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Ukleja M, Kricks L, Torrens G, Peschiera I, Rodrigues-Lopes I, Krupka M, García-Fernández J, Melero R, Del Campo R, Eulalio A, Mateus A, López-Bravo M, Rico AI, Cava F, Lopez D. Flotillin-mediated stabilization of unfolded proteins in bacterial membrane microdomains. Nat Commun 2024; 15:5583. [PMID: 38961085 PMCID: PMC11222466 DOI: 10.1038/s41467-024-49951-1] [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: 02/21/2024] [Accepted: 06/26/2024] [Indexed: 07/05/2024] Open
Abstract
The function of many bacterial processes depends on the formation of functional membrane microdomains (FMMs), which resemble the lipid rafts of eukaryotic cells. However, the mechanism and the biological function of these membrane microdomains remain unclear. Here, we show that FMMs in the pathogen methicillin-resistant Staphylococcus aureus (MRSA) are dedicated to confining and stabilizing proteins unfolded due to cellular stress. The FMM scaffold protein flotillin forms a clamp-shaped oligomer that holds unfolded proteins, stabilizing them and favoring their correct folding. This process does not impose a direct energy cost on the cell and is crucial to survival of ATP-depleted bacteria, and thus to pathogenesis. Consequently, FMM disassembling causes the accumulation of unfolded proteins, which compromise MRSA viability during infection and cause penicillin re-sensitization due to PBP2a unfolding. Thus, our results indicate that FMMs mediate ATP-independent stabilization of unfolded proteins, which is essential for bacterial viability during infection.
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Affiliation(s)
- Marta Ukleja
- Department of Microbiology, National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, 28049, Spain
| | - Lara Kricks
- Department of Microbiology, National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, 28049, Spain
| | - Gabriel Torrens
- Department of Molecular Biology, Umeå University, Umeå, SE-901 87, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS). Umeå Center for Microbial Research (UCMR). Science for Life Laboratory (SciLifeLab), Umeå, SE-901 87, Sweden
| | - Ilaria Peschiera
- Department of Microbiology, National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, 28049, Spain
| | - Ines Rodrigues-Lopes
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, 3004-504, Coimbra, Portugal
| | - Marcin Krupka
- Department of Microbiology, National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, 28049, Spain
| | - Julia García-Fernández
- Department of Microbiology, National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, 28049, Spain
| | - Roberto Melero
- Department of Structural Biology, National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, 28049, Spain
| | - Rosa Del Campo
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Ramón y Cajal Hospital, 28034, Madrid, Spain
| | - Ana Eulalio
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, 3004-504, Coimbra, Portugal
- Department of Life Sciences, Center for Bacterial Resistance Biology, Imperial College London, London, SW7 2AZ, United Kingdom
| | - André Mateus
- The Laboratory for Molecular Infection Medicine Sweden (MIMS). Umeå Center for Microbial Research (UCMR). Science for Life Laboratory (SciLifeLab), Umeå, SE-901 87, Sweden
- Department of Chemistry, Umeå University, Umeå, SE-901 87, Sweden
| | - María López-Bravo
- Department of Microbiology, National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, 28049, Spain
| | - Ana I Rico
- Department of Microbiology, National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, 28049, Spain
| | - Felipe Cava
- Department of Molecular Biology, Umeå University, Umeå, SE-901 87, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS). Umeå Center for Microbial Research (UCMR). Science for Life Laboratory (SciLifeLab), Umeå, SE-901 87, Sweden
| | - Daniel Lopez
- Department of Microbiology, National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, 28049, Spain.
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2
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Maree M, Ushijima Y, Fernandes PB, Higashide M, Morikawa K. SCC mec transformation requires living donor cells in mixed biofilms. Biofilm 2024; 7:100184. [PMID: 38440091 PMCID: PMC10909703 DOI: 10.1016/j.bioflm.2024.100184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 01/26/2024] [Accepted: 02/05/2024] [Indexed: 03/06/2024] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen that has emerged through the horizontal acquisition of the staphylococcal cassette chromosome mec (SCCmec). Previously, we showed that SCCmec from heat-killed donors can be transferred via natural transformation in biofilms at frequencies of 10-8-10-7. Here, we show an improved transformation assay of SCCmec with frequencies up to 10-2 using co-cultured biofilms with living donor cells. The Ccr-attB system played an important role in SCCmec transfer, and the deletion of ccrAB recombinase genes reduced the frequency ∼30-fold. SCCmec could be transferred from either MRSA or methicillin-resistant coagulase-negative staphylococci to some methicillin-sensitive S. aureus recipients. In addition, the transformation of other plasmid or chromosomal genes is enhanced by using living donor cells. This study emphasizes the role of natural transformation as an evolutionary ability of S. aureus and in MRSA emergence.
