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Xiao X, Li Y, Li L, Xiong YQ. Identification of Methicillin-Resistant Staphylococcus aureus (MRSA) Genetic Factors Involved in Human Endothelial Cells Damage, an Important Phenotype Correlated with Persistent Endovascular Infection. Antibiotics (Basel) 2022; 11:antibiotics11030316. [PMID: 35326779 PMCID: PMC8944730 DOI: 10.3390/antibiotics11030316] [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: 01/30/2022] [Revised: 02/18/2022] [Accepted: 02/24/2022] [Indexed: 01/18/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of life-threatening endovascular infections. Endothelial cell (EC) damage is a key factor in the pathogenesis of these syndromes. However, genetic factors related to the EC damage have not been well studied. This study aims to identify genetic determinants that impact human EC damage by screening the genome-wide Nebraska Transposon Mutant Library (NTML). A well-established MTT assay was used to test the in vitro damage of human EC cell line (HMEC-1) caused by each mutant strain in the NTML. We first confirmed some global regulators and genes positively impact the EC damage, which is consistent with published results. These data support the utility of the high-throughput approach. Importantly, we demonstrated 317 mutants significantly decreased the EC damage, while only 6 mutants enhanced the EC damage vs. parental JE2 strain. The majority of these genes have not been previously defined to affect human EC damage. Interestingly, many of these newly identified genes are involved in metabolism, genetic and environmental information processing, and cellular processes. These results advance our knowledge of staphylococcal genetic factors related to human EC damage which may provide novel targets for the development of effective agents against MRSA endovascular infection.
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Affiliation(s)
- Xia Xiao
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA 90502, USA; (X.X.); (Y.L.); (L.L.)
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China
| | - Yi Li
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA 90502, USA; (X.X.); (Y.L.); (L.L.)
| | - Liang Li
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA 90502, USA; (X.X.); (Y.L.); (L.L.)
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Yan Q. Xiong
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA 90502, USA; (X.X.); (Y.L.); (L.L.)
- David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Correspondence: ; Tel.: +1-310-222-3545
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Kwiecinski JM, Kratofil RM, Parlet CP, Surewaard BGJ, Kubes P, Horswill AR. Staphylococcus aureus uses the ArlRS and MgrA cascade to regulate immune evasion during skin infection. Cell Rep 2021; 36:109462. [PMID: 34320352 PMCID: PMC8450000 DOI: 10.1016/j.celrep.2021.109462] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 05/01/2021] [Accepted: 07/09/2021] [Indexed: 01/20/2023] Open
Abstract
Skin is one of the most common sites of host immune response against Staphylococcus aureus infection. Here, through a combination of in vitro assays, mouse models, and intravital imaging, we find that S. aureus immune evasion in skin is controlled by a cascade composed of the ArlRS two-component regulatory system and its downstream effector, MgrA. S. aureus lacking either ArlRS or MgrA is less virulent and unable to form correct abscess structure due to de-repression of a giant surface protein, Ebh. These S. aureus mutants also have decreased expression of immune evasion factors (leukocidins, chemotaxis-inhibitory protein of S. aureus [CHIPS], staphylococcal complement inhibitor [SCIN], and nuclease) and are unable to kill neutrophils, block their chemotaxis, degrade neutrophil extracellular traps, and survive direct neutrophil attack. The combination of disrupted abscess structure and reduced immune evasion factors makes S. aureus susceptible to host defenses. ArlRS and MgrA are therefore the main regulators of S. aureus immune evasion and promising treatment targets.
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Affiliation(s)
- Jakub M Kwiecinski
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA; Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow 30387, Poland
| | - Rachel M Kratofil
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB T2N 4Z6, Canada; Calvin, Phoebe, and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Corey P Parlet
- Department of Veterans Affairs, Iowa City VA Medical Center, Iowa City, IA 52246, USA; Department of Microbiology and Immunology, University of Iowa, Iowa City, IA 52242, USA
| | - Bas G J Surewaard
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB T2N 4Z6, Canada; Calvin, Phoebe, and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Paul Kubes
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB T2N 4Z6, Canada; Calvin, Phoebe, and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA; Department of Veterans Affairs, Eastern Colorado Health Care System, Aurora, CO 80045, USA.
