51
|
Ménard G, Rouillon A, Ghukasyan G, Emily M, Felden B, Donnio PY. Galleria mellonella Larvae as an Infection Model to Investigate sRNA-Mediated Pathogenesis in Staphylococcus aureus. Front Cell Infect Microbiol 2021; 11:631710. [PMID: 33954118 PMCID: PMC8089379 DOI: 10.3389/fcimb.2021.631710] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 03/26/2021] [Indexed: 11/30/2022] Open
Abstract
Small regulatory RNAs (sRNAs) are key players in bacterial regulatory networks. Monitoring their expression inside living colonized or infected organisms is essential for identifying sRNA functions, but few studies have looked at sRNA expression during host infection with bacterial pathogens. Insufficient in vivo studies monitoring sRNA expression attest to the difficulties in collecting such data, we therefore developed a non-mammalian infection model using larval Galleria mellonella to analyze the roles of Staphylococcus aureus sRNAs during larval infection and to quickly determine possible sRNA involvement in staphylococcal virulence before proceeding to more complicated animal testing. We began by using the model to test infected larvae for immunohistochemical evidence of infection as well as host inflammatory responses over time. To monitor sRNA expression during infection, total RNAs were extracted from the larvae and invading bacteria at different time points. The expression profiles of the tested sRNAs were distinct and they fluctuated over time, with expression of both sprD and sprC increased during infection and associated with mortality, while rnaIII expression remained barely detectable over time. A strong correlation was observed between sprD expression and the mortality. To confirm these results, we used sRNA-knockout mutants to investigate sRNA involvement in Staphylococcus aureus pathogenesis, finding that the decrease in death rates is delayed when either sprD or sprC was lacking. These results demonstrate the relevance of this G. mellonella model for investigating the role of sRNAs as transcriptional regulators involved in staphylococcal virulence. This insect model provides a fast and easy method for monitoring sRNA (and mRNA) participation in S. aureus pathogenesis, and can also be used for other human bacterial pathogens.
Collapse
Affiliation(s)
- Guillaume Ménard
- Univ Rennes, CHU Rennes, INSERM, BRM [Bacterial Regulatory RNAs and Medicine], SB2H (service de Bactériologie Hygiène-Hospitalière), UMR_S 1230, F-35000, Rennes, France
| | - Astrid Rouillon
- Univ Rennes, INSERM, BRM (Bacterial Regulatory RNAs and Medicine), UMR_S 1230, F-35000, Rennes, France
| | - Gevorg Ghukasyan
- Univ Rennes, CNRS, INSERM, BIOSIT (Biologie, Santé, Innovation Technologique de Rennes), UMS 3480, US_S018, F-35000, Rennes, France
| | - Mathieu Emily
- Institut Agro, CNRS, Univ Rennes, IRMAR (Institut de recherche Mathématique de Rennes), UMR 6625, F-35000, Rennes, France
| | - Brice Felden
- Univ Rennes, INSERM, BRM (Bacterial Regulatory RNAs and Medicine), UMR_S 1230, F-35000, Rennes, France
| | - Pierre-Yves Donnio
- Univ Rennes, CHU Rennes, INSERM, BRM [Bacterial Regulatory RNAs and Medicine], SB2H (service de Bactériologie Hygiène-Hospitalière), UMR_S 1230, F-35000, Rennes, France
| |
Collapse
|
52
|
Kasela M, Grzegorczyk A, Nowakowicz-Dębek B, Malm A. The Prevalence of Virulence Determinants and Antibiotic Resistance Patterns in Methicillin-Resistant Staphylococcus aureus in a Nursing Home in Poland. Pathogens 2021; 10:pathogens10040427. [PMID: 33916758 PMCID: PMC8065860 DOI: 10.3390/pathogens10040427] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/30/2021] [Accepted: 03/31/2021] [Indexed: 11/16/2022] Open
Abstract
Nursing homes (NH) contribute to the regional spread of methicillin-resistant Staphylococcus aureus (MRSA). Moreover, residents are vulnerable to the colonization and subsequent infection of MRSA etiology. We aimed at investigating the molecular and phenotypic characteristics of 21 MRSA collected from the residents and personnel in an NH (Lublin, Poland) during 2018. All MRSA were screened for 20 genes encoding virulence determinants (sea-see, eta, etb, tst, lukS-F-PV, eno, cna, ebpS, fib, bbp, fnbA, fnbB, icaADBC) and for resistance to 18 antimicrobials. To establish the relatedness and clonal complexes of MRSA in NH we applied multiple-locus variable-number tandem-repeat fingerprinting (MLVF), pulse field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. We identified four sequence types (ST) among two clonal complexes (CC): ST (CC22) known as EMRSA-15 as well as three novel STs—ST6295 (CC8), ST6293 (CC8) and ST6294. All tested MRSA were negative for sec, eta, etb, lukS-F-PV, bbp and ebpS genes. The most prevalent gene encoding toxin was sed (52.4%; n = 11/21), and adhesins were eno and fnbA (100%). Only 9.5% (n = 2/21) of MRSA were classified as multidrug-resistant. The emergence of novel MRSA with a unique virulence and the presence of epidemic clone EMRSA-15 creates challenges for controlling the spread of MRSA in NH.
Collapse
Affiliation(s)
- Martyna Kasela
- Department of Pharmaceutical Microbiology, Medical University of Lublin, 20-093 Lublin, Poland; (A.G.); (A.M.)
- Correspondence:
| | - Agnieszka Grzegorczyk
- Department of Pharmaceutical Microbiology, Medical University of Lublin, 20-093 Lublin, Poland; (A.G.); (A.M.)
| | - Bożena Nowakowicz-Dębek
- Department of Animal Hygiene and Environmental Hazards, University of Life Sciences in Lublin, 20-950 Lublin, Poland;
| | - Anna Malm
- Department of Pharmaceutical Microbiology, Medical University of Lublin, 20-093 Lublin, Poland; (A.G.); (A.M.)
| |
Collapse
|
53
|
|
54
|
Staphylococcus aureus Trigger Factor Is Involved in Biofilm Formation and Cooperates with the Chaperone PpiB. J Bacteriol 2021; 203:JB.00681-20. [PMID: 33468596 DOI: 10.1128/jb.00681-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 01/07/2021] [Indexed: 12/18/2022] Open
Abstract
Peptidyl-prolyl cis/trans isomerases (PPIases) are enzymes that assist in protein folding around proline-peptide bonds, and they often possess chaperone activity. Staphylococcus aureus encodes three PPIases, i.e., PrsA, PpiB, and trigger factor (TF). Previous work by our group demonstrated a role for both PrsA and PpiB in S. aureus; however, TF remains largely unstudied. Here, we identify a role for TF in S. aureus biofilm formation and demonstrate cooperation between TF and the cytoplasmic PPIase PpiB. Mutation of the tig gene (encoding TF) led to reduced biofilm development in vitro but no significant attenuation of virulence in a mouse model of infection. To investigate whether TF possesses chaperone activity, we analyzed the ability of a tig mutant to survive acid and base stress. While there was no significant decrease for a tig mutant, a ppiB tig double mutant exhibited significant decreases in cell viability after acid and base challenges. We then demonstrated that a ppiB tig double mutant had exacerbated phenotypes in vitro and in vivo, compared to either single mutant. Finally, in vivo immunoprecipitation of epitope-tagged PpiB revealed that PpiB interacted with 4 times the number of proteins when TF was absent from the cell, suggesting that it may be compensating for the loss of TF. Interestingly, the only proteins found to interact with TF were TF itself, fibronectin-binding protein B (FnBPB), and the chaperone protein ClpB. Collectively, these results support the first phenotype for S. aureus TF and demonstrate a greater network of cooperation between chaperone proteins in Staphylococcus aureus IMPORTANCE S. aureus encodes a large number of virulence factors that aid the bacterium in survival and pathogenesis. These virulence factors have a wide variety of functions; however, they must all be properly secreted in order to be functional. Bacterial chaperone proteins often assist in secretion by trafficking proteins to secretion machinery or assisting in proper protein folding. Here, we report that the S. aureus chaperone TF contributes to biofilm formation and cooperates with the chaperone PpiB to regulate S. aureus virulence processes. These data highlight the first known role for TF in S. aureus and suggest that S. aureus chaperone proteins may be involved in a greater regulatory network in the cell.
Collapse
|
55
|
Brandenburg KS, Weaver AJ, Karna SLR, Leung KP. The impact of simultaneous inoculation of Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans on rodent burn wounds. Burns 2021; 47:1818-1832. [PMID: 33771422 DOI: 10.1016/j.burns.2021.02.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 01/13/2021] [Accepted: 02/18/2021] [Indexed: 12/27/2022]
Abstract
Burn wound infection often involves a diverse combination of bacterial and fungal pathogens. In this study, we characterize the mixed species burn wound infection by inoculating the burn surface with 1 × 103/4/5 CFU of Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans in a 1:1:1 ratio. Using the revised Walker-Mason scald burn rat model, 168 male Sprague-Dawley rats (350-450 g) subject to ∼10% TBSA burn injury, with or without inoculation, were evaluated for 11 days after burn. In the wound, P. aeruginosa and S. aureus formed robust biofilms as determined by the bacterial tissue load, ∼1 × 109 CFU/g, and expression of key biofilm genes. Interestingly, within 3 days C. albicans achieved tissue loads of ∼1 × 106 CFU/g, but its numbers were significantly reduced beyond the limit of detection in the burn wound by day 7 in partial-thickness injuries and by day 11 in full-thickness injuries. The pathogenic biofilms contributed to burn depth progression, increased release of HMGB-1 into circulation from injured tissue, and significantly elevated the numbers of circulating innate immune cells (Neutrophils, Monocytes, and Basophils). This robust model of multi-species burn wound infection will serve as the basis for the development of new antimicrobials for combating biofilm-based wound infections.
Collapse
Affiliation(s)
- Kenneth S Brandenburg
- Division of Combat Wound Repair, US Army Institute of Surgical Research, JBSA Fort Sam Houston, TX 78234, USA.
| | - Alan J Weaver
- Division of Combat Wound Repair, US Army Institute of Surgical Research, JBSA Fort Sam Houston, TX 78234, USA.
| | - S L Rajasekhar Karna
- Division of Combat Wound Repair, US Army Institute of Surgical Research, JBSA Fort Sam Houston, TX 78234, USA.
| | - Kai P Leung
- Division of Combat Wound Repair, US Army Institute of Surgical Research, JBSA Fort Sam Houston, TX 78234, USA.
| |
Collapse
|
56
|
de Morais SD, Kak G, Menousek JP, Kielian T. Immunopathogenesis of Craniotomy Infection and Niche-Specific Immune Responses to Biofilm. Front Immunol 2021; 12:625467. [PMID: 33708216 PMCID: PMC7940520 DOI: 10.3389/fimmu.2021.625467] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/05/2021] [Indexed: 02/06/2023] Open
Abstract
Bacterial infections in the central nervous system (CNS) can be life threatening and often impair neurological function. Biofilm infection is a complication following craniotomy, a neurosurgical procedure that involves the removal and replacement of a skull fragment (bone flap) to access the brain for surgical intervention. The incidence of infection following craniotomy ranges from 1% to 3% with approximately half caused by Staphylococcus aureus (S. aureus). These infections present a significant therapeutic challenge due to the antibiotic tolerance of biofilm and unique immune properties of the CNS. Previous studies have revealed a critical role for innate immune responses during S. aureus craniotomy infection. Experiments using knockout mouse models have highlighted the importance of the pattern recognition receptor Toll-like receptor 2 (TLR2) and its adaptor protein MyD88 for preventing S. aureus outgrowth during craniotomy biofilm infection. However, neither molecule affected bacterial burden in a mouse model of S. aureus brain abscess highlighting the distinctions between immune regulation of biofilm vs. planktonic infection in the CNS. Furthermore, the immune responses elicited during S. aureus craniotomy infection are distinct from biofilm infection in the periphery, emphasizing the critical role for niche-specific factors in dictating S. aureus biofilm-leukocyte crosstalk. In this review, we discuss the current knowledge concerning innate immunity to S. aureus craniotomy biofilm infection, compare this to S. aureus biofilm infection in the periphery, and discuss the importance of anatomical location in dictating how biofilm influences inflammatory responses and its impact on bacterial clearance.
Collapse
Affiliation(s)
- Sharon Db de Morais
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, United States
| | - Gunjan Kak
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, United States
| | - Joseph P Menousek
- Department of Neurosurgery, University of Nebraska Medical Center, Omaha, NE, United States
| | - Tammy Kielian
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, United States
| |
Collapse
|
57
|
Lee JW, Somerville T, Kaye SB, Romano V. Staphylococcus aureus Keratitis: Incidence, Pathophysiology, Risk Factors and Novel Strategies for Treatment. J Clin Med 2021; 10:jcm10040758. [PMID: 33668633 PMCID: PMC7918096 DOI: 10.3390/jcm10040758] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/09/2021] [Accepted: 02/09/2021] [Indexed: 02/07/2023] Open
Abstract
Bacterial keratitis is a devastating condition that can rapidly progress to serious complications if not treated promptly. Certain causative microorganisms such as Staphylococcus aureus and Pseudomonas aeruginosa are notorious for their resistance to antibiotics. Resistant bacterial keratitis results in poorer outcomes such as scarring and the need for surgical intervention. Thorough understanding of the causative pathogen and its virulence factors is vital for the discovery of novel treatments to avoid further antibiotic resistance. While much has been previously reported on P. aeruginosa, S. aureus has been less extensively studied. This review aims to give a brief overview of S. aureus epidemiology, pathophysiology and clinical characteristics as well as summarise the current evidence for potential novel therapies.
