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Costa FG, Mills KB, Crosby HA, Horswill AR. The Staphylococcus aureus regulatory program in a human skin-like environment. mBio 2024; 15:e0045324. [PMID: 38546267 PMCID: PMC11077960 DOI: 10.1128/mbio.00453-24] [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: 02/16/2024] [Accepted: 03/04/2024] [Indexed: 04/09/2024] Open
Abstract
Staphylococcus aureus is a Gram-positive pathogen responsible for the majority of skin and soft tissue infections (SSTIs). S. aureus colonizes the anterior nares of approximately 20%-30% of the population and transiently colonizes the skin, thereby increasing the risk of developing SSTIs and more serious infections. Current laboratory models that mimic the skin surface environment are expensive, require substantial infrastructure, and limit the scope of bacterial physiology studies under human skin conditions. To overcome these limitations, we developed a cost-effective, open-source, chemically defined media recipe termed skin-like medium (SLM) that incorporates key aspects of the human skin surface environment and supports growth of several staphylococcal species. We utilized SLM to investigate the transcriptional response of methicillin-resistant Staphylococcus aureus (MRSA) following growth in SLM compared to a commonly used laboratory media. Through RNA-seq analysis, we observed the upregulation of several virulence factors, including genes encoding functions involved in adhesion, proteolysis, and cytotoxicity. To further explore these findings, we conducted quantitative reverse transcription-PCR (qRT-PCR) experiments to determine the influence of media composition, pH, and temperature on the transcriptional response of key factors involved in adhesion and virulence. We also demonstrated that MRSA primed in SLM adhered better to human corneocytes and demonstrated adhesin-specific phenotypes that previously required genetic manipulation. This improved adherence to corneocytes was dependent on both acidic pH and growth in SLM. These results support the potential utility of SLM as an in vitro model for assessing staphylococcal physiology and metabolism on human skin. IMPORTANCE Staphylococcus aureus is the major cause of skin diseases, and its increased prevalence in skin colonization and infections present a need to understand its physiology in this environment. The work presented here outlines S. aureus upregulation of colonization and virulence factors using a newly developed medium that strives to replicate the human skin surface environment and demonstrates roles for adhesins clumping factor A (ClfA), serine-rich repeat glycoprotein adhesin (SraP), and the fibronectin binding proteins (Fnbps) in human corneocyte adherence.
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Affiliation(s)
- Flavia G. Costa
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Krista B. Mills
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Heidi A. Crosby
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Alexander R. Horswill
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Veterans Affairs, Eastern Colorado Healthcare System, Aurora, Colorado, USA
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Costa FG, Mills KB, Crosby HA, Horswill AR. The Staphylococcus aureus regulatory program in a human skin-like environment. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.24.563767. [PMID: 37961268 PMCID: PMC10634794 DOI: 10.1101/2023.10.24.563767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Staphylococcus aureus is a Gram-positive pathogen responsible for the majority of skin and soft tissue infections (SSTIs). S. aureus colonizes the anterior nares of approximately 20-30% of the population and transiently colonizes the skin, thereby increasing the risk of developing SSTIs and more serious infections. Current laboratory models that mimic the skin surface environment are expensive, require substantial infrastructure, and limit the scope of bacterial physiology studies under human skin conditions. To overcome these limitations, we developed a cost-effective, open-source, chemically defined media recipe termed skin-like media (SLM) that incorporates key aspects of the human skin surface environment and supports growth of several Staphylococcal species. We utilized SLM to investigate the transcriptional response of methicillin-resistant S. aureus (MRSA) following growth in SLM compared to a commonly used laboratory media. Through RNA-seq analysis, we observed the upregulation of several virulence factors, including genes encoding functions involved in adhesion, proteolysis, and cytotoxicity. To further explore these findings, we conducted qRT-PCR experiments to determine the influence of media composition, pH, and temperature on the transcriptional response of key factors involved in adhesion and virulence. We also demonstrated that MRSA primed in SLM adhered better to human corneocytes and demonstrated adhesin-specific phenotypes that previously required genetic manipulation. These results support the potential utility of SLM as an in vitro model for assessing Staphylococcal physiology and metabolism on human skin. Importance Staphylococcus aureus is the major cause of skin diseases, and its increased prevalence in skin colonization and infections present a need to understand its physiology in this environment. The work presented here outlines S. aureus upregulation of colonization and virulence factors using a newly developed media that strives to replicate the human skin surface environment, and demonstrates roles for adhesins ClfA, SraP, and Fnbps in human corneocyte adherence.
