1
|
Bhosle VK, Sun C, Patel S, Ho TWW, Westman J, Ammendolia DA, Langari FM, Fine N, Toepfner N, Li Z, Sharma M, Glogauer J, Capurro MI, Jones NL, Maynes JT, Lee WL, Glogauer M, Grinstein S, Robinson LA. The chemorepellent, SLIT2, bolsters innate immunity against Staphylococcus aureus. eLife 2023; 12:e87392. [PMID: 37773612 PMCID: PMC10541174 DOI: 10.7554/elife.87392] [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: 03/03/2023] [Accepted: 09/10/2023] [Indexed: 10/01/2023] Open
Abstract
Neutrophils are essential for host defense against Staphylococcus aureus (S. aureus). The neuro-repellent, SLIT2, potently inhibits neutrophil chemotaxis, and might, therefore, be expected to impair antibacterial responses. We report here that, unexpectedly, neutrophils exposed to the N-terminal SLIT2 (N-SLIT2) fragment kill extracellular S. aureus more efficiently. N-SLIT2 amplifies reactive oxygen species production in response to the bacteria by activating p38 mitogen-activated protein kinase that in turn phosphorylates NCF1, an essential subunit of the NADPH oxidase complex. N-SLIT2 also enhances the exocytosis of neutrophil secondary granules. In a murine model of S. aureus skin and soft tissue infection (SSTI), local SLIT2 levels fall initially but increase subsequently, peaking at 3 days after infection. Of note, the neutralization of endogenous SLIT2 worsens SSTI. Temporal fluctuations in local SLIT2 levels may promote neutrophil recruitment and retention at the infection site and hasten bacterial clearance by augmenting neutrophil oxidative burst and degranulation. Collectively, these actions of SLIT2 coordinate innate immune responses to limit susceptibility to S. aureus.
Collapse
Affiliation(s)
- Vikrant K Bhosle
- Cell Biology Program, The Hospital for Sick Children Research InstituteTorontoCanada
| | - Chunxiang Sun
- Faculty of Dentistry, University of TorontoTorontoCanada
| | - Sajedabanu Patel
- Cell Biology Program, The Hospital for Sick Children Research InstituteTorontoCanada
| | - Tse Wing Winnie Ho
- The Keenan Research Centre for Biomedical Science, Unity Health TorontoTorontoCanada
- Department of Laboratory Medicine & Pathobiology, Medical Sciences Building, University of TorontoTorontoCanada
| | - Johannes Westman
- Cell Biology Program, The Hospital for Sick Children Research InstituteTorontoCanada
| | - Dustin A Ammendolia
- Cell Biology Program, The Hospital for Sick Children Research InstituteTorontoCanada
- Department of Molecular Genetics, Medical Sciences Building, University of TorontoTorontoCanada
| | - Fatemeh Mirshafiei Langari
- Program in Molecular Medicine, The Hospital for Sick Children Research InstituteTorontoCanada
- Department of Biochemistry, Medical Sciences Building, University of TorontoTorontoCanada
| | - Noah Fine
- Faculty of Dentistry, University of TorontoTorontoCanada
| | - Nicole Toepfner
- Department of Pediatrics, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität DresdenDresdenGermany
| | - Zhubing Li
- Cell Biology Program, The Hospital for Sick Children Research InstituteTorontoCanada
| | - Manraj Sharma
- Cell Biology Program, The Hospital for Sick Children Research InstituteTorontoCanada
| | - Judah Glogauer
- Cell Biology Program, The Hospital for Sick Children Research InstituteTorontoCanada
- Faculty of Dentistry, University of TorontoTorontoCanada
| | - Mariana I Capurro
- Cell Biology Program, The Hospital for Sick Children Research InstituteTorontoCanada
| | - Nicola L Jones
- Cell Biology Program, The Hospital for Sick Children Research InstituteTorontoCanada
- Division of Gastroenterology, Hepatology and Nutrition, The Hospital for Sick ChildrenTorontoCanada
- Department of Physiology, Medical Sciences Building, University of TorontoTorontoCanada
- Department of Paediatrics, Temerty Faculty of Medicine, University of TorontoTorontoCanada
| | - Jason T Maynes
- Program in Molecular Medicine, The Hospital for Sick Children Research InstituteTorontoCanada
- Department of Anesthesia and Pain Medicine, The Hospital for Sick ChildrenTorontoCanada
- Department of Anesthesiology & Pain Medicine, Temerty Faculty of Medicine, University of TorontoTorontoCanada
| | - Warren L Lee
- The Keenan Research Centre for Biomedical Science, Unity Health TorontoTorontoCanada
- Department of Laboratory Medicine & Pathobiology, Medical Sciences Building, University of TorontoTorontoCanada
- Department of Biochemistry, Medical Sciences Building, University of TorontoTorontoCanada
- Department of Medicine and Interdepartmental Division of Critical Care Medicine, Temerty Faculty of Medicine, University of TorontoTorontoCanada
| | - Michael Glogauer
- Faculty of Dentistry, University of TorontoTorontoCanada
- Department of Dental Oncology and Maxillofacial Prosthetics, University Health Network, Princess Margaret Cancer CentreTorontoCanada
- Centre for Advanced Dental Research and Care, Mount Sinai HospitalTorontoCanada
| | - Sergio Grinstein
- Cell Biology Program, The Hospital for Sick Children Research InstituteTorontoCanada
- The Keenan Research Centre for Biomedical Science, Unity Health TorontoTorontoCanada
- Department of Biochemistry, Medical Sciences Building, University of TorontoTorontoCanada
| | - Lisa A Robinson
- Cell Biology Program, The Hospital for Sick Children Research InstituteTorontoCanada
- Department of Paediatrics, Temerty Faculty of Medicine, University of TorontoTorontoCanada
- Institute of Medical Science, University of Toronto, Medical Sciences Building, University of TorontoTorontoCanada
- Division of Nephrology, The Hospital for Sick ChildrenTorontoCanada
| |
Collapse
|
2
|
Lehman SM, Kongari R, Glass AM, Koert M, Ray MD, Plaut RD, Stibitz S. Phage K gp102 Drives Temperature-Sensitive Antibacterial Activity on USA300 MRSA. Viruses 2022; 15:17. [PMID: 36680060 PMCID: PMC9861931 DOI: 10.3390/v15010017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/15/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022] Open
Abstract
There is widespread interest in using obligately lytic bacteriophages ("phages") to treat human bacterial infections. Among Staphylococcus aureus infections, the USA300 lineage is a frequent cause of invasive disease. We observed that phage K, a model S. aureus myophage, exhibits temperature-sensitive growth on USA300 strains, with the wild-type phage providing poorer growth suppression in broth and forming smaller and fainter plaques at 37 °C vs. 30 °C. We isolated 65 mutants of phage K that had improved plaquing characteristics at 37 °C when compared to the parental phage. In all 65 mutants, this phenotype was attributable to loss-of-function (LoF) mutations in gp102, which encodes a protein of unknown function that has homologs only among the Herelleviridae (SPO1-like myophages infecting gram-positive bacteria). Additional experiments with representative mutants consistently showed that the temperature-sensitive plaque phenotype was specific to USA300 MRSA strains and that Gp102 disruption was correlated with improved suppression of bacterial growth in broth and improved antibacterial activity in a mouse model of upper respiratory tract infection. The same genotype and in vitro phenotypes could be replicated in close relatives of phage K. Gp102 disruption did not have a detectable effect on adsorption but did delay cell culture lysis relative to wild-type under permissive infection conditions, suggesting that gp102 conservation might be maintained by selective pressure for more rapid replication. Expression of gp102 on a plasmid was toxic to both an MSSA and a USA300 MRSA strain. Molecular modeling predicts a protein with two helix-turn-helix domains that displays some similarity to DNA-binding proteins such as transcription factors. While its function remains unclear, gp102 is a conserved gene that is important to the infection process of Kayvirus phages, and it appears that the manner in which USA300 strains defend against them at 37 °C can be overcome by gp102 LoF mutations.
Collapse
|
3
|
Antimicrobial activity against Staphylococcus aureus and genome features of Lactiplantibacillus plantarum LR-14 from Sichuan pickles. Arch Microbiol 2022; 204:637. [PMID: 36127470 DOI: 10.1007/s00203-022-03232-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 08/27/2022] [Accepted: 08/30/2022] [Indexed: 11/02/2022]
Abstract
The persistence of Staphylococcus aureus within biofilm can lead to contamination of medical devices and life-threatening infections. Luckily, lactic acid bacteria (LAB) have an inhibitory effect on the growth of these bacteria. This study aims to select LAB strains from fermented vegetables, and analyze their potential inhibition activities against S. aureus. In total, 45 isolates of LAB were successfully isolated from Sichuan pickles, and the CFS of Lactiplantibacillus plantarum LR-14 exerted the strongest inhibitory effect against S. aureus. Moreover, S. aureus cells in planktonic and biofilm states both wrinkled and damaged when treated with the CFS of L. plantarum LR-14. In addition, whole genome sequencing analysis indicates that L. plantarum LR-14 contains various functional genes, including predicted extracellular polysaccharides (EPS) biosynthesis genes, and genes participating in the synthesis and metabolism of fatty acid, implying that L. plantarum LR-14 has the potential to be used as a probiotic with multiple functions.
