drug-resistant (XDR) P. aeruginosa. An XDR isolate P. aeruginosa 12196 was treated with clinically relevant concentrations of polymyxin B (2 mg/L) and enrofloxacin (1 mg/L) alone or in combination. Metabolome profiles were investigated from bacterial samples collected at 1-and 4-h posttreatment using liquid chromatography with tandem mass spectrometry (LC-MS/MS), and data were analyzed using univariate and multivariate statistics. Significantly perturbed metabolites (q < 0.05, fold change ≥ 2) were subjected to pathway analysis. The synergistic killing by polymyxin B–enrofloxacin combination was initially driven by polymyxin B as indicated by the perturbation of lipid metabolites at 1 h in particular. The killing was subsequently driven by enrofloxacin via the inhibition of DNA replication, resulting in the accumulation of nucleotides at 4 h. Furthermore, the combination uniquely altered levels of metabolites in energy metabolism and cell envelope biogenesis. Most importantly, the combination significantly minimized polymyxin resistance via the inhibition of lipid A modification pathway, which was most evident at 4 h. This is the first study to elucidate the synergistic mechanism of polymyxin B–enrofloxacin combination against XDR P. aeruginosa. The metabolomics approach taken in this study highlights its power to elucidate the mechanism of synergistic killing by antibiotic combinations at the systems level.
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Affiliation(s)
- Yu-Wei Lin
- Monash Biomedicine Discovery Institute, Infection and Immunity Program and Department of Microbiology, Monash University, Clayton, VIC, Australia
| | - Mei-Ling Han
- Monash Biomedicine Discovery Institute, Infection and Immunity Program and Department of Microbiology, Monash University, Clayton, VIC, Australia
| | - Jinxin Zhao
- Monash Biomedicine Discovery Institute, Infection and Immunity Program and Department of Microbiology, Monash University, Clayton, VIC, Australia
| | - Yan Zhu
- Monash Biomedicine Discovery Institute, Infection and Immunity Program and Department of Microbiology, Monash University, Clayton, VIC, Australia
| | - Gauri Rao
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, United States
| | - Alan Forrest
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, United States
| | - Jiangning Song
- Monash Biomedicine Discovery Institute, Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | - Keith S Kaye
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Paul Hertzog
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia.,Department of Molecular and Translational Sciences, School of Clinical Sciences at Monash Health, Monash University, Clayton, VIC, Australia
| | - Anthony Purcell
- Monash Biomedicine Discovery Institute, Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | - Darren Creek
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Qi Tony Zhou
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, IN, United States
| | - Tony Velkov
- Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, VIC, Australia
| | - Jian Li
- Monash Biomedicine Discovery Institute, Infection and Immunity Program and Department of Microbiology, Monash University, Clayton, VIC, Australia
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Wang T, Flint S, Palmer J. Magnesium and calcium ions: roles in bacterial cell attachment and biofilm structure maturation. BIOFOULING 2019; 35:959-974. [PMID: 31687841 DOI: 10.1080/08927014.2019.1674811] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 09/27/2019] [Indexed: 06/10/2023]
Abstract
The ubiquitous divalent cations magnesium and calcium are important nutrients required by bacteria for growth and cell maintenance. Multi-faceted roles are shown both in bacterial initial attachment and biofilm maturation. The effects of calcium and magnesium can be highlighted in physio-chemical interactions, gene regulation and bio-macromolecular structural modification, which lead to either promotion or inhibition of biofilms. This review outlines recent research addressing phenotypic changes and mechanisms undertaken by calcium and magnesium in affecting bacterial biofilm formation.
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Affiliation(s)
- Tianyang Wang
- Institute of Food Science and Technology, School of Food and Advanced Technology, Massey University, New Zealand
| | - Steve Flint
- Institute of Food Science and Technology, School of Food and Advanced Technology, Massey University, New Zealand
| | - Jon Palmer
- Institute of Food Science and Technology, School of Food and Advanced Technology, Massey University, New Zealand
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Production of Norspermidine Contributes to Aminoglycoside Resistance in pmrAB Mutants of Pseudomonas aeruginosa. Antimicrob Agents Chemother 2019; 63:AAC.01044-19. [PMID: 31383668 DOI: 10.1128/aac.01044-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 07/25/2019] [Indexed: 12/18/2022] Open
Abstract
Emergence of resistance to polymyxins in Pseudomonas aeruginosa is mainly due to mutations in two-component systems that promote the addition of 4-amino-4-deoxy-l-arabinose to the lipopolysaccharide (LPS) through upregulation of operon arnBCADTEF-ugd (arn) expression. Here, we demonstrate that mutations occurring in different domains of histidine kinase PmrB or in response regulator PmrA result in coresistance to aminoglycosides and colistin. All seventeen clinical strains tested exhibiting such a cross-resistance phenotype were found to be pmrAB mutants. As shown by gene deletion experiments, the decreased susceptibility of the mutants to aminoglycosides was independent from operon arn but required the efflux system MexXY-OprM and the products of three genes, PA4773-PA4774-PA4775, that are cotranscribed and activated with genes pmrAB Gene PA4773 (annotated as speD2 in the PAO1 genome) and PA4774 (speE2) are predicted to encode enzymes involved in biosynthesis of polyamines. Comparative analysis of cell surface extracts of an in vitro selected pmrAB mutant, called AB16.2, and derivatives lacking PA4773, PA4774, and PA4775 revealed that these genes were needed for norspermidine production via a pathway that likely uses 1,3-diaminopropane, a precursor of polyamines. Altogether, our results suggest that norspermidine decreases the self-promoted uptake pathway of aminoglycosides across the outer membrane and, thereby, potentiates the activity of efflux pump MexXY-OprM.