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Evolution of protease activation and specificity via alpha-2-macroglobulin-mediated covalent capture. Nat Commun 2023; 14:768. [PMID: 36765057 PMCID: PMC9918453 DOI: 10.1038/s41467-023-36099-7] [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: 08/07/2022] [Accepted: 01/13/2023] [Indexed: 02/12/2023] Open
Abstract
Tailoring of the activity and specificity of proteases is critical for their utility across industrial, medical and research purposes. However, engineering or evolving protease catalysts is challenging and often labour intensive. Here, we describe a generic method to accelerate this process based on yeast display. We introduce the protease selection system A2Mcap that covalently captures protease catalysts by repurposed alpha-2-macroglobulin (A2Ms). To demonstrate the utility of A2Mcap for protease engineering we exemplify the directed activity and specificity evolution of six serine proteases. This resulted in a variant of Staphylococcus aureus serin-protease-like (Spl) protease SplB, an enzyme used for recombinant protein processing, that no longer requires activation by N-terminal signal peptide removal. SCHEMA-based domain shuffling was used to map the specificity determining regions of Spl proteases, leading to a chimeric scaffold that supports specificity switching via subdomain exchange. The ability of A2Mcap to overcome key challenges en route to tailor-made proteases suggests easier access to such reagents in the future.
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In Silico Genome-Scale Analysis of Molecular Mechanisms Contributing to the Development of a Persistent Infection with Methicillin-Resistant Staphylococcus aureus (MRSA) ST239. Int J Mol Sci 2022; 23:ijms232416086. [PMID: 36555727 PMCID: PMC9781258 DOI: 10.3390/ijms232416086] [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: 10/30/2022] [Revised: 12/05/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022] Open
Abstract
The increasing frequency of isolation of methicillin-resistant Staphylococcus aureus (MRSA) limits the chances for the effective antibacterial therapy of staphylococcal diseases and results in the development of persistent infection such as bacteremia and osteomyelitis. The aim of this study was to identify features of the MRSAST239 0943-1505-2016 (SA943) genome that contribute to the formation of both acute and chronic musculoskeletal infections. The analysis was performed using comparative genomics data of the dominant epidemic S. aureus lineages, namely ST1, ST8, ST30, ST36, and ST239. The SA943 genome encodes proteins that provide resistance to the host's immune system, suppress immunological memory, and form biofilms. The molecular mechanisms of adaptation responsible for the development of persistent infection were as follows: amino acid substitution in PBP2 and PBP2a, providing resistance to ceftaroline; loss of a large part of prophage DNA and restoration of the nucleotide sequence of beta-hemolysin, that greatly facilitates the escape of phagocytosed bacteria from the phagosome and formation of biofilms; dysfunction of the AgrA system due to the presence of psm-mec and several amino acid substitutions in the AgrC; partial deletion of the nucleotide sequence in genomic island vSAβ resulting in the loss of two proteases of Spl-operon; and deletion of SD repeats in the SdrE amino acid sequence.
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Chlebicka K, Bonar E, Suder P, Ostyn E, Felden B, Wladyka B, Pinel-Marie ML. Impacts of the Type I Toxin-Antitoxin System, SprG1/SprF1, on Staphylococcus aureus Gene Expression. Genes (Basel) 2021; 12:genes12050770. [PMID: 34070083 PMCID: PMC8158120 DOI: 10.3390/genes12050770] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/14/2021] [Accepted: 05/16/2021] [Indexed: 11/16/2022] Open
Abstract
Type I toxin-antitoxin (TA) systems are widespread genetic modules in bacterial genomes. They express toxic peptides whose overexpression leads to growth arrest or cell death, whereas antitoxins regulate the expression of toxins, acting as labile antisense RNAs. The Staphylococcus aureus (S. aureus) genome contains and expresses several functional type I TA systems, but their biological functions remain unclear. Here, we addressed and challenged experimentally, by proteomics, if the type I TA system, the SprG1/SprF1 pair, influences the overall gene expression in S. aureus. Deleted and complemented S. aureus strains were analyzed for their proteomes, both intracellular and extracellular, during growth. Comparison of intracellular proteomes among the strains points to the SprF1 antitoxin as moderately downregulating protein expression. In the strain naturally expressing the SprG1 toxin, cytoplasmic proteins are excreted into the medium, but this is not due to unspecific cell leakages. Such a toxin-driven release of the cytoplasmic proteins may modulate the host inflammatory response that, in turn, could amplify the S. aureus infection spread.