Collapse
|
4
|
Egholm C, Özcan A, Breu D, Boyman O. Type 2 immune predisposition results in accelerated neutrophil aging causing susceptibility to bacterial infection. Sci Immunol 2022; 7:eabi9733. [PMID: 35594340 DOI: 10.1126/sciimmunol.abi9733] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Atopic individuals show enhanced type 2 immune cell responses and a susceptibility to infections with certain bacteria and viruses. Although patients with allergic diseases harbor normal counts of circulating neutrophils, these cells exert deficient effector functions. However, the underlying mechanism of this dysregulation of neutrophils remains ill defined. Here, we find that development, aging, and elimination of neutrophils are accelerated in mice with a predisposition to type 2 immunity, which, in turn, causes susceptibility to infection with several bacteria. Neutrophil-mediated immunity to bacterial infection was greatly decreased in mice with a genetic or induced bias to type 2 immunity. Abrogation of interleukin-4 (IL-4) receptor signaling in these animals fully restored their antibacterial defense, which largely depended on Ly6G+ neutrophils. IL-4 signals accelerated the maturation of neutrophils in the bone marrow and caused their rapid release to the circulation and periphery. IL-4-stimulated neutrophils aged more rapidly in the periphery, as evidenced by their phenotypic and functional changes, including their decreased phagocytosis of bacterial particles. Moreover, neutrophils from type 2 immune predisposed mice were eliminated at a higher rate by apoptosis and phagocytosis by macrophages and dendritic cells. Collectively, IL-4 signaling-mediated neutrophil aging constitutes an important adaptive deficiency in type 2 inflammation, contributing to recurrent bacterial infections.
Collapse
Affiliation(s)
- Cecilie Egholm
- Department of Immunology, University Hospital Zurich, Zurich, Switzerland
| | - Alaz Özcan
- Department of Immunology, University Hospital Zurich, Zurich, Switzerland
| | - Daniel Breu
- Department of Immunology, University Hospital Zurich, Zurich, Switzerland
| | - Onur Boyman
- Department of Immunology, University Hospital Zurich, Zurich, Switzerland.,Faculty of Medicine, University of Zurich, Zurich, Switzerland
| |
Collapse
|
5
|
Özcan A, Collado-Diaz V, Egholm C, Tomura M, Gunzer M, Halin C, Kolios AGA, Boyman O. CCR7-guided neutrophil redirection to skin-draining lymph nodes regulates cutaneous inflammation and infection. Sci Immunol 2022; 7:eabi9126. [PMID: 35119939 DOI: 10.1126/sciimmunol.abi9126] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Neutrophils are the first nonresident effector immune cells that migrate to a site of infection or inflammation; however, improper control of neutrophil responses can cause considerable tissue damage. Here, we found that neutrophil responses in inflamed or infected skin were regulated by CCR7-dependent migration and phagocytosis of neutrophils in draining lymph nodes (dLNs). In mouse models of Toll-like receptor-induced skin inflammation and cutaneous Staphylococcus aureus infection, neutrophils migrated from the skin to the dLNs via lymphatic vessels in a CCR7-mediated manner. In the dLNs, these neutrophils were phagocytosed by lymph node-resident type 1 and type 2 conventional dendritic cells. CCR7 up-regulation on neutrophils was a conserved mechanism across different tissues and was induced by a broad range of microbial stimuli. In the context of cutaneous immune responses, disruption of CCR7 interactions by selective CCR7 deficiency of neutrophils resulted in increased antistaphylococcal immunity and aggravated skin inflammation. Thus, neutrophil homing to and clearance in skin-dLNs affects cutaneous immunity versus pathology.
Collapse
Affiliation(s)
- A Özcan
- Department of Immunology, University Hospital Zurich, Zurich, Switzerland
| | - V Collado-Diaz
- Institute of Pharmaceutical Sciences, ETH Zurich, Zurich, Switzerland
| | - C Egholm
- Department of Immunology, University Hospital Zurich, Zurich, Switzerland
| | - M Tomura
- Laboratory of Immunology, Faculty of Pharmacy, Osaka Ohtani University, Tondabayashi, Osaka 584-8540, Japan
| | - M Gunzer
- Institute for Experimental Immunology and Imaging, University Hospital, University Duisburg-Essen, Essen, Germany.,Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany
| | - C Halin
- Institute of Pharmaceutical Sciences, ETH Zurich, Zurich, Switzerland
| | - A G A Kolios
- Department of Immunology, University Hospital Zurich, Zurich, Switzerland
| | - O Boyman
- Department of Immunology, University Hospital Zurich, Zurich, Switzerland.,Faculty of Medicine, University of Zurich, Zurich, Switzerland
| |
Collapse
|
6
|
Wang Y, Dikeman D, Zhang J, Ackerman N, Kim S, Alphonse MP, Ortines RV, Liu H, Joyce DP, Dillen CA, Thompson JM, Thomas AA, Plaut RD, Miller LS, Archer NK. CCR2 contributes to host defense against Staphylococcus aureus orthopedic implant-associated infections in mice. J Orthop Res 2022; 40:409-419. [PMID: 33713394 PMCID: PMC8435538 DOI: 10.1002/jor.25027] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/19/2021] [Accepted: 03/10/2021] [Indexed: 02/04/2023]
Abstract
C-C motif chemokine receptor 2 (CCR2) is an important mediator of myeloid cell chemotaxis during inflammation and infection. Myeloid cells such as monocytes, macrophages, and neutrophils contribute to host defense during orthopedic implant-associated infections (OIAI), but whether CCR2-mediated chemotaxis is involved remains unclear. Therefore, a Staphylococcus aureus OIAI model was performed by surgically placing an orthopedic-grade titanium implant and inoculating a bioluminescent S. aureus strain in knee joints of wildtype (wt) and CCR2-deficient mice. In vivo bioluminescent signals significantly increased in CCR2-deficient mice compared with wt mice at later time points (Days 14-28), which was confirmed with ex vivo colony-forming unit enumeration. S. aureus γ-hemolysin utilizes CCR2 to induce host cell lysis. However, there were no differences in bacterial burden when the OIAI model was performed with a parental versus a mutant γ-hemolysin-deficient S. aureus strain, indicating that the protection was mediated by the host cell function of CCR2 rather than γ-hemolysin virulence. Although CCR2-deficient and wt mice had similar cellular infiltrates in the infected joint tissue, CCR2-deficient mice had reduced myeloid cells and γδ T cells in the draining lymph nodes. Taken together, CCR2 contributed to host defense at later time points during an OIAI by increasing immune cell infiltrates in the draining lymph nodes, which likely contained the infection and prevented invasive spread.
Collapse
Affiliation(s)
- Yu Wang
- Department of Dermatology, Johns Hopkins University School
of Medicine, Baltimore, Maryland, USA
| | - Dustin Dikeman
- Department of Dermatology, Johns Hopkins University School
of Medicine, Baltimore, Maryland, USA
| | - Jeffrey Zhang
- Department of Dermatology, Johns Hopkins University School
of Medicine, Baltimore, Maryland, USA
| | - Nicole Ackerman
- Department of Dermatology, Johns Hopkins University School
of Medicine, Baltimore, Maryland, USA
| | - Sophia Kim
- Department of Dermatology, Johns Hopkins University School
of Medicine, Baltimore, Maryland, USA
| | - Martin P. Alphonse
- Department of Dermatology, Johns Hopkins University School
of Medicine, Baltimore, Maryland, USA
| | - Roger V. Ortines
- Department of Dermatology, Johns Hopkins University School
of Medicine, Baltimore, Maryland, USA
| | - Haiyun Liu
- Department of Dermatology, Johns Hopkins University School
of Medicine, Baltimore, Maryland, USA
| | - Daniel P. Joyce
- Department of Dermatology, Johns Hopkins University School
of Medicine, Baltimore, Maryland, USA
| | - Carly A. Dillen
- Department of Dermatology, Johns Hopkins University School
of Medicine, Baltimore, Maryland, USA
| | - John M. Thompson
- Department of Orthopaedic Surgery, Johns Hopkins University
School of Medicine, Baltimore, Maryland, USA
| | - Abigail A. Thomas
- Division of Bacterial Parasitic, and Allergenic Products,
Center for Biologics Evaluation and Research, Food and Drug Administration, Silver
Spring, Maryland, USA
| | - Roger D. Plaut
- Division of Bacterial Parasitic, and Allergenic Products,
Center for Biologics Evaluation and Research, Food and Drug Administration, Silver
Spring, Maryland, USA
| | - Lloyd S. Miller
- Department of Dermatology, Johns Hopkins University School
of Medicine, Baltimore, Maryland, USA,Department of Immunology, Janssen Research and Development,
Spring House, Pennsylvania, USA
| | - Nathan K. Archer
- Department of Dermatology, Johns Hopkins University School
of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
7
|
Barua N, Huang L, Li C, Yang Y, Luo M, Wei WI, Wong KT, Lo NWS, Kwok KO, Ip M. Comparative Study of Two-Dimensional (2D) vs. Three-Dimensional (3D) Organotypic Kertatinocyte-Fibroblast Skin Models for Staphylococcus aureus (MRSA) Infection. Int J Mol Sci 2021; 23:ijms23010299. [PMID: 35008727 PMCID: PMC8745520 DOI: 10.3390/ijms23010299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/24/2021] [Accepted: 12/25/2021] [Indexed: 01/03/2023] Open
Abstract
The invasion of skin tissue by Staphylococcus aureus is mediated by mechanisms that involve sequential breaching of the different stratified layers of the epidermis. Induction of cell death in keratinocytes is a measure of virulence and plays a crucial role in the infection progression. We established a 3D-organotypic keratinocyte-fibroblast co-culture model to evaluate whether a 3D-skin model is more effective in elucidating the differences in the induction of cell death by Methicillin-resistant Staphylococcus aureus (MRSA) than in comparison to 2D-HaCaT monolayers. We investigated the difference in adhesion, internalization, and the apoptotic index in HaCaT monolayers and our 3D-skin model using six strains of MRSA representing different clonal types, namely, ST8, ST30, ST59, ST22, ST45 and ST239. All the six strains exhibited internalization in HaCaT cells. Due to cell detachment, the invasion study was limited up to two and a half hours. TUNEL assay showed no significant difference in the cell death induced by the six MRSA strains in the HaCaT cells. Our 3D-skin model provided a better insight into the interactions between the MRSA strains and the human skin during the infection establishment as we could study the infection of MRSA in our skin model up to 48 h. Immunohistochemical staining together with TUNEL assay in the 3D-skin model showed co-localization of the bacteria with the apoptotic cells demonstrating the induction of apoptosis by the bacteria and revealed the variation in bacterial transmigration among the MRSA strains. The strain representing ST59 showed maximum internalization in HaCaT cells and the maximum cell death as measured by Apoptotic index in the 3D-skin model. Our results show that 3D-skin model might be more likely to imitate the physiological response of skin to MRSA infection than 2D-HaCaT monolayer keratinocyte cultures and will enhance our understanding of the difference in pathogenesis among different MRSA strains.