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Affiliation(s)
- Mais Maree
- Institute of Medicine, University of Tsukuba, Japan
| | | | | | - Masato Higashide
- Kotobiken Medical Laboratories, Inc., Kamiyokoba, Tsukuba, Japan
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3
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Lewis IA. Boundary flux analysis: an emerging strategy for investigating metabolic pathway activity in large cohorts. Curr Opin Biotechnol 2024; 85:103027. [PMID: 38061263 DOI: 10.1016/j.copbio.2023.103027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 11/02/2023] [Accepted: 11/15/2023] [Indexed: 02/09/2024]
Abstract
Many biological phenotypes are rooted in metabolic pathway activity rather than the concentrations of individual metabolites. Despite this, most metabolomics studies only capture steady-state metabolism - not metabolic flux. Although sophisticated metabolic flux analysis strategies have been developed, these methods are technically challenging and difficult to implement in large-cohort studies. Recently, a new boundary flux analysis (BFA) approach has emerged that captures large-scale metabolic flux phenotypes by quantifying changes in metabolite levels in the media of cultured cells. This approach is advantageous because it is relatively easy to implement yet captures complex metabolic flux phenotypes. We describe the opportunities and challenges of BFA and illustrate how it can be harnessed to investigate a wide transect of biological phenomena.
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Affiliation(s)
- Ian A Lewis
- Alberta Centre for Advanced Diagnostics, Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada.
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4
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Ge Y, Li D, Wang N, Shi Y, Guo G, Fang L, Zou Q, Liu Q. Unveiling the fructose metabolism system in Staphylococcus aureus: insights into the regulatory role of FruR and the FruRKT operon in bacterial fitness. BMC Microbiol 2024; 24:13. [PMID: 38177984 PMCID: PMC10765703 DOI: 10.1186/s12866-023-03151-x] [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: 09/05/2023] [Accepted: 12/11/2023] [Indexed: 01/06/2024] Open
Abstract
BACKGROUND The utilization of fructose as a carbon source and energy provider plays a crucial role in bacterial metabolism. Additionally, fructose metabolism directly impacts the pathogenicity and virulence of certain pathogenic microorganisms. RESULTS In this study, we report the discovery of a fructose phosphotransferase system (PTS) in S. aureus. This system comprises three genes, namely fruR, fruK, and fruT, which are co-located in an operon that is indispensable for fructose utilization in S. aureus. Our findings confirm that these three genes are transcribed from a single promoter located upstream of the fruRKT operon. The fruR gene encodes a DeoR-type transcriptional regulator, designated as FruR, which represses the expression of the fruRKT operon by direct binding to its promoter region. Significantly, our experimental data demonstrate that the fruRKT operon can be induced by fructose, suggesting a potential regulatory mechanism involving intracellular fructose-1-phosphate as a direct inducer. Furthermore, we conducted RNA-seq analysis to investigate the specificity of FruR regulation in S. aureus, revealing that the fruRKT operon is predominantly regulated by FruR. CONCLUSIONS In summary, this study has uncovered a fructose phosphotransferase system (PTS) in S. aureus, highlighting the essential role of the fruR, fruK, and fruT genes in fructose utilization. We confirmed their co-location within an operon and established FruR as a key regulator by binding to the operon's promoter. Importantly, we demonstrated that fructose can induce this operon, possibly through intracellular fructose-1-phosphate. Our identification of this PTS system represents the initial characterization of a fructose metabolism system in S. aureus.
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Affiliation(s)
- Yan Ge
- West China Biopharmaceutical Research Institute, West China Hospital, Sichuan University, Chengdu, China
| | - Daiyu Li
- West China Biopharmaceutical Research Institute, West China Hospital, Sichuan University, Chengdu, China
| | - Ning Wang
- West China Biopharmaceutical Research Institute, West China Hospital, Sichuan University, Chengdu, China
| | - Yun Shi
- West China Biopharmaceutical Research Institute, West China Hospital, Sichuan University, Chengdu, China
| | - Gang Guo
- West China Biopharmaceutical Research Institute, West China Hospital, Sichuan University, Chengdu, China
| | - Liyuan Fang
- Genomics Center of Core Facilities, West China Hospital, Sichuan University, Chengdu, China
| | - Quanming Zou
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, China
| | - Qiang Liu
- West China Biopharmaceutical Research Institute, West China Hospital, Sichuan University, Chengdu, China.
