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Bowden LC, Finlinson J, Jones B, Berges BK. Beyond the double helix: the multifaceted landscape of extracellular DNA in Staphylococcus aureus biofilms. Front Cell Infect Microbiol 2024; 14:1400648. [PMID: 38903938 PMCID: PMC11188362 DOI: 10.3389/fcimb.2024.1400648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Accepted: 05/17/2024] [Indexed: 06/22/2024] Open
Abstract
Staphylococcus aureus forms biofilms consisting of cells embedded in a matrix made of proteins, polysaccharides, lipids, and extracellular DNA (eDNA). Biofilm-associated infections are difficult to treat and can promote antibiotic resistance, resulting in negative healthcare outcomes. eDNA within the matrix contributes to the stability, growth, and immune-evasive properties of S. aureus biofilms. eDNA is released by autolysis, which is mediated by murein hydrolases that access the cell wall via membrane pores formed by holin-like proteins. The eDNA content of S. aureus biofilms varies among individual strains and is influenced by environmental conditions, including the presence of antibiotics. eDNA plays an important role in biofilm development and structure by acting as an electrostatic net that facilitates protein-cell and cell-cell interactions. Because of eDNA's structural importance in biofilms and its ubiquitous presence among S. aureus isolates, it is a potential target for therapeutics. Treatment of biofilms with DNase can eradicate or drastically reduce them in size. Additionally, antibodies that target DNABII proteins, which bind to and stabilize eDNA, can also disperse biofilms. This review discusses the recent literature on the release, structure, and function of eDNA in S. aureus biofilms, in addition to a discussion of potential avenues for targeting eDNA for biofilm eradication.
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Affiliation(s)
| | | | | | - Bradford K. Berges
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT, United States
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Hofer LK, Jurcisek JA, Elmaraghy C, Goodman SD, Bakaletz LO. Z-Form Extracellular DNA in Pediatric CRS May Provide a Mechanism for Recalcitrance to Treatment. Laryngoscope 2024; 134:1564-1571. [PMID: 37597166 PMCID: PMC10875147 DOI: 10.1002/lary.30986] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/21/2023] [Accepted: 08/09/2023] [Indexed: 08/21/2023]
Abstract
OBJECTIVES We examined sinus mucosal samples recovered from pediatric chronic rhinosinusitis (CRS) patients for the presence of Z-form extracellular DNA (eDNA) due to its recently elucidated role in pathogenesis of disease. Further, we immunolabeled these specimens for the presence of both members of the bacterial DNA-binding DNABII protein family, integration host factor (IHF) and histone-like protein (HU), due to their known role in converting common B-DNA to the rare Z-form. METHODS Sinus mucosa samples recovered from 20 patients during functional endoscopic sinus surgery (FESS) were immunolabelled for B- and Z-DNA, as well as for both bacterial DNABII proteins. RESULTS Nineteen of 20 samples (95%) included areas rich in eDNA, with the majority in the Z-form. Areas positive for B-DNA were restricted to the most distal regions of the mucosal specimen. Labeling for both DNABII proteins was observed on B- and Z-DNA, which aligned with the role of these proteins in the B-to-Z DNA conversion. CONCLUSIONS Abundant Z-form eDNA in culture-positive pediatric CRS samples suggested that bacterial DNABII proteins were responsible for the conversion of eukaryotic B-DNA that had been released into the luminal space by PMNs during NETosis, to the Z-form. The presence of both DNABII proteins on B-DNA and Z-DNA supported the known role of these bacterial proteins in the B-to-Z DNA conversion. Given that Z-form DNA both stabilizes the bacterial biofilm and inactivates PMN NET-mediated killing of trapped bacteria, we hypothesize that this conversion may be contributing to the chronicity and recalcitrance of CRS to treatment. LEVEL OF EVIDENCE NA Laryngoscope, 134:1564-1571, 2024.
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Affiliation(s)
- Llwyatt K. Hofer
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children’s Hospital
| | - Joseph A. Jurcisek
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children’s Hospital
| | - Charles Elmaraghy
- The Ohio State University College of Medicine
- Department of Otolaryngology-Head and Neck Surgery, The Ohio State University Wexner Medical Center
- Department of Pediatric Otolaryngology, Nationwide Children’s Hospital
| | - Steven D. Goodman
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children’s Hospital
- The Ohio State University College of Medicine
| | - Lauren O. Bakaletz
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children’s Hospital
- The Ohio State University College of Medicine
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3
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Heward E, Saeed H, Bate S, Rajai A, Molloy J, Isba R, Ashcroft DM, Hay AD, Nichani JR, Bruce IA. Risk factors associated with the development of chronic suppurative otitis media in children: Systematic review and meta-analysis. Clin Otolaryngol 2024; 49:62-73. [PMID: 37794685 DOI: 10.1111/coa.14102] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 08/08/2023] [Accepted: 09/21/2023] [Indexed: 10/06/2023]
Abstract
OBJECTIVES Chronic suppurative otitis media (CSOM) is defined as persistent discharge through a tympanic membrane perforation for greater than 2 weeks. It is associated with a significant disease burden, including hearing loss, and reducing its incidence could significantly improve short- and long-term health. We aimed to identify risk factors associated with the development of CSOM in children. DESIGN AND SETTING Systematic review and meta-analysis of studies set in community, primary and secondary care settings, identified from Medline, Embase and Cochrane databases from 2000 to 2022. PARTICIPANTS Children 16 years old and below. MAIN OUTCOME MEASURES Clinical diagnosis of CSOM. RESULTS In total, 739 papers were screened, with 12 deemed eligible for inclusion in the systematic review, of which, 10 were included in the meta-analysis. Risk factors examined included perinatal, patient, dietary, environmental and parental factors. Meta-analysis results indicate that atopy (RR = 1.18, 95% CI [1.01-1.37], p = .04, 2 studies); and birth weight <2500 g (RR = 1.79 [1.27-2.50], p < .01, 2 studies) are associated with an increased risk of CSOM development. Factors not associated were male sex (RR = 0.96 [0.82-1.13], p = .62, 8 studies); exposure to passive smoking (RR = 1.27 [0.81-2.01], p = .30, 3 studies); and parental history of otitis media (RR = 1.14 [0.59-2.20], p = .69, 2 studies). CONCLUSION Optimal management of risk factors associated with CSOM development will help reduce the burden of disease and prevent disease progression or recurrence. The current quality of evidence in the literature is variable and heterogeneous. Future studies should aim to use standardised classification systems to define risk factors to allow meta-analysis.