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Han X, Liu Y, Ma Y, Zhang M, He Z, Siriwardena TN, Xu H, Bai Y, Zhang X, Reymond JL, Qiao M. Peptide dendrimers G3KL and TNS18 inhibit Pseudomonas aeruginosa biofilms. Appl Microbiol Biotechnol 2019; 103:5821-5830. [PMID: 31101943 DOI: 10.1007/s00253-019-09801-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 03/19/2019] [Accepted: 03/27/2019] [Indexed: 01/06/2023]
Abstract
Herein we report that peptide dendrimers G3KL and TNS18, which were recently reported to control multidrug-resistant bacteria such as Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii, strongly inhibit biofilm formation by P. aeruginosa PA14 below their minimum inhibitory concentration (MIC) value, under which conditions they also strongly affect swarming motility. Eradication of preformed biofilms, however, required concentrations above the MIC values. Scanning electron microscopy observation and confocal laser scanning micrographs showed that peptide dendrimers can destroy the biofilm morphological structure and thickness in a dose-dependent manner, even make the biofilm dispersed completely. Membrane potential analysis indicated that planktonic cells treated with peptide dendrimers presented an increase in fluorescence intensity, suggesting that cytoplasmic membrane could be the target of G3KL and TNS18 similarly to polymyxin B. RNA-seq analysis showed that the expressions of genes in the arnBCADTEF operon-regulating lipid A modification resulting in resistance to AMPs are differentially affected between these three compounds, suggesting that each compound targets the cell membrane but in different manner. Potent activity on planktonic cells and biofilms of P. aeruginosa suggests that peptide dendrimers G3KL and TNS18 are promising candidates of clinical development for treating infections.
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Affiliation(s)
- Xiao Han
- The Key Laboratory of Molecular Microbiology and Technology Ministry of Education, Nankai University, Tianjin, 300071, China
| | - Yujie Liu
- The Key Laboratory of Molecular Microbiology and Technology Ministry of Education, Nankai University, Tianjin, 300071, China
| | - Yibing Ma
- The Key Laboratory of Molecular Microbiology and Technology Ministry of Education, Nankai University, Tianjin, 300071, China
| | - Mengqing Zhang
- Electricity Information and Automation College, Civil Aviation University of China, Tianjin, 300300, China
| | - Zhengjin He
- Key Laboratory of Systems Biology, State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Thissa N Siriwardena
- Department of Chemistry and Biochemistry, University of Bern, 3012, Bern, Switzerland
| | - Haijin Xu
- The Key Laboratory of Molecular Microbiology and Technology Ministry of Education, Nankai University, Tianjin, 300071, China
| | - Yanling Bai
- The Key Laboratory of Molecular Microbiology and Technology Ministry of Education, Nankai University, Tianjin, 300071, China
| | - Xiuming Zhang
- The Key Laboratory of Molecular Microbiology and Technology Ministry of Education, Nankai University, Tianjin, 300071, China
| | - Jean-Louis Reymond
- Department of Chemistry and Biochemistry, University of Bern, 3012, Bern, Switzerland.
| | - Mingqiang Qiao
- The Key Laboratory of Molecular Microbiology and Technology Ministry of Education, Nankai University, Tianjin, 300071, China.