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5
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Gao Y, Poudel S, Seif Y, Shen Z, Palsson BO. Elucidating the CodY regulon in Staphylococcus aureus USA300 substrains TCH1516 and LAC. mSystems 2023; 8:e0027923. [PMID: 37310465 PMCID: PMC10470025 DOI: 10.1128/msystems.00279-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 04/25/2023] [Indexed: 06/14/2023] Open
Abstract
CodY is a conserved broad-acting transcription factor that regulates the expression of genes related to amino acid metabolism and virulence in Gram-positive bacteria. Here, we performed the first in vivo determination of CodY target genes using a novel CodY monoclonal antibody in methicillin-resistant Staphylococcus aureus (MRSA) USA300. Our results showed (i) the same 135 CodY promoter binding sites regulating the 165 target genes identified in two closely related virulent S. aureus USA300 TCH1516 and LAC strains; (ii) the differential binding intensity for the same target genes under the same conditions was due to sequence differences in the same CodY-binding site in the two strains; (iii) a CodY regulon comprising 72 target genes that are differentially regulated relative to a CodY deletion strain, representing genes that are mainly involved in amino acid transport and metabolism, inorganic ion transport and metabolism, transcription and translation, and virulence, all based on transcriptomic data; and (iv) CodY systematically regulated central metabolic flux to generate branched-chain amino acids (BCAAs) by mapping the CodY regulon onto a genome-scale metabolic model of S. aureus. Our study performed the first system-level analysis of CodY in two closely related USA300 TCH1516 and LAC strains, revealing new insights into the similarities and differences of CodY regulatory roles between the closely related strains. IMPORTANCE With the increasing availability of whole-genome sequences for many strains within the same pathogenic species, a comparative analysis of key regulators is needed to understand how the different strains uniquely coordinate metabolism and expression of virulence. To successfully infect the human host, Staphylococcus aureus USA300 relies on the transcription factor CodY to reorganize metabolism and express virulence factors. While CodY is a known key transcription factor, its target genes are not characterized on a genome-wide basis. We performed a comparative analysis to describe the transcriptional regulation of CodY between two dominant USA300 strains. This study motivates the characterization of common pathogenic strains and an evaluation of the possibility of developing specialized treatments for major strains circulating in the population.
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Affiliation(s)
- Ye Gao
- Department of Biological Sciences, University of California San Diego, La Jolla, California, USA
- Department of Bioengineering, University of California San Diego, La Jolla, California, USA
| | - Saugat Poudel
- Department of Bioengineering, University of California San Diego, La Jolla, California, USA
| | - Yara Seif
- Department of Bioengineering, University of California San Diego, La Jolla, California, USA
| | - Zeyang Shen
- Department of Bioengineering, University of California San Diego, La Jolla, California, USA
| | - Bernhard O. Palsson
- Department of Bioengineering, University of California San Diego, La Jolla, California, USA
- Department of Pediatrics, University of California San Diego, La Jolla, California, USA
- Bioinformatics and Systems Biology Program, University of California San Diego, La Jolla, California, USA
- Novo Nordisk Foundation Center for Biosustainability, Kongens Lyngby, Denmark
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6
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Tiwari S, Nizet O, Dillon N. Development of a high-throughput minimum inhibitory concentration (HT-MIC) testing workflow. Front Microbiol 2023; 14:1079033. [PMID: 37303796 PMCID: PMC10249070 DOI: 10.3389/fmicb.2023.1079033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 04/24/2023] [Indexed: 06/13/2023] Open
Abstract
The roots of the minimum inhibitory concentration (MIC) determination go back to the early 1900s. Since then, the test has undergone modifications and advancements in an effort to increase its dependability and accuracy. Although biological investigations use an ever-increasing number of samples, complicated processes and human error sometimes result in poor data quality, which makes it challenging to replicate scientific conclusions. Automating manual steps using protocols decipherable by machine can ease procedural difficulties. Originally relying on manual pipetting and human vision to determine the results, modern broth dilution MIC testing procedures have incorporated microplate readers to enhance sample analysis. However, current MIC testing procedures are unable to simultaneously evaluate a large number of samples efficiently. Here, we have created a proof-of-concept workflow using the Opentrons OT-2 robot to enable high-throughput MIC testing. We have further optimized the analysis by incorporating Python programming for MIC assignment to streamline the automation. In this workflow, we performed MIC tests on four different strains, three replicates per strain, and analyzed a total of 1,152 wells. Comparing our workflow to a conventional plate MIC procedure, we find that the HT-MIC method is 800% faster while simultaneously boasting a 100% accuracy. Our high-throughput MIC workflow can be adapted in both academic and clinical settings since it is faster, more efficient, and as accurate than many conventional methods.