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Affiliation(s)
- Elliot Heward
- Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, Manchester, UK
- Manchester Academic Health Science Centre, Research and Innovation, Manchester University NHS Foundation Trust, Manchester, UK
| | - Haroon Saeed
- Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, Manchester, UK
- Manchester Academic Health Science Centre, Research and Innovation, Manchester University NHS Foundation Trust, Manchester, UK
| | - Sebastian Bate
- Manchester Academic Health Science Centre, Research and Innovation, Manchester University NHS Foundation Trust, Manchester, UK
- Division of Population Health, Health Services Research, and Primary Care, Centre for Biostatistics, School of Health Sciences, University of Manchester, Manchester, UK
| | - Azita Rajai
- Manchester Academic Health Science Centre, Research and Innovation, Manchester University NHS Foundation Trust, Manchester, UK
- Division of Population Health, Health Services Research, and Primary Care, Centre for Biostatistics, School of Health Sciences, University of Manchester, Manchester, UK
| | - John Molloy
- Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, Manchester, UK
- Royal Manchester Children's Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester, UK
| | - Rachel Isba
- Royal Manchester Children's Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester, UK
- Lancaster Medical School, Lancaster University, Health Innovation One, Lancaster, UK
| | - Darren M Ashcroft
- Division of Pharmacy & Optometry, Faculty of Biology, Medicine and Health, School of Health Sciences, University of Manchester, Manchester, UK
- NIHR Greater Manchester Patient Safety Translational Research Centre (PSTRC), University of Manchester, Manchester, UK
| | - Alastair D Hay
- Centre for Academic Primary Care, Bristol Medical School, Population Health Sciences, University of Bristol, Bristol, UK
| | - Jaya R Nichani
- Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, Manchester, UK
- Manchester Academic Health Science Centre, Research and Innovation, Manchester University NHS Foundation Trust, Manchester, UK
- Royal Manchester Children's Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester, UK
| | - Iain A Bruce
- Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, Manchester, UK
- Manchester Academic Health Science Centre, Research and Innovation, Manchester University NHS Foundation Trust, Manchester, UK
- Royal Manchester Children's Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester, UK
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Dedhia K, Li Y, Stallings VA, Germiller J, Giordano T, Dailey J, Kong M, Durkin A, Legg-Jack I, Nessen S, Schapira MM. Association of Diet Patterns and Post-Operative Tympanostomy Tube Otorrhea: A Pilot Study. Laryngoscope 2023; 133:3575-3581. [PMID: 36960887 DOI: 10.1002/lary.30672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/21/2023] [Accepted: 03/08/2023] [Indexed: 03/25/2023]
Abstract
OBJECTIVE The objective of this study was to explore diet patterns in children with tympanostomy tube placement (TTP) complicated by postoperative tympanostomy tube otorrhea. STUDY DESIGN Cross-sectional survey and retrospective cohort study. METHODS Caregivers of children (0-12 years old), at a tertiary-care pediatric hospital who underwent TTP within 6 months to 2 years prior to enrollment were included. Children with a history of Down syndrome, cleft palate, craniofacial syndromes, known immunodeficiency, or a non-English-speaking family were excluded. Our primary outcome variable was the number of otorrhea episodes. The primary predictor was diet patterns, particularly dessert intake, which was captured through a short food questionnaire. RESULTS A total of 286 participants were included in this study. The median age was 1.8 years (IQR, 1.3, 2.9). A total of 174 (61%) participants reported at least one episode of otorrhea. Children who consumed dessert at least two times per week had a higher risk of otorrhea compared to children who consumed one time per week or less (odds ratio [OR], 3.22, 95% Confidence Interval [CI]: 1.69, 6.12). The odds ratio increase continued when considering more stringent criteria for otorrhea (multiple episodes or one episode occurring 4 weeks after surgery), with a 2.33 (95% CI: 1.24, 4.39) higher odds of otorrhea in children with dessert intake at least 2 times per week. CONCLUSIONS Our pilot data suggest that episodes of otorrhea among children with TTP were associated with more frequent dessert intake. Future studies using prospectively administered diet questionnaires are necessary to confirm these findings. LEVEL OF EVIDENCE 4 Laryngoscope, 133:3575-3581, 2023.