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Affiliation(s)
- Kinga Chlebicka
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland; (K.C.); (E.B.)
| | - Emilia Bonar
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland; (K.C.); (E.B.)
| | - Piotr Suder
- Department of Analytical Chemistry and Biochemistry, Faculty of Materials Science and Ceramics, AGH University of Science and Technology, 31-007 Krakow, Poland;
| | - Emeline Ostyn
- Inserm, BRM [Bacterial Regulatory RNAs and Medicine]—UMR_S 1230, 35000 Rennes, France;
| | - Brice Felden
- Inserm, BRM [Bacterial Regulatory RNAs and Medicine]—UMR_S 1230, 35000 Rennes, France;
| | - Benedykt Wladyka
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland; (K.C.); (E.B.)
- Correspondence: (B.W.); (M.-L.P.-M.); Tel.: +48-126646511 (B.W.); +33-223234850 (M.-L.P.-M.)
| | - Marie-Laure Pinel-Marie
- Inserm, BRM [Bacterial Regulatory RNAs and Medicine]—UMR_S 1230, 35000 Rennes, France;
- Correspondence: (B.W.); (M.-L.P.-M.); Tel.: +48-126646511 (B.W.); +33-223234850 (M.-L.P.-M.)
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Alatorre-Barajas JA, Alcántar-Zavala E, Gil-Rivas MG, Estrada-Zavala E, Ochoa-Terán A, Gochi-Ponce Y, Montes-Ávila J, Cabrera A, Trujillo-Navarrete B, Rivera-Lugo YY, Alonso-Núñez G, Reynoso-Soto EA, Medina-Franco JL. Synthesis of covalent bonding MWCNT-oligoethylene linezolid conjugates and their antibacterial activity against bacterial strains. RSC Adv 2021; 11:28912-28924. [PMID: 35478546 PMCID: PMC9038137 DOI: 10.1039/d1ra04691h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 08/24/2021] [Indexed: 01/18/2023] Open
Abstract
Nowadays, infectious diseases caused by drug-resistant bacteria have become especially important. Linezolid is an antibacterial drug active against clinically important Gram positive strains; however, resistance showed by these bacteria has been reported. Nanotechnology has improved a broad area of science, such as medicine, developing new drug delivery and transport systems. In this work, several covalently bounded conjugated nanomaterials were synthesized from multiwalled carbon nanotubes (MWCNTs), a different length oligoethylene chain (Sn), and two linezolid precursors (4 and 7), and they were evaluated in antibacterial assays. Interestingly, due to the intrinsic antibacterial activity of the amino-oligoethylene linezolid analogues, these conjugated nanomaterials showed significant antibacterial activity against various tested bacterial strains in a radial diffusion assay and microdilution method, including Gram negative strains as Escherichia coli (11 mm, 6.25 μg mL−1) and Salmonella typhi (14 mm, ≤0.78 μg mL−1), which are not inhibited by linezolid. The results show a significant effect of the oligoethylene chain length over the antibacterial activity. Molecular docking of amino-oligoethylene linezolid analogs shows a more favorable interaction of the S2-7 analog in the PTC of E. coli. New MWCNTs amino-oligoethylene linezolid conjugates having outstanding activity against Gram negative strains.![]()
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Affiliation(s)
- José A. Alatorre-Barajas
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/ IT de Tijuana, Tijuana, B. C., Mexico
| | - Eleazar Alcántar-Zavala
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/ IT de Tijuana, Tijuana, B. C., Mexico
| | - M. Graciela Gil-Rivas
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/ IT de Tijuana, Tijuana, B. C., Mexico
| | - Edgar Estrada-Zavala
- Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Sinaloa, Culiacán, Sin, Mexico
| | - Adrián Ochoa-Terán
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/ IT de Tijuana, Tijuana, B. C., Mexico
| | - Y. Gochi-Ponce
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/ IT de Tijuana, Tijuana, B. C., Mexico
| | - Julio Montes-Ávila
- Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Sinaloa, Culiacán, Sin, Mexico
| | - Alberto Cabrera
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/ IT de Tijuana, Tijuana, B. C., Mexico
| | - Balter Trujillo-Navarrete
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/ IT de Tijuana, Tijuana, B. C., Mexico
| | - Yazmin Yorely Rivera-Lugo
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/ IT de Tijuana, Tijuana, B. C., Mexico
| | - Gabriel Alonso-Núñez
- Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Ensenada, B. C, Mexico
| | - Edgar A. Reynoso-Soto
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/ IT de Tijuana, Tijuana, B. C., Mexico
| | - J. L. Medina-Franco
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
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