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Affiliation(s)
- Suman Tiwari
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX, United States
| | - Oliver Nizet
- La Jolla Country Day School, La Jolla, CA, United States
| | - Nicholas Dillon
- Department of Biological Sciences, University of Texas at Dallas, Richardson, TX, United States
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7
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Swaney MH, Nelsen A, Sandstrom S, Kalan LR. Sweat and Sebum Preferences of the Human Skin Microbiota. Microbiol Spectr 2023; 11:e0418022. [PMID: 36602383 PMCID: PMC9927561 DOI: 10.1128/spectrum.04180-22] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 12/06/2022] [Indexed: 01/06/2023] Open
Abstract
The microorganisms inhabiting human skin must overcome numerous challenges that typically impede microbial growth, including low pH, osmotic pressure, and low nutrient availability. Yet the skin microbiota thrive on the skin and have adapted to these stressful conditions. The limited nutrients available for microbial use in this unique niche include those from host-derived sweat, sebum, and corneocytes. Here, we have developed physiologically relevant, synthetic skin-like growth media composed of compounds present in sweat and sebum. We find that skin-associated bacterial species exhibit unique growth profiles at different concentrations of artificial sweat and sebum. Most strains evaluated demonstrate a preference for high sweat concentrations, while the sebum preference is highly variable, suggesting that the capacity for sebum utilization may be a driver of the skin microbial community structure. In particular, the prominent skin commensal Staphylococcus epidermidis exhibits the strongest preference for sweat while growing equally well across sebum concentrations. Conversely, the growth of Corynebacterium kefirresidentii, another dominant skin microbiome member, is dependent on increasing concentrations of both sweat and sebum but only when sebum is available, suggesting a lipid requirement of this species. Furthermore, we observe that strains with similar growth profiles in the artificial media cluster by phylum, suggesting that phylogeny is a key factor in sweat and sebum use. Importantly, these findings provide an experimental rationale for why different skin microenvironments harbor distinct microbiome communities. In all, our study further emphasizes the importance of studying microorganisms in an ecologically relevant context, which is critical for our understanding of their physiology, ecology, and function on the skin. IMPORTANCE The human skin microbiome is adapted to survive and thrive in the harsh environment of the skin, which is low in nutrient availability. To study skin microorganisms in a system that mimics the natural skin environment, we developed and tested a physiologically relevant, synthetic skin-like growth medium that is composed of compounds found in the human skin secretions sweat and sebum. We find that most skin-associated bacterial species tested prefer high concentrations of artificial sweat but that artificial sebum concentration preference varies from species to species, suggesting that sebum utilization may be an important contributor to skin microbiome composition. This study demonstrates the utility of a skin-like growth medium, which can be applied to diverse microbiological systems, and underscores the importance of studying microorganisms in an ecologically relevant context.