Collapse
Affiliation(s)
- Nilakshi Barua
- Department of Microbiology, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong 999077, China; (N.B.); (C.L.); (Y.Y.); (M.L.); (K.T.W.); (N.W.S.L.)
| | - Lin Huang
- Department of Surgery, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong 999077, China;
| | - Carmen Li
- Department of Microbiology, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong 999077, China; (N.B.); (C.L.); (Y.Y.); (M.L.); (K.T.W.); (N.W.S.L.)
| | - Ying Yang
- Department of Microbiology, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong 999077, China; (N.B.); (C.L.); (Y.Y.); (M.L.); (K.T.W.); (N.W.S.L.)
| | - Mingjing Luo
- Department of Microbiology, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong 999077, China; (N.B.); (C.L.); (Y.Y.); (M.L.); (K.T.W.); (N.W.S.L.)
- Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology (SIAT), Chinese Academy of Sciences, Shenzhen 518055, China
| | - Wan In Wei
- JC School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong 999077, China; (W.I.W.); (K.O.K.)
| | - Kam Tak Wong
- Department of Microbiology, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong 999077, China; (N.B.); (C.L.); (Y.Y.); (M.L.); (K.T.W.); (N.W.S.L.)
| | - Norman Wai Sing Lo
- Department of Microbiology, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong 999077, China; (N.B.); (C.L.); (Y.Y.); (M.L.); (K.T.W.); (N.W.S.L.)
| | - Kin On Kwok
- JC School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong 999077, China; (W.I.W.); (K.O.K.)
| | - Margaret Ip
- Department of Microbiology, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong 999077, China; (N.B.); (C.L.); (Y.Y.); (M.L.); (K.T.W.); (N.W.S.L.)
- Correspondence: ; Tel.: +852-35051265
| |
Collapse
|
8
|
Boone JM, Fountain K, Williams J, Lloyd DH, Killick R, Rodriguez Barbón A, Stidworthy MF, Loeffler A. Diseases and histopathological findings from lesional pinnae of 10 bats. VETERINARY RECORD CASE REPORTS 2021. [DOI: 10.1002/vrc2.145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Johann M. Boone
- Department of Clinical Science and Services Royal Veterinary College, Hatfield, North Mymms Hertfordshire UK
| | - Kay Fountain
- Department of Biology and Biochemistry University of Bath Claverton Down Bath UK
| | - Jonathan Williams
- Department of Pathobiology and Population Sciences Royal Veterinary College, Hatfield, North Mymms Hertfordshire UK
| | - David H. Lloyd
- Department of Clinical Science and Services Royal Veterinary College, Hatfield, North Mymms Hertfordshire UK
| | | | | | - Mark F. Stidworthy
- Pathology Division International Zoo Veterinary Group Station House, Keighley West Yorkshire UK
| | - Anette Loeffler
- Department of Clinical Science and Services Royal Veterinary College, Hatfield, North Mymms Hertfordshire UK
| |
Collapse
|
9
|
Hassanen EI, Ragab E. In Vivo and In Vitro Assessments of the Antibacterial Potential of Chitosan-Silver Nanocomposite Against Methicillin-Resistant Staphylococcus aureus-Induced Infection in Rats. Biol Trace Elem Res 2021; 199:244-257. [PMID: 32306284 DOI: 10.1007/s12011-020-02143-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/02/2020] [Indexed: 12/18/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most threatening multidrug-resistant bacteria worldwide. Owing to their efficient antimicrobial properties, nanoparticles have been widely used as an alternative approach for combating the antibiotic-resistant bacteria. Consequently, this study was designed to compare in between the bactericidal effect of low doses (5 mg/kg bwt) of nanoparticles of chitosan (Ch-NPs), silver (Ag-NPs), and chitosan-silver nanocomposites (Ch-Ag NCs) both in vitro and in vivo against experimentally chronic infection induced by methicillin-resistant Staphylococcus aureus (MRSA). The three forms of nanoparticles were tested for their in vitro antimicrobial potential against MRSA by detection of MICs and MBCs using microdilution method. In vivo, thirty-five male albino Wistar rats were used and divided into five groups (n = 7). Group l (negative control), group 2 (MRSA infected and untreated), groups 3, 4, and 5 (MRSA infected then treated with Ch-NPs, Ag-NPs, and Ch-Ag NCs respectively for 7 days). After 6 weeks, blood samples were collected then rats were euthanized to collect different organs (liver, spleen, lungs, and kidneys). Some of them were kept in 10% formalin for histopathological investigations while others used for bacterial re-isolation. Ch-Ag NCs showed the lowest MIC and MBC among the tested nanoparticles. Moreover, the highest histopathological scoring was observed in the infected and untreated group while the lowest scoring was detected in groups treated with Ch-Ag NCs in comparison with the negative control group. The highest bacterial count was noticed in the infected and untreated group followed by those treated with Ch-NPs while the lowest count was observed in group treated with Ch-Ag NCs. Depending on these results, it can be concluded that Ch-Ag NCs have a strong bactericidal effect against MRSA and may be used as alternative option to antibiotics.
Collapse
Affiliation(s)
- Eman I Hassanen
- Pathology Department, Faculty of Veterinary Medicine, Cairo University, PO Box 12211, Giza, Egypt
| | - Eman Ragab
- Microbiology Department, Faculty of Veterinary Medicine, Cairo University, PO Box 12211, Giza, Egypt.
| |
Collapse
|
10
|
IgE Effector Mechanisms, in Concert with Mast Cells, Contribute to Acquired Host Defense against Staphylococcusaureus. Immunity 2020; 53:793-804.e9. [PMID: 32910906 DOI: 10.1016/j.immuni.2020.08.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 06/02/2020] [Accepted: 08/06/2020] [Indexed: 12/21/2022]
Abstract
Allergies are considered to represent mal-directed type 2 immune responses against mostly innocuous exogenous compounds. Immunoglobulin E (IgE) antibodies are a characteristic feature of allergies and mediate hypersensitivity against allergens through activation of effector cells, particularly mast cells (MCs). Although the physiological functions of this dangerous branch of immunity have remained enigmatic, recent evidence shows that allergic immune reactions can help to protect against the toxicity of venoms. Because bacteria are a potent alternative source of toxins, we assessed the possible role of allergy-like type 2 immunity in antibacterial host defense. We discovered that the adaptive immune response against Staphylococcus aureus (SA) skin infection substantially improved systemic host defense against secondary SA infections in mice. Moreover, this acquired protection depended on IgE effector mechanisms and MCs. Importantly, our results reveal a previously unknown physiological function of allergic immune responses, IgE antibodies, and MCs in host defense against a pathogenic bacterium.
Collapse
|
11
|
Hu B, Berkey C, Feliciano T, Chen X, Li Z, Chen C, Amini S, Nai MH, Lei QL, Ni R, Wang J, Leow WR, Pan S, Li YQ, Cai P, Miserez A, Li S, Lim CT, Wu YL, Odom TW, Dauskardt RH, Chen X. Thermal-Disrupting Interface Mitigates Intercellular Cohesion Loss for Accurate Topical Antibacterial Therapy. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1907030. [PMID: 32072703 PMCID: PMC7702719 DOI: 10.1002/adma.201907030] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 01/12/2020] [Indexed: 05/10/2023]
Abstract
Bacterial infections remain a leading threat to global health because of the misuse of antibiotics and the rise in drug-resistant pathogens. Although several strategies such as photothermal therapy and magneto-thermal therapy can suppress bacterial infections, excessive heat often damages host cells and lengthens the healing time. Here, a localized thermal managing strategy, thermal-disrupting interface induced mitigation (TRIM), is reported, to minimize intercellular cohesion loss for accurate antibacterial therapy. The TRIM dressing film is composed of alternative microscale arrangement of heat-responsive hydrogel regions and mechanical support regions, which enables the surface microtopography to have a significant effect on disrupting bacterial colonization upon infrared irradiation. The regulation of the interfacial contact to the attached skin confines the produced heat and minimizes the risk of skin damage during thermoablation. Quantitative mechanobiology studies demonstrate the TRIM dressing film with a critical dimension for surface features plays a critical role in maintaining intercellular cohesion of the epidermis during photothermal therapy. Finally, endowing wound dressing with the TRIM effect via in vivo studies in S. aureus infected mice demonstrates a promising strategy for mitigating the side effects of photothermal therapy against a wide spectrum of bacterial infections, promoting future biointerface design for antibacterial therapy.