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Rao RT, Sivakumar N, Jayakumar K. Analyses of Livestock-Associated Staphylococcus aureus Pan-Genomes Suggest Virulence Is Not Primary Interest in Evolution of Its Genome. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2020; 23:224-236. [PMID: 31009331 DOI: 10.1089/omi.2019.0005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Staphylococcus aureus is not only part of normal flora but also an opportunistic pathogen relevant to microbial genomics, public health, and veterinary medicine. In addition to being a well-known human pathogen, S. aureus causes various infections in economically important livestock animals such as cows, sheep, goats, and pigs. There are very few studies that have examined the pan-genome of S. aureus or the host-specific strains' pan-genomes. We report on livestock-associated S. aureus' (LA-SA) pan-genome and suggest that virulence is not the primary interest in evolution of its genome. LA-SA' complete genomes were retrieved from the NCBI and pan-genome was constructed by high-speed Roary pipeline. The pan-genome size was 4637 clusters, whereas 42.46% of the pan-genome was associated with the core genome. We found 1268 genes were associated with the strain-unique genome, and the remaining 1432 cluster with the accessory genome. COG (clusters of orthologous group of proteins) analysis of the core genes revealed 34% of clusters related to metabolism responsible for amino acid and inorganic ion transport (COG categories E and P), followed by carbohydrate metabolism (category G). Virulent gene analysis revealed the core genes responsible for antiphagocytosis and iron uptake. The fluidity of pan-genome was calculated as 0.082 ± 0.025. Importantly, the positive selection analysis suggested a slower rate of evolution among the LA-SA genomes. We call for comparative microbial and pan-genome research between human and LA-SA that can help further understand the evolution of virulence and thus inform future microbial diagnostics and drug discovery.
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Affiliation(s)
- Relangi Tulasi Rao
- 1 Department of Animal Behaviour & Physiology, School of Biological Sciences, Madurai Kamaraj University, Madurai, Tamil Nadu, India
| | - Natesan Sivakumar
- 2 Department of Molecular Microbiology, School of Biotechnology, Madurai Kamaraj University, Madurai, Tamil Nadu, India
| | - Kannan Jayakumar
- 1 Department of Animal Behaviour & Physiology, School of Biological Sciences, Madurai Kamaraj University, Madurai, Tamil Nadu, India
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Kwiecinski JM, Horswill AR. Staphylococcus aureus bloodstream infections: pathogenesis and regulatory mechanisms. Curr Opin Microbiol 2020; 53:51-60. [PMID: 32172183 DOI: 10.1016/j.mib.2020.02.005] [Citation(s) in RCA: 121] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/03/2020] [Accepted: 02/05/2020] [Indexed: 12/15/2022]
Abstract
Staphylococcus aureus is an opportunistic pathogen that normally colonizes the human anterior nares. At the same time, this pathogen is one of the leading causes of life-threatening bloodstream infections, such as sepsis and endocarditis. In this review we will present the current understanding of the pathogenesis of these invasive infections, focusing on the mechanisms of S. aureus clearance from the bloodstream by the immune system, and how this pathogen hijacks the host defense and coagulation systems and further interacts with the blood vessel endothelium. Additionally, we will delve into the regulatory mechanisms S. aureus employs during an invasive infection. These new insights into host-pathogen interactions show promising avenues for the development of novel therapies for treating bloodstream infections.
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Affiliation(s)
- Jakub M Kwiecinski
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, USA
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, USA; Department of Veterans Affairs, Eastern Colorado Health Care System, Denver, USA.
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Yan H, Wang Q, Teng M, Li X. The DNA-binding mechanism of the TCS response regulator ArlR from Staphylococcus aureus. J Struct Biol 2019; 208:107388. [PMID: 31520693 DOI: 10.1016/j.jsb.2019.09.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/05/2019] [Accepted: 09/10/2019] [Indexed: 10/26/2022]
Abstract
ArlRS is an essential two-component system in Staphylococcus aureus that regulates the transcription of virulence factors and participate in numerous pathogenic and symbiotic processes. In this work, we identified different DNA binding properties and oligomerization states among the DNA-binding domain of ArlR (ArlRDBD) and the phosphorylated and unphosphorylated full-length ArlR. Based on a 2.5-Å resolution crystal structure of ArlRDBD and subsequent mutagenesis experiments, we confirmed the DNA-binding site of ArlR and the preferred binding sequences in the agr promoter that enables the DNA recognition process. Finally, we propose a putative transcription regulation mechanism for ArlR. This work will facilitate our understanding of the DNA binding affinity regulatory mechanism between the phosphorylated and unphosphorylated response regulator in the two-component system.