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Affiliation(s)
- Kavita Dedhia
- Division of Otolaryngology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, U.S.A
- Department of Otorhinolaryngology-Head and Neck Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A
| | - Yun Li
- Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A
- Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, U.S.A
- University of Pennsylvania Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A
| | - Virginia A Stallings
- Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, U.S.A
| | - John Germiller
- Division of Otolaryngology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, U.S.A
- Department of Otorhinolaryngology-Head and Neck Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A
| | - Terri Giordano
- Division of Otolaryngology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, U.S.A
| | - Julia Dailey
- Division of Otolaryngology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, U.S.A
| | - Maria Kong
- Division of Otolaryngology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, U.S.A
| | - Alexandra Durkin
- Division of Otolaryngology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, U.S.A
| | - Ibikari Legg-Jack
- University of Pennsylvania Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A
| | - Sarah Nessen
- University of Pennsylvania Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A
| | - Marilyn M Schapira
- Department of Internal Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, U.S.A
- Center for Health Equity Research and Promotion, Philadelphia VA Medical Center, Philadelphia, Pennsylvania, U.S.A
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5
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Jones JW, Ballard DP, Hillman TA, Chen DA. Outcomes of Mastoidectomy With Antibiotic Catheter Irrigation for Patients With Draining Ventilation Tubes. EAR, NOSE & THROAT JOURNAL 2023; 102:673-679. [PMID: 34130511 DOI: 10.1177/01455613211025742] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVES To evaluate the effectiveness of mastoidectomy with antibiotic catheter irrigation in patients with chronic tympanostomy tube otorrhea. METHODS A chart review of adult and pediatric patients with persistent tympanostomy tube otorrhea who had failed outpatient medical management and underwent mastoidectomy with placement of a temporary indwelling catheter for antibiotic instillation was performed. Patients were retrospectively followed for recurrent drainage after 2 months and outcomes were categorized as resolution (0-1 episodes of otorrhea or otitis media with effusion during follow-up), improvement (2-3 episodes), or continued episodic (>3 episodes). RESULTS There were 22 patients and 23 operated ears. Median age was 46 years (interquartile range, IQR = 29-65). The median duration of otorrhea from referral was 5.5 months (IQR = 2.8-12). Following surgery, 14 ears had resolution of drainage, 6 had improvement, and 3 had episodic. The observed percentage of resolved/improved ears (87%) was significant (P = .0005, 95% CI = 67.9%-95.5%). Median follow-up time was 25 months (IQR = 12-59). Pre and postoperative pure tone averages improved (difference of medians = -3.3 dB, P = .02) with no significant difference in word recognition scores (P = .68). Methicillin-resistant Staphylococcus aureus was the most common isolated microbe while no growth was most frequently noted on intraoperative cultures. CONCLUSIONS Mastoidectomy with antibiotic catheter irrigation may be an effective surgical strategy, and single stage alternative to intravenous antibiotics, for select patients with persistent tube otorrhea who have failed topical and oral antibiotics.
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Affiliation(s)
- Joel W Jones
- Pittsburgh Ear Associates, Allegheny General Hospital, Pittsburgh, PA, USA
- Department of Otolaryngology-Head & Neck Surgery, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - Daniel P Ballard
- Pittsburgh Ear Associates, Allegheny General Hospital, Pittsburgh, PA, USA
| | - Todd A Hillman
- Pittsburgh Ear Associates, Allegheny General Hospital, Pittsburgh, PA, USA
| | - Douglas A Chen
- Pittsburgh Ear Associates, Allegheny General Hospital, Pittsburgh, PA, USA
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Inhibitory Effect of Thymol on Tympanostomy Tube Biofilms of Methicillin-Resistant Staphylococcus aureus and Ciprofloxacin-Resistant Pseudomonas aeruginosa. Microorganisms 2022; 10:microorganisms10091867. [PMID: 36144469 PMCID: PMC9505391 DOI: 10.3390/microorganisms10091867] [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: 05/24/2022] [Revised: 09/13/2022] [Accepted: 09/14/2022] [Indexed: 11/17/2022] Open
Abstract
The formation of antibiotic-resistant strain biofilms in tympanostomy tubes results in persistent and refractory otorrhea. In the present study, we investigated the in vitro antibiofilm activity of thymol against biofilms formed by methicillin-resistant Staphylococcus aureus (MRSA) and ciprofloxacin-resistant Pseudomonas aeruginosa (CRPA), using live and dead bacterial staining and adhesion, biofilm formation, biofilm eradication, and biofilm hydrolytic activity assays. The antibiofilm activity of thymol against tympanostomy tube biofilms formed by MRSA and CRPA strains was examined using a scanning electron microscope. In response to thymol treatment, we detected significant concentration-dependent reductions in the viability and adhesion of MRSA and CRPA. Exposure to thymol also inhibited the formation of both MRSA and CRPA biofilms. Furthermore, thymol was observed to enhance the eradication of preformed mature biofilms produced by MRSA and CRPA and also promoted a reduction in the rates of MRSA and CRPA hydrolysis. Exposure to thymol eradicated extracellular polysaccharide present in the biofilm matrix produced by MRSA and CRPA. Additionally, thymol was observed to significantly eradicate MRSA and CRPA biofilms that had formed on the surface on tympanostomy tubes. Collectively, our findings indicate that thymol is an effective inhibitor of MRSA and CRPA biofilms, and accordingly has potential utility as a therapeutic agent for the treatment of biofilm-associated refractory post-tympanostomy tube otorrhea resulting from MRSA and CRPA infection.