Collapse
Affiliation(s)
- Benhui Hu
- Key Laboratory of Clinical and Medical Engineering, School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, 211166, P. R. China
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Christopher Berkey
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Timothy Feliciano
- Department of Materials Science and Engineering and Department of Chemistry, Northwestern University, Evanston, IL, 60208, USA
| | - Xiaohong Chen
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Xiamen University, Xiamen, Fujian, 361102, P. R. China
| | - Zhuyun Li
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Chao Chen
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Shahrouz Amini
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Mui Hoon Nai
- Department of Biomedical Engineering, Mechanobiology Institute, Institute for Health Innovation and Technology (iHealthtech) National University of Singapore, 9 Engineering Drive 1, Singapore, 117576, Singapore
| | - Qun-Li Lei
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore
| | - Ran Ni
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore
| | - Juan Wang
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Wan Ru Leow
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Shaowu Pan
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Yong-Qiang Li
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Pingqiang Cai
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Ali Miserez
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Shuzhou Li
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Chwee Teck Lim
- Department of Biomedical Engineering, Mechanobiology Institute, Institute for Health Innovation and Technology (iHealthtech) National University of Singapore, 9 Engineering Drive 1, Singapore, 117576, Singapore
| | - Yun-Long Wu
- Fujian Provincial Key Laboratory of Innovative Drug Target Research and State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Xiamen University, Xiamen, Fujian, 361102, P. R. China
| | - Teri W Odom
- Department of Materials Science and Engineering and Department of Chemistry, Northwestern University, Evanston, IL, 60208, USA
| | - Reinhold H Dauskardt
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Xiaodong Chen
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| |
Collapse
|
12
|
Wuescher LM, Nishat S, Worth RG. Characterization of a transgenic mouse model of chronic conditional platelet depletion. Res Pract Thromb Haemost 2019; 3:704-712. [PMID: 31624790 PMCID: PMC6781920 DOI: 10.1002/rth2.12255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 08/10/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Platelets are widely recognized for their role in maintaining hemostasis. Recently, platelets have become appreciated for their varying roles in immunity, neuroprotection, and other physiological processes. While there are currently excellent methods to transiently deplete platelets and models of thrombocytopenia, studying the roles of platelets in chronic processes can be challenging. OBJECTIVE Phenotypic characterization of the PF4-DTR mouse model of conditional platelet depletion compared to antibody depletion. METHODS We describe the ability of the PF4-DTR mouse to maintain chronic platelet depletion, along with examining the bleeding phenotype compared to antibody-mediated platelet depletion. RESULTS Systemic administration of diphtheria toxin resulted in >99% platelet depletion that can be maintained for >2 weeks. When compared to an antibody depletion model, PF4-DTR mice showed similar phenotypes when challenged with tail bleed and saphenous vein measurements of hemostasis. Mice depleted with diphtheria toxin were also able to undergo adoptive transfer of platelets. If the frequency and amount of diphtheria toxin is reduced, mice can be maintained at >40% depletion for >28 days, showing that this model is tunable. CONCLUSIONS When compared to the gold standard of antibody-mediated depletion, PF4-DTR mice showed similar phenotypes and should be considered an important tool for examining the impact of thrombocytopenia over longer periods of time.
Collapse
Affiliation(s)
- Leah M. Wuescher
- Department of Medical Microbiology and ImmunologyUniversity of Toledo College of Medicine and Life SciencesToledoOhio
| | - Sharmeen Nishat
- Department of Medical Microbiology and ImmunologyUniversity of Toledo College of Medicine and Life SciencesToledoOhio
| | - Randall G. Worth
- Department of Medical Microbiology and ImmunologyUniversity of Toledo College of Medicine and Life SciencesToledoOhio
| |
Collapse
|
13
|
Efficacy of photoactivated Myrciaria cauliflora extract against Staphylococcus aureus infection – A pilot study. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2019; 191:107-115. [DOI: 10.1016/j.jphotobiol.2018.12.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 12/12/2018] [Accepted: 12/16/2018] [Indexed: 01/11/2023]
|
14
|
Gajenthra Kumar N, Contaifer D, Baker PRS, Ekroos K, Jefferson KK, Wijesinghe DS. Untargeted lipidomic analysis to broadly characterize the effects of pathogenic and non-pathogenic staphylococci on mammalian lipids. PLoS One 2018; 13:e0206606. [PMID: 30379915 PMCID: PMC6209338 DOI: 10.1371/journal.pone.0206606] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 10/16/2018] [Indexed: 11/19/2022] Open
Abstract
Modification of the host lipidome via secreted enzymes is an integral, but often overlooked aspect of bacterial pathogenesis. In the current era of prevalent antibiotic resistance, knowledge regarding critical host pathogen lipid interactions has the potential for use in developing novel antibacterial agents. While most studies to date on this matter have focused on specific lipids, or select lipid classes, this provides an incomplete picture. Modern methods of untargeted lipidomics have the capacity to overcome these gaps in knowledge and provide a comprehensive understanding of the role of lipid metabolism in the pathogenesis of infections. In an attempt to determine the role of lipid modifying enzymes produced by staphylococci, we exposed bovine heart lipids, a standardized model for the mammalian lipidome, to spent medium from staphylococcal cultures, and analyzed lipid molecular changes by MS/MSALL shotgun lipidomics. We elucidate distinct effects of different staphylococcal isolates, including 4 clinical isolates of the pathogenic species Staphylococcus aureus, a clinical isolate of the normally commensal species S. epidermidis, and the non-pathogenic species S. carnosus. Two highly virulent strains of S. aureus had a more profound effect on mammalian lipids and modified more lipid classes than the other staphylococcal strains. Our studies demonstrate the utility of the applied untargeted lipidomics methodology to profile lipid changes induced by different bacterial secretomes. Finally, we demonstrate the promise of this lipidomics approach in assessing the specificity of bacterial enzymes for mammalian lipid classes. Our data suggests that there may be a correlation between the bacterial expression of lipid-modifying enzymes and virulence, and could facilitate the guided discovery of lipid pathways required for bacterial infections caused by S. aureus and thereby provide insights into the generation of novel antibacterial agents.
Collapse
Affiliation(s)
- Naren Gajenthra Kumar
- Department of Microbiology and Immunology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Daniel Contaifer
- Department of Pharmacotherapy and Outcomes Sciences, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | | | - Kim Ekroos
- Lipidomics Consulting Ltd., Esbo, Finland
| | - Kimberly K. Jefferson
- Department of Microbiology and Immunology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Dayanjan S. Wijesinghe
- Department of Pharmacotherapy and Outcomes Sciences, School of Pharmacy, Virginia Commonwealth University, Richmond, Virginia, United States of America
| |
Collapse
|
15
|
Brady RA, Mocca CP, Plaut RD, Takeda K, Burns DL. Comparison of the immune response during acute and chronic Staphylococcus aureus infection. PLoS One 2018; 13:e0195342. [PMID: 29596507 PMCID: PMC5875981 DOI: 10.1371/journal.pone.0195342] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 03/20/2018] [Indexed: 01/15/2023] Open
Abstract
Staphylococcus aureus bacteria are able to grow in a planktonic state that is associated with acute infections and in biofilms that are associated with chronic infections. Acute infections, such as skin infections, are often self-limiting. However, chronic infections, such as implant infections, can be difficult to clear and may require surgical intervention. The host immune response may contribute to the different outcomes often associated with these two disease types. We used proteomic arrays and two murine models for an initial, descriptive characterization of the contribution of the host immune response to outcomes of acute versus chronic S. aureus disease. We compared the immune responses between a model of self-limiting skin and soft tissue infection caused by the planktonic form of S. aureus versus a model of surgical mesh implant infection, which we show to be caused by a bacterial biofilm. The significantly altered host cytokines and chemokines were largely different in the two models, with responses diminished by 21 days post-implantation in surgical mesh infection. Because bacterial levels remained constant during the 21 days that the surgical mesh infection was followed, those cytokines that are significantly increased during chronic infection are not likely effective in eradicating biofilm. Comparison of the levels of cytokines and chemokines in acute versus chronic S. aureus infection can provide a starting point for evaluation of the role of specific immune factors that are present in one disease manifestation but not the other.
Collapse
Affiliation(s)
- Rebecca A. Brady
- Division of Bacterial, Parasitic, and Allergenic Products, Center for Biologics Evaluation and Research, FDA, Silver Spring, Maryland, United States of America
- * E-mail:
| | - Christopher P. Mocca
- Division of Bacterial, Parasitic, and Allergenic Products, Center for Biologics Evaluation and Research, FDA, Silver Spring, Maryland, United States of America
| | - Roger D. Plaut
- Division of Bacterial, Parasitic, and Allergenic Products, Center for Biologics Evaluation and Research, FDA, Silver Spring, Maryland, United States of America
| | - Kazuyo Takeda
- Microscopy and Imaging Core Facility, Center for Biologics Evaluation and Research, FDA, Silver Spring, Maryland, United States of America
| | - Drusilla L. Burns
- Division of Bacterial, Parasitic, and Allergenic Products, Center for Biologics Evaluation and Research, FDA, Silver Spring, Maryland, United States of America
| |
Collapse
|
16
|
Burleson SCM, Freebern WJ, Burleson FG, Burleson GR, Johnson VJ, Luebke RW. Host Resistance Assays. Methods Mol Biol 2018; 1803:117-145. [PMID: 29882137 DOI: 10.1007/978-1-4939-8549-4_9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The goal of immunotoxicity testing is to obtain data useful for immunotoxicity safety assessment. Guidance in the performance of immunotoxicity safety evaluations is provided in documents from the US EPA for chemicals and the ICH S8 document for pharmaceuticals. The ICH S8 document outlines a tiered approach that includes (1) standard toxicity studies with associated hematology, immune system organ weights, and histopathology data; (2) functional assays, such as cytotoxic T lymphocyte (CTL) assays, natural killer (NK) cell assays, respiratory burst, phagocytosis, and T-cell-dependent antibody response (TDAR) assays; and (3) host resistance assays. Host resistance assays are considered the gold standard in immunotoxicity testing and provide a critical overview of the extent to which innate, adaptive, and homeostatic regulatory immune functions are integrated to protect the host. Both comprehensive and targeted host resistance assays are available, each with distinct advantages. This chapter serves to provide a general overview of the various assays that may be used, as well as a summary of procedures.