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Affiliation(s)
- Hui Yan
- Hefei National Laboratory for Physical Sciences at Microscale, National Synchrotron Radiation Laboratory, School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China
| | - Qing Wang
- Hefei National Laboratory for Physical Sciences at Microscale, National Synchrotron Radiation Laboratory, School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China
| | - Maikun Teng
- Hefei National Laboratory for Physical Sciences at Microscale, National Synchrotron Radiation Laboratory, School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China.
| | - Xu Li
- Hefei National Laboratory for Physical Sciences at Microscale, National Synchrotron Radiation Laboratory, School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China.
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Kwiecinski JM, Crosby HA, Valotteau C, Hippensteel JA, Nayak MK, Chauhan AK, Schmidt EP, Dufrêne YF, Horswill AR. Staphylococcus aureus adhesion in endovascular infections is controlled by the ArlRS-MgrA signaling cascade. PLoS Pathog 2019; 15:e1007800. [PMID: 31116795 PMCID: PMC6548404 DOI: 10.1371/journal.ppat.1007800] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 06/04/2019] [Accepted: 04/30/2019] [Indexed: 12/31/2022] Open
Abstract
Staphylococcus aureus is a leading cause of endovascular infections. This bacterial pathogen uses a diverse array of surface adhesins to clump in blood and adhere to vessel walls, leading to endothelial damage, development of intravascular vegetations and secondary infectious foci, and overall disease progression. In this work, we describe a novel strategy used by S. aureus to control adhesion and clumping through activity of the ArlRS two-component regulatory system, and its downstream effector MgrA. Utilizing a combination of in vitro cellular assays, and single-cell atomic force microscopy, we demonstrated that inactivation of this ArlRS—MgrA cascade inhibits S. aureus adhesion to a vast array of relevant host molecules (fibrinogen, fibronectin, von Willebrand factor, collagen), its clumping with fibrinogen, and its attachment to human endothelial cells and vascular structures. This impact on S. aureus adhesion was apparent in low shear environments, and in physiological levels of shear stress, as well as in vivo in mouse models. These effects were likely mediated by the de-repression of giant surface proteins Ebh, SraP, and SasG, caused by inactivation of the ArlRS—MgrA cascade. In our in vitro assays, these giant proteins collectively shielded the function of other surface adhesins and impaired their binding to cognate ligands. Finally, we demonstrated that the ArlRS—MgrA regulatory cascade is a druggable target through the identification of a small-molecule inhibitor of ArlRS signaling. Our findings suggest a novel approach for the pharmacological treatment and prevention of S. aureus endovascular infections through targeting the ArlRS—MgrA regulatory system. Adhesion is central to the success of Staphylococcus aureus as a bacterial pathogen. We describe a novel mechanism through which S. aureus alters adhesion to ligands by regulating expression of giant inhibitory surface proteins. These giant proteins shield normal surface adhesins, preventing binding to ligands commonly found in the bloodstream and vessel walls. Using this unique regulatory scheme, S. aureus can bypass the need for individualized regulation of numerous adhesins to control overall adhesive properties. Our study establishes the importance of these giant proteins for S. aureus pathogenesis and demonstrates that a single regulatory cascade can be targeted for treating infections.
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Affiliation(s)
- Jakub M. Kwiecinski
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Heidi A. Crosby
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Claire Valotteau
- Institute of Life Sciences, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Joseph A. Hippensteel
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Manasa K. Nayak
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Anil K. Chauhan
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Eric P. Schmidt
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Yves F. Dufrêne
- Institute of Life Sciences, Université catholique de Louvain, Louvain-la-Neuve, Belgium
- Walloon Excellence in Life Sciences and Biotechnology (WELBIO), Wallonia, Belgium
| | - Alexander R. Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, United States of America
- Department of Veterans Affairs Eastern Colorado Healthcare System, Denver, Colorado, United States of America
- * E-mail:
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Artificial Selection for Pathogenicity Mutations in Staphylococcus aureus Identifies Novel Factors Relevant to Chronic Infection. Infect Immun 2019; 87:IAI.00884-18. [PMID: 30642903 DOI: 10.1128/iai.00884-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 01/10/2019] [Indexed: 02/06/2023] Open
Abstract
Adaptation of Staphylococcus aureus to host microenvironments during chronic infection involves spontaneous mutations, yet changes underlying adaptive phenotypes remain incompletely explored. Here, we employed artificial selection and whole-genome sequencing to better characterize spontaneous chromosomal mutations that alter two pathogenicity phenotypes relevant to chronic infection in S. aureus: intracellular invasiveness and intracellular cytotoxicity. We identified 23 genes whose alteration coincided with enhanced virulence, 11 that were previously known and 12 (52%) that had no previously described role in S. aureus pathogenicity. Using precision genome editing, transposon mutants, and gene complementation, we empirically assessed the contributions of individual genes to the two virulence phenotypes. We functionally validated 14 of 21 genes tested as measurably influencing invasion and/or cytotoxicity, including 8 newly implicated by this study. We identified inactivating mutations (murA, ndhC, and a hypothetical membrane protein) and gain-of-function mutations (aroE Thr182Ile, yhcF Thr74Ile, and Asp486Glu in a hypothetical peptidase) in previously unrecognized S. aureus virulence genes that enhance pathogenesis when introduced into a clean genetic background, as well as a novel activating mutation in the known virulence regulator gene saeS (Ala106Thr). Investigation of potentially epistatic interactions identified a tufA mutation (Ala271Val) that enhances virulence only in the context of purine operon repressor gene (purR) inactivation. This project reveals a functionally diverse range of genes affected by gain- or loss-of-function mutations that contribute to S. aureus adaptive virulence phenotypes. More generally, the work establishes artificial selection as a means to determine the genetic mechanisms underlying complex bacterial phenotypes relevant to adaptation during infection.