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7
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Goodman SD, Bakaletz LO. Bacterial Biofilms Utilize an Underlying Extracellular DNA Matrix Structure That Can Be Targeted for Biofilm Resolution. Microorganisms 2022; 10:microorganisms10020466. [PMID: 35208922 PMCID: PMC8878592 DOI: 10.3390/microorganisms10020466] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/11/2022] [Accepted: 02/15/2022] [Indexed: 12/16/2022] Open
Abstract
Bacterial biofilms contribute significantly to the antibiotic resistance, pathogenesis, chronicity and recurrence of bacterial infections. Critical to the stability and survival of extant biofilms is the extracellular DNA (eDNA)-dependent matrix which shields the resident bacteria from hostile environments, allows a sessile metabolic state, but also encourages productive interactions with biofilm-inclusive bacteria. Given the importance of the eDNA, approaches to this area of research have been to target not just the eDNA, but also the additional constituent structural components which appear to be widespread. Chief among these is a ubiquitous two-member family of bacterial nucleoid associated proteins (the DNABII proteins) responsible for providing structural integrity to the eDNA and thereby the biofilm. Moreover, this resultant novel eDNA-rich secondary structure can also be targeted for disruption. Here, we provide an overview of both what is known about the eDNA-dependent matrix, as well as the resultant means that have resulted in biofilm resolution. Results obtained to date have been highly supportive of continued development of DNABII-targeted approaches, which is encouraging given the great global need for improved methods to medically manage, or ideally prevent biofilm-dependent infections, which remains a highly prevalent burden worldwide.
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Rogers JV, Hall VL, McOsker CC. Crumbling the Castle: Targeting DNABII Proteins for Collapsing Bacterial Biofilms as a Therapeutic Approach to Treat Disease and Combat Antimicrobial Resistance. Antibiotics (Basel) 2022; 11:104. [PMID: 35052981 PMCID: PMC8773079 DOI: 10.3390/antibiotics11010104] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/02/2022] [Accepted: 01/10/2022] [Indexed: 12/15/2022] Open
Abstract
Antimicrobial resistance (AMR) is a concerning global threat that, if not addressed, could lead to increases in morbidity and mortality, coupled with societal and financial burdens. The emergence of AMR bacteria can be attributed, in part, to the decreased development of new antibiotics, increased misuse and overuse of existing antibiotics, and inadequate treatment options for biofilms formed during bacterial infections. Biofilms are complex microbiomes enshrouded in a self-produced extracellular polymeric substance (EPS) that is a primary defense mechanism of the resident microorganisms against antimicrobial agents and the host immune system. In addition to the physical protective EPS barrier, biofilm-resident bacteria exhibit tolerance mechanisms enabling persistence and the establishment of recurrent infections. As current antibiotics and therapeutics are becoming less effective in combating AMR, new innovative technologies are needed to address the growing AMR threat. This perspective article highlights such a product, CMTX-101, a humanized monoclonal antibody that targets a universal component of bacterial biofilms, leading to pathogen-agnostic rapid biofilm collapse and engaging three modes of action-the sensitization of bacteria to antibiotics, host immune enablement, and the suppression of site-specific tissue inflammation. CMTX-101 is a new tool used to enhance the effectiveness of existing, relatively inexpensive first-line antibiotics to fight infections while promoting antimicrobial stewardship.
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Affiliation(s)
| | | | - Charles C. McOsker
- Clarametyx Biosciences, Inc., 1275 Kinnear Rd, Columbus, OH 43212, USA; (J.V.R.); (V.L.H.)
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A Humanized Monoclonal Antibody Potentiates Killing by Antibiotics of Diverse Biofilm-Forming Respiratory Tract Pathogens. Antimicrob Agents Chemother 2022; 66:e0187721. [DOI: 10.1128/aac.01877-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
New strategies to treat diseases wherein biofilms contribute significantly to pathogenesis are needed as biofilm-resident bacteria are highly recalcitrant to antibiotics due to physical biofilm architecture and a canonically quiescent metabolism, among many additional attributes. We, and others, have shown that when biofilms are dispersed or disrupted, bacteria released from biofilm residence are in a distinct physiologic state that, in part, renders these bacteria highly sensitive to killing by specific antibiotics. We sought to demonstrate the breadth of ability of a recently humanized monoclonal antibody against an essential biofilm structural element (DNABII protein) to disrupt biofilms formed by respiratory tract pathogens and potentiate antibiotic-mediated killing of bacteria released from biofilm residence.
Biofilms formed by six respiratory tract pathogens were significantly disrupted by the humanized monoclonal antibody in a dose- and time-dependent manner, as corroborated by CLSM imaging. Bacteria newly released from the biofilms of 3 of 6 species were significantly more sensitive than their planktonic counterparts to killing by 2 of 3 antibiotics currently used clinically and were now also equally as sensitive to killing by the 3
rd
antibiotic. The remaining 3 pathogens were significantly more susceptible to killing by all 3 antibiotics.
A humanized monoclonal antibody directed against protective epitopes of a DNABII protein effectively released six diverse respiratory tract pathogens from biofilm residence in a phenotypic state that was now as, or significantly more, sensitive to killing by three antibiotics currently indicated for use clinically. These data support this targeted, combinatorial, species-agnostic therapy to mitigate chronic bacterial diseases.