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Tierney AR, Rather PN. Roles of two-component regulatory systems in antibiotic resistance. Future Microbiol 2019; 14:533-552. [PMID: 31066586 DOI: 10.2217/fmb-2019-0002] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Two-component regulatory systems (TCSs) are a major mechanism by which bacteria sense and respond to changes in their environment. TCSs typically consist of two proteins that bring about major regulation of the cell genome through coordinated action mediated by phosphorylation. Environmental conditions that activate TCSs are numerous and diverse and include exposure to antibiotics as well as conditions inside a host. The resulting regulatory action often involves activation of antibiotic defenses and changes to cell physiology that increase antibiotic resistance. Examples of resistance mechanisms enacted by TCSs contained in this review span those found in both Gram-negative and Gram-positive species and include cell surface modifications, changes in cell permeability, increased biofilm formation, and upregulation of antibiotic-degrading enzymes.
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Affiliation(s)
- Aimee Rp Tierney
- Department of Microbiology & Immunology, Emory University School of Medicine, Atlanta, GA, 30322 USA
| | - Philip N Rather
- Department of Microbiology & Immunology, Emory University School of Medicine, Atlanta, GA, 30322 USA.,Research Service, Department of Veterans' Affairs, Atlanta VA Health Care System, Decatur, GA, 30033 USA
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Bhagirath AY, Li Y, Patidar R, Yerex K, Ma X, Kumar A, Duan K. Two Component Regulatory Systems and Antibiotic Resistance in Gram-Negative Pathogens. Int J Mol Sci 2019; 20:E1781. [PMID: 30974906 PMCID: PMC6480566 DOI: 10.3390/ijms20071781] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/05/2019] [Accepted: 04/08/2019] [Indexed: 12/17/2022] Open
Abstract
Gram-negative pathogens such as Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa are the leading cause of nosocomial infections throughout the world. One commonality shared among these pathogens is their ubiquitous presence, robust host-colonization and most importantly, resistance to antibiotics. A significant number of two-component systems (TCSs) exist in these pathogens, which are involved in regulation of gene expression in response to environmental signals such as antibiotic exposure. While the development of antimicrobial resistance is a complex phenomenon, it has been shown that TCSs are involved in sensing antibiotics and regulating genes associated with antibiotic resistance. In this review, we aim to interpret current knowledge about the signaling mechanisms of TCSs in these three pathogenic bacteria. We further attempt to answer questions about the role of TCSs in antimicrobial resistance. We will also briefly discuss how specific two-component systems present in K. pneumoniae, A. baumannii, and P. aeruginosa may serve as potential therapeutic targets.
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Affiliation(s)
- Anjali Y Bhagirath
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
| | - Yanqi Li
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
| | - Rakesh Patidar
- Department of Microbiology, Faculty of Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
| | - Katherine Yerex
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
| | - Xiaoxue Ma
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
| | - Ayush Kumar
- Department of Microbiology, Faculty of Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
| | - Kangmin Duan
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
- Department of Medical Microbiology & Infectious Diseases, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
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Comparative Metabolomics and Transcriptomics Reveal Multiple Pathways Associated with Polymyxin Killing in Pseudomonas aeruginosa. mSystems 2019; 4:mSystems00149-18. [PMID: 30637340 PMCID: PMC6325167 DOI: 10.1128/msystems.00149-18] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 12/06/2018] [Indexed: 02/07/2023] Open
Abstract
Pseudomonas aeruginosa has been highlighted by the recent WHO Global Priority Pathogen List due to multidrug resistance. Without new antibiotics, polymyxins remain a last-line therapeutic option for this difficult-to-treat pathogen. The emergence of polymyxin resistance highlights the growing threat to our already very limited antibiotic armamentarium and the urgency to understand the exact mechanisms of polymyxin activity and resistance. Integration of the correlative metabolomics and transcriptomics results in the present study discovered that polymyxin treatment caused significant perturbations in the biosynthesis of lipids, lipopolysaccharide, and peptidoglycan, central carbon metabolism, and oxidative stress. Importantly, lipid A modifications were surprisingly rapid in response to polymyxin treatment at clinically relevant concentrations. This is the first study to reveal the dynamics of polymyxin-induced cellular responses at the systems level, which highlights that combination therapy should be considered to minimize resistance to the last-line polymyxins. The results also provide much-needed mechanistic information which potentially benefits the discovery of new-generation polymyxins. Polymyxins are a last-line therapy against multidrug-resistant Pseudomonas aeruginosa; however, resistance to polymyxins has been increasingly reported. Therefore, understanding the mechanisms of polymyxin activity and resistance is crucial for preserving their clinical usefulness. This study employed comparative metabolomics and transcriptomics to