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Affiliation(s)
- Mary Hannah Swaney
- Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, USA
- Microbiology Doctoral Training Program, University of Wisconsin, Madison, Wisconsin, USA
| | - Amanda Nelsen
- Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, USA
| | - Shelby Sandstrom
- Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, USA
| | - Lindsay R. Kalan
- Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, USA
- Department of Medicine, Division of Infectious Disease, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, USA
- M. G. DeGroote Institute for Infectious Disease Research, David Braley Centre for Antibiotic Discovery, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
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8
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Mapar M, Rydzak T, Groves RA, Lewis IA. Biomarker enrichment medium: A defined medium for metabolomic analysis of microbial pathogens. Front Microbiol 2022; 13:957158. [PMID: 35935218 PMCID: PMC9354526 DOI: 10.3389/fmicb.2022.957158] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 06/27/2022] [Indexed: 11/13/2022] Open
Abstract
Microbes have diverse metabolic capabilities and differences in these phenotypes are critical for differentiating strains, species, and broader taxa of microorganisms. Recent advances in liquid chromatography-mass spectrometry (LC-MS) allow researchers to track the complex combinations of molecules that are taken up by each cell type and to quantify the rates that individual metabolites enter or exit the cells. This metabolomics-based approach allows complex metabolic phenotypes to be captured in a single assay, enables computational models of microbial metabolism to be constructed, and can serve as a diagnostic approach for clinical microbiology. Unfortunately, metabolic phenotypes are directly affected by the molecular composition of the culture medium and many traditional media are subject to molecular-level heterogeneity. Herein, we show that commercially sourced Mueller Hinton (MH) medium, a Clinical and Laboratory Standards Institute (CLSI) approved medium for clinical microbiology, has significant lot-to-lot and supplier-to-supplier variability in the concentrations of individual nutrients. We show that this variability does not affect microbial growth rates but does affect the metabolic phenotypes observed in vitro—including metabolic phenotypes that distinguish six common pathogens. To address this, we used a combination of isotope-labeling, substrate exclusion, and nutritional supplementation experiments using Roswell Park Memorial Institute (RPMI) medium to identify the specific nutrients used by the microbes to produce diagnostic biomarkers, and to formulate a Biomarker Enrichment Medium (BEM) as an alternative to complex undefined media for metabolomics research, clinical diagnostics, antibiotic susceptibility testing, and other applications where the analysis of stable microbial metabolic phenotypes is important.
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9
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Cordero M, García-Fernández J, Acosta IC, Yepes A, Avendano-Ortiz J, Lisowski C, Oesterreicht B, Ohlsen K, Lopez-Collazo E, Förstner KU, Eulalio A, Lopez D. The induction of natural competence adapts staphylococcal metabolism to infection. Nat Commun 2022; 13:1525. [PMID: 35314690 PMCID: PMC8938553 DOI: 10.1038/s41467-022-29206-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 03/03/2022] [Indexed: 11/26/2022] Open
Abstract
A central question concerning natural competence is why orthologs of competence genes are conserved in non-competent bacterial species, suggesting they have a role other than in transformation. Here we show that competence induction in the human pathogen Staphylococcus aureus occurs in response to ROS and host defenses that compromise bacterial respiration during infection. Bacteria cope with reduced respiration by obtaining energy through fermentation instead. Since fermentation is energetically less efficient than respiration, the energy supply must be assured by increasing the glycolytic flux. The induction of natural competence increases the rate of glycolysis in bacteria that are unable to respire via upregulation of DNA- and glucose-uptake systems. A competent-defective mutant showed no such increase in glycolysis, which negatively affects its survival in both mouse and Galleria infection models. Natural competence foster genetic variability and provides S. aureus with additional nutritional and metabolic possibilities, allowing it to proliferate during infection.
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Affiliation(s)
- Mar Cordero
- National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), 28049, Madrid, Spain
| | - Julia García-Fernández
- National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), 28049, Madrid, Spain
| | - Ivan C Acosta
- National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), 28049, Madrid, Spain
| | - Ana Yepes
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, 97080, Würzburg, Germany
- Institute for Molecular Infection Biology (IMIB), University of Würzburg, 97080, Würzburg, Germany
| | - Jose Avendano-Ortiz
- The Innate Immune Response and Tumor Immunology Group, IdiPaz La Paz University Hospital, 28046, Madrid, Spain
| | - Clivia Lisowski
- Institute for Molecular Infection Biology (IMIB), University of Würzburg, 97080, Würzburg, Germany
| | - Babett Oesterreicht
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, 97080, Würzburg, Germany
- Institute for Molecular Infection Biology (IMIB), University of Würzburg, 97080, Würzburg, Germany
| | - Knut Ohlsen
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, 97080, Würzburg, Germany
- Institute for Molecular Infection Biology (IMIB), University of Würzburg, 97080, Würzburg, Germany
| | - Eduardo Lopez-Collazo
- The Innate Immune Response and Tumor Immunology Group, IdiPaz La Paz University Hospital, 28046, Madrid, Spain
- CIBER of Respiratory Diseases (CIBERES), Madrid, Spain
| | - Konrad U Förstner
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, 97080, Würzburg, Germany
- Institute for Molecular Infection Biology (IMIB), University of Würzburg, 97080, Würzburg, Germany
- Information Centre for Life Science (ZBMED), 50931, Cologne, Germany
- TH Köln - University of Applied Sciences, 50578, Cologne, Germany
| | - Ana Eulalio
- Institute for Molecular Infection Biology (IMIB), University of Würzburg, 97080, Würzburg, Germany
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, 3004-504, Coimbra, Portugal
- Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, 3810-193, Aveiro, Portugal
| | - Daniel Lopez
- National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), 28049, Madrid, Spain.