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10
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Extracellular DNA (eDNA). A Major Ubiquitous Element of the Bacterial Biofilm Architecture. Int J Mol Sci 2021; 22:ijms22169100. [PMID: 34445806 PMCID: PMC8396552 DOI: 10.3390/ijms22169100] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/19/2021] [Accepted: 08/20/2021] [Indexed: 12/22/2022] Open
Abstract
After the first ancient studies on microbial slime (the name by which the biofilm matrix was initially indicated), multitudes of studies on the morphology, composition and physiology of biofilms have arisen. The emergence of the role that biofilms play in the pathogenesis of recalcitrant and persistent clinical infections, such as periprosthetic orthopedic infections, has reinforced scientific interest. Extracellular DNA (eDNA) is a recently uncovered component that is proving to be almost omnipresent in the extracellular polymeric substance (EPS) of biofilm. This macromolecule is eliciting unprecedented consideration for the critical impact on the pathogenesis of chronic clinical infections. After a systematic review of the literature, an updated description of eDNA in biofilms is presented, with a special focus on the latest findings regarding its fundamental structural role and the contribution it makes to the complex architecture of bacterial biofilms through interactions with a variety of other molecular components of the biofilm matrix.
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11
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Devaraj A, Novotny LA, Robledo-Avila FH, Buzzo JR, Mashburn-Warren L, Jurcisek JA, Tjokro NO, Partida-Sanchez S, Bakaletz LO, Goodman SD. The extracellular innate-immune effector HMGB1 limits pathogenic bacterial biofilm proliferation. J Clin Invest 2021; 131:e140527. [PMID: 34396989 DOI: 10.1172/jci140527] [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: 05/22/2020] [Accepted: 07/01/2021] [Indexed: 12/11/2022] Open
Abstract
Herein, we describe an extracellular function of the vertebrate high-mobility group box 1 protein (HMGB1) in the proliferation of bacterial biofilms. Within host cells, HMGB1 functions as a DNA architectural protein, similar to the ubiquitous DNABII family of bacterial proteins; despite that, these proteins share no amino acid sequence identity. Extracellularly, HMGB1 induces a proinflammatory immune response, whereas the DNABII proteins stabilize the extracellular DNA-dependent matrix that maintains bacterial biofilms. We showed that when both proteins converged on extracellular DNA within bacterial biofilms, HMGB1, unlike the DNABII proteins, disrupted biofilms both in vitro (including the high-priority ESKAPEE pathogens) and in vivo in 2 distinct animal models, albeit with induction of a strong inflammatory response that we attenuated by a single engineered amino acid change. We propose a model where extracellular HMGB1 balances the degree of induced inflammation and biofilm containment without excessive release of biofilm-resident bacteria.
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Affiliation(s)
- Aishwarya Devaraj
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Laura A Novotny
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Frank H Robledo-Avila
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - John R Buzzo
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Lauren Mashburn-Warren
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Joseph A Jurcisek
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Natalia O Tjokro
- Division of Periodontology, Diagnostic Sciences, and Dental Hygiene, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, California, USA
| | - Santiago Partida-Sanchez
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA
| | - Lauren O Bakaletz
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA
| | - Steven D Goodman
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA
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12
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Novotny LA, Chiang T, Goodman SD, Elmaraghy CA, Bakaletz LO. Humanized Anti-DNABII Fab Fragments Plus Ofloxacin Eradicated Biofilms in Experimental Otitis Media. Laryngoscope 2021; 131:E2698-E2704. [PMID: 33666254 DOI: 10.1002/lary.29497] [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: 12/11/2020] [Revised: 02/15/2021] [Accepted: 02/22/2021] [Indexed: 02/01/2023]
Abstract
OBJECTIVES/HYPOTHESIS To evaluate the ability of humanized monoclonal antibody fragments directed against a bacterial DNABII protein plus ofloxacin delivered directly into the chinchilla middle ear via tympanostomy tube (TT) to enhance the ability of ofloxacin to eradicate biofilms formed by nontypeable Haemophilus influenzae (NTHI). STUDY DESIGN A blinded pre-clinical study of comparative efficacy of single versus combinatorial treatment strategies. METHODS NTHI was allowed to form biofilms in the middle ears of chinchillas prior to TT placement. Ofloxacin, humanized Fab fragments against a bacterial DNABII protein that disrupts biofilms or Fab fragments plus ofloxacin were instilled into the middle ear via TT. For two consecutive days, ofloxacin was delivered twice-a-day, Fab fragments were delivered once-a-day, or these treatments were combined. Relative biofilm resolution (as determined via two outcome measures) and eradication of viable NTHI were assessed 1-day later. RESULTS Whereas ofloxacin alone did not resolve biofilms or eradicate NTHI from the middle ear, delivery of Fab fragments significantly reduced both biofilms and NTHI burden over this short course of treatment. Notably, co-delivery of ofloxacin plus humanized Fab fragments eradicated both NTHI and biofilms from the middle ear, an enhanced outcome compared to receipt of either treatment alone. CONCLUSION This study demonstrated a powerful combinatorial approach to release bacteria from their protective biofilms and rapidly render them vulnerable to killing by a previously ineffective antibiotic. An approach to combine ofloxacin with humanized Fab fragments that disrupt biofilms has tremendous potential to quickly resolve chronic otorrhea suffered by children with chronic suppurative otitis media or chronic post-tympanostomy tube otorrhea and thereby improve their quality of life. LEVEL OF EVIDENCE NA Laryngoscope, 2021.
