Understanding the Virulence of Staphylococcus pseudintermedius: A Major Role of Pore-Forming Toxins
Staphylococcus pseudintermedius is responsible for severe and necrotizing infections in humans and dogs. Contrary to S. aureus, the pathophysiological mechanisms involved in this virulence are incompletely understood. We previously showed the intracellular cytotoxicity induced after internalization...
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Frontiers Media S.A.
2018-06-01
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| Series: | Frontiers in Cellular and Infection Microbiology |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fcimb.2018.00221/full |
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| author | Yousef Maali Cédric Badiou Patrícia Martins-Simões Patrícia Martins-Simões Patrícia Martins-Simões Elisabeth Hodille Elisabeth Hodille Michele Bes Michele Bes François Vandenesch François Vandenesch François Vandenesch Gérard Lina Gérard Lina Gérard Lina Alan Diot Frederic Laurent Frederic Laurent Frederic Laurent Sophie Trouillet-Assant Sophie Trouillet-Assant Sophie Trouillet-Assant |
| author_facet | Yousef Maali Cédric Badiou Patrícia Martins-Simões Patrícia Martins-Simões Patrícia Martins-Simões Elisabeth Hodille Elisabeth Hodille Michele Bes Michele Bes François Vandenesch François Vandenesch François Vandenesch Gérard Lina Gérard Lina Gérard Lina Alan Diot Frederic Laurent Frederic Laurent Frederic Laurent Sophie Trouillet-Assant Sophie Trouillet-Assant Sophie Trouillet-Assant |
| author_sort | Yousef Maali |
| collection | DOAJ |
| description | Staphylococcus pseudintermedius is responsible for severe and necrotizing infections in humans and dogs. Contrary to S. aureus, the pathophysiological mechanisms involved in this virulence are incompletely understood. We previously showed the intracellular cytotoxicity induced after internalization of S. pseudintermedius. Herein, we aimed to identify the virulence factors responsible for this cytotoxic activity. After addition of filtered S. pseudintermedius supernatants in culture cell media, MG63 cells, used as representative of non-professional phagocytic cells (NPPc), released a high level of LDH, indicating that the cytotoxicity was mainly mediated by secreted factors. Accordingly, we focused our attention on S. pseudintermedius toxins. In silico analysis found the presence of two PSMs (δ-toxin and PSMε) as well as Luk-I leukotoxin, the presence of which was confirmed by PCR in all clinical strains tested (n = 17). Recombinant Luk-I leukotoxin had no cytotoxic activity on NPPc but the ectopic expression of the CXCR2 receptor in U937 cells conferred cytotoxity to Luk-I. This is in agreement with the lack of Luk-I effect on NPPc and the previous report of Luk-I cytoxic activity on immune cells. Contrary to Luk-I, synthetic δ-toxin and PSMε had a strong cytotoxic activity on NPPc. The secretion of δ-toxin and PSMε at cytotoxic concentrations by S. pseudintermedius in culture supernatant was confirmed by HPLC-MS. In addition, the supplementation of such supernatants with human serum, known to inhibit PSM, induced a complete abolition of cytotoxicity which indicates that PSMs are the key players in the cytotoxic phenotype of NPPc. The results suggest that the severity of S. pseudintermedius infections is, at least in part, explained by a combined action of Luk-I that specifically targets immune cells expressing the CXCR2 receptor, and PSMs that disrupt cell membranes whatever the cell types. The present study strengthens the key role of PSMs in virulence of the different species belonging to Staphylococcus genus. |
| first_indexed | 2024-04-12T04:10:04Z |
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| language | English |
| last_indexed | 2024-04-12T04:10:04Z |
| publishDate | 2018-06-01 |
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| series | Frontiers in Cellular and Infection Microbiology |