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, 97080, Würzburg, Germany.
- Institute for Molecular Infection Biology (IMIB), University of Würzburg, 97080, Würzburg, Germany.
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10
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Elhakim YA, Ali AE, Hosny AEDMS, Abdeltawab NF. Zinc Deprivation as a Promising Approach for Combating Methicillin-Resistant Staphylococcus aureus: A Pilot Study. Pathogens 2021; 10:1228. [PMID: 34684179 PMCID: PMC8540720 DOI: 10.3390/pathogens10101228] [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: 07/20/2021] [Revised: 09/06/2021] [Accepted: 09/15/2021] [Indexed: 12/23/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections are a global health burden with an urgent need for antimicrobial agents. Studies have shown that host immune responses limit essential metals such as zinc during infection, leading to the limitation of bacterial virulence. Thus, the deprivation of zinc as an important co-factor for the activity of many S. aureus enzymes can be a potential antimicrobial approach. However, the effect of zinc deprivation on S. aureus and MRSA is not fully understood. Therefore, the current study aimed to dissect the effects of zinc deprivation on S. aureus hemolytic activity and biofilm formation through employing biochemical and genetic approaches to study the effect of zinc deprivation on S. aureus growth and virulence. Chemically defined media (CDM) with and without ZnCl2, was used to assess the effect of zinc deprivation on growth, biofilm formation, and hemolytic activity in methicillin-susceptible S. aureus (MSSA) RN6390 and MRSA N315 strains. Zinc deprivation decreased the growth of RN6390 and N315 S. aureus strains significantly by 1.5-2 folds, respectively compared to the zinc physiological range encountered by the bacteria in the human body (7-20 µM) (p < 0.05). Zinc deprivation significantly reduced biofilm formation by 1.5 folds compared to physiological levels (p < 0.05). Moreover, the hemolytic activity of RN6390 and N315 S. aureus strains was significantly decreased by 20 and 30 percent, respectively compared to physiological zinc levels (p < 0.05). Expression of biofilm-associated transcripts levels at late stage of biofilm formation (20 h) murein hydrolase activator A (cidA) and cidB were downregulated by 3 and 5 folds, respectively (p < 0.05) suggested an effect on extracellular DNA production. Expression of hemolysins-associated genes (hld, hlb, hla) was downregulated by 3, 5, and 10 folds, respectively, in absence of zinc (p < 0.001). Collectively the current study showed that zinc deprivation in vitro affected growth, biofilm formation, and hemolytic activity of S. aureus. Our in vitro findings suggested that zinc deprivation can be a potential supportive anti-biofilm formation and antihemolytic approach to contain MRSA topical infections.
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Affiliation(s)
- Yomna A. Elhakim
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt; (Y.A.E.); (A.E.-D.M.S.H.)
| | - Amal E. Ali
- Department of Microbiology and Immunology, Faculty of Pharmacy, Future University in Egypt, New Cairo 12311, Egypt;
| | - Alaa El-Dien M. S. Hosny
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt; (Y.A.E.); (A.E.-D.M.S.H.)
- Department of Microbiology and Immunology, Faculty of Pharmacy, Modern University for Technology and Information (MTI), Cairo 12055, Egypt
| | - Nourtan F. Abdeltawab
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt; (Y.A.E.); (A.E.-D.M.S.H.)