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Głowacka-Rutkowska A, Gozdek A, Empel J, Gawor J, Żuchniewicz K, Kozińska A, Dębski J, Gromadka R, Łobocka M. The Ability of Lytic Staphylococcal Podovirus vB_SauP_phiAGO1.3 to Coexist in Equilibrium With Its Host Facilitates the Selection of Host Mutants of Attenuated Virulence but Does Not Preclude the Phage Antistaphylococcal Activity in a Nematode Infection Model. Front Microbiol 2019; 9:3227. [PMID: 30713528 PMCID: PMC6346686 DOI: 10.3389/fmicb.2018.03227] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 12/12/2018] [Indexed: 12/22/2022] Open
Abstract
Phage vB_SauP_phiAGO1.3 (phiAGO1.3) is a polyvalent Staphylococcus lytic podovirus with a 17.6-kb genome (Gozdek et al., 2018). It can infect most of the Staphylococcus aureus human isolates of dominant clonal complexes. We show that a major factor contributing to the wide host range of phiAGO1.3 is a lack or sparcity of target sites for certain restriction-modification systems of types I and II in its genome. Phage phiAGO1.3 requires for adsorption β-O-GlcNAcylated cell wall teichoic acid, which is also essential for the expression of methicillin resistance. Under certain conditions an exposure of S. aureus to phiAGO1.3 can lead to the establishment of a mixed population in which the bacteria and phages remain in equilibrium over multiple generations. This is reminiscent of the so called phage carrier state enabling the co-existence of phage-resistant and phage-sensitive cells supporting a continuous growth of the bacterial and phage populations. The stable co-existence of bacteria and phage favors the emergence of phage-resistant variants of the bacterium. All phiAGO1.3-resistant cells isolated from the phage-carrier-state cultures contained a mutation inactivating the two-component regulatory system ArlRS, essential for efficient expression of numerous S. aureus virulence-associated traits. Moreover, the mutants were unaffected in their susceptibility to infection with an unrelated, polyvalent S. aureus phage of the genus Kayvirus. The ability of phiAGO1.3 to establish phage-carrier-state cultures did not preclude its antistaphylococcal activity in vivo in an S. aureus nematode infection model. Taken together our results suggest that phiAGO1.3 could be suitable for the therapeutic application in humans and animals, alone or in cocktails with Kayvirus phages. It might be especially useful in the treatment of infections with the majority of methicillin-resistant S. aureus strains.
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Affiliation(s)
- Aleksandra Głowacka-Rutkowska
- Department of Microbial Biochemistry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Agnieszka Gozdek
- Department of Microbial Biochemistry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Joanna Empel
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, Warsaw, Poland
| | - Jan Gawor
- Laboratory of DNA Sequencing and Oligonucleotide Synthesis, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Karolina Żuchniewicz
- Laboratory of DNA Sequencing and Oligonucleotide Synthesis, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Aleksandra Kozińska
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, Warsaw, Poland
| | - Janusz Dębski
- Laboratory of Mass Spectrometry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Robert Gromadka
- Laboratory of DNA Sequencing and Oligonucleotide Synthesis, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Małgorzata Łobocka
- Department of Microbial Biochemistry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
- Autonomous Department of Microbial Biology, Faculty of Agriculture and Biology, Warsaw University of Life Sciences, Warsaw, Poland
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