Collapse
Affiliation(s)
- Jason W. Lee
- School of Medicine, University of Liverpool, Liverpool L69 3GE, UK;
| | - Tobi Somerville
- Department of Eye and Vision Science, University of Liverpool, Liverpool L7 8TX, UK; (T.S.); (S.B.K.)
- St Paul’s Eye Unit, Royal Liverpool University Hospital, Liverpool L7 8XP, UK
| | - Stephen B. Kaye
- Department of Eye and Vision Science, University of Liverpool, Liverpool L7 8TX, UK; (T.S.); (S.B.K.)
- St Paul’s Eye Unit, Royal Liverpool University Hospital, Liverpool L7 8XP, UK
| | - Vito Romano
- Department of Eye and Vision Science, University of Liverpool, Liverpool L7 8TX, UK; (T.S.); (S.B.K.)
- St Paul’s Eye Unit, Royal Liverpool University Hospital, Liverpool L7 8XP, UK
- Correspondence:
| |
Collapse
|
58
|
Jorch SK, Deppermann C. Intravital Imaging Allows Organ-Specific Insights Into Immune Functions. Front Cell Dev Biol 2021; 9:623906. [PMID: 33644061 PMCID: PMC7905207 DOI: 10.3389/fcell.2021.623906] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/12/2021] [Indexed: 12/24/2022] Open
Abstract
Leukocytes are among the most mobile and versatile cells that have many essential functions in homeostasis and survival. Especially cells from the innate immune system, i.e., neutrophils and macrophages, play an important role as rapid first responders against invading microorganisms. With the advent of novel imaging techniques, new ways of visualizing innate immune cells have become available in recent years, thereby enabling more and more detailed discoveries about their nature, function and interaction partners. Besides intravital spinning-disc and 2-photon microscopy, clearing and 3D-imaging techniques provide new insights into the mechanism of innate immune cell behavior in their natural environment. This mini review focuses on the contributions of novel-imaging techniques to provide insight into the functions of neutrophils and macrophages under homeostasis and in infections. Imaging setups for different organs like the liver, kidney, heart, lung, and the peritoneal cavity are discussed as well as the current limitations of these imaging techniques.
Collapse
Affiliation(s)
- Selina K Jorch
- Institute of Experimental Immunology, University Hospital of Bonn, Rheinische Friedrich-Wilhelms Universität, Bonn, Germany
| | - Carsten Deppermann
- Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| |
Collapse
|
59
|
Zondervan NA, Martins Dos Santos VAP, Suarez-Diez M, Saccenti E. Phenotype and multi-omics comparison of Staphylococcus and Streptococcus uncovers pathogenic traits and predicts zoonotic potential. BMC Genomics 2021; 22:102. [PMID: 33541265 PMCID: PMC7860044 DOI: 10.1186/s12864-021-07388-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 01/13/2021] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Staphylococcus and Streptococcus species can cause many different diseases, ranging from mild skin infections to life-threatening necrotizing fasciitis. Both genera consist of commensal species that colonize the skin and nose of humans and animals, and of which some can display a pathogenic phenotype. RESULTS We compared 235 Staphylococcus and 315 Streptococcus genomes based on their protein domain content. We show the relationships between protein persistence and essentiality by integrating essentiality predictions from two metabolic models and essentiality measurements from six large-scale transposon mutagenesis experiments. We identified clusters of strains within species based on proteins associated to similar biological processes. We built Random Forest classifiers that predicted the zoonotic potential. Furthermore, we identified shared attributes between of Staphylococcus aureus and Streptococcus pyogenes that allow them to cause necrotizing fasciitis. CONCLUSIONS Differences observed in clustering of strains based on functional groups of proteins correlate with phenotypes such as host tropism, capability to infect multiple hosts and drug resistance. Our method provides a solid basis towards large-scale prediction of phenotypes based on genomic information.
Collapse
Affiliation(s)
- Niels A Zondervan
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708WE, Wageningen, Netherlands
| | - Vitor A P Martins Dos Santos
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708WE, Wageningen, Netherlands
- LifeGlimmer GmBH, Markelstraße 38, 12163, Berlin, Germany
| | - Maria Suarez-Diez
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708WE, Wageningen, Netherlands
| | - Edoardo Saccenti
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708WE, Wageningen, Netherlands.
| |
Collapse
|
60
|
Wang J, Zhang M, Wang M, Zang J, Zhang X, Hang T. Structural insights into the intermolecular interaction of the adhesin SdrC in the pathogenicity of Staphylococcus aureus. ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS 2021; 77:47-53. [PMID: 33620037 DOI: 10.1107/s2053230x21000741] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 01/21/2021] [Indexed: 11/10/2022]
Abstract
Staphylococcus aureus is an opportunistic disease-causing pathogen that is widely found in the community and on medical equipment. A series of virulence factors secreted by S. aureus can trigger severe diseases such as sepsis, endocarditis and toxic shock, and thus have a great impact on human health. The transformation of S. aureus from a colonization state to a pathogenic state during its life cycle is intimately associated with the initiation of bacterial aggregation and biofilm accumulation. SdrC, an S. aureus surface protein, can act as an adhesin to promote cell attachment and aggregation by an unknown mechanism. Here, structural studies demonstrate that SdrC forms a unique dimer through intermolecular interaction. It is proposed that the dimerization of SdrC enhances the efficiency of bacteria-host attachment and therefore contributes to the pathogenicity of S. aureus.
Collapse
Affiliation(s)
- Junchao Wang
- School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei, Anhui 230601, People's Republic of China
| | - Min Zhang
- School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei, Anhui 230601, People's Republic of China
| | - Mingzhu Wang
- Institute of Health Sciences and Technology, Anhui University, 111 Jiulong Road, Hefei, Anhui 230601, People's Republic of China
| | - Jianye Zang
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Center for Excellence in Biomacromolecules, Collaborative Innovation Center of Chemistry for Life Sciences and School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, People's Republic of China
| | - Xuan Zhang
- Hefei National Laboratory for Physical Sciences at Microscale, CAS Center for Excellence in Biomacromolecules, Collaborative Innovation Center of Chemistry for Life Sciences and School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, People's Republic of China
| | - Tianrong Hang
- School of Life Sciences, Anhui University, 111 Jiulong Road, Hefei, Anhui 230601, People's Republic of China
| |
Collapse
|
61
|
Pidwill GR, Gibson JF, Cole J, Renshaw SA, Foster SJ. The Role of Macrophages in Staphylococcus aureus Infection. Front Immunol 2021; 11:620339. [PMID: 33542723 PMCID: PMC7850989 DOI: 10.3389/fimmu.2020.620339] [Citation(s) in RCA: 119] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 12/02/2020] [Indexed: 12/23/2022] Open
Abstract
Staphylococcus aureus is a member of the human commensal microflora that exists, apparently benignly, at multiple sites on the host. However, as an opportunist pathogen it can also cause a range of serious diseases. This requires an ability to circumvent the innate immune system to establish an infection. Professional phagocytes, primarily macrophages and neutrophils, are key innate immune cells which interact with S. aureus, acting as gatekeepers to contain and resolve infection. Recent studies have highlighted the important roles of macrophages during S. aureus infections, using a wide array of killing mechanisms. In defense, S. aureus has evolved multiple strategies to survive within, manipulate and escape from macrophages, allowing them to not only subvert but also exploit this key element of our immune system. Macrophage-S. aureus interactions are multifaceted and have direct roles in infection outcome. In depth understanding of these host-pathogen interactions may be useful for future therapeutic developments. This review examines macrophage interactions with S. aureus throughout all stages of infection, with special emphasis on mechanisms that determine infection outcome.
Collapse
Affiliation(s)
- Grace R Pidwill
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom.,Florey Institute, University of Sheffield, Sheffield, United Kingdom
| | - Josie F Gibson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom.,Florey Institute, University of Sheffield, Sheffield, United Kingdom.,The Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Joby Cole
- Florey Institute, University of Sheffield, Sheffield, United Kingdom.,Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Stephen A Renshaw
- Florey Institute, University of Sheffield, Sheffield, United Kingdom.,The Bateson Centre, University of Sheffield, Sheffield, United Kingdom.,Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Simon J Foster
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom.,Florey Institute, University of Sheffield, Sheffield, United Kingdom
| |
Collapse
|
62
|
Andersson T, Bläckberg A, Lood R, Ertürk Bergdahl G. Development of a Molecular Imprinting-Based Surface Plasmon Resonance Biosensor for Rapid and Sensitive Detection of Staphylococcus aureus Alpha Hemolysin From Human Serum. Front Cell Infect Microbiol 2020; 10:571578. [PMID: 33330120 PMCID: PMC7715021 DOI: 10.3389/fcimb.2020.571578] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 10/26/2020] [Indexed: 12/12/2022] Open
Abstract
Stapylococcus aureus is a common infectious agent in e.g. sepsis, associated with both high mortality rates and severe long-term effects. The cytolytic protein α-hemolysin has repeatedly been shown to enhance the virulence of S. aureus. Combined with an unhindered spread of multi drug-resistant strains, this has triggered research into novel anti virulence (i.e. anti α-hemolysin) drugs. Their functionality will depend on our ability to identify infections that might be alleviated by such. We therefore saw a need for detection methods that could identify individuals suffering from S. aureus infections where α-hemolysin was a major determinant. Molecular imprinted polymers were subsequently prepared on gold coated sensor chips. Used in combination with a surface plasmon resonance biosensor, α-hemolysin could therethrough be quantified from septic blood samples (n = 9), without pre-culturing of the infectious agent. The biosensor recognized α-hemolysin with high affinity (KD = 2.75 x 10-7 M) and demonstrated a statistically significant difference (p < 0.0001) between the α-hemolysin response and potential sample contaminants. The detection scheme proved equally good, or better, when compared to antibody-based detection methods. This novel detection scheme constitutes a more rapid, economical, and user-friendly alternative to many methods currently in use. Heightening both reproducibility and sensitivity, molecular imprinting in combination with surface plasmon resonance (SPR)-technology could be a versatile new tool in clinical- and research-settings alike.
Collapse
Affiliation(s)
- Tilde Andersson
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Anna Bläckberg
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
- Department of Infection Medicine, Skåne University Hospital, Lund, Sweden
| | - Rolf Lood
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Gizem Ertürk Bergdahl
- Division of Infection Medicine, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| |
Collapse
|
63
|
Nickol ME, Lyle SM, Dennehy B, Kindrachuk J. Dysregulated Host Responses Underlie 2009 Pandemic Influenza-Methicillin Resistant Staphylococcus aureus Coinfection Pathogenesis at the Alveolar-Capillary Barrier. Cells 2020; 9:E2472. [PMID: 33202895 PMCID: PMC7696554 DOI: 10.3390/cells9112472] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 11/11/2020] [Accepted: 11/11/2020] [Indexed: 02/04/2023] Open
Abstract
Influenza viruses are a continual public health concern resulting in 3-5 million severe infections annually despite intense vaccination campaigns and messaging. Secondary bacterial infections, including Staphylococcus aureus, result in increased morbidity and mortality during seasonal epidemics and pandemics. While coinfections can result in deleterious pathologic consequences, including alveolar-capillary barrier disruption, the underlying mechanisms are poorly understood. We have characterized host- and pathogen-centric mechanisms contributing to influenza-bacterial coinfections in a primary cell coculture model of the alveolar-capillary barrier. Using 2009 pandemic influenza (pH1N1) and methicillin-resistant S. aureus (MRSA), we demonstrate that coinfection resulted in dysregulated barrier function. Preinfection with pH1N1 resulted in modulation of adhesion- and invasion-associated MRSA virulence factors during lag phase bacterial replication. Host response modulation in coinfected alveolar epithelial cells were primarily related to TLR- and inflammatory response-mediated cell signaling events. While less extensive in cocultured endothelial cells, coinfection resulted in changes to cellular stress response- and TLR-related signaling events. Analysis of cytokine expression suggested that cytokine secretion might play an important role in coinfection pathogenesis. Taken together, we demonstrate that coinfection pathogenesis is related to complex host- and pathogen-mediated events impacting both epithelial and endothelial cell regulation at the alveolar-capillary barrier.
Collapse
Affiliation(s)
- Michaela E. Nickol
- Laboratory of Emerging and Re-Emerging Viruses, Department of Medical Microbiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada; (M.E.N.); (S.M.L.); (B.D.)
| | - Sarah M. Lyle
- Laboratory of Emerging and Re-Emerging Viruses, Department of Medical Microbiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada; (M.E.N.); (S.M.L.); (B.D.)
| | - Brendan Dennehy
- Laboratory of Emerging and Re-Emerging Viruses, Department of Medical Microbiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada; (M.E.N.); (S.M.L.); (B.D.)
| | - Jason Kindrachuk
- Laboratory of Emerging and Re-Emerging Viruses, Department of Medical Microbiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada; (M.E.N.); (S.M.L.); (B.D.)