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11
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Environmental conditions dictate differential evolution of vancomycin resistance in Staphylococcus aureus. Commun Biol 2021; 4:793. [PMID: 34172889 PMCID: PMC8233327 DOI: 10.1038/s42003-021-02339-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 06/09/2021] [Indexed: 02/06/2023] Open
Abstract
While microbiological resistance to vancomycin in Staphylococcus aureus is rare, clinical vancomycin treatment failures are common, and methicillin-resistant S. aureus (MRSA) strains isolated from patients after prolonged vancomycin treatment failure remain susceptible. Adaptive laboratory evolution was utilized to uncover mutational mechanisms associated with MRSA vancomycin resistance in a physiological medium as well as a bacteriological medium used in clinical susceptibility testing. Sequencing of resistant clones revealed shared and media-specific mutational outcomes, with an overlap in cell wall regulons (walKRyycHI, vraSRT). Evolved strains displayed similar properties to resistant clinical isolates in their genetic and phenotypic traits. Importantly, resistant phenotypes that developed in physiological media did not translate into resistance in bacteriological media. Further, a bacteriological media-specific mechanism for vancomycin resistance associated with a mutated mprF was confirmed. This study bridges the gap between the understanding of clinical and microbiological vancomycin resistance in S. aureus and expands the number of allelic variants (18 ± 4 mutations for the top 5 mutated genes) that result in vancomycin resistance phenotypes.
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Mrochen DM, Fernandes de Oliveira LM, Raafat D, Holtfreter S. Staphylococcus aureus Host Tropism and Its Implications for Murine Infection Models. Int J Mol Sci 2020; 21:E7061. [PMID: 32992784 PMCID: PMC7582387 DOI: 10.3390/ijms21197061] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 09/22/2020] [Accepted: 09/22/2020] [Indexed: 12/11/2022] Open
Abstract
Staphylococcus aureus (S. aureus) is a pathobiont of humans as well as a multitude of animal species. The high prevalence of multi-resistant and more virulent strains of S. aureus necessitates the development of new prevention and treatment strategies for S. aureus infection. Major advances towards understanding the pathogenesis of S. aureus diseases have been made using conventional mouse models, i.e., by infecting naïve laboratory mice with human-adapted S.aureus strains. However, the failure to transfer certain results obtained in these murine systems to humans highlights the limitations of such models. Indeed, numerous S. aureus vaccine candidates showed promising results in conventional mouse models but failed to offer protection in human clinical trials. These limitations arise not only from the widely discussed physiological differences between mice and humans, but also from the lack of attention that is paid to the specific interactions of S. aureus with its respective host. For instance, animal-derived S. aureus lineages show a high degree of host tropism and carry a repertoire of host-specific virulence and immune evasion factors. Mouse-adapted S.aureus strains, humanized mice, and microbiome-optimized mice are promising approaches to overcome these limitations and could improve transferability of animal experiments to human trials in the future.
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Affiliation(s)
- Daniel M. Mrochen
- Department of Immunology, Institute of Immunology and Transfusion Medicine, University Medicine Greifswald, Ferdinand-Sauerbruch-Strasse DZ 7, 17475 Greifswald, Germany; (L.M.F.d.O.); (D.R.); (S.H.)
| | - Liliane M. Fernandes de Oliveira
- Department of Immunology, Institute of Immunology and Transfusion Medicine, University Medicine Greifswald, Ferdinand-Sauerbruch-Strasse DZ 7, 17475 Greifswald, Germany; (L.M.F.d.O.); (D.R.); (S.H.)
| | - Dina Raafat
- Department of Immunology, Institute of Immunology and Transfusion Medicine, University Medicine Greifswald, Ferdinand-Sauerbruch-Strasse DZ 7, 17475 Greifswald, Germany; (L.M.F.d.O.); (D.R.); (S.H.)
- Department of Microbiology and Immunology, Faculty of Pharmacy, Alexandria University, 21521 Alexandria, Egypt
| | - Silva Holtfreter
- Department of Immunology, Institute of Immunology and Transfusion Medicine, University Medicine Greifswald, Ferdinand-Sauerbruch-Strasse DZ 7, 17475 Greifswald, Germany; (L.M.F.d.O.); (D.R.); (S.H.)