| spelling | doaj.art-c7ba0231070147cbb337c8093352657c2022-12-22T03:48:31ZengFrontiers Media S.A.Frontiers in Cellular and Infection Microbiology2235-29882018-06-01810.3389/fcimb.2018.00221382091Understanding the Virulence of Staphylococcus pseudintermedius: A Major Role of Pore-Forming ToxinsYousef Maali0Cédric Badiou1Patrícia Martins-Simões2Patrícia Martins-Simões3Patrícia Martins-Simões4Elisabeth Hodille5Elisabeth Hodille6Michele Bes7Michele Bes8François Vandenesch9François Vandenesch10François Vandenesch11Gérard Lina12Gérard Lina13Gérard Lina14Alan Diot15Frederic Laurent16Frederic Laurent17Frederic Laurent18Sophie Trouillet-Assant19Sophie Trouillet-Assant20Sophie Trouillet-Assant21Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale, U1111, Centre National de la Recherche Scientifique, UMR5308, Université de Lyon 1, École Normale Supérieure de Lyon, Team “Pathogenesis of Staphylococcal Infections”, Lyon, FranceCentre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale, U1111, Centre National de la Recherche Scientifique, UMR5308, Université de Lyon 1, École Normale Supérieure de Lyon, Team “Pathogenesis of Staphylococcal Infections”, Lyon, FranceCentre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale, U1111, Centre National de la Recherche Scientifique, UMR5308, Université de Lyon 1, École Normale Supérieure de Lyon, Team “Pathogenesis of Staphylococcal Infections”, Lyon, FranceInstitut des Agents Infectieux, Hospices Civils de Lyon, Lyon, FranceCentre National de Référence des Staphylocoques, Hospices Civils de Lyon, Lyon, FranceCentre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale, U1111, Centre National de la Recherche Scientifique, UMR5308, Université de Lyon 1, École Normale Supérieure de Lyon, Team “Pathogenesis of Staphylococcal Infections”, Lyon, FranceInstitut des Agents Infectieux, Hospices Civils de Lyon, Lyon, FranceInstitut des Agents Infectieux, Hospices Civils de Lyon, Lyon, FranceCentre National de Référence des Staphylocoques, Hospices Civils de Lyon, Lyon, FranceCentre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale, U1111, Centre National de la Recherche Scientifique, UMR5308, Université de Lyon 1, École Normale Supérieure de Lyon, Team “Pathogenesis of Staphylococcal Infections”, Lyon, FranceInstitut des Agents Infectieux, Hospices Civils de Lyon, Lyon, FranceCentre National de Référence des Staphylocoques, Hospices Civils de Lyon, Lyon, FranceCentre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale, U1111, Centre National de la Recherche Scientifique, UMR5308, Université de Lyon 1, École Normale Supérieure de Lyon, Team “Pathogenesis of Staphylococcal Infections”, Lyon, FranceInstitut des Agents Infectieux, Hospices Civils de Lyon, Lyon, FranceCentre National de Référence des Staphylocoques, Hospices Civils de Lyon, Lyon, FranceCentre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale, U1111, Centre National de la Recherche Scientifique, UMR5308, Université de Lyon 1, École Normale Supérieure de Lyon, Team “Pathogenesis of Staphylococcal Infections”, Lyon, FranceCentre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale, U1111, Centre National de la Recherche Scientifique, UMR5308, Université de Lyon 1, École Normale Supérieure de Lyon, Team “Pathogenesis of Staphylococcal Infections”, Lyon, FranceInstitut des Agents Infectieux, Hospices Civils de Lyon, Lyon, FranceCentre National de Référence des Staphylocoques, Hospices Civils de Lyon, Lyon, FranceCentre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale, U1111, Centre National de la Recherche Scientifique, UMR5308, Université de Lyon 1, École Normale Supérieure de Lyon, Team “Pathogenesis of Staphylococcal Infections”, Lyon, FranceInstitut des Agents Infectieux, Hospices Civils de Lyon, Lyon, FranceLaboratoire Commun de Recherche Lyon Sud, Hospices Civils de