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada
| |
Collapse
|
64
|
Wu S, Lei L, Bao C, Liu J, Weir MD, Ren K, Schneider A, Oates TW, Liu J, Xu HHK. An injectable and antibacterial calcium phosphate scaffold inhibiting Staphylococcus aureus and supporting stem cells for bone regeneration. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 120:111688. [PMID: 33545850 DOI: 10.1016/j.msec.2020.111688] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 10/26/2020] [Accepted: 10/27/2020] [Indexed: 02/08/2023]
Abstract
Staphylococcus aureus (S. aureus) is the major pathogen for osteomyelitis, which can lead to bone necrosis and destruction. There has been no report on antibacterial calcium phosphate cement (CPC) against S. aureus. The aims of this study were to: (1) develop novel antibacterial CPC-chitosan-alginate microbead scaffold; (2) investigate mechanical and antibacterial properties of CPC-chitosan-penicillin-alginate scaffold; (3) evaluate the encapsulation and delivery of human umbilical cord mesenchymal stem cells (hUCMSCs). Flexural strength, elastic modulus and work-of-fracture of the CPC-chitosan-penicillin-alginate microbeads scaffold and CPC-chitosan scaffold were evaluated. Penicillin release profile and antibacterial effects on S. aureus were determined. The hUCMSC delivery and release from penicillin-alginate microbeads were investigated. Injectable CPC-chitosan-penicillin-alginate microbeads scaffold was developed for the first time. CPC-chitosan-penicillin-alginate microbeads scaffold had a flexural strength of 3.16 ± 0.55 MPa, matching that of cancellous bone. With sustained penicillin release, the new scaffold had strong antibacterial effects on S. aureus, with an inhibition zone diameter of 32.2 ± 2.5 mm, greater than that of penicillin disk control (15.1 ± 2.0 mm) (p < 0.05). Furthermore, this injectable and antibacterial scaffold had no toxic effects, yielding excellent hUCMSC viability, which was similar to that of CPC control without antibacterial activity (p > 0.05). CPC-chitosan-penicillin-microbeads scaffold had injectability, good strength, strong antibacterial effects, and good biocompatibility to support stem cell viability for osteogenesis. CPC-chitosan-penicillin-microbeads scaffold is promising for dental, craniofacial and orthopedic applications to combat infections and promote bone regeneration.
Collapse
Affiliation(s)
- Shizhou Wu
- Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China; Biomaterials & Tissue Engineering Division, Department of Advanced Oral Sciences and Therapeutics, University of Maryland Dental School, Baltimore, MD 21201, USA
| | - Lei Lei
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, China
| | - Chongyun Bao
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, China
| | - Jin Liu
- Biomaterials & Tissue Engineering Division, Department of Advanced Oral Sciences and Therapeutics, University of Maryland Dental School, Baltimore, MD 21201, USA; Key Laboratory of Shannxi for Craniofacial Precision Medicine Research, Clinical Research Center of Shannxi for Dental and Maxillofacial Diseases, College of Stomatology, Xi'an Jiaotong University, Shannxi 710004, China
| | - Michael D Weir
- Biomaterials & Tissue Engineering Division, Department of Advanced Oral Sciences and Therapeutics, University of Maryland Dental School, Baltimore, MD 21201, USA
| | - Ke Ren
- Department of Neural and Pain Sciences, School of Dentistry, Program in Neuroscience, University of Maryland, Baltimore, MD 21201, USA
| | - Abraham Schneider
- Department of Oncology and Diagnostic Sciences, University of Maryland School of Dentistry, Baltimore, USA; Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Thomas W Oates
- Biomaterials & Tissue Engineering Division, Department of Advanced Oral Sciences and Therapeutics, University of Maryland Dental School, Baltimore, MD 21201, USA
| | - Jun Liu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, China.
| | - Hockin H K Xu
- Biomaterials & Tissue Engineering Division, Department of Advanced Oral Sciences and Therapeutics, University of Maryland Dental School, Baltimore, MD 21201, USA; Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Center for Stem Cell Biology and Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| |
Collapse
|
65
|
Chen H, Yang H, Weir MD, Schneider A, Ren K, Homayounfar N, Oates TW, Zhang K, Liu J, Hu T, Xu HHK. An antibacterial and injectable calcium phosphate scaffold delivering human periodontal ligament stem cells for bone tissue engineering. RSC Adv 2020; 10:40157-40170. [PMID: 35520873 PMCID: PMC9057516 DOI: 10.1039/d0ra06873j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/26/2020] [Indexed: 02/05/2023] Open
Abstract
Osteomyelitis and post-operative infections are major problems in orthopedic, dental and craniofacial surgeries. It is highly desirable for a tissue engineering construct to kill bacteria, while simultaneously delivering stem cells and enhancing cell function and tissue regeneration. The objectives of this study were to: (1) develop a novel injectable calcium phosphate cement (CPC) scaffold containing antibiotic ornidazole (ORZ) while encapsulating human periodontal ligament stem cells (hPDLSCs), and (2) investigate the inhibition efficacy against Staphylococcus aureus (S. aureus) and the promotion of hPDLSC function for osteogenesis for the first time. ORZ was incorporated into a CPC-chitosan scaffold. hPDLSCs were encapsulated in alginate microbeads (denoted hPDLSCbeads). The ORZ-loaded CPCC+hPDLSCbeads scaffold was fully injectable, and had a flexural strength of 3.50 ± 0.92 MPa and an elastic modulus of 1.30 ± 0.45 GPa, matching those of natural cancellous bone. With 6 days of sustained ORZ release, the CPCC+10ORZ (10% ORZ) scaffold had strong antibacterial effects on S. aureus, with an inhibition zone of 12.47 ± 1.01 mm. No colonies were observed in the CPCC+10ORZ group from 3 to 7 days. ORZ-containing scaffolds were biocompatible with hPDLSCs. CPCC+10ORZ+hPDLSCbeads scaffold with osteogenic medium had 2.4-fold increase in alkaline phosphatase (ALP) activity and bone mineral synthesis by hPDLSCs, as compared to the control group (p < 0.05). In conclusion, the novel antibacterial construct with stem cell delivery had injectability, good strength, strong antibacterial effects and biocompatibility, supporting osteogenic differentiation and bone mineral synthesis of hPDLSCs. The injectable and mechanically-strong CPCC+10ORZ+hPDLSCbeads construct has great potential for treating bone infections and promoting bone regeneration.
Collapse
Affiliation(s)
- Hong Chen
- Department of Endodontics, College of Stomatological, Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education Chongqing China.,State Key Laboratory of Oral Diseases, Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, National Clinical Research Centre for Oral Diseases, Sichuan University Chengdu China .,Department of Advanced Oral Sciences and Therapeutics, University of Maryland Dental School Baltimore MD 21201 USA
| | - Hui Yang
- State Key Laboratory of Oral Diseases, Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, National Clinical Research Centre for Oral Diseases, Sichuan University Chengdu China
| | - Michael D Weir
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland Dental School Baltimore MD 21201 USA
| | - Abraham Schneider
- Department of Oncology and Diagnostic Sciences, University of Maryland School of Dentistry Baltimore USA.,Member, Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine Baltimore MD 21201 USA
| | - Ke Ren
- Department of Neural and Pain Sciences, School of Dentistry, Program in Neuroscience, University of Maryland Baltimore MD 21201 USA
| | - Negar Homayounfar
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland Dental School Baltimore MD 21201 USA
| | - Thomas W Oates
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland Dental School Baltimore MD 21201 USA
| | - Ke Zhang
- Department of Orthodontics, School of Stomatology, Capital Medical University Beijing China
| | - Jin Liu
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland Dental School Baltimore MD 21201 USA .,Key Laboratory of Shannxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University Xi'an Shannxi China
| | - Tao Hu
- State Key Laboratory of Oral Diseases, Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, National Clinical Research Centre for Oral Diseases, Sichuan University Chengdu China
| | - Hockin H K Xu
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland Dental School Baltimore MD 21201 USA .,Member, Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine Baltimore MD 21201 USA.,Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine Baltimore MD 21201 USA
| |
Collapse
|
66
|
Sun H, Pulakat L, Anderson DW. Challenges and New Therapeutic Approaches in the Management of Chronic Wounds. Curr Drug Targets 2020; 21:1264-1275. [PMID: 32576127 DOI: 10.2174/1389450121666200623131200] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 05/10/2020] [Accepted: 05/20/2020] [Indexed: 02/07/2023]
Abstract
Chronic non-healing wounds are estimated to cost the US healthcare $28-$31 billion per year. Diabetic ulcers, arterial and venous ulcers, and pressure ulcers are some of the most common types of chronic wounds. The burden of chronic wounds continues to rise due to the current epidemic of obesity and diabetes and the increase in elderly adults in the population who are more vulnerable to chronic wounds than younger individuals. This patient population is also highly vulnerable to debilitating infections caused by opportunistic and multi-drug resistant pathogens. Reduced microcirculation, decreased availability of cytokines and growth factors that promote wound closure and healing, and infections by multi-drug resistant and biofilm forming microbes are some of the critical factors that contribute to the development of chronic non-healing wounds. This review discusses novel approaches to understand chronic wound pathology and methods to improve chronic wound care, particularly when chronic wounds are infected by multi-drug resistant, biofilm forming microbes.
Collapse
Affiliation(s)
- Hongmin Sun
- Division of Cardiovascular Medicine, Department of Medicine, University of Missouri, Columbia, Missouri 65212, United States
| | - Lakshmi Pulakat
- Division of Cardiovascular Medicine, Department of Medicine, University of Missouri, Columbia, Missouri 65212, United States
| | | |
Collapse
|
67
|
Abstract
Platelets are increasingly being recognized for playing roles beyond thrombosis and hemostasis. Today we know that they mediate inflammation by direct interactions with innate immune cells or secretion of cytokines/chemokines. Here we review their interactions with neutrophils and monocytes/macrophages in infection and sepsis, stroke, myocardial infarction and venous thromboembolism. We discuss new roles for platelet surface receptors like GPVI or GPIb and also look at platelet contributions to the formation of neutrophil extracellular traps (NETs) as well as to deep vein thrombosis during infection, e.g. in COVID-19 patients.
Collapse
Affiliation(s)
- Kimberly Martinod
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Belgium
| | - Carsten Deppermann
- Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| |
Collapse
|
68
|
Bennett MR, Thomsen IP. Epidemiological and Clinical Evidence for the Role of Toxins in S. aureus Human Disease. Toxins (Basel) 2020; 12:toxins12060408. [PMID: 32575633 PMCID: PMC7354447 DOI: 10.3390/toxins12060408] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus asymptomatically colonizes approximately 30–50% of the population and is a leading cause of bacteremia, bone/joint infections, and skin infections in the US. S. aureus has become a major public health threat due to antibiotic resistance and an increasing number of failed vaccine attempts. To develop new anti-staphylococcal preventive therapies, it will take a more thorough understanding of the current role S. aureus virulence factors play in contributing to human disease. This review focuses on the clinical association of individual toxins with S. aureus infection as well as attempted treatment options. Further understanding of these associations will increase understanding of toxins and their importance to S. aureus pathogenesis.
Collapse
Affiliation(s)
- Monique R. Bennett
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA;
- Vanderbilt Vaccine Research Program, Nashville, TN 37232, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Isaac P. Thomsen
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA;
- Vanderbilt Vaccine Research Program, Nashville, TN 37232, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Correspondence:
| |
Collapse
|
69
|
Wang X, Cao Z, Zhang M, Meng L, Ming Z, Liu J. Bioinspired oral delivery of gut microbiota by self-coating with biofilms. SCIENCE ADVANCES 2020; 6:eabb1952. [PMID: 32637620 PMCID: PMC7314526 DOI: 10.1126/sciadv.abb1952] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 05/08/2020] [Indexed: 05/05/2023]
Abstract
Transplanting beneficial bacteria to the gut microbiome can positively modulate the bacterial composition and remains of great interest in prevention and treatment. However, environmental assaults and rapid transit times in the gastrointestinal (GI) tract result in low oral bioavailability and limited intestinal colonization. Here, we describe a bioinspired strategy of self-coating with biofilms that endows the transplanted gut microbiota with superior resistance and adhesion capacity. Using clinical Bacillus subtilis as a model probiotic bacterium, biofilm-coated probiotics demonstrate substantially improved GI tract tolerance and mucoadhesion in mice and swine. In particular, coated probiotics exhibit a 125-fold higher oral bioavailability and a 17 times greater intestinal colonization than uncoated bacteria in the porcine model. With notable ability to survive and reside in the GI tract, coated bacteria further show a significantly enhanced decolonization effect in mice colonized with Staphylococcus aureus. Self-coating with biofilms suggests a robust platform for oral doses of gut microbiota.
Collapse
|
70
|
The antibiotics resistance mechanism and pathogenicity of cold stressed Staphylococcus aureus. Lebensm Wiss Technol 2020. [DOI: 10.1016/j.lwt.2020.109274] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
71
|
Tham EH, Koh E, Common JEA, Hwang IY. Biotherapeutic Approaches in Atopic Dermatitis. Biotechnol J 2020; 15:e1900322. [PMID: 32176834 DOI: 10.1002/biot.201900322] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 02/24/2020] [Indexed: 12/15/2022]
Abstract
The skin microbiome plays a central role in inflammatory skin disorders such as atopic dermatitis (AD). In AD patients, an imbalance between pathogenic Staphylococcus aureus (S. aureus) and resident skin symbionts creates a state of dysbiosis which induces immune dysregulation and impairs skin barrier function. There are now exciting new prospects for microbiome-based interventions for AD prevention. In the hopes of achieving sustained control and management of disease in AD patients, current emerging biotherapeutic strategies aim to harness the skin microbiome associated with health by restoring a more diverse symbiotic skin microbiome, while selectively removing pathogenic S. aureus. Examples of such strategies are demonstrated in skin microbiome transplants, phage-derived anti-S. aureus endolysins, monoclonal antibodies, and quorum sensing (QS) inhibitors. However, further understanding of the skin microbiome and its role in AD pathogenesis is still needed to understand how these biotherapeutics alter the dynamics of the microbiome community; to optimize patient selection, drug delivery, and treatment duration; overcome rapid recolonization upon treatment cessation; and improve efficacy to allow these therapeutic options to eventually reach routine clinical practice.