Collapse
Affiliation(s)
| | - Wendy Jo Freebern
- Bristol-Myers Squibb Company, Immunotoxicology, New Brunswick, NJ, USA
| | | | - Gary R Burleson
- Burleson Research Technologies, Inc. (BRT), Morrisville, NC, USA
| | - Victor J Johnson
- Burleson Research Technologies, Inc. (BRT), Morrisville, NC, USA
| | - Robert W Luebke
- United States Environmental Protection Agency, Cardiopulmonary and Immunotoxicology Branch, Environmental Public Health Division, National Health and Environmental Effects Laboratory, Office of Research and Development, Research Triangle Park, NC, USA.,Burleson Research Technologies, Inc., Morrisville, NC, USA
| |
Collapse
|
17
|
Abstract
The interleukin-17 (IL-17) family cytokines, such as IL-17A and IL-17F, play
important protective roles in host immune response to a variety of infections
such as bacterial, fungal, parasitic, and viral. The IL-17R signaling and
downstream pathways mediate induction of proinflammatory molecules which
participate in control of these pathogens. However, the production of IL-17 can
also mediate pathology and inflammation associated with infections. In this
review, we will discuss the yin-and-yang roles of IL-17 in host immunity to
pathogens.
Collapse
Affiliation(s)
- Shibali Das
- Department of Molecular Microbiology, Washington University in St. Louis, St Louis, MO, USA
| | - Shabaana Khader
- Department of Molecular Microbiology, Washington University in St. Louis, St Louis, MO, USA
| |
Collapse
|
18
|
Kaur S, Harjai K, Chhibber S. In Vivo Assessment of Phage and Linezolid Based Implant Coatings for Treatment of Methicillin Resistant S. aureus (MRSA) Mediated Orthopaedic Device Related Infections. PLoS One 2016; 11:e0157626. [PMID: 27333300 PMCID: PMC4917197 DOI: 10.1371/journal.pone.0157626] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 06/02/2016] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus comprises up to two-thirds of all pathogens in orthopaedic implant infections with two species respectively Staphylococcus aureus and Staphylococcus epidermidis, being the predominate etiological agents isolated. Further, with the emergence of methicillin-resistant S. aureus (MRSA), treatment of S. aureus implant infections has become more difficult, thus representing a devastating complication. Use of local delivery system consisting of S.aureus specific phage along with linezolid (incorporated in biopolymer) allowing gradual release of the two agents at the implant site represents a new, still unexplored treatment option (against orthopaedic implant infections) that has been studied in an animal model of prosthetic joint infection. Naked wire, hydroxypropyl methylcellulose (HPMC) coated wire and phage and /or linezolid coated K-wire were surgically implanted into the intra-medullary canal of mouse femur bone of respective groups followed by inoculation of S.aureus ATCC 43300(MRSA). Mice implanted with K-wire coated with both the agents i.e phage as well as linezolid (dual coated wires) showed maximum reduction in bacterial adherence, associated inflammation of the joint as well as faster resumption of locomotion and motor function of the limb. Also, all the coating treatments showed no emergence of resistant mutants. Use of dual coated implants incorporating lytic phage (capable of self-multiplication) as well as linezolid presents an attractive and aggressive early approach in preventing as well as treating implant associated infections caused by methicillin resistant S. aureus strains as assessed in a murine model of experimental joint infection.
Collapse
Affiliation(s)
- Sandeep Kaur
- Department of Microbiology, Panjab University, Chandigarh-160014, India
| | - Kusum Harjai
- Department of Microbiology, Panjab University, Chandigarh-160014, India
| | - Sanjay Chhibber
- Department of Microbiology, Panjab University, Chandigarh-160014, India
- * E-mail:
| |
Collapse
|
19
|
Arunachalam K, Ascêncio SD, Soares IM, Souza Aguiar RW, da Silva LI, de Oliveira RG, Balogun SO, de Oliveira Martins DT. Gallesia integrifolia (Spreng.) Harms: In vitro and in vivo antibacterial activities and mode of action. JOURNAL OF ETHNOPHARMACOLOGY 2016; 184:128-137. [PMID: 26945980 DOI: 10.1016/j.jep.2016.03.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 02/16/2016] [Accepted: 03/01/2016] [Indexed: 06/05/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Gallesia integrifolia (Phytolaccaceae) is commonly known as "pau-d'alho" in Brazil or "garlic plant" due to the strong scent of garlic peculiar to all parts of the plant. The bark decoction is used for the treatment of microbial infections among other diseases by different ethnic groups in Brazil, Peruvian Amazonians, Bolivia and Mosetene Indians. This study aimed to advance in the antibacterial activity and characterize the mode of action of the hydroethanolic extract of the inner stem bark of G. integrifolia (HEGi) using in vivo and in vitro experimental models. MATERIALS AND METHODS The qualitative and quantitative phytochemical analyzes of HEGi were carried out using colorimetric and HPLC technique. The cytotoxic potential of HEGi was evaluated against CHO-K1 cells by Alamar blue assay and its acute toxicity was assessed by the Hippocratic screening test using Swiss-Webster mice. The antibacterial activity was evaluated by micro- dilution method against ten strains of Gram-positive and Gram-negative bacteria. The mode of action of HEGi was investigated by outer membrane permeability, nucleotide leakage and potassium efflux assays. In vivo infection model was established by using Staphylococcus aureus infection model Wistar rats. RESULTS Qualitative phytochemical analysis of HEGi revealed the presence of saponins, alkaloids, phenolic compounds and flavonoids. Phytochemical quantification of HEGi showed that higher total phenolic (80.10±0.62mg GAE/g) and flavonoid (16.10±0.03mg RE/g) contents. HPLC fingerprint analysis revealed the presence of gallic acid, rutin, and morin. In the Alamar blue assay no cytotoxic effect of HEGi in CHO-K1 cells was observed up to 200µg/mL, and no signs or symptoms of acute toxicity were observed in mice of both sexes at higher doses of up to 2000mg/kg, p.o. HEGi demonstrated bacteriostatic effect against selected Gram positive and Gram negative bacterial pathogens. Its mode of action is associated, at least partly, with changes in the permeability of bacterial membranes, evidenced by the increased entry of hydrophobic antibiotic in Pseudomonas aeruginosa, intense K(+) efflux and nucleotides leakage in Shigella flexneri, Streptococcus pyogenes and S. aureus. HEGi attenuated the experimental blood borne S. aureus infection in rats at all the tested doses levels (10, 50 and 250mg/kg). CONCLUSION HEGi is safe at the dose tested when used acutely, and it presented broad antibacterial effect, which support its traditional use in the treatment of bacterial infections. It contains well known important phytochemicals, recognized to be active against bacterial pathogens in vitro and might be collectively responsible for the antibacterial activity of HEGi. It is bacteriostatic in nature, with membrane perturbation being one of it mode of action. HEGi represent a potential phytotherapic antibacterial agent.
Collapse
Affiliation(s)
- Karuppusamy Arunachalam
- Department of Basic Sciences in Health, Faculty of Medicine, Federal University of Mato Grosso (UFMT), Av. Fernando Correa da Costa, no. 2367, Coxipó, Cuiabá, Mato Grosso 78060-900, Brazil
| | - Sérgio Donizeti Ascêncio
- Research Laboratory of Natural Products, Federal University of Tocantins, Faculty of Medicine, Palmas, Tocantins 77020-210, Brazil
| | - Ilsamar Mendes Soares
- Research Laboratory of Natural Products, Federal University of Tocantins, Faculty of Medicine, Palmas, Tocantins 77020-210, Brazil
| | | | - Larissa Irene da Silva
- Department of Basic Sciences in Health, Faculty of Medicine, Federal University of Mato Grosso (UFMT), Av. Fernando Correa da Costa, no. 2367, Coxipó, Cuiabá, Mato Grosso 78060-900, Brazil
| | - Ruberlei Godinho de Oliveira
- Department of Basic Sciences in Health, Faculty of Medicine, Federal University of Mato Grosso (UFMT), Av. Fernando Correa da Costa, no. 2367, Coxipó, Cuiabá, Mato Grosso 78060-900, Brazil
| | - Sikiru Olaitan Balogun
- Department of Basic Sciences in Health, Faculty of Medicine, Federal University of Mato Grosso (UFMT), Av. Fernando Correa da Costa, no. 2367, Coxipó, Cuiabá, Mato Grosso 78060-900, Brazil
| | - Domingos Tabajara de Oliveira Martins
- Department of Basic Sciences in Health, Faculty of Medicine, Federal University of Mato Grosso (UFMT), Av. Fernando Correa da Costa, no. 2367, Coxipó, Cuiabá, Mato Grosso 78060-900, Brazil.