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Genetic Determinants Enabling Medium-Dependent Adaptation to Nafcillin in Methicillin-Resistant Staphylococcus aureus. mSystems 2020; 5:5/2/e00828-19. [PMID: 32234776 PMCID: PMC7112963 DOI: 10.1128/msystems.00828-19] [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] [Indexed: 11/20/2022] Open
Abstract
Antimicrobial susceptibility testing standards driving clinical decision-making have centered around the use of cation-adjusted Mueller-Hinton broth (CA-MHB) as the medium with the notion of supporting bacterial growth, without consideration of recapitulating the in vivo environment. However, it is increasingly recognized that various medium conditions have tremendous influence on antimicrobial activity, which in turn may have major implications on the ability of in vitro susceptibility assays to predict antibiotic activity in vivo. To elucidate differential growth optimization and antibiotic resistance mechanisms, adaptive laboratory evolution was performed in the presence or absence of the antibiotic nafcillin with methicillin-resistant Staphylococcus aureus (MRSA) TCH1516 in either (i) CA-MHB, a traditional bacteriological nutritionally rich medium, or (ii) Roswell Park Memorial Institute (RPMI), a medium more reflective of the in vivo host environment. Medium adaptation analysis showed an increase in growth rate in RPMI, but not CA-MHB, with mutations in apt, adenine phosphoribosyltransferase, and the manganese transporter subunit, mntA, occurring reproducibly in parallel replicate evolutions. The medium-adapted strains showed no virulence attenuation. Continuous exposure of medium-adapted strains to increasing concentrations of nafcillin led to medium-specific evolutionary strategies. Key reproducibly occurring mutations were specific for nafcillin adaptation in each medium type and did not confer resistance in the other medium environment. Only the vraRST operon, a regulator of membrane- and cell wall-related genes, showed mutations in both CA-MHB- and RPMI-evolved strains. Collectively, these results demonstrate the medium-specific genetic adaptive responses of MRSA and establish adaptive laboratory evolution as a platform to study clinically relevant resistance mechanisms.IMPORTANCE The ability of pathogens such as Staphylococcus aureus to evolve resistance to antibiotics used in the treatment of infections has been an important concern in the last decades. Resistant acquisition usually translates into treatment failure and puts patients at risk of unfavorable outcomes. Furthermore, the laboratory testing of antibiotic resistance does not account for the different environment the bacteria experiences within the human body, leading to results that do not translate into the clinic. In this study, we forced methicillin-resistant S. aureus to develop nafcillin resistance in two different environments, a laboratory environment and a physiologically more relevant environment. This allowed us to identify genetic changes that led to nafcillin resistance under both conditions. We concluded that not only does the environment dictate the evolutionary strategy of S. aureus to nafcillin but also that the evolutionary strategy is specific to that given environment.
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Sun X, Dai Y, Tan G, Liu Y, Li N. Integration Analysis of m 6A-SNPs and eQTLs Associated With Sepsis Reveals Platelet Degranulation and Staphylococcus aureus Infection are Mediated by m 6A mRNA Methylation. Front Genet 2020; 11:7. [PMID: 32174955 PMCID: PMC7054457 DOI: 10.3389/fgene.2020.00007] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 01/06/2020] [Indexed: 12/22/2022] Open
Abstract
Sepsis is a major threat with high mortality rate for critically ill patients. Response to pathogen infection by the host immune system is a key biological process involved in the onset and development of sepsis. Heterogeneous host genome variation, especially single nucleotide polymorphisms (SNPs), has long been suggested to contribute to differences in disease progression. However, the function of SNPs located in non-coding regions remains to be elucidated. Recently, m6A mRNA modification levels were revealed to differ at SNPs. As m6A is a crucial regulator of gene expression, these SNPs might control genes by changing the m6A level on mRNA. To investigate the potential role of m6A SNPs in sepsis, we integrated m6A-SNP and expression quantitative trait loci (eQTLs) data. Analysis revealed 15,720 m6A-cis-eQTLs and 381 m6A-trans-eQTLs associated with sepsis. We identified 1321 genes as locations of m6A-cis-eQTLs. These were enriched in platelet degranulation and Staphylococcus aureus infection pathways, which are vital for the pathophysiological process of sepsis. We conclude that m6A modification of mRNA plays a very important role in sepsis, with m6A-cis-eQTLs potentially having the most effect on individual variation in sepsis progression.
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Affiliation(s)
- Xuri Sun
- Department of Critical Care Medicine, The Second Affiliated Hospital, Fujian Medical University, Quanzhou, China.,Respiratory Medicine Center of Fujian Province, Quanzhou, China
| | - Yishuang Dai
- Department of Outpatient operating room, The Second Affiliated Hospital, Fujian Medical University, Quanzhou, China
| | - Guoliang Tan
- Department of Critical Care Medicine, The Second Affiliated Hospital, Fujian Medical University, Quanzhou, China.,Respiratory Medicine Center of Fujian Province, Quanzhou, China
| | - Yuqi Liu
- Department of Critical Care Medicine, The Second Affiliated Hospital, Fujian Medical University, Quanzhou, China.,Respiratory Medicine Center of Fujian Province, Quanzhou, China
| | - Neng Li
- Department of Pathogenic Biology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
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