Collapse
Affiliation(s)
- Elizabeth Huiwen Tham
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119228, Singapore.,Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, National University Health System, Singapore, 119074, Singapore
| | - Elvin Koh
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119228, Singapore.,NUS Synthetic Biology for Clinical and Technological Innovation, National University of Singapore, Singapore, 119228, Singapore
| | - John E A Common
- Skin Research Institute of Singapore, A*STAR, Singapore, 308232, Singapore
| | - In Young Hwang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119228, Singapore.,NUS Synthetic Biology for Clinical and Technological Innovation, National University of Singapore, Singapore, 119228, Singapore
| |
Collapse
|
72
|
Biofilm Production Ability, Virulence and Antimicrobial Resistance Genes in Staphylococcus aureus from Various Veterinary Hospitals. Pathogens 2020; 9:pathogens9040264. [PMID: 32260416 PMCID: PMC7238219 DOI: 10.3390/pathogens9040264] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 03/21/2020] [Accepted: 03/25/2020] [Indexed: 12/13/2022] Open
Abstract
: Staphylococcus aureus (S. aureus) is one of the most clinically important zoonotic pathogens, but an understanding of the prevalence, biofilm formulation ability, virulence, and antimicrobial resistance genes of S. aureus from veterinary hospitals is lacking. By characterizing S. aureus in different origins of veterinary hospitals in Guangzhou, China, in 2019, we identified with the presence of S. aureus in pets (17.1%), veterinarians (31.7%), airborne dust (19.1%), environmental surfaces (4.3%), and medical device surfaces (10.8%). Multilocus sequence typing (MLST) and Staphylococcus protein A (spa) typing analyses demonstrated methicillin-sensitive S. aureus (MSSA) ST398-t571, MSSA ST188-t189, and methicillin-resistant S. aureus (MRSA) ST59-t437 were the most prevalent lineage. S. aureus with similar pulsed-field gel electrophoresis (PFGE) types distributed widely in different kinds of samples. The crystal violet straining assays revealed 100% (3/3) of MRSA ST59 and 81.8% (9/11) of MSSA ST188 showed strong biofilm formulation ability, whereas other STs (ST1, ST5, ST7, ST15, ST88, ST398, ST3154 and ST5353) showed weak biofilm production ability. Polymerase chain reaction (PCR) confirmed the most prevalent leucocidin, staphylococcal enterotoxins, ica operon, and adhesion genes were lukD-lukE (49.0%), sec-sel (15.7%), icaA-icaB-icaC-icaR (100.0%), and fnbB-cidA-fib-ebps-eno (100.0%), respectively. Our study showed that the isolates with strong biofilm production ability had a higher prevalence in clfA, clfB, fnbA and sdrC genes compared to the isolates with weak biofilm production ability. Furthermore, 2 ST1-MRSA isolates with tst gene and 1 ST88-MSSA isolate with lukS/F-PV gene were detected. In conclusion, the clonal dissemination of S. aureus of different origins in veterinary hospitals may have occurred; the biofilm production capacity of S. aureus is strongly correlated with ST types; some adhesion genes such as clfA, clfB, fnbA, and sdrC may pose an influence on biofilm production ability and the emergence of lukS/F-PV and tst genes in S. aureus from veterinary hospitals should raise our vigilance.
Collapse
|
73
|
Small Molecules Produced by Commensal Staphylococcus epidermidis Disrupt Formation of Biofilms by Staphylococcus aureus. Appl Environ Microbiol 2020; 86:AEM.02539-19. [PMID: 31862721 DOI: 10.1128/aem.02539-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 12/16/2019] [Indexed: 11/20/2022] Open
Abstract
The microbiota influences host health through several mechanisms, including protecting it from pathogen colonization. Staphylococcus epidermidis is one of the most frequently found species in the skin microbiota, and its presence can limit the development of pathogens such as Staphylococcus aureus S. aureus causes diverse types of infections ranging from skin abscesses to bloodstream infections. Given the increasing prevalence of S. aureus drug-resistant strains, it is imperative to search for new strategies for treatment and prevention. Thus, we investigated the activity of molecules produced by a commensal S. epidermidis isolate against S. aureus biofilms. We showed that molecules present in S. epidermidis cell-free conditioned media (CFCM) caused a significant reduction in biofilm formation in most S. aureus clinical isolates, including all 4 agr types and agr-defective strains, without any impact on growth. S. epidermidis molecules also disrupted established S. aureus biofilms and reduced the antibiotic concentration required to eliminate them. Preliminary characterization of the active compound showed that its activity is resistant to heat, protease inhibitors, trypsin, proteinase K, and sodium periodate treatments, suggesting that it is not proteinaceous. RNA sequencing revealed that S. epidermidis-secreted molecules modulate the expression of hundreds of S. aureus genes, some of which are associated with biofilm production. Biofilm formation is one of the main virulence factors of S. aureus and has been associated with chronic infections and antimicrobial resistance. Therefore, molecules that can counteract this virulence factor may be promising alternatives as novel therapeutic agents to control S. aureus infections.IMPORTANCE S. aureus is a leading agent of infections worldwide, and its main virulence characteristic is the ability to produce biofilms on surfaces such as medical devices. Biofilms are known to confer increased resistance to antimicrobials and to the host immune responses, requiring aggressive antibiotic treatment and removal of the infected surface. Here, we investigated a new source of antibiofilm compounds, the skin microbiome. Specifically, we found that a commensal strain of S. epidermidis produces molecules with antibiofilm activity, leading to a significant decrease of S. aureus biofilm formation and to a reduction of previously established biofilms. The molecules potentiated the activity of antibiotics and affected the expression of hundreds of S. aureus genes, including those associated with biofilm formation. Our research highlights the search for compounds that can aid us in the fight against S. aureus infections.
Collapse
|
74
|
Stochastic Expression of Sae-Dependent Virulence Genes during Staphylococcus aureus Biofilm Development Is Dependent on SaeS. mBio 2020; 11:mBio.03081-19. [PMID: 31937649 PMCID: PMC6960292 DOI: 10.1128/mbio.03081-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The intricate process of biofilm formation in the human pathogen Staphylococcus aureus involves distinct stages during which a complex mixture of matrix molecules is produced and modified throughout the developmental cycle. Early in biofilm development, a subpopulation of cells detaches from its substrate in an event termed "exodus" that is mediated by SaePQRS-dependent stochastic expression of a secreted staphylococcal nuclease, which degrades extracellular DNA within the matrix, causing the release of cells and subsequently allowing for the formation of metabolically heterogenous microcolonies. Since the SaePQRS regulatory system is involved in the transcriptional control of multiple S. aureus virulence factors, the expression of several additional virulence genes was examined within a developing biofilm by introducing fluorescent gene reporter plasmids into wild-type S. aureus and isogenic regulatory mutants and growing these strains in a microfluidic system that supplies the bacteria with a constant flow of media while simultaneously imaging developing biofilms in 5-min intervals. This study demonstrated that multiple virulence genes, including nuc, were expressed stochastically within a specialized subpopulation of cells in nascent biofilms. We demonstrated that virulence genes regulated by SaePQRS were stochastically expressed in nearly all strains examined whereas Agr-regulated genes were expressed more homogenously within maturing microcolonies. The commonly used Newman strain contains a variant of SaeS (SaeSP) that confers constitutive kinase activity to the protein and caused this strain to lack the stochastic expression pattern observed in other strain backgrounds. Importantly, repair of the SaeSP allele resulting in reversion to the well-conserved SaeS L allele found in other strains restored stochastic expression in this strain.IMPORTANCE Staphylococcus aureus is an important human pathogen capable of colonizing diverse tissue types and inducing severe disease in both immunocompromised and otherwise healthy individuals. Biofilm infections caused by this bacterial species are of particular concern because of their persistence, even in the face of intensive therapeutic intervention. The results of the current study demonstrate the stochastic nature of Sae-mediated virulence gene expression in S. aureus and indicate that this regulatory system may function as a "bistable switch" in a manner similar to that seen with regulators controlling competence gene expression in Bacillus subtilis and persister cell formation in Escherichia coli The results of this study provide a new perspective on the complex mechanisms utilized by S. aureus during the establishment of infections.
Collapse
|
75
|
Sarhan SR, Hashim HO, Al-Shuhaib MBS. The Gly152Val mutation possibly confers resistance to beta-lactam antibiotics in ovine Staphylococcus aureus isolates. Open Vet J 2019; 9:339-348. [PMID: 32042657 PMCID: PMC6971359 DOI: 10.4314/ovj.v9i4.12] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 11/21/2019] [Indexed: 12/30/2022] Open
Abstract
Background: The mecA gene is a key factor that allows bacterial cells to resist several antibiotics. Aim: This study was conducted to detect the mecA gene polymorphism in ovine wounds and its possible association with the structure and function of penicillin binding protein A2 (PBP2A). Methods: One genetic locus of 1,967 bp that covered the majority of the coding regions of the mecA gene within methicillin-resistant Staphylococcus aureus (MRSA) DNA sequences was designed. Results: In addition to standard microbiological tests, PCR-sequencing reactions and phylogenetic analyses confirmed the identity of the targeted MRSA bacteria. Seven novel missense SNPs, including N57T, N115Y, D120N, D139N, G152V, E189K, and F211V, were observed in the mecA amplicons. Multiple state-of-the-art in silico tools were utilized to assess the consequences of each observed SNP in terms of its effect on the corresponding PBP2A protein structure and function. It was shown that some MRSA isolates exhibited a highly PBP2A-damaging SNP, G152V, which showed an entirely deleterious effect on the PBP2A. Furthermore, G152V induced an alteration in the PBP2A interaction with its receptor, which presumably reduced its affinity to bind with the beta-lactams. Conclusion: The present report indicated a possible role for the observed deleterious G152V SNP in the reduction of PBP2A binding with beta-lactams, which has led to a remarkable increase in MRSA’s resistance to antibiotics.
Collapse
Affiliation(s)
- Sarhan R Sarhan
- Department of Pharmacology and Physiology, College of Veterinary Medicine, Wasit University, Wasit, Iraq
| | - Hayder O Hashim
- Department of Clinical Laboratory Sciences, College of Pharmacy, University of Babylon, Iraq
| | - Mohammed Baqur S Al-Shuhaib
- Department of Animal Production, College of Agriculture, Al-Qasim Green University, Al-Qasim, Babil 51001, Iraq
| |
Collapse
|
76
|
Wu S, Liu Y, Lei L, Zhang H. Virulence of methicillin-resistant Staphylococcus aureus modulated by the YycFG two-component pathway in a rat model of osteomyelitis. J Orthop Surg Res 2019; 14:433. [PMID: 31831035 PMCID: PMC6909630 DOI: 10.1186/s13018-019-1508-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Accepted: 12/04/2019] [Indexed: 02/07/2023] Open
Abstract
Objectives Methicillin-resistant Staphylococcus aureus (MRSA) strains present an urgent medical problem in osteomyelitis cases. Our previous study indicated that the YycFG two-component regulatory pathway is associated with the bacterial biofilm organization of MRSA strains. The aim of this study was to investigate the regulatory roles of ASyycG in the bacterial biofilm formation and the pathogenicity of MRSA strains using an antisense RNA strategy. Methods An ASyycG-overexpressing MRSA clinical isolate was constructed. The bacterial growth was monitored, and the biofilm biomass on bone specimens was examined using scanning electron microscopy and confocal laser scanning microscopy. Furthermore, quantitative RT-PCR (QRT-PCR) analysis was used to measure the expression of yycF/G/H and icaA/D in the MRSA and ASyycG strains. The expression of the YycG protein was quantified by Western blot assays. We validated the role of ASyycG in the invasive ability and pathogenicity of the strains in vivo using histology and peptide nucleic acid fluorescent in situ hybridization. Results The results showed that overexpression of ASyycG lead to a reduction in biofilm formation and exopolysaccharide (EPS) synthesis compared to the control MRSA strains. The ASyycG strains exhibited decreased expression of the yycF/G/H and icaA/D genes. Furthermore, Western blot data showed that the production of the YycG protein was inhibited in the ASyycG strains. In addition, we demonstrated that ASyycG suppressed the invasive ability and pathogenicity of the strain in vivo using an SPF (specific pathogen free) rat model. Conclusion In summary, the overexpression of ASyycG leads to a reduction in biofilm formation and bacterial pathogenicity in vivo, which provides a potential target for the management of MRSA-induced osteomyelitis.