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Affiliation(s)
- Laura A Novotny
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, U.S.A
| | - Tendy Chiang
- The Ohio State University College of Medicine, Columbus, Ohio, U.S.A.,Department of Otolaryngology-Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio, U.S.A.,Department of Pediatric Otolaryngology, Nationwide Children's Hospital, Columbus, Ohio, U.S.A
| | - Steven D Goodman
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, U.S.A.,The Ohio State University College of Medicine, Columbus, Ohio, U.S.A
| | - Charles A Elmaraghy
- The Ohio State University College of Medicine, Columbus, Ohio, U.S.A.,Department of Otolaryngology-Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio, U.S.A.,Department of Pediatric Otolaryngology, Nationwide Children's Hospital, Columbus, Ohio, U.S.A
| | - Lauren O Bakaletz
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, U.S.A.,The Ohio State University College of Medicine, Columbus, Ohio, U.S.A.,Department of Otolaryngology-Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio, U.S.A
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Devaraj A, González JF, Eichar B, Thilliez G, Kingsley RA, Baker S, Allard MW, Bakaletz LO, Gunn JS, Goodman SD. Enhanced biofilm and extracellular matrix production by chronic carriage versus acute isolates of Salmonella Typhi. PLoS Pathog 2021; 17:e1009209. [PMID: 33465146 PMCID: PMC7815147 DOI: 10.1371/journal.ppat.1009209] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 12/02/2020] [Indexed: 01/01/2023] Open
Abstract
Salmonella Typhi is the primary causative agent of typhoid fever; an acute systemic infection that leads to chronic carriage in 3–5% of individuals. Chronic carriers are asymptomatic, difficult to treat and serve as reservoirs for typhoid outbreaks. Understanding the factors that contribute to chronic carriage is key to development of novel therapies to effectively resolve typhoid fever. Herein, although we observed no distinct clustering of chronic carriage isolates via phylogenetic analysis, we demonstrated that chronic isolates were phenotypically distinct from acute infection isolates. Chronic carriage isolates formed significantly thicker biofilms with greater biomass that correlated with significantly higher relative levels of extracellular DNA (eDNA) and DNABII proteins than biofilms formed by acute infection isolates. Importantly, extracellular DNABII proteins include integration host factor (IHF) and histone-like protein (HU) that are critical to the structural integrity of bacterial biofilms. In this study, we demonstrated that the biofilm formed by a chronic carriage isolate in vitro, was susceptible to disruption by a specific antibody against DNABII proteins, a successful first step in the development of a therapeutic to resolve chronic carriage. Salmonella Typhi, a human restricted pathogen is the primary etiologic agent of typhoid fever, an acute systemic infection that has a global incidence of 21 million cases annually. Although the acute infection is resolved by antibiotics, 3–5% of individuals develop chronic carriage that is difficult to resolve with antibiotics. A majority of these indivuals serve as reservoirs for further spread of the disease. Understanding the differences between acute and chronic carrier strains is key to design novel targeted approaches to undermine carriage. Here, we demonstrated that chronic carrier strains although not genotypically distinct from acute strains, formed thicker biofilms with greater relative levels of extracellular eDNA and DNABII proteins than those formed by acute infection isolates. We also demonstrated that an antibody against DNABII proteins significantly disrupted biofilms formed by a chronic carrier strain and therefore supported development of therapeutic use of this antibody to attenuate chronic carriage.
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Affiliation(s)
- Aishwarya Devaraj
- Center for Microbial Pathogenesis, Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Juan F. González
- Center for Microbial Pathogenesis, Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, United States of America
- Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
| | - Bradley Eichar
- Center for Microbial Pathogenesis, Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, United States of America
| | | | - Robert A. Kingsley
- Quadram Institute Bioscience, Norwich, United Kingdom
- University of East Anglia, Norwich, United Kingdom
| | - Stephen Baker
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Marc W. Allard
- Food and Drug Administration-FDA, College Park, Maryland, United States of America
| | - Lauren O. Bakaletz
- Center for Microbial Pathogenesis, Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
- Infectious Diseases Institute, The Ohio State University, Columbus, Ohio, United States of America
| | - John S. Gunn
- Center for Microbial Pathogenesis, Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, United States of America
- Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
- Infectious Diseases Institute, The Ohio State University, Columbus, Ohio, United States of America
- Oral and GI Microbiology Research Affinity Group, Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- * E-mail: (JSG); (SDG)
| | - Steven D. Goodman
- Center for Microbial Pathogenesis, Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
- Infectious Diseases Institute, The Ohio State University, Columbus, Ohio, United States of America
- Oral and GI Microbiology Research Affinity Group, Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- * E-mail: (JSG); (SDG)
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Sédillot-Daniel È, Voizard B, Vallières É, Woods O, Quintal MC. Chronic suppurative otomastoiditis due to nontuberculous mycobacteria: A case series. Int J Pediatr Otorhinolaryngol 2020; 138:110375. [PMID: 33152966 DOI: 10.1016/j.ijporl.2020.110375] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 09/04/2020] [Accepted: 09/04/2020] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Eight new cases of chronic otomastoiditis due to nontuberculous mycobacteria were reported at Center Hospitalier Universitaire Sainte-Justine (CHUSJ) between 2008 and 2018. In the literature, only 89 cases have been described since 1972. This case series aims to define the clinical presentation, infectious pathogens, as well as diagnostic and therapeutic means employed in cases of nontuberculous mycobacteria otitis media encountered in our tertiary pediatric reference center. METHODS All cases of otitis media caused by nontuberculous mycobacteria diagnosed at Sainte-Justine between 2008 and 2018 were reviewed. Species identification was retrieved from the Laboratoire de Santé Publique du Québec, Quebec's provincial public health and reference laboratory. RESULTS All 8 cases occurred in immunocompetent children. Clinical features on presentation were chronic tympanostomy tube otorrhea with abundant granulation tissue in 7 cases. CT scan demonstrated coalescent mastoiditis in 3 cases. The median delay between initial presentation and identification of nontuberculous mycobacteria was 81 days. Seven patients had a Mycobacterium (M.) abscessus complex infection. Treatment consisted of weekly microscopic granulation debridement, a combined systemic antibiotic therapy for an average duration of 21 weeks, as well as instillation of boric acid into the middle ear. While 3 cases required at least one mastoidectomy, 2 cases were treated only medically. CONCLUSION Nontuberculous mycobacteria otitis media is a rare clinical entity, for which high clinical suspicion and specific microbiological analyses could minimize diagnostic delay. The use of boric acid as a desiccating agent may allow for a better local control.