Lyon-bioMérieux, Pierre Bénite, FranceStaphylococcus pseudintermedius is responsible for severe and necrotizing infections in humans and dogs. Contrary to S. aureus, the pathophysiological mechanisms involved in this virulence are incompletely understood. We previously showed the intracellular cytotoxicity induced after internalization of S. pseudintermedius. Herein, we aimed to identify the virulence factors responsible for this cytotoxic activity. After addition of filtered S. pseudintermedius supernatants in culture cell media, MG63 cells, used as representative of non-professional phagocytic cells (NPPc), released a high level of LDH, indicating that the cytotoxicity was mainly mediated by secreted factors. Accordingly, we focused our attention on S. pseudintermedius toxins. In silico analysis found the presence of two PSMs (δ-toxin and PSMε) as well as Luk-I leukotoxin, the presence of which was confirmed by PCR in all clinical strains tested (n = 17). Recombinant Luk-I leukotoxin had no cytotoxic activity on NPPc but the ectopic expression of the CXCR2 receptor in U937 cells conferred cytotoxity to Luk-I. This is in agreement with the lack of Luk-I effect on NPPc and the previous report of Luk-I cytoxic activity on immune cells. Contrary to Luk-I, synthetic δ-toxin and PSMε had a strong cytotoxic activity on NPPc. The secretion of δ-toxin and PSMε at cytotoxic concentrations by S. pseudintermedius in culture supernatant was confirmed by HPLC-MS. In addition, the supplementation of such supernatants with human serum, known to inhibit PSM, induced a complete abolition of cytotoxicity which indicates that PSMs are the key players in the cytotoxic phenotype of NPPc. The results suggest that the severity of S. pseudintermedius infections is, at least in part, explained by a combined action of Luk-I that specifically targets immune cells expressing the CXCR2 receptor, and PSMs that disrupt cell membranes whatever the cell types. The present study strengthens the key role of PSMs in virulence of the different species belonging to Staphylococcus genus.https://www.frontiersin.org/article/10.3389/fcimb.2018.00221/fullStaphylococcus pseudintermediuspore-forming toxinsphenol-soluble modulinsleukotoxin Luk-ICXCR2 receptorcytotoxicity |
| spellingShingle | Yousef Maali Cédric Badiou Patrícia Martins-Simões Patrícia Martins-Simões Patrícia Martins-Simões Elisabeth Hodille Elisabeth Hodille Michele Bes Michele Bes François Vandenesch François Vandenesch François Vandenesch Gérard Lina Gérard Lina Gérard Lina Alan Diot Frederic Laurent Frederic Laurent Frederic Laurent Sophie Trouillet-Assant Sophie Trouillet-Assant Sophie Trouillet-Assant Understanding the Virulence of Staphylococcus pseudintermedius: A Major Role of Pore-Forming Toxins Frontiers in Cellular and Infection Microbiology Staphylococcus pseudintermedius pore-forming toxins phenol-soluble modulins leukotoxin Luk-I CXCR2 receptor cytotoxicity |
| title | Understanding the Virulence of Staphylococcus pseudintermedius: A Major Role of Pore-Forming Toxins |
| title_full | Understanding the Virulence of Staphylococcus pseudintermedius: A Major Role of Pore-Forming Toxins |
| title_fullStr | Understanding the Virulence of Staphylococcus pseudintermedius: A Major Role of Pore-Forming Toxins |
| title_full_unstemmed | Understanding the Virulence of Staphylococcus pseudintermedius: A Major Role of Pore-Forming Toxins |
| title_short | Understanding the Virulence of Staphylococcus pseudintermedius: A Major Role of Pore-Forming Toxins |
| title_sort | understanding the virulence of staphylococcus pseudintermedius a major role of pore forming toxins |
| topic | Staphylococcus pseudintermedius pore-forming toxins phenol-soluble modulins leukotoxin Luk-I CXCR2 receptor cytotoxicity |
| url | https://www.frontiersin.org/article/10.3389/fcimb.2018.00221/full |
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