Collapse
Affiliation(s)
- Shizhou Wu
- Department of Orthopedics, West China Hospital, Sichuan University, No.37 Guoxue Alley, Chengdu City, 610041, Sichuan, China
| | - Yunjie Liu
- West China School of Public Health, Sichuan University, Chengdu, China
| | - Lei Lei
- State Key Laboratory of Oral Diseases, Department of Preventive Dentistry, West China Hospital of Stomatology, Sichuan University, NO.14 Renmin South Road, Chengdu City, 610041, Sichuan, China.
| | - Hui Zhang
- Department of Orthopedics, West China Hospital, Sichuan University, No.37 Guoxue Alley, Chengdu City, 610041, Sichuan, China.
| |
Collapse
|
77
|
Nano-graphene oxide improved the antibacterial property of antisense yycG RNA on Staphylococcus aureus. J Orthop Surg Res 2019; 14:305. [PMID: 31492154 PMCID: PMC6731568 DOI: 10.1186/s13018-019-1356-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 08/29/2019] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Staphylococcus aureus (S. aureus) has the potential to opportunistically cause infectious diseases, including osteomyelitis, skin infections, pneumonia, and diarrhea. We previously reported that ASyycG RNA reduced the transcripts of virulent genes, and biofilm formation of S. aureus. Currently, graphene oxide (GO) nanosheets are used to efficiently deliver nucleic acids with favorable biocompatibility. METHODS In the current study, a GO-based recombinant pDL278 ASyycG vector transformation strategy was developed. The particle size distributions and zeta-potential of the GO-PEI-based ASyycG were evaluated. The ASyycG plasmids were labeled with gene-encoding enhanced green fluorescent protein (ASyycG-eGFP). Quantitative real-time PCR assays were performed to investigate the expression of yycF/G/H and icaADB genes. Biofilm biomass and bacterial viability of S. aureus were evaluated by scanning electron microscopy and confocal laser scanning microscopy. We found that the expression of the yycG gene was inversely correlated with levels of the ASyycG transcripts and that the GO-PEI-ASyycG strain had the lowest expression of biofilm organization-associated genes. RESULTS The results showed that the GO-based strategy significantly increased ASyycG transformation as a delivery system compared to the conventional competence-stimulating peptide strategy. Furthermore, GO-PEI-ASyycG suppressed bacterial biofilm aggregation and improved bactericidal effects on S. aureus after 24 h biofilm establishment. CONCLUSIONS Our findings demonstrated that nano-GO with antisense yycG RNA is a more effective and relatively stable strategy for the management of S. aureus infections.
Collapse
|
78
|
Wu S, Liu Y, Zhang H, Lei L. A new transformation method with nanographene oxides of antisense carrying yycG RNA improved antibacterial properties on methicillin-resistant Staphylococcus aureus biofilm. J Vet Med Sci 2019; 81:1540-1546. [PMID: 31447460 PMCID: PMC6863726 DOI: 10.1292/jvms.19-0216] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Staphylococcus aureus has the potential to opportunistically cause
infectious diseases. The aim of this study was to determine the antimicrobial effects of
novel graphene oxide (GO)-polyethylenimine (PEI)-based antisense yycG
(ASyycG) on the inhibition of methicillin-resistant S.
aureus (MRSA) biofilm formation. In current study, a novel GO-PEI-based
recombinant ASyycG vector transformation strategy was developed to
produce ASyycG. The mechanical features including zeta-potential and
particle size distributions were evaluated by: GO; GO-PEI and
GO-PEI-ASyycG. The recombinant ASyycG vector was
transformed into MRSA cells, and the expression levels of the yycF/G and
icaADB genes were determined and compared by quantitative real-time PCR
(qPCR) assays. The recombinant ASyycG plasmids were subsequently modified
with a gene encoding enhanced green fluorescent protein (ASyycG-eGFP) as
a reporter gene, and the transformation efficiency was assessed by the fluorescence
intensity. The biofilm biomass and bacterial viability of the MRSA strains were evaluated
by crystal violet assay, colony-forming unit assays and confocal laser scanning
microscopy. The results showed that the Z-average sizes of GO-PEI-ASyycG
were much larger than those of GO or GO-PEI. The GO-PEI-based strategy significantly
increased the efficiency of ASyycG transformation. The
GO-PEI-ASyycG-transformed MRSA strain had the lowest expression levels
of the biofilm formation-associated genes. Furthermore, GO-PEI-ASyycG
suppressed biofilm aggregation and improved bactericidal effects on the MRSA after 24 hr
of biofilm establishment. Our findings demonstrated that GO-PEI based antisense
yycG RNA will be an effective method for management of MRSA
infections.
Collapse
Affiliation(s)
- Shizhou Wu
- Department of Orthopedics, West China Hospital, Sichuan University, Chengdu, 610041, China.,State Key Laboratory of Oral Diseases, Department of Preventive Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Yunjie Liu
- West China School of Public Health, Sichuan University, Chengdu, 610041, China
| | - Hui Zhang
- Department of Orthopedics, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Lei Lei
- State Key Laboratory of Oral Diseases, Department of Preventive Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| |
Collapse
|
79
|
Contribution of hla Regulation by SaeR to Staphylococcus aureus USA300 Pathogenesis. Infect Immun 2019; 87:IAI.00231-19. [PMID: 31209148 DOI: 10.1128/iai.00231-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 06/11/2019] [Indexed: 02/08/2023] Open
Abstract
The SaeRS two-component system in Staphylococcus aureus is critical for regulation of many virulence genes, including hla, which encodes alpha-toxin. However, the impact of regulation of alpha-toxin by Sae on S. aureus pathogenesis has not been directly addressed. Here, we mutated the SaeR-binding sequences in the hla regulatory region and determined the contribution of this mutation to hla expression and pathogenesis in strain USA300 JE2. Western blot analyses revealed drastic reduction of alpha-toxin levels in the culture supernatants of SaeR-binding mutant in contrast to the marked alpha-toxin production in the wild type. The SaeR-binding mutation had no significant effect on alpha-toxin regulation by Agr, MgrA, and CcpA. In animal studies, we found that the SaeR-binding mutation did not contribute to USA300 JE2 pathogenesis using a rat infective endocarditis model. However, in a rat skin and soft tissue infection model, the abscesses on rats infected with the mutant were significantly smaller than the abscesses on those infected with the wild type but similar to the abscesses on those infected with a saeR mutant. These studies indicated that there is a direct effect of hla regulation by SaeR on pathogenesis but that the effect depends on the animal model used.
Collapse
|
80
|
Abstract
Staphylococcus aureus is responsible for a broad range of infections. This pathogen has a vast arsenal of virulence factors at its disposal, but avirulent strains are frequently isolated as the cause of clinical infections. These isolates have a mutated agr locus and have been believed to have no evolutionary future. Here we show that a fraction of Agr-negative strains can repair their mutated agr locus with mechanisms resembling phase variation. The agr revertants sustain an Agr OFF state as long as they exist as a minority but can activate their Agr system upon phagocytosis. These revertant cells might function as a cryptic insurance strategy to survive immune-mediated host stress that arises during infection. Staphylococcus aureus is an important human pathogen whose success is largely attributed to its vast arsenal of virulence factors that facilitate its invasion into, and survival within, the human host. The expression of these virulence factors is controlled by the quorum sensing accessory gene regulator (Agr) system. However, a large proportion of clinical S. aureus isolates are consistently found to have a mutationally inactivated Agr system. These mutants have a survival advantage in the host but are considered irreversible mutants. Here we show, for the first time, that a fraction of Agr-negative mutants can revert their Agr activity. By serially passaging Agr-negative strains and screening for phenotypic reversion of hemolysis and subsequent sequencing, we identified two mutational events responsible for reversion: a genetic duplication plus inversion event and a poly(A) tract alteration. Additionally, we demonstrate that one clinical Agr-negative methicillin-resistant S. aureus (MRSA) isolate could reproducibly generate Agr-revertant colonies with a poly(A) tract genetic mechanism. We also show that these revertants activate their Agr system upon phagocytosis. We propose a model in which a minor fraction of Agr-negative S. aureus strains are phase variants that can revert their Agr activity and may act as a cryptic insurance strategy against host-mediated stress.
Collapse
|
81
|
Sharma-Kuinkel BK, Tkaczyk C, Bonnell J, Yu L, Tovchigrechko A, Tabor DE, Park LP, Ruffin F, Esser MT, Sellman BR, Fowler VG, Ruzin A. Associations of pathogen-specific and host-specific characteristics with disease outcome in patients with Staphylococcus aureus bacteremic pneumonia. Clin Transl Immunology 2019; 8:e01070. [PMID: 31360464 PMCID: PMC6640002 DOI: 10.1002/cti2.1070] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 06/24/2019] [Accepted: 06/30/2019] [Indexed: 11/08/2022] Open
Abstract
Objective To understand the relationships of Staphylococcus aureus (SA) bacteremic pneumonia (SABP) outcome with patient‐specific and SA‐specific variables. Methods We analysed SA bloodstream isolates and matching sera in SABP patients by sequencing SA isolates (n = 50) and measuring in vitro AT production, haemolytic activity and expression of ClfA and ClfB. Controls were sera from gram‐negative bacteremia patients with or without pneumonia and uninfected subjects. Levels of IgGs, IgMs and neutralizing antibodies (NAbs) against SA antigens were quantified and analysed by one‐way ANOVA. Associations of patient outcomes with patient variables, antibody levels and isolate characteristics were evaluated by univariate and multivariate logistic regression analyses. Results SABP patients had higher levels of IgGs against eight virulence factors and anti‐alpha toxin (AT) NAbs than uninfected controls. Levels of IgG against AT and IgMs against ClfA, FnbpA and SdrC were higher in clinically cured SABP patients than in clinical failures. Anti‐LukAB NAb levels were elevated in all cohorts. Increased odds of cure correlated with higher haemolytic activity of SA strains, longer time between surgery and bacteremia (> 30 days), longer duration of antibiotic therapy, lower acute physiology and total APACHE II scores, lack of persistent fever for > 72 h and higher levels of antibodies against AT (IgG), ClfA (IgM), FnbpA (IgM) and SdrC (IgM). Discussion Limitations included the cross‐sectional observational nature of the study, small sample size and inability to measure antibody levels against all SA virulence factors. Conclusion Our results suggest that SABP patients may benefit from immunotherapy targeting multiple SA antigens.
Collapse
Affiliation(s)
- Batu K Sharma-Kuinkel
- Division of Infectious Diseases, Department of Medicine, Duke University Durham NC USA
| | | | | | - Li Yu
- Statistical Sciences, AstraZeneca Gaithersburg MD USA
| | | | | | - Lawrence P Park
- Division of Infectious Diseases, Department of Medicine, Duke University Durham NC USA
| | - Felicia Ruffin
- Division of Infectious Diseases, Department of Medicine, Duke University Durham NC USA
| | - Mark T Esser
- Microbial Sciences, AstraZeneca Gaithersburg MD USA
| | | | - Vance G Fowler
- Division of Infectious Diseases, Department of Medicine, Duke University Durham NC USA
| | - Alexey Ruzin
- Microbial Sciences, AstraZeneca Gaithersburg MD USA
| |
Collapse
|
82
|
Keogh RA, Zapf RL, Trzeciak E, Null GG, Wiemels RE, Carroll RK. Novel Regulation of Alpha-Toxin and the Phenol-Soluble Modulins by Peptidyl-Prolyl cis/trans Isomerase Enzymes in Staphylococcus aureus. Toxins (Basel) 2019; 11:toxins11060343. [PMID: 31208155 PMCID: PMC6628628 DOI: 10.3390/toxins11060343] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/10/2019] [Accepted: 06/12/2019] [Indexed: 02/07/2023] Open
Abstract
Peptidyl-prolyl cis/trans isomerases (PPIases) are enzymes that catalyze the cis-to-trans isomerization around proline bonds, allowing proteins to fold into their correct confirmation. Previously, we identified two PPIase enzymes in Staphylococcus aureus (PpiB and PrsA) that are involved in the regulation of virulence determinants and have shown that PpiB contributes to S. aureus virulence in a murine abscess model of infection. Here, we further examine the role of these PPIases in S. aureus virulence and, in particular, their regulation of hemolytic toxins. Using murine abscess and systemic models of infection, we show that a ppiB mutant in a USA300 background is attenuated for virulence but that a prsA mutant is not. Deletion of the ppiB gene leads to decreased bacterial survival in macrophages and nasal epithelial cells, while there is no significant difference when prsA is deleted. Analysis of culture supernatants reveals that a ppiB mutant strain has reduced levels of the phenol-soluble modulins and that both ppiB and prsA mutants have reduced alpha-toxin activity. Finally, we perform immunoprecipitation to identify cellular targets of PpiB and PrsA. Results suggest a novel role for PpiB in S. aureus protein secretion. Collectively, our results demonstrate that PpiB and PrsA influence S. aureus toxins via distinct mechanisms, and that PpiB but not PrsA contributes to disease.
Collapse
Affiliation(s)
- Rebecca A Keogh
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
| | - Rachel L Zapf
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
| | - Emily Trzeciak
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
| | - Gillian G Null
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
| | - Richard E Wiemels
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
| | - Ronan K Carroll
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
- The Infectious and Tropical Disease Institute, Ohio University, Athens, OH 45701, USA.
| |
Collapse
|
83
|
Abstract
Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality worldwide. Despite broad literature including basic and translational scientific studies, many gaps in our understanding of host-pathogen interactions remain. In this review, pathogen virulence factors that drive lung infection and injury are discussed in relation to their associated host immune pathways. CAP epidemiology is considered, with a focus on Staphylococcus aureus and Streptococcus pneumoniae as primary pathogens. Bacterial factors involved in nasal colonization and subsequent virulence are illuminated. A particular emphasis is placed on bacterial pore-forming toxins, host cell death, and inflammasome activation. Identified host-pathogen interactions are then examined by linking pathogen factors to aberrant host response pathways in the context of acute lung injury in both primary and secondary infection. While much is known regarding bacterial virulence and host immune responses, CAP management is still limited to mostly supportive care. It is likely that improvements in therapy will be derived from combinatorial targeting of both pathogen virulence factors and host immunomodulation.