| |
Collapse
|
20
|
Morisaki A, Hosono M, Murakami T, Sakaguchi M, Suehiro Y, Nishimura S, Sakon Y, Yasumizu D, Kawase T, Shibata T. Effect of negative pressure wound therapy followed by tissue flaps for deep sternal wound infection after cardiovascular surgery: propensity score matching analysis. Interact Cardiovasc Thorac Surg 2016; 23:397-402. [PMID: 27199380 DOI: 10.1093/icvts/ivw141] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 04/19/2016] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVES Deep sternal wound infection (DSWI) after cardiovascular surgery via median sternotomy remains a severe complication associated with a drastic decrease in the quality of life. We assessed the risk factors for in-hospital death caused by DSWI and the available treatments for DSWI. METHODS Between January 1991 and August 2015, we retrospectively reviewed 73 patients (51 males and 22 females, mean age 67.5 ± 10.3 years) who developed DSWI after cardiovascular surgery via median sternotomy. Pathogenic bacteria mainly comprised methicillin-resistant Staphylococcus aureus (MRSA) (49.3%). Fifteen patients (20.5%) died in hospital with DSWI. Treatment of DSWI consisted of open daily irrigation (up to 2006) or negative pressure wound therapy (NPWT) (2007 onwards), followed by primary closure or reconstruction of tissue flaps. We assessed the risk factors for in-hospital mortality from DSWI by comparing data from the 15 patients who died and the 58 survivors using propensity score matching analysis of the treatments used for DSWI. RESULTS Univariate analysis identified age, use of intra-aortic balloon pumping, prolonged mechanical ventilation, tracheotomy, prolonged intensive care unit stay, postoperative low output syndrome, postoperative myocardial infarction, postoperative renal failure, postoperative use of haemodialysis, postoperative pneumonia, postoperative cerebral disorder, MRSA infection, NPWT and tissue flaps as being associated with in-hospital mortality (P < 0.05). Multivariate analysis identified NPWT (odds ratio, 0.062; 95% confidence interval, 0.004-0.897; P = 0.041) and tissue flaps (odds ratio, 0.022; 95% confidence interval, 0.000-0.960; P = 0.048) as independently associated with reduced in-hospital mortality after DSWI. On comparing 22 patients receiving NPWT with 22 not on NPWT using propensity score matching, patients on NPWT had significantly lower in-hospital mortality than those without NPWT (NPWT vs non-NPWT, 5 vs 36%, P = 0.021). In DSWI infected by MRSA, NPWT significantly reduced the in-hospital mortality caused by DSWI (NPWT vs non-NPWT, 0 vs 52%, P = 0.003). CONCLUSIONS NPWT and tissue flaps may be favourable factors associated with reduced in-hospital mortality attributable to DSWI. NPWT as a bridge therapy to tissue flaps may play a major role in treating DSWI and improve the prognosis for patients with MRSA-infected DSWI.
Collapse
Affiliation(s)
- Akimasa Morisaki
- Department of Cardiovascular Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Mitsuharu Hosono
- Department of Cardiovascular Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Takashi Murakami
- Department of Cardiovascular Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Masanori Sakaguchi
- Department of Cardiovascular Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Yasuo Suehiro
- Department of Cardiovascular Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Shinsuke Nishimura
- Department of Cardiovascular Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Yoshito Sakon
- Department of Cardiovascular Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Daisuke Yasumizu
- Department of Cardiovascular Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Takumi Kawase
- Department of Cardiovascular Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Toshihiko Shibata
- Department of Cardiovascular Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan
| |
Collapse
|
21
|
Importance of B Lymphocytes and the IgG-Binding Protein Sbi in Staphylococcus aureus Skin Infection. Pathogens 2016; 5:pathogens5010012. [PMID: 26828524 PMCID: PMC4810133 DOI: 10.3390/pathogens5010012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 01/19/2016] [Accepted: 01/21/2016] [Indexed: 12/31/2022] Open
Abstract
Recurrent Staphylococcus aureus infections are common, suggesting that immunity elicited by these infections is not protective. We previously reported that S. aureus skin infection (SSTI) elicited antibody-mediated immunity against secondary SSTI in BALB/c mice. In this study, we investigated the role of humoral immunity and the IgG-binding proteins Sbi and SpA in S. aureus SSTI. We found that B lymphocyte-deficient μMT mice were highly susceptible to infection, compared with congenic BALB/c mice. Importantly, transfer of immune serum protected μMT mice, demonstrating an appropriate response to protective antibody. We found that deletion of sbi, but not spa, impaired virulence, as assessed by skin lesion severity, and that Sbi-mediated virulence required B lymphocytes/antibody. Furthermore, neither Sbi nor SpA impaired the elicited antibody response or protection against secondary SSTI. Taken together, these findings highlight a B lymphocyte/antibody-dependent role of Sbi in the pathogenesis of S. aureus SSTI, and demonstrate that neither Sbi nor SpA interfered with elicited antibody-mediated immunity.
Collapse
|
22
|
Abstract
PURPOSE OF REVIEW Staphylococcus aureus is the most common cause of skin and soft tissue infections (SSTI) in the United States and elsewhere. Recurrent infections occur frequently in patients with S. aureus SSTI, underscoring the need to better understand the nature of protective immunity against these infections. Here, we review recent findings concerning the host factors that predispose to S. aureus SSTI. RECENT FINDINGS Recurrent infections occur in nearly half of all patients with S. aureus SSTI. Epidemiologic and environmental factors, such as exposure to healthcare, age, and household contacts with S. aureus SSTI, and contaminated household fomites are associated with recurrence. The majority of the population has evidence of antistaphylococcal antibodies, but whether these are protective remains enigmatic. In contrast, recent clinical and experimental findings clearly highlight the critical roles of innate and T cell-mediated immunity in defense against these infections. S. aureus interferes with innate and adaptive immunity by a number of recently elucidated mechanisms. SUMMARY Recurrent S. aureus SSTIs are common, suggesting incomplete or absent protective immunity among these patients. Our understanding of protective immunity against recurrent infections is incomplete, and further basic and translational investigation is urgently needed to design strategies to prevent and treat these infections.
Collapse
|
23
|
Chan LC, Chaili S, Filler SG, Barr K, Wang H, Kupferwasser D, Edwards JE, Xiong YQ, Ibrahim AS, Miller LS, Schmidt CS, Hennessey JP, Yeaman MR. Nonredundant Roles of Interleukin-17A (IL-17A) and IL-22 in Murine Host Defense against Cutaneous and Hematogenous Infection Due to Methicillin-Resistant Staphylococcus aureus. Infect Immun 2015; 83:4427-37. [PMID: 26351278 PMCID: PMC4598415 DOI: 10.1128/iai.01061-15] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 08/28/2015] [Indexed: 12/12/2022] Open
Abstract
Staphylococcus aureus is the leading cause of skin and skin structure infections (SSSI) in humans. Moreover, the high frequency of recurring SSSI due to S. aureus, particularly methicillin-resistant S. aureus (MRSA) strains, suggests that infection induces suboptimal anamnestic defenses. The present study addresses the hypothesis that interleukin-17A (IL-17A) and IL-22 play distinct roles in immunity to cutaneous and invasive MRSA infection in a mouse model of SSSI. Mice were treated with specific neutralizing antibodies against IL-17A and/or IL-22 and infected with MRSA, after which the severity of infection and host immune response were determined. Neutralization of either IL-17A or IL-22 reduced T cell and neutrophil infiltration and host defense peptide elaboration in lesions. These events corresponded with increased abscess severity, MRSA viability, and CFU density in skin. Interestingly, combined inhibition of IL-17A and IL-22 did not worsen abscesses but did increase gamma interferon (IFN-γ) expression at these sites. The inhibition of IL-22 led to a reduction in IL-17A expression, but not vice versa. These results suggest that the expression of IL-17A is at least partially dependent on IL-22 in this model. Inhibition of IL-17A but not IL-22 led to hematogenous dissemination to kidneys, which correlated with decreased T cell infiltration in renal tissue. Collectively, these findings indicate that IL-17A and IL-22 have complementary but nonredundant roles in host defense against cutaneous versus hematogenous infection. These insights may support targeted immune enhancement or other novel approaches to address the challenge of MRSA infection.