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Affiliation(s)
- Ève Sédillot-Daniel
- Division of Pediatric Otorhinolaryngology, Centre Hospitalier Universitaire Sainte-Justine (CHUSJ), Université de Montréal, Montreal, Quebec, Canada.
| | - Béatrice Voizard
- Division of Pediatric Otorhinolaryngology, Centre Hospitalier Universitaire Sainte-Justine (CHUSJ), Université de Montréal, Montreal, Quebec, Canada.
| | - Émilie Vallières
- Department of Clinical Laboratory Medicine, Division of Microbiology, Centre Hospitalier Universitaire Sainte-Justine (CHUSJ), Université de Montréal, Montreal, Quebec, Canada; Department of Pediatrics, Division of Infectious Diseases, Centre Hospitalier Universitaire Sainte-Justine (CHUSJ), Université de Montréal, Montreal, Quebec, Canada
| | - Owen Woods
- Division of Pediatric Otorhinolaryngology, Centre Hospitalier Universitaire Sainte-Justine (CHUSJ), Université de Montréal, Montreal, Quebec, Canada.
| | - Marie-Claude Quintal
- Division of Pediatric Otorhinolaryngology, Centre Hospitalier Universitaire Sainte-Justine (CHUSJ), Université de Montréal, Montreal, Quebec, Canada.
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Targeting a bacterial DNABII protein with a chimeric peptide immunogen or humanised monoclonal antibody to prevent or treat recalcitrant biofilm-mediated infections. EBioMedicine 2020; 59:102867. [PMID: 32651162 PMCID: PMC7502671 DOI: 10.1016/j.ebiom.2020.102867] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/02/2020] [Accepted: 06/15/2020] [Indexed: 12/21/2022] Open
Abstract
Background: Chronic and recurrent bacterial diseases are recalcitrant to treatment due to the ability of the causative agents to establish biofilms, thus development of means to prevent or resolve these structures are greatly needed. Our approach targets the DNABII family of bacterial DNA-binding proteins, which serve as critical structural components within the extracellular DNA scaffold of biofilms formed by all bacterial species tested to date. DNABII-directed antibodies rapidly disrupt biofilms and release the resident bacteria which promote their subsequent clearance by either host immune effectors or antibiotics that are now effective at a notably reduced concentration. Methods: First, as a therapeutic approach, we used intact IgG or Fab fragments against a chimeric peptide immunogen designed to target protective epitopes within the DNA-binding tip domains of integration host factor to disrupt established biofilms in vitro and to mediate resolution of existing disease in vivo. Second, we performed preventative active immunisation with the chimeric peptide to induce the formation of antibody that blocks biofilm formation and disease development in a model of viral-bacterial superinfection. Further, toward the path for clinical use, we humanised a monoclonal antibody against the chimeric peptide immunogen, then characterised and validated that it maintained therapeutic efficacy. Findings: We demonstrated efficacy of each approach in two well-established pre-clinical models of otitis media induced by the prevalent respiratory tract pathogen nontypeable Haemophilus influenzae, a common biofilm disease. Interpretation: Collectively, our data revealed two approaches with substantive efficacy and potential for broad application to combat diseases with a biofilm component. Funding Supported by R01 DC011818 to LOB and SDG.
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16
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Moraxella catarrhalis phase-variable loci show differences in expression during conditions relevant to disease. PLoS One 2020; 15:e0234306. [PMID: 32555615 PMCID: PMC7302503 DOI: 10.1371/journal.pone.0234306] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 05/22/2020] [Indexed: 11/29/2022] Open
Abstract
Moraxella catarrhalis is a human-adapted, opportunistic bacterial pathogen of the respiratory mucosa. Although asymptomatic colonization of the nasopharynx is common, M. catarrhalis can ascend into the middle ear, where it is a prevalent causative agent of otitis media in children, or enter the lower respiratory tract, where it is associated with acute exacerbations of chronic obstructive pulmonary disease in adults. Phase variation is the high frequency, random, reversible switching of gene expression that allows bacteria to adapt to different host microenvironments and evade host defences, and is most commonly mediated by simple DNA sequence repeats. Bioinformatic analysis of five closed M. catarrhalis genomes identified 17 unique simple DNA sequence repeat tracts that were variable between strains, indicating the potential to mediate phase variable expression of the associated genes. Assays designed to assess simple sequence repeat variation under conditions mimicking host infection demonstrated that phase variation of uspA1 (ubiquitous surface protein A1) from high to low expression occurs over 72 hours of biofilm passage, while phase variation of uspA2 (ubiquitous surface protein A2) to high expression variants occurs during repeated exposure to human serum, as measured by mRNA levels. We also identify and confirm the variable expression of two novel phase variable genes encoding a Type III DNA methyltransferase (modO), and a conserved hypothetical permease (MC25239_RS00020). These data reveal the repertoire of phase variable genes mediated by simple sequence repeats in M. catarrhalis and demonstrate that modulation of expression under conditions mimicking human infection is attributed to changes in simple sequence repeat length.