investigate the responses of polymyxin-susceptible P. aeruginosa PAK (polymyxin B MIC, 1 mg/liter) and its polymyxin-resistant pmrB mutant PAKpmrB6 (MIC, 16 mg/liter) to polymyxin B (4, 8, and 128 mg/liter) at 1, 4, and 24 h, respectively. Our results revealed that polymyxin B at 4 mg/liter induced different metabolic and transcriptomic responses between polymyxin-susceptible and -resistant P. aeruginosa. In strain PAK, polymyxin B significantly activated PmrAB and the mediated arn operon, leading to increased 4-amino-4-deoxy-L-arabinose (L-Ara4N) synthesis and the addition to lipid A. In contrast, polymyxin B did not increase lipid A modification in strain PAKpmrB6. Moreover, the syntheses of lipopolysaccharide and peptidoglycan were significantly decreased in strain PAK but increased in strain PAKpmrB6 due to polymyxin B treatment. In addition, 4 mg/liter polymyxin B significantly perturbed phospholipid and fatty acid levels and induced oxidative stress in strain PAK, but not in PAKpmrB6. Notably, the increased trehalose-6-phosphate levels indicate that polymyxin B potentially caused osmotic imbalance in both strains. Furthermore, 8 and 128 mg/liter polymyxin B significantly elevated lipoamino acid levels and decreased phospholipid levels but without dramatic changes in lipid A modification in wild-type and mutant strains, respectively. Overall, this systems study is the first to elucidate the complex and dynamic interactions of multiple cellular pathways associated with the polymyxin mode of action against P. aeruginosa. IMPORTANCEPseudomonas aeruginosa has been highlighted by the recent WHO Global Priority Pathogen List due to multidrug resistance. Without new antibiotics, polymyxins remain a last-line therapeutic option for this difficult-to-treat pathogen. The emergence of polymyxin resistance highlights the growing threat to our already very limited antibiotic armamentarium and the urgency to understand the exact mechanisms of polymyxin activity and resistance. Integration of the correlative metabolomics and transcriptomics results in the present study discovered that polymyxin treatment caused significant perturbations in the biosynthesis of lipids, lipopolysaccharide, and peptidoglycan, central carbon metabolism, and oxidative stress. Importantly, lipid A modifications were surprisingly rapid in response to polymyxin treatment at clinically relevant concentrations. This is the first study to reveal the dynamics of polymyxin-induced cellular responses at the systems level, which highlights that combination therapy should be considered to minimize resistance to the last-line polymyxins. The results also provide much-needed mechanistic information which potentially benefits the discovery of new-generation polymyxins.
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Moffatt JH, Harper M, Boyce JD. Mechanisms of Polymyxin Resistance. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1145:55-71. [PMID: 31364071 DOI: 10.1007/978-3-030-16373-0_5] [Citation(s) in RCA: 107] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Polymyxin antibiotics are increasingly being used as last-line therapeutic options against a number of multidrug resistant bacteria. These antibiotics show strong bactericidal activity against a range of Gram-negative bacteria, but with the increased use of these antibiotics resistant strains are emerging at an alarming rate. Furthermore, some Gram-negative species, such as Neisseria meningitidis, Proteus mirabilis and Burkholderia spp., are intrinsically resistant to the action of polymyxins. Most identified polymyxin resistance mechanisms in Gram-negative bacteria involve changes to the lipopolysaccharide (LPS) structure, as polymyxins initially interact with the negatively charged lipid A component of LPS. The controlled addition of positively charged residues such as 4-amino-L-arabinose, phosphoethanolamine and/or galactosamine to LPS results in a reduced negative charge on the bacterial surface and therefore reduced interaction between the polymyxin and the LPS. Polymyxin resistant species produce LPS that intrinsically contains one or more of these additions. While the genes necessary for most of these additions are chromosomally encoded, plasmid-borne phosphoethanolamine transferases (mcr-1 to mcr-8) have recently been identified and these plasmids threaten to increase the rate of dissemination of clinically relevant colistin resistance. Uniquely, Acinetobacter baumannii can also become highly resistant to polymyxins via spontaneous mutations in the lipid A biosynthesis genes lpxA, lpxC or lpxD such that they produce no LPS or lipid A. A range of other non-LPS-dependent polymyxin resistance mechanisms has also been identified in bacteria, but these generally result in only low levels of resistance. These include increased anionic capsular polysaccharide production in Klebsiella pneumoniae, expression of efflux systems such as MtrCDE in N. meningitidis, and altered expression of outer membrane proteins in a small number of species.
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Affiliation(s)
- Jennifer H Moffatt
- Biomedicine Discovery Institute, Infection and Immunity Program and Department of Microbiology, Monash University, Clayton, Australia
| | - Marina Harper
- Biomedicine Discovery Institute, Infection and Immunity Program and Department of Microbiology, Monash University, Clayton, Australia.,Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Australia
| | - John D Boyce
- Biomedicine Discovery Institute, Infection and Immunity Program and Department of Microbiology, Monash University, Clayton, Australia. .,Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Australia.
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