Collapse
Affiliation(s)
- Liana C Chan
- Division of Molecular Medicine, Harbor-UCLA Medical Center, Torrance, California, USA St. John's Cardiovascular Research Center, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Siyang Chaili
- Division of Infectious Diseases, Harbor-UCLA Medical Center, Torrance, California, USA St. John's Cardiovascular Research Center, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Scott G Filler
- Division of Infectious Diseases, Harbor-UCLA Medical Center, Torrance, California, USA St. John's Cardiovascular Research Center, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, USA Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Kevin Barr
- Division of Molecular Medicine, Harbor-UCLA Medical Center, Torrance, California, USA
| | - Huiyuan Wang
- Division of Molecular Medicine, Harbor-UCLA Medical Center, Torrance, California, USA
| | - Deborah Kupferwasser
- Division of Molecular Medicine, Harbor-UCLA Medical Center, Torrance, California, USA
| | - John E Edwards
- Division of Infectious Diseases, Harbor-UCLA Medical Center, Torrance, California, USA St. John's Cardiovascular Research Center, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, USA Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Yan Q Xiong
- Division of Infectious Diseases, Harbor-UCLA Medical Center, Torrance, California, USA St. John's Cardiovascular Research Center, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, USA Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Ashraf S Ibrahim
- Division of Infectious Diseases, Harbor-UCLA Medical Center, Torrance, California, USA St. John's Cardiovascular Research Center, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, USA Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Lloyd S Miller
- Department of Dermatology, Johns Hopkins University, Baltimore, Maryland, USA
| | | | | | - Michael R Yeaman
- Division of Molecular Medicine, Harbor-UCLA Medical Center, Torrance, California, USA Division of Infectious Diseases, Harbor-UCLA Medical Center, Torrance, California, USA St. John's Cardiovascular Research Center, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, USA Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| |
Collapse
|
24
|
The adherens junctions control susceptibility to Staphylococcus aureus α-toxin. Proc Natl Acad Sci U S A 2015; 112:14337-42. [PMID: 26489655 DOI: 10.1073/pnas.1510265112] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus is both a transient skin colonizer and a formidable human pathogen, ranking among the leading causes of skin and soft tissue infections as well as severe pneumonia. The secreted bacterial α-toxin is essential for S. aureus virulence in these epithelial diseases. To discover host cellular factors required for α-toxin cytotoxicity, we conducted a genetic screen using mutagenized haploid human cells. Our screen identified a cytoplasmic member of the adherens junctions, plekstrin-homology domain containing protein 7 (PLEKHA7), as the second most significantly enriched gene after the known α-toxin receptor, a disintegrin and metalloprotease 10 (ADAM10). Here we report a new, unexpected role for PLEKHA7 and several components of cellular adherens junctions in controlling susceptibility to S. aureus α-toxin. We find that despite being injured by α-toxin pore formation, PLEKHA7 knockout cells recover after intoxication. By infecting PLEKHA7(-/-) mice with methicillin-resistant S. aureus USA300 LAC strain, we demonstrate that this junctional protein controls disease severity in both skin infection and lethal S. aureus pneumonia. Our results suggest that adherens junctions actively control cellular responses to a potent pore-forming bacterial toxin and identify PLEKHA7 as a potential nonessential host target to reduce S. aureus virulence during epithelial infections.
Collapse
|
25
|
Ito K, Saito A, Fujie T, Nishiwaki K, Miyazaki H, Kinoshita M, Saitoh D, Ohtsubo S, Takeoka S. Sustainable antimicrobial effect of silver sulfadiazine-loaded nanosheets on infection in a mouse model of partial-thickness burn injury. Acta Biomater 2015; 24:87-95. [PMID: 26079191 DOI: 10.1016/j.actbio.2015.05.035] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 05/21/2015] [Accepted: 05/27/2015] [Indexed: 01/01/2023]
Abstract
Partial-thickness burn injury has the potential for reepithelialization and heals within 3weeks. If the wound is infected by bacteria before reepithelization, however, the depth of disruption increases and the lesion easily progresses to the full-thickness dermal layers. In the treatment of partial-thickness burn injury, it is important to prevent the wound area from bacterial infection with an antimicrobial dressing. Here, we have tested the antimicrobial properties of polymeric ultra-thin films composed of poly(lactic acid) (termed "PLA nanosheets"), which have high flexibility, adhesive strength and transparency, and silver sulfadiazine (AgSD), which exhibits antimicrobial efficacy. The AgSD-loaded nanosheet released Ag(+) for more than 3days, and exerted antimicrobial efficacy against methicillin-resistant Staphylococcus aureus (MRSA) in an in vitro Kirby-Bauer test. By contrast, a cell viability assay indicated that the dose of AgSD used in the PLA nanosheets did not show significant cytotoxicity toward fibroblasts. In vivo evaluation using a mouse model of infection in a partial-thickness burn wound demonstrated that the nanosheet significantly reduced the number of MRSA bacteria on the lesion (more than 10(5)-fold) and suppressed the inflammatory reaction, thereby preventing a protracted wound healing process.
Collapse
|
26
|
Proteomic Identification of saeRS-Dependent Targets Critical for Protective Humoral Immunity against Staphylococcus aureus Skin Infection. Infect Immun 2015; 83:3712-21. [PMID: 26169277 DOI: 10.1128/iai.00667-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 07/05/2015] [Indexed: 12/16/2022] Open
Abstract
Recurrent Staphylococcus aureus skin and soft tissue infections (SSTIs) are common despite detectable antibody responses, leading to the belief that the immune response elicited by these infections is not protective. We recently reported that S. aureus USA300 SSTI elicits antibodies that protect against recurrent SSTI in BALB/c but not C57BL/6 mice, and in this study, we aimed to uncover the specificity of the protective antibodies. Using a proteomic approach, we found that S. aureus SSTI elicited broad polyclonal antibody responses in both BALB/c and C57BL/6 mice and identified 10 S. aureus antigens against which antibody levels were significantly higher in immune BALB/c serum. Four of the 10 antigens identified are regulated by the saeRS operon, suggesting a dominant role for saeRS in protection. Indeed, infection with USA300Δsae failed to protect against secondary SSTI with USA300, despite eliciting a strong polyclonal antibody response against antigens whose expression is not regulated by saeRS. Moreover, the antibody repertoire after infection with USA300Δsae lacked antibodies specific for 10 saeRS-regulated antigens, suggesting that all or a subset of these antigens are necessary to elicit protective immunity. Infection with USA300Δhla elicited modest protection against secondary SSTI, and complementation of USA300Δsae with hla restored protection but incompletely. Together, these findings support a role for both Hla and other saeRS-regulated antigens in eliciting protection and suggest that host differences in immune responses to saeRS-regulated antigens may determine whether S. aureus infection elicits protective or nonprotective immunity against recurrent infection.
Collapse
|
27
|
RNA-Seq Analysis of the Host Response to Staphylococcus aureus Skin and Soft Tissue Infection in a Mouse Model. PLoS One 2015; 10:e0124877. [PMID: 25901897 PMCID: PMC4406450 DOI: 10.1371/journal.pone.0124877] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 03/18/2015] [Indexed: 12/30/2022] Open
Abstract
Staphylococcus aureus is a leading cause of skin and soft tissue infections (SSTI), which are primarily self-limiting. We conducted a comprehensive analysis of the host transcriptome during a S. aureus SSTI to provide insight on the protective mechanisms that thwart these infections. We utilized a murine SSTI model in which one ear is epicutaneously challenged while the other is not. We then harvested these infected and uninfected ears, as well as ears from naïve mice, at one, four, and seven days post-challenge, and performed RNA sequencing (RNA-seq) using the Illumina platform. RNA-seq data demonstrated a robust response at the site of infection. Comparison of gene expression profiles between infected ears and the non-infected ears of challenged mice defined the local response to infection, while comparisons of expression profiles of non-infected ears from challenged mice to ears of naïve mice revealed changes in gene expression levels away from the site indicative of a systemic response. Over 1000 genes exhibited increased expression locally at all tested time points. The local response was more robust than the systemic response. Through evaluation of the RNA-seq data using the Upstream Regulator Analytic as part of the Ingenuity Pathway Analysis software package, we found that changes in the activation and inhibition of regulatory pathways happen first locally, and lag behind systemically. The activated pathways are highly similar at all three time points during SSTI, suggesting a stable global response over time. Transcript increases and pathway activation involve pro- and anti-inflammatory mediators, chemotaxis, cell signaling, keratins, and TH1/TH17 cytokines. Transcript decreases and pathway inhibition demonstrate that metabolic genes and anti-inflammatory pathways are repressed. These data provide insight on the host responses that may aid in resolution of this self-limited S. aureus infection, and may shed light on potential immune correlates of protection for staphylococcal SSTI.
Collapse
|
28
|
Kobayashi SD, Malachowa N, DeLeo FR. Pathogenesis of Staphylococcus aureus abscesses. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:1518-27. [PMID: 25749135 DOI: 10.1016/j.ajpath.2014.11.030] [Citation(s) in RCA: 178] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 11/13/2014] [Accepted: 11/21/2014] [Indexed: 01/06/2023]
Abstract
Staphylococcus aureus causes many types of human infections and syndromes-most notably skin and soft tissue infections. Abscesses are a frequent manifestation of S. aureus skin and soft tissue infections and are formed, in part, to contain the nidus of infection. Polymorphonuclear leukocytes (neutrophils) are the primary cellular host defense against S. aureus infections and a major component of S. aureus abscesses. These host cells contain and produce many antimicrobial agents that are effective at killing bacteria, but can also cause non-specific damage to host tissues and contribute to the formation of abscesses. By comparison, S. aureus produces several molecules that also contribute to the formation of abscesses. Such molecules include those that recruit neutrophils, cause host cell lysis, and are involved in the formation of the fibrin capsule surrounding the abscess. Herein, we review our current knowledge of the mechanisms and processes underlying the formation of S. aureus abscesses, including the involvement of polymorphonuclear leukocytes, and provide a brief overview of therapeutic approaches.