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Marom T, Habashi N, Cohen R, Tamir SO. Role of Biofilms in Post-Tympanostomy Tube Otorrhea. EAR, NOSE & THROAT JOURNAL 2020; 99:22S-29S. [PMID: 32204627 DOI: 10.1177/0145561320914437] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
OBJECTIVE Nearly half of children who undergo tympanostomy tube (TT) insertion may experience otorrhea following surgery. We sought to review the evidence for the role of bacterial biofilms in post-tympanostomy tube otorrhea (PTTO) and the accumulated experience regarding the preventive measures for biofilm formation/adhesion on TTs. METHODS English literature search for relevant MeSH keywords was conducted in the following databases: MEDLINE (via PubMed), Ovid Medline, Google Scholar, and Clinical Evidence (BMJ Publishing) between January 1, 1995, and December 31, 2019. Subsequently, articles were reviewed and included if biofilm was evident in PTTO. RESULTS There is an increased evidence supporting the role of biofilms in PTTO. Studies on TT design and material suggest that nitinol and/or silicone TTs had a lower risk for PTTO and that biofilms appeared in specific areas, such as the perpendicular junction of the T-tubes and the round rims of the Paparella-type tubes. Biofilm-component DNAB-II protein family was present in half of children with PTTO, and targeting this protein may lead to biofilm collapse and serve as a potential strategy for PTTO treatment. Novel approaches for the prevention of biofilm-associated PTTO include changing the inherent tube composition; tube coating with antibiotics, polymers, plant extracts, or other biofilm-resistant materials; impregnation with antimicrobial compounds; and surface alterations by ion-bombardment or surface ionization, which are still under laboratory investigation. CONCLUSIONS Currently, there is no type of TT on which bacteria will not adhere. The challenges of treating PTTO indicate the need for further research in optimization of TT design, composition, and coating.
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Affiliation(s)
- Tal Marom
- Department of Otolaryngology-Head and Neck Surgery, Samson 511918Assuta Ashdod University Hospital, Faculty of Health Sciences, Ben Gurion University, Ashdod, Israel
| | - Nadeem Habashi
- Department of Otolaryngology-Head and Neck Surgery, Samson 511918Assuta Ashdod University Hospital, Faculty of Health Sciences, Ben Gurion University, Ashdod, Israel
| | - Robert Cohen
- Association Clinique et Thérapeutique Infantile du Val-de-Marne, Saint-Maur des Fossés, France.,Paris Est University, IMRB-GRC GEMINI, Créteil, France
| | - Sharon Ovnat Tamir
- Department of Otolaryngology-Head and Neck Surgery, Samson 511918Assuta Ashdod University Hospital, Faculty of Health Sciences, Ben Gurion University, Ashdod, Israel
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Alderson MR, Murphy T, Pelton SI, Novotny LA, Hammitt LL, Kurabi A, Li JD, Thornton RB, Kirkham LAS. Panel 8: Vaccines and immunology. Int J Pediatr Otorhinolaryngol 2020; 130 Suppl 1:109839. [PMID: 31948716 PMCID: PMC7153269 DOI: 10.1016/j.ijporl.2019.109839] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To review and highlight significant advances made towards vaccine development and understanding of the immunology of otitis media (OM) since the 19th International Symposium on Recent Advances in Otitis Media (ISOM) in 2015, as well as identify future research directions and knowledge gaps. DATA SOURCES PubMed database, National Library of Medicine. REVIEW METHODS Key topics were assigned to each panel member for detailed review. Draft reviews were collated, circulated, and thoroughly discussed when the panel met at the 20th ISOM in June 2019. The final manuscript was prepared with input from all panel members. CONCLUSIONS Since 2015 there have been a number of studies assessing the impact of licensed pneumococcal vaccines on OM. While these studies have confirmed that these vaccines are effective in preventing carriage and/or disease caused by vaccine serotypes, OM caused by non-vaccine serotype pneumococci and other otopathogens remains a significant health care burden globally. Development of multi-species vaccines is challenging but essential to reducing the global burden of OM. Influenza vaccination has been shown to prevent acute OM, and with novel vaccines against nontypeable Haemophilus influenzae (NTHi), Moraxella catarrhalis and Respiratory Syncytial Virus (RSV) in clinical trials, the potential to significantly prevent OM is within reach. Research into alternative vaccine delivery strategies has demonstrated the power of maternal and mucosal vaccination for OM prevention. Future OM vaccine trials must include molecular diagnostics of middle ear effusion, for detection of viruses and bacteria that are persisting in biofilms and to enable accurate assessment of vaccine impact on OM etiology. Understanding population differences in natural and vaccine-induced immune responses to otopathogens is also important for development of the most effective OM vaccines. Improved understanding of the interaction between otopathogens will also advance development of effective therapies and encourage the assessment of the indirect benefits of vaccination. IMPLICATIONS FOR PRACTICE While NTHi and M. catarrhalis are the predominant otopathogens, funding opportunities to drive vaccine development for these species are limited due to a focus on prevention of childhood mortality rather than morbidity. Delivery of a comprehensive report on the high financial and social costs of OM, including the potential for OM vaccines to reduce antibiotic use and subsequent development of antimicrobial resistance (AMR), would likely assist in engaging stakeholders to recognize the value of prevention of OM and increase support for efforts on OM vaccine development. Vaccine trials with OM prevention as a clinical end-point are challenging, however a focus on developing assays that measure functional correlates of protection would facilitate OM vaccine development.
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Affiliation(s)
| | - Tim Murphy
- Clinical and Translational Research Center, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | - Stephen I Pelton
- Boston