Collapse
|
84
|
Harris TA, Gattu S, Propheter DC, Kuang Z, Bel S, Ruhn KA, Chara AL, Edwards M, Zhang C, Jo JH, Raj P, Zouboulis CC, Kong HH, Segre JA, Hooper LV. Resistin-like Molecule α Provides Vitamin-A-Dependent Antimicrobial Protection in the Skin. Cell Host Microbe 2019; 25:777-788.e8. [PMID: 31101494 DOI: 10.1016/j.chom.2019.04.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 03/17/2019] [Accepted: 04/15/2019] [Indexed: 12/27/2022]
Abstract
Vitamin A deficiency increases susceptibility to skin infection. However, the mechanisms by which vitamin A regulates skin immunity remain unclear. Here, we show that resistin-like molecule α (RELMα), a small secreted cysteine-rich protein, is expressed by epidermal keratinocytes and sebocytes and serves as an antimicrobial protein that is required for vitamin-A-dependent resistance to skin infection. RELMα was induced by microbiota colonization of the murine skin, was bactericidal in vitro, and was protected against bacterial infection of the skin in vivo. RELMα expression required dietary vitamin A and was induced by the therapeutic vitamin A analog isotretinoin, which protected against skin infection in a RELMα-dependent manner. The RELM family member Resistin was expressed in human skin, was induced by vitamin A analogs, and killed skin bacteria, indicating a conserved function for RELM proteins in skin innate immunity. Our findings provide insight into how vitamin A promotes resistance to skin infection.
Collapse
Affiliation(s)
- Tamia A Harris
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Sureka Gattu
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Daniel C Propheter
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Zheng Kuang
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Shai Bel
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kelly A Ruhn
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Andrew L Chara
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Marshall Edwards
- Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Chenlu Zhang
- Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jay-Hyun Jo
- Dermatology Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH, Bethesda, MD 20892, USA
| | - Prithvi Raj
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Christos C Zouboulis
- Department of Dermatology, Venereology, Allergology and Immunology, Dessau Medical Center, Brandenburg Medical School Theodore Fontane, 06847 Dessau, Germany
| | - Heidi H Kong
- Dermatology Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH, Bethesda, MD 20892, USA
| | - Julia A Segre
- Translational and Functional Genomics Branch, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - Lora V Hooper
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; The Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| |
Collapse
|
85
|
Zheng Y, Shang W, Peng H, Rao Y, Zhao X, Hu Z, Yang Y, Hu Q, Tan L, Xiong K, Li S, Zhu J, Hu X, Zhou R, Li M, Rao X. Virulence Determinants Are Required for Brain Abscess Formation Through Staphylococcus aureus Infection and Are Potential Targets of Antivirulence Factor Therapy. Front Microbiol 2019; 10:682. [PMID: 31024479 PMCID: PMC6460967 DOI: 10.3389/fmicb.2019.00682] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 03/19/2019] [Indexed: 11/24/2022] Open
Abstract
Bacterial brain abscesses (BAs) are difficult to treat with conventional antibiotics. Thus, the development of alternative therapeutic strategies for BAs is of high priority. Identifying the virulence determinants that contribute to BA formation induced by Staphylococcus aureus would improve the effectiveness of interventions for this disease. In this study, RT-qPCR was performed to compare the expression levels of 42 putative virulence determinants of S. aureus strains Newman and XQ during murine BA formation, ear colonization, and bacteremia. The alterations in the expression levels of 23 genes were further confirmed through specific TaqMan RT-qPCR. Eleven S. aureus genes that persistently upregulated expression levels during BA infection were identified, and their functions in BA formation were confirmed through isogenic mutant experiments. Bacterial loads and BA volumes in mice infected with isdA, isdC, lgt, hla, or spa deletion mutants and the hla/spa double mutant strain were lower than those in mice infected with the wild-type Newman strain. The therapeutic application of monoclonal antibodies against Hla and SpA decreased bacterial loads and BA volume in mice infected with Newman. This study provides insights into the virulence determinants that contribute to staphylococcal BA formation and a paradigm for antivirulence factor therapy against S. aureus infections.
Collapse
Affiliation(s)
- Ying Zheng
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University, Key Laboratory of Microbial Engineering under the Educational Committee in Chongqing, Chongqing, China
| | - Weilong Shang
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University, Key Laboratory of Microbial Engineering under the Educational Committee in Chongqing, Chongqing, China
| | - Huagang Peng
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University, Key Laboratory of Microbial Engineering under the Educational Committee in Chongqing, Chongqing, China
| | - Yifan Rao
- Institute of Modern Biopharmaceuticals, School of Life Sciences, Southwest University, Chongqing, China
| | - Xia Zhao
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University, Key Laboratory of Microbial Engineering under the Educational Committee in Chongqing, Chongqing, China
| | - Zhen Hu
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University, Key Laboratory of Microbial Engineering under the Educational Committee in Chongqing, Chongqing, China
| | - Yi Yang
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University, Key Laboratory of Microbial Engineering under the Educational Committee in Chongqing, Chongqing, China
| | - Qiwen Hu
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University, Key Laboratory of Microbial Engineering under the Educational Committee in Chongqing, Chongqing, China
| | - Li Tan
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University, Key Laboratory of Microbial Engineering under the Educational Committee in Chongqing, Chongqing, China
| | - Kun Xiong
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University, Key Laboratory of Microbial Engineering under the Educational Committee in Chongqing, Chongqing, China
| | - Shu Li
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University, Key Laboratory of Microbial Engineering under the Educational Committee in Chongqing, Chongqing, China
| | - Junmin Zhu
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University, Key Laboratory of Microbial Engineering under the Educational Committee in Chongqing, Chongqing, China
| | - Xiaomei Hu
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University, Key Laboratory of Microbial Engineering under the Educational Committee in Chongqing, Chongqing, China
| | - Renjie Zhou
- Department of Emergency, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Ming Li
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University, Key Laboratory of Microbial Engineering under the Educational Committee in Chongqing, Chongqing, China
| | - Xiancai Rao
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University, Key Laboratory of Microbial Engineering under the Educational Committee in Chongqing, Chongqing, China
| |
Collapse
|
86
|
Vidal C, Moulin F, Nassif X, Galmiche L, Borgel D, Charbit A, Picard C, Mira JP, Lortholary O, Jamet A, Toubiana J. Fulminant arterial vasculitis as an unusual complication of disseminated staphylococcal disease due to the emerging CC1 methicillin-susceptible Staphylococcus aureus clone: a case report. BMC Infect Dis 2019; 19:302. [PMID: 30943907 PMCID: PMC6446405 DOI: 10.1186/s12879-019-3933-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 03/24/2019] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Staphylococcus aureus has emerged as a leading cause of invasive severe diseases with a high rate of morbidity and mortality worldwide. The wide spectrum of clinical manifestations and outcome observed in staphylococcal illness may be a consequence of both microbial factors and variability of the host immune response. CASE PRESENTATION A 14-years old child developed limb ischemia with gangrene following S. aureus bloodstream infection. Histopathology revealed medium-sized arterial vasculitis. The causing strain belonged to the emerging clone CC1-MSSA and numerous pathogenesis-related genes were identified. Patient's genotyping revealed functional variants associated with severe infections. A combination of virulence and host factors might explain this unique severe form of staphylococcal disease. CONCLUSION A combination of virulence and genetic host factors might explain this unique severe form of staphylococcal disease.
Collapse
Affiliation(s)
- Charles Vidal
- Department of Microbiology, Necker Enfants-malades hospital, APHP, Paris Descartes University, Paris, EU, France
| | - Florence Moulin
- Department of Pediatric Intensive Care Unit, Necker Enfants-Malades Hospital, APHP, Paris Descartes University, Paris, EU, France
| | - Xavier Nassif
- Department of Microbiology, Necker Enfants-malades hospital, APHP, Paris Descartes University, Paris, EU, France
| | - Louise Galmiche
- Pathology Department, Necker Enfants-Malades Hospital, APHP, Paris Descartes University, Paris, EU, France
| | - Delphine Borgel
- Department of Hematology, Necker Enfants-Malades Hospital, APHP, Paris Descartes University, Paris, EU, France
| | - Alain Charbit
- Necker-Enfants-Malades Institute, INSERM U1151; CNRS UMR8253, Paris, France
| | - Capucine Picard
- Center for the Study of Primary Immunodeficiencies, Necker Enfants Malades Hospital, APHP, Paris Descartes University, Paris, EU, France.,IHU Imagine, Laboratory of Human Genetics of Infectious Diseases, INSERM U1163, Paris, EU, France
| | - Jean-Paul Mira
- Medical Intensive Care Unit, Cochin Hospital, AP-HP, Paris Descartes University, Paris, EU, France.,Department of Infection, Immunity and Inflammation, Institut Cochin, INSERM U1016, Paris, EU, France
| | - Olivier Lortholary
- Department of Infectious Diseases and Tropical Medicine, Necker Enfants-Malades Hospital, Necker-Pasteur Infectious Diseases Center, Université Paris Descartes, IHU Imagine, Paris, EU, France
| | - Anne Jamet
- Department of Microbiology, Necker Enfants-malades hospital, APHP, Paris Descartes University, Paris, EU, France.,Necker-Enfants-Malades Institute, INSERM U1151; CNRS UMR8253, Paris, France
| | - Julie Toubiana
- Department of Infection, Immunity and Inflammation, Institut Cochin, INSERM U1016, Paris, EU, France. .,Department of General Pediatrics and Pediatric Infectious Diseases, Necker Enfants-Malades Hospital, APHP, Paris Descartes University, 149 rue de Sèvres, 75015, Paris, EU, France.
| |
Collapse
|
87
|
Fleitas Martínez O, Cardoso MH, Ribeiro SM, Franco OL. Recent Advances in Anti-virulence Therapeutic Strategies With a Focus on Dismantling Bacterial Membrane Microdomains, Toxin Neutralization, Quorum-Sensing Interference and Biofilm Inhibition. Front Cell Infect Microbiol 2019; 9:74. [PMID: 31001485 PMCID: PMC6454102 DOI: 10.3389/fcimb.2019.00074] [Citation(s) in RCA: 152] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 03/05/2019] [Indexed: 12/11/2022] Open
Abstract
Antimicrobial resistance constitutes one of the major challenges facing humanity in the Twenty-First century. The spread of resistant pathogens has been such that the possibility of returning to a pre-antibiotic era is real. In this scenario, innovative therapeutic strategies must be employed to restrict resistance. Among the innovative proposed strategies, anti-virulence therapy has been envisioned as a promising alternative for effective control of the emergence and spread of resistant pathogens. This review presents some of the anti-virulence strategies that are currently being developed, it will cover strategies focused on quench pathogen quorum sensing (QS) systems, disassemble of bacterial functional membrane microdomains (FMMs), disruption of biofilm formation and bacterial toxin neutralization.
Collapse
Affiliation(s)
- Osmel Fleitas Martínez
- Programa de Pós-Graduação em Patologia Molecular, Faculdade de Medicina, Universidade de Brasília, Brasília, Brazil.,Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, Brazil
| | - Marlon Henrique Cardoso
- Programa de Pós-Graduação em Patologia Molecular, Faculdade de Medicina, Universidade de Brasília, Brasília, Brazil.,Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, Brazil.,S-inova Biotech, Programa de Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, Brazil
| | - Suzana Meira Ribeiro
- Programa de Pós-Graduação em Ciências da Saúde, Universidade Federal da Grande Dourados, Dourados, Brazil
| | - Octavio Luiz Franco
- Programa de Pós-Graduação em Patologia Molecular, Faculdade de Medicina, Universidade de Brasília, Brasília, Brazil.,Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, Brazil.,S-inova Biotech, Programa de Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, Brazil
| |
Collapse
|
88
|
Frutis-Murillo M, Sandoval-Carrillo MA, Alva-Murillo N, Ochoa-Zarzosa A, López-Meza JE. Immunomodulatory molecules regulate adhesin gene expression in Staphylococcus aureus: Effect on bacterial internalization into bovine mammary epithelial cells. Microb Pathog 2019; 131:15-21. [PMID: 30930221 DOI: 10.1016/j.micpath.2019.03.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 03/11/2019] [Accepted: 03/25/2019] [Indexed: 11/26/2022]
Abstract
Staphylococcus aureus is a major pathogen of subclinical bovine mastitis that usually is chronic and recurrent, which has been related to its ability to internalize into bovine mammary epithelial cells (bMECs). Previously, we reported that short and medium fatty acids and cholecalciferol reduce S. aureus internalization into pretreated-bMECs with these molecules suggesting a role as immunomodulatory agents. Hence, we assessed the role of sodium butyrate (NaB), sodium octanoate (NaO) and cholecalciferol on S. aureus adhesin expression and its internalization into bMECs. S. aureus pre-treated 2 h with 0.5 mM or 2 mM NaB showed a reduction in internalization into bMECs (∼35% and ∼55%; respectively), which coincided with a down-regulated expression of clumping factor B (ClfB). Also, the S. aureus internalization reduction by 2 mM NaB (2 h) agreed with a down-regulated expression of sdrC. Moreover, the 2 mM NaB (24 h) pre-treatment induced bacterial internalization (∼3-fold), which was related with an up-regulation of spa, clfB and sdrC genes. Also, NaO (0.25 mM and 1 mM) only reduced S. aureus internalization when bacteria were grown 2 h with this molecule but there was no relationship with adhesin expression. In addition, cholecalciferol (50 nM) reduced bacteria internalization at similar levels (∼50%) when bacteria were grown 2 and 24 h in broth supplemented with this compound, which correlated with spa and sdrC mRNA expression down-regulated at 2 h, and fnba and clfB mRNA expression decreased at 24 h. In conclusion, our data support the fact that fatty acids and cholecalciferol regulate adhesin gene expression as well as bacteria internalization in nonprofessional phagocytic cells, which may lead to development of anti-virulence agents for control of pathogens.