Collapse
Affiliation(s)
- Scott D Kobayashi
- Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana
| | - Natalia Malachowa
- Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana
| | - Frank R DeLeo
- Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana.
| |
Collapse
|
29
|
Oscherwitz J, Cease KB. Identification and validation of a linear protective neutralizing epitope in the β-pore domain of alpha toxin. PLoS One 2015; 10:e0116882. [PMID: 25635901 PMCID: PMC4311967 DOI: 10.1371/journal.pone.0116882] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 12/16/2014] [Indexed: 02/07/2023] Open
Abstract
The plethora of virulence factors associated with Staphylococcus aureus make this bacterium an attractive candidate for a molecularly-designed epitope-focused vaccine. This approach, which necessitates the identification of neutralizing epitopes for incorporation into a vaccine construct, is being evaluated for pathogens where conventional approaches have failed to elicit protective humoral responses, like HIV-1 and malaria, but may also hold promise for pathogens like S. aureus, where the elicitation of humoral immunity against multiple virulence factors may be required for development of an effective vaccine. Among the virulence factors employed by S. aureus, animal model and epidemiological data suggest that alpha toxin, a multimeric β-pore forming toxin like protective antigen from Bacillus anthracis, is particularly critical, yet no candidate neutralizing epitopes have been delineated in alpha toxin to date. We have previously shown that a linear determinant in the 2β2-2β3 loop of the pore forming domain of B. anthracis protective antigen is a linear neutralizing epitope. Antibody against this site is highly potent for neutralizing anthrax lethal toxin in vitro and for protection of rabbits in vivo from virulent B. anthracis. We hypothesized that sequences in the β-pore of S. aureus alpha toxin that share structural and functional homology to β-pore sequences in protective antigen would contain a similarly critical neutralizing epitope. Using an in vivo mapping strategy employing peptide immunogens, an optimized in vitro toxin neutralization assay, and an in vivo dermonecrosis model, we have now confirmed the presence of this epitope in alpha toxin, termed the pore neutralizing determinant. Antibody specific for this determinant neutralizes alpha toxin in vitro, and is highly effective for mitigating dermonecrosis and bacterial growth in a mouse model of S. aureus USA300 skin infection. The delineation of this linear neutralizing determinant in alpha toxin could facilitate the development of an epitope-focused vaccine against S. aureus.
Collapse
Affiliation(s)
- Jon Oscherwitz
- Division of Hematology-Oncology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, 48105, United States of America; VA Ann Arbor Healthcare System, 2215 Fuller Road, Ann Arbor, Michigan, 48105, United States of America
| | - Kemp B Cease
- Division of Hematology-Oncology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, 48105, United States of America; VA Ann Arbor Healthcare System, 2215 Fuller Road, Ann Arbor, Michigan, 48105, United States of America
| |
Collapse
|
30
|
Tóth E, Huszár K, Bencsura P, Kulcsár PI, Vodicska B, Nyeste A, Welker Z, Tóth S, Welker E. Restriction enzyme body doubles and PCR cloning: on the general use of type IIs restriction enzymes for cloning. PLoS One 2014; 9:e90896. [PMID: 24618593 PMCID: PMC3949710 DOI: 10.1371/journal.pone.0090896] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 02/06/2014] [Indexed: 11/25/2022] Open
Abstract
The procedure described here allows the cloning of PCR fragments containing a recognition site of the restriction endonuclease (Type IIP) used for cloning in the sequence of the insert. A Type IIS endonuclease - a Body Double of the Type IIP enzyme - is used to generate the same protruding palindrome. Thus, the insert can be cloned to the Type IIP site of the vector without digesting the PCR product with the same Type IIP enzyme. We achieve this by incorporating the recognition site of a Type IIS restriction enzyme that cleaves the DNA outside of its recognition site in the PCR primer in such a way that the cutting positions straddle the desired overhang sequence. Digestion of the PCR product by the Body Double generates the required overhang. Hitherto the use of Type IIS restriction enzymes in cloning reactions has only been used for special applications, the approach presented here makes Type IIS enzymes as useful as Type IIP enzymes for general cloning purposes. To assist in finding Body Double enzymes, we summarised the available Type IIS enzymes which are potentially useful for Body Double cloning and created an online program (http://group.szbk.u-szeged.hu/welkergr/body_double/index.html) for the selection of suitable Body Double enzymes and the design of the appropriate primers.
Collapse
Affiliation(s)
- Eszter Tóth
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Krisztina Huszár
- Institute of Molecular Pharmacology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Petra Bencsura
- Institute of Molecular Pharmacology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Péter István Kulcsár
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Barbara Vodicska
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Antal Nyeste
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Zsombor Welker
- Institute of Molecular Pharmacology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Szilvia Tóth
- Institute of Molecular Pharmacology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Ervin Welker
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
- Institute of Molecular Pharmacology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
- * E-mail:
| |
Collapse
|
31
|
Role of antibodies in protection elicited by active vaccination with genetically inactivated alpha hemolysin in a mouse model of staphylococcus aureus skin and soft tissue infections. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2014; 21:622-7. [PMID: 24574539 DOI: 10.1128/cvi.00051-14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Due to the emergence of highly virulent community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections, S. aureus has become a major threat to public health. A majority of CA-MRSA skin and soft tissue infections in the United States are caused by S. aureus USA300 strains that are known to produce high levels of alpha hemolysin (Hla). Therefore, vaccines that contain inactivated forms of this toxin are currently being developed. In this study, we sought to determine the immune mechanisms of protection for this antigen using a vaccine composed of a genetically inactivated form of Hla (HlaH35L). Using a murine model of skin and soft tissue infections (SSTI), we found that BALB/c mice were protected by vaccination with HlaH35L; however, Jh mice, which are deficient in mature B lymphocytes and lack IgM and IgG in their serum, were not protected. Passive immunization with anti-HlaH35L antibodies conferred protection against bacterial colonization. Moreover, we found a positive correlation between the total antibody concentration induced by active vaccination and reduced bacterial levels. Animals that developed detectable neutralizing antibody titers after active vaccination were significantly protected from infection. These data demonstrate that antibodies to Hla represent the major mechanism of protection afforded by active vaccination with inactivated Hla in this murine model of SSTI, and in this disease model, antibody levels correlate with protection. These results provide important information for the future development and evaluation of S. aureus vaccines.
Collapse
|
32
|
Popov L, Kovalski J, Grandi G, Bagnoli F, Amieva MR. Three-Dimensional Human Skin Models to Understand Staphylococcus aureus Skin Colonization and Infection. Front Immunol 2014; 5:41. [PMID: 24567733 PMCID: PMC3915142 DOI: 10.3389/fimmu.2014.00041] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 01/23/2014] [Indexed: 01/23/2023] Open
Abstract
Staphylococcus aureus is both a major bacterial pathogen as well as a common member of the human skin microbiota. Due to its widespread prevalence as an asymptomatic skin colonizer and its importance as a source of skin and soft tissue infections, an improved understanding of how S. aureus attaches to, grows within, and breaches the stratified layers of the epidermis is of critical importance. Three-dimensional organotypic human skin culture models are informative and tractable experimental systems for future investigations of the interactions between S. aureus and the multi-faceted skin tissue. We propose that S. aureus virulence factors, primarily appreciated for their role in pathogenesis of invasive infections, play alternative roles in promoting asymptomatic bacterial growth within the skin. Experimental manipulations of these cultures will provide insight into the many poorly understood molecular interactions occurring at the interface between S. aureus and stratified human skin tissue.
Collapse
Affiliation(s)
- Lauren Popov
- Microbiology and Immunology, Stanford University School of Medicine , Stanford, CA , USA
| | - Joanna Kovalski
- Program in Epithelial Biology, Stanford University School of Medicine , Stanford, CA , USA
| | | | | | - Manuel R Amieva
- Microbiology and Immunology, Stanford University School of Medicine , Stanford, CA , USA ; Pediatrics, Stanford University School of Medicine , Stanford, CA , USA
| |
Collapse
|
33
|
Brady RA, Mocca CP, Prabhakara R, Plaut RD, Shirtliff ME, Merkel TJ, Burns DL. Evaluation of genetically inactivated alpha toxin for protection in multiple mouse models of Staphylococcus aureus infection. PLoS One 2013; 8:e63040. [PMID: 23658662 PMCID: PMC3639205 DOI: 10.1371/journal.pone.0063040] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 03/28/2013] [Indexed: 11/19/2022] Open
Abstract
Staphylococcus aureus is a major human pathogen and a leading cause of nosocomial and community-acquired infections. Development of a vaccine against this pathogen is an important goal. While S. aureus protective antigens have been identified in the literature, the majority have only been tested in a single animal model of disease. We wished to evaluate the ability of one S. aureus vaccine antigen to protect in multiple mouse models, thus assessing whether protection in one model translates to protection in other models encompassing the full breadth of infections the pathogen can cause. We chose to focus on genetically inactivated alpha toxin mutant HlaH35L. We evaluated the protection afforded by this antigen in three models of infection using the same vaccine dose, regimen, route of immunization, adjuvant, and challenge strain. When mice were immunized with HlaH35L and challenged via a skin and soft tissue infection model, HlaH35L immunization led to a less severe infection and decreased S. aureus levels at the challenge site when compared to controls. Challenge of HlaH35L-immunized mice using a systemic infection model resulted in a limited, but statistically significant decrease in bacterial colonization as compared to that observed with control mice. In contrast, in a prosthetic implant model of chronic biofilm infection, there was no significant difference in bacterial levels when compared to controls. These results demonstrate that vaccines may confer protection against one form of S. aureus disease without conferring protection against other disease presentations and thus underscore a significant challenge in S. aureus vaccine development.
Collapse
Affiliation(s)
- Rebecca A. Brady
- Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America
| | - Christopher P. Mocca
- Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America
| | - Ranjani Prabhakara
- Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America
| | - Roger D. Plaut
- Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America
| | - Mark E. Shirtliff
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, Maryland, United States of America
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Tod J. Merkel
- Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America
| | - Drusilla L. Burns
- Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America
- * E-mail:
| |
Collapse
|