Collapse
Affiliation(s)
- Minerva Frutis-Murillo
- Centro Multidisciplinario de Estudios en Biotecnología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, Mexico
| | - Marcelo Alejandro Sandoval-Carrillo
- Centro Multidisciplinario de Estudios en Biotecnología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, Mexico
| | - Nayeli Alva-Murillo
- Departamento de Biología, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Guanajuato, Mexico
| | - Alejandra Ochoa-Zarzosa
- Centro Multidisciplinario de Estudios en Biotecnología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, Mexico
| | - Joel E López-Meza
- Centro Multidisciplinario de Estudios en Biotecnología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, Mexico.
| |
Collapse
|
89
|
Artificial Selection for Pathogenicity Mutations in Staphylococcus aureus Identifies Novel Factors Relevant to Chronic Infection. Infect Immun 2019; 87:IAI.00884-18. [PMID: 30642903 DOI: 10.1128/iai.00884-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 01/10/2019] [Indexed: 02/06/2023] Open
Abstract
Adaptation of Staphylococcus aureus to host microenvironments during chronic infection involves spontaneous mutations, yet changes underlying adaptive phenotypes remain incompletely explored. Here, we employed artificial selection and whole-genome sequencing to better characterize spontaneous chromosomal mutations that alter two pathogenicity phenotypes relevant to chronic infection in S. aureus: intracellular invasiveness and intracellular cytotoxicity. We identified 23 genes whose alteration coincided with enhanced virulence, 11 that were previously known and 12 (52%) that had no previously described role in S. aureus pathogenicity. Using precision genome editing, transposon mutants, and gene complementation, we empirically assessed the contributions of individual genes to the two virulence phenotypes. We functionally validated 14 of 21 genes tested as measurably influencing invasion and/or cytotoxicity, including 8 newly implicated by this study. We identified inactivating mutations (murA, ndhC, and a hypothetical membrane protein) and gain-of-function mutations (aroE Thr182Ile, yhcF Thr74Ile, and Asp486Glu in a hypothetical peptidase) in previously unrecognized S. aureus virulence genes that enhance pathogenesis when introduced into a clean genetic background, as well as a novel activating mutation in the known virulence regulator gene saeS (Ala106Thr). Investigation of potentially epistatic interactions identified a tufA mutation (Ala271Val) that enhances virulence only in the context of purine operon repressor gene (purR) inactivation. This project reveals a functionally diverse range of genes affected by gain- or loss-of-function mutations that contribute to S. aureus adaptive virulence phenotypes. More generally, the work establishes artificial selection as a means to determine the genetic mechanisms underlying complex bacterial phenotypes relevant to adaptation during infection.
Collapse
|
90
|
Chen X, Alonzo F. Bacterial lipolysis of immune-activating ligands promotes evasion of innate defenses. Proc Natl Acad Sci U S A 2019; 116:3764-3773. [PMID: 30755523 PMCID: PMC6397559 DOI: 10.1073/pnas.1817248116] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Commensal and pathogenic bacteria hydrolyze host lipid substrates with secreted lipases and phospholipases for nutrient acquisition, colonization, and infection. Bacterial lipase activity on mammalian lipids and phospholipids can promote release of free fatty acids from lipid stores, detoxify antimicrobial lipids, and facilitate membrane dissolution. The gram-positive bacterium Staphylococcus aureus secretes at least two lipases, Sal1 and glycerol ester hydrolase (Geh), with specificities for short- and long-chain fatty acids, respectively, each with roles in the hydrolysis of environmental lipids. In a recent study from our group, we made the unexpected observation that Geh released by S. aureus inhibits activation of innate immune cells. Herein, we investigated the possibility that S. aureus lipases interface with the host immune system to blunt innate immune recognition of the microbe. We found that the Geh lipase, but not other S. aureus lipases, prevents activation of innate cells in culture. Mutation of geh leads to enhancement of proinflammatory cytokine production during infection, increased innate immune activity, and improved clearance of the bacterium in infected tissue. These in vitro and in vivo effects on innate immunity were not due to direct functions of the lipase on mammalian cells, but rather a result of inactivation of S. aureus lipoproteins, a major pathogen-associated molecular pattern (PAMP) of extracellular gram-positive bacteria, via ester hydrolysis. Altogether, these studies provide insight into an adaptive trait that masks microbial recognition by innate immune cells through targeted inactivation of a broadly conserved PAMP.
Collapse
Affiliation(s)
- Xi Chen
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153
| | - Francis Alonzo
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153
| |
Collapse
|
91
|
Yong YY, Dykes GA, Choo WS. Biofilm formation by staphylococci in health-related environments and recent reports on their control using natural compounds. Crit Rev Microbiol 2019; 45:201-222. [PMID: 30786799 DOI: 10.1080/1040841x.2019.1573802] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Staphylococci are Gram-positive bacteria that are ubiquitous in the environment and able to form biofilms on a range of surfaces. They have been associated with a range of human health issues such as medical device-related infection, localized skin infection, or direct infection caused by toxin production. The extracellular material produced by these bacteria resists antibiotics and host defence mechanism which complicates the treatment process. The commonly reported Staphylococcus species are Staphylococcus aureus and S. epidermidis as they inhabit human bodies. However, the emergence of other staphylococci, such as S. haemolyticus, S. lugdunensis, S. saprophyticus, S. capitis, S. saccharolyticus, S. warneri, S. cohnii, and S. hominis, is also of concern and they have been associated with biofilm formation. This review critically assesses recent cases on the biofilm formation by S. aureus, S. epidermidis, and other staphylococci reported in health-related environments. The control of biofilm formation by staphylococci using natural compounds is specifically discussed as they represent potential anti-biofilm agents which may reduce the burden of antibiotic resistance.
Collapse
Affiliation(s)
- Yi Yi Yong
- a School of Science , Monash University Malaysia , Selangor , Malaysia
| | - Gary A Dykes
- b School of Public Health , Curtin University , Bentley , Australia
| | - Wee Sim Choo
- a School of Science , Monash University Malaysia , Selangor , Malaysia
| |
Collapse
|
92
|
Methicillin-resistant Staphylococcus aureus carriage among medical students of Jimma University, Southwest Ethiopia. Heliyon 2019; 5:e01191. [PMID: 30775580 PMCID: PMC6360348 DOI: 10.1016/j.heliyon.2019.e01191] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 12/07/2018] [Accepted: 01/28/2019] [Indexed: 10/28/2022] Open
Abstract
Objectives Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are often difficult to manage due to its resistance to multiple antibiotics. This study aimed to determine the nasal carriage of MRSA and its antimicrobial susceptibility patterns among medical students at the Jimma University medical center (JUMC), Southwest Ethiopia. Methods An institution based cross-sectional study was conducted at the JUMC from May to August; 2016. A total of 371 participants were systematically selected. Demographic data was collected using pre-designed questionnaire. Nasal swabs were collected following standard microbiological methods. MRSA was detected using cefoxitin (30μg) disc (Oxoid, UK); and antimicrobial susceptibility tests were performed by disc diffusion method. Results A total of 371 students were included. Of these, 84.9% (315/371) were males. The overall prevalence of nasal carriage of S. aureus and MRSA among medical students at JUMC were 22.1% (82/371) and 8.4 % (31/371), respectively. The carriage rate of MRSA among medical intern (20% (16/80)) was higher compared with clinical year-I (3.6% (6/166)) and year-II (7.2% (9/125)) students. Resistance against trimethoprim-sulfamethoxazole, tetracycline and ciprofloxacin were 83.9%, 64.5% and 51.6%, respectively. Longer stay in hospital was significantly associated with the acquisition of MRSA (X2 = 6.93, P value = 0.031). Conclusion The prevalence of nasal carriage of MRSA was high. Longer stay in hospital environment was associated with the acquisition of MRSA. These findings suggest that infection control efforts focusing the performance of antimicrobial stewardship could have a significant impact on MRSA incidence in this setting.
Collapse
|
93
|
Soltani E, Farrokhi E, Zamanzad B, Shahini Shams Abadi M, Deris F, Soltani A, Gholipour A. Prevalence and distribution of adhesins and the expression of fibronectin-binding protein (FnbA and FnbB) among Staphylococcus aureus isolates from Shahrekord Hospitals. BMC Res Notes 2019; 12:49. [PMID: 30670071 PMCID: PMC6341569 DOI: 10.1186/s13104-019-4055-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 01/08/2019] [Indexed: 11/18/2022] Open
Abstract
Objective One of the most important causes of nosocomial infections is Staphylococcus aureus. The aim of this study was to determine the frequency of these genes and the rate of expression of these genes during nasal colonization among the personnel of Kashani and Hajar hospitals. Results In this Analytical-descriptive study, 240 nasal swab specimens were collected from personnel of different departments of Kashani and Hajar hospitals in Shahr-e-kord. Nasal specimens were cultured and 110 Staphylococcus strains were isolated. Based on the results, 110 carriers of Staphylococcus aureus were identified. The frequency of clfA, clfB, fnbA and fnbB genes were 36.3%, 86.3%, 7.2% and 43.6% respectively. It was also observed that the fnbA gene showed no expression, but of 95 clfB-positive samples, 73 isolates (76.8%) were expressed clfB gene. This study showed that the abundance of these genes varies in nasal colonization. It was also observed that clfB gene with a high frequency and high expression rate has an important role in nose colonization. These results not only provide insight into the factors involved in S. aureus colonization but also provide potential therapeutic targets.
Collapse
Affiliation(s)
- Emad Soltani
- Cellular and Molecular Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Effat Farrokhi
- Cellular and Molecular Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Behnam Zamanzad
- Cellular and Molecular Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Milad Shahini Shams Abadi
- Department of Bacteriology & Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Fatemeh Deris
- Department of Epidemiology and Biostatistics, School of Health, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Amin Soltani
- Medical Plants Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Abolfazl Gholipour
- Cellular and Molecular Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran. .,Department of Microbiology and Immunology, Cellular and Molecular Research Center, Shahrekord University of Medical Sciences, Shahrekord, IR, Iran.
| |
Collapse
|
94
|
Mohamed N, Timofeyeva Y, Jamrozy D, Rojas E, Hao L, Silmon de Monerri NC, Hawkins J, Singh G, Cai B, Liberator P, Sebastian S, Donald RGK, Scully IL, Jones CH, Creech CB, Thomsen I, Parkhill J, Peacock SJ, Jansen KU, Holden MTG, Anderson AS. Molecular epidemiology and expression of capsular polysaccharides in Staphylococcus aureus clinical isolates in the United States. PLoS One 2019; 14:e0208356. [PMID: 30641545 PMCID: PMC6331205 DOI: 10.1371/journal.pone.0208356] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Accepted: 11/15/2018] [Indexed: 12/14/2022] Open
Abstract
Staphylococcus aureus capsular polysaccharides (CP) are important virulence factors under evaluation as vaccine antigens. Clinical S. aureus isolates have the biosynthetic capability to express either CP5 or CP8 and an understanding of the relationship between CP genotype/phenotype and S. aureus epidemiology is valuable. Using whole genome sequencing, the clonal relatedness and CP genotype were evaluated for disease-associated S. aureus isolates selected from the Tigecycline Evaluation and Surveillance Trial (T.E.S.T) to represent different geographic regions in the United States (US) during 2004 and 2009–10. Thirteen prominent clonal complexes (CC) were identified, with CC5, 8, 30 and 45 representing >80% of disease isolates. CC5 and CC8 isolates were CP type 5 and, CC30 and CC45 isolates were CP type 8. Representative isolates from prevalent CC were susceptible to in vitro opsonophagocytic killing elicited by anti-CP antibodies, demonstrating that susceptibility to opsonic killing is not linked to the genetic lineage. However, as not all S. aureus isolates may express CP, isolates representing the diversity of disease isolates were assessed for CP production. While approximately 35% of isolates (primarily CC8) did not express CP in vitro, CP expression could be clearly demonstrated in vivo for 77% of a subset of these isolates (n = 20) despite the presence of mutations within the capsule operon. CP expression in vivo was also confirmed indirectly by measuring an increase in CP specific antibodies in mice infected with CP5 or CP8 isolates. Detection of antigen expression in vivo in relevant disease states is important to support the inclusion of these antigens in vaccines. Our findings confirm the validity of CP as vaccine targets and the potential of CP-based vaccines to contribute to S. aureus disease prevention.
Collapse
Affiliation(s)
- Naglaa Mohamed
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - Yekaterina Timofeyeva
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - Dorota Jamrozy
- The Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Eduardo Rojas
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - Li Hao
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | | | - Julio Hawkins
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - Guy Singh
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - Bing Cai
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - Paul Liberator
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - Shite Sebastian
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - Robert G. K. Donald
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - Ingrid L. Scully
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - C. Hal Jones
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | - C. Buddy Creech
- Vanderbilt Vaccine Research Program, Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Isaac Thomsen
- Vanderbilt Vaccine Research Program, Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Julian Parkhill
- The Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Sharon J. Peacock
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Kathrin U. Jansen
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
| | | | - Annaliesa S. Anderson
- Pfizer Vaccine Research and Development, Pearl River, New York, United States of America
- * E-mail:
| |
Collapse
|
95
|
Corynebacterium pseudodiphtheriticum Exploits Staphylococcus aureus Virulence Components in a Novel Polymicrobial Defense Strategy. mBio 2019; 10:mBio.02491-18. [PMID: 30622190 PMCID: PMC6325251 DOI: 10.1128/mbio.02491-18] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
While some individuals are nasally colonized with S. aureus, the underlying factors that determine colonization are not understood. There is increasing evidence that indicates that resident bacteria play a role; some commensal species can eradicate S. aureus from the nasal cavity. Among these, Corynebacterium pseudodiphtheriticum can eliminate S. aureus from the human nose. We sought to understand this phenomenon at a molecular level and found that C. pseudodiphtheriticum produces a factor(s) that specifically kills S. aureus. While resistant S. aureus isolates were recovered at a low frequency, resistance came at the cost of attenuated virulence in these strains. Molecular dissection of the specific strategies used by C. pseudodiphtheriticum to kill S. aureus could lead to the development of novel treatments or therapies. Furthermore, commensal competition that requires virulence components of the competitor may represent an exciting and unexplored possibility for development of novel antimicrobial compounds. Commensal bacteria in the human nasal cavity are known to suppress opportunistic pathogen colonization by competing for limited space and nutrients. It has become increasingly apparent that some commensal bacteria also produce toxic compounds that directly inhibit or kill incoming competitors. Numerous studies suggest that microbial species-specific interactions can affect human nasal colonization by the opportunistic pathogen Staphylococcus aureus. However, the complex and dynamic molecular interactions that mediate these effects on S. aureus nasal colonization are often difficult to study and remain poorly understood. Here, we show that Corynebacterium pseudodiphtheriticum, a common member of the normal nasal microbiota, mediates contact-independent bactericidal activity against S. aureus, including methicillin-resistant S. aureus (MRSA). Bacterial interaction assays revealed that S. aureus isolates that were spontaneously resistant to C. pseudodiphtheriticum killing could be recovered at a low frequency. To better understand the pathways associated with killing and resistance, a S. aureus transposon mutant library was utilized to select for resistant mutant strains. We found that insertional inactivation of agrC, which codes for the sensor kinase of the Agr quorum sensing (Agr QS) system that regulates expression of many virulence factors in S. aureus, conferred resistance to killing. Analysis of the spontaneously resistant S. aureus isolates revealed that each showed decreased expression of the Agr QS components. Targeted analysis of pathways regulated by Agr QS revealed that loss of the phenol-soluble modulins (PSMs), which are effectors of Agr QS, also conferred resistance to bactericidal activity. Transmission electron microscopy analysis revealed that C. pseudodiphtheriticum induced dramatic changes to S. aureus cell surface morphology that likely resulted in cell lysis. Taken together, these data suggest that C. pseudodiphtheriticum-mediated killing of S. aureus requires S. aureus virulence components. While S. aureus can overcome targeted killing, this occurs at the cost of attenuated virulence; loss of Agr QS activity would phenotypically resemble a S. aureus commensal state that would be unlikely to be associated with disease. Commensal competition resulting in dampened virulence of the competitor may represent an exciting and unexplored possibility for development of novel antimicrobial compounds.
Collapse
|
96
|
Côté-Gravel J, Malouin F. Symposium review: Features of Staphylococcus aureus mastitis pathogenesis that guide vaccine development strategies. J Dairy Sci 2018; 102:4727-4740. [PMID: 30580940 DOI: 10.3168/jds.2018-15272] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Accepted: 10/07/2018] [Indexed: 12/25/2022]
Abstract
Bovine mastitis affects animal health and welfare and milk production and quality, and it challenges the economic success of dairy farms. Staphylococcus aureus is one of the most commonly found pathogens in clinical mastitis but it also causes subclinical, persistent, and difficult-to-treat intramammary infections. Because of the failure of conventional antibiotic treatments and increasing pressure and concern from experts and consumers over the use of antibiotics in the dairy industry, many attempts have been made over the years to develop a vaccine for the prevention and control of Staph. aureus intramammary infections. Still, no commercially available vaccine formulation demonstrates sufficient protection and cost-effective potential. Multiple factors account for the lack of protection, including inadequate vaccine targets, high diversity among mastitis-provoking strains, cow-to-cow variation in immune response, and a failure to elicit an immune response that is appropriate for protection against a highly complex pathogen. The purpose of this review is to summarize key concepts related to the pathogenesis of Staph. aureus, and its interaction with the host, as well as to describe recent vaccine development strategies for prevention and control of Staph. aureus mastitis.
Collapse
Affiliation(s)
- Julie Côté-Gravel
- Centre d'Étude et de Valorisation de la Diversité Microbienne (CEVDM), Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, Canada, J1K 2R1
| | - François Malouin
- Centre d'Étude et de Valorisation de la Diversité Microbienne (CEVDM), Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, Canada, J1K 2R1.
| |
Collapse
|
97
|
Singh N, Rajwade J, Paknikar KM. Transcriptome analysis of silver nanoparticles treated Staphylococcus aureus reveals potential targets for biofilm inhibition. Colloids Surf B Biointerfaces 2018; 175:487-497. [PMID: 30572157 DOI: 10.1016/j.colsurfb.2018.12.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 11/13/2018] [Accepted: 12/12/2018] [Indexed: 12/21/2022]
Abstract
The biofilms of Staphylococcus aureus on the implanted materials and chronic wounds are life-threatening and are a substantial financial burden on the healthcare system. Silver nanoparticles (SNP), known for their multi-level physiological effects in planktonic cells could be a promising agent in the treatment of biofilm-related infections also. To gain insight into the effects of SNP on various physiological processes in biofilms we studied the transcriptome of Staphylococcus aureus ATCC 29213. To distinguish between 'nanoparticles-specific' and 'ion-specific' effect of silver, we performed a comparative analysis of the functional genes in response to Ag+. As compared to untreated biofilms, 21% (i.e. 629 genes) and 28.5% (i. e. 830 genes) of the total functional coding genes were differentially regulated upon exposure to SNP and Ag+. Genes encoding capsular polysaccharides, intercellular adhesion, virulence were downregulated in SNP and Ag+ treated biofilms. Genes involved in carbohydrate, protein metabolism including DNA and RNA synthesis, oxidative stress etc. were differentially expressed. Further, activation of efflux pumps and multidrug export proteins was observed, which clearly indicates the presence of metal stress resistance determinants in S. aureus. Silver blocked the integration of mobile genetic elements in S. aureus genome. Our study points out quorum sensing and virulence determinants as possible targets for inhibition of biofilms possibly with/without existing antibiotics. However, further studies on these aspects are warranted. Scanning electron microscopy (SEM) and confocal microscopy revealed changes in biofilm morphology, architecture and thickness in presence of silver nanoparticles and ionic silver, substantiating the transcriptome data.
Collapse
Affiliation(s)
- Nimisha Singh
- Nanobioscience Group, Agharkar Research Institute, G. G. Agarkar Road, Pune, 411 004, India; Savitribai Phule Pune University, Ganeshkhind, Pune 411 007, India
| | - Jyutika Rajwade
- Nanobioscience Group, Agharkar Research Institute, G. G. Agarkar Road, Pune, 411 004, India; Savitribai Phule Pune University, Ganeshkhind, Pune 411 007, India.
| | - K M Paknikar
- Nanobioscience Group, Agharkar Research Institute, G. G. Agarkar Road, Pune, 411 004, India; Savitribai Phule Pune University, Ganeshkhind, Pune 411 007, India.
| |
Collapse
|
98
|
Ziegenfuss SJ, Helgerson AF, Matos B, Dombroski-Brokman AM. Ultraviolet Light Efficacy for Decontamination of Safety Glasses. APPLIED BIOSAFETY 2018. [DOI: 10.1177/1535676018786962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
99
|
Surewaard BGJ, Thanabalasuriar A, Zeng Z, Tkaczyk C, Cohen TS, Bardoel BW, Jorch SK, Deppermann C, Bubeck Wardenburg J, Davis RP, Jenne CN, Stover KC, Sellman BR, Kubes P. α-Toxin Induces Platelet Aggregation and Liver Injury during Staphylococcus aureus Sepsis. Cell Host Microbe 2018; 24:271-284.e3. [PMID: 30033122 DOI: 10.1016/j.chom.2018.06.017] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 05/15/2018] [Accepted: 06/27/2018] [Indexed: 01/09/2023]
Abstract
During sepsis, small blood vessels can become occluded by large platelet aggregates of poorly understood etiology. During Staphylococcal aureus infection, sepsis severity is linked to the bacterial α-toxin (α-hemolysin, AT) through unclear mechanisms. In this study, we visualized intravascular events in the microcirculation and found that intravenous AT injection induces rapid platelet aggregation, forming dynamic micro-thrombi in the microcirculation. These aggregates are retained in the liver sinusoids and kidney glomeruli, causing multi-organ dysfunction. Acute staphylococcal infection results in sequestration of most bacteria by liver macrophages. Platelets are initially recruited to these macrophages and help eradicate S. aureus. However, at later time points, AT causes aberrant and damaging thrombosis throughout the liver. Treatment with an AT neutralizing antibody (MEDI4893∗) prevents platelet aggregation and subsequent liver damage, without affecting the initial and beneficial platelet recruitment. Thus, AT neutralization may represent a promising approach to combat staphylococcal-induced intravascular coagulation and organ dysfunction.
Collapse
Affiliation(s)
- Bas G J Surewaard
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada; Department of Medical Microbiology, University Medical Center, Utrecht, the Netherlands
| | - Ajitha Thanabalasuriar
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Zhutian Zeng
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Christine Tkaczyk
- Department of Microbial Sciences, Medimmune, LLC, Gaithersburg, MD, USA
| | - Taylor S Cohen
- Department of Microbial Sciences, Medimmune, LLC, Gaithersburg, MD, USA
| | - Bart W Bardoel
- Department of Medical Microbiology, University Medical Center, Utrecht, the Netherlands
| | - Selina K Jorch
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Carsten Deppermann
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Juliane Bubeck Wardenburg
- Department of Pediatrics and Division of Pediatric Critical Care Medicine at Washington University School of Medicine, St. Louis, MO, USA
| | - Rachelle P Davis
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada; Department of Microbiology, Immunology and Infectious Disease, University of Calgary, Calgary, AB, Canada
| | - Craig N Jenne
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada; Department of Microbiology, Immunology and Infectious Disease, University of Calgary, Calgary, AB, Canada
| | - Kendall C Stover
- Department of Microbial Sciences, Medimmune, LLC, Gaithersburg, MD, USA
| | - Bret R Sellman
- Department of Microbial Sciences, Medimmune, LLC, Gaithersburg, MD, USA
| | - Paul Kubes
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada.
| |
Collapse
|
100
|
Kang SJ, Choi SM, Choi JA, Choi JU, Oh TH, Kim SE, Kim UJ, Won EJ, Jang HC, Park KH, Shin JH, Kweon SS, Jung SI. Factors affecting the clinical relevance of Corynebacterium striatum isolated from blood cultures. PLoS One 2018; 13:e0199454. [PMID: 29928059 PMCID: PMC6013186 DOI: 10.1371/journal.pone.0199454] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Accepted: 06/07/2018] [Indexed: 02/07/2023] Open
Abstract
This study aimed to identify clinical or microbiological factors affecting the clinical relevance of Corynebacterium striatum isolated from blood cultures. A total of 64 isolates from 51 patients identified as C. striatum by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S rRNA gene sequencing were assessed. More than two blood cultures were positive in 25 (48.1%) patients. Diabetes, solid tumor, and a history of previous exposure to antibiotics were more common in patients with multiple positive blood cultures. Charlson comorbidity scores were also higher, and more isolates were recovered after 48 hours of hospital stay in patients with multiple positive blood cultures. Strains recovered from patients with multiple positive blood cultures produced significantly more biofilm. Based on multilocus sequence typing (MLST), sequence type (ST) 20 (31.3%) was the most dominant, followed by ST2 (20.3%) and ST23 (10.9%). There was no relationship between the number of positive blood culture sets and sequence typing. In multivariate analyses, Carlson comorbidity score (odds ratio [OR], 1.91; 95% confidence interval [CI], 1.09–3.36; P = 0.03) and biofilm formation were associated with multiple positive blood cultures (OR, 17.43; 95% CI, 3.71–81.91; P = 0.03). This study provides evidence that the biofilm phenotype could contribute to determining the clinical significance of C. striatum in patients with severe underlying conditions. The predominance of certain STs suggests the relatedness of C. striatum infection and the nosocomial environment.
Collapse
Affiliation(s)
- Seung Ji Kang
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, South Korea
| | - Su-Mi Choi
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, South Korea
| | - Jin-A Choi
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, South Korea
| | - Jin Un Choi
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, South Korea
| | - Tae-Hoon Oh
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, South Korea
| | - Seong Eun Kim
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, South Korea
| | - Uh Jin Kim
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, South Korea
| | - Eun Jeong Won
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, South Korea
| | - Hee-Chang Jang
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, South Korea
| | - Kyung-Hwa Park
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, South Korea
| | - Jong Hee Shin
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, South Korea
| | - Sun-Seog Kweon
- Department of Preventive Medicine, Chonnam National University Medical School, Gwangju, South Korea
| | - Sook-In Jung
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, South Korea
- * E-mail:
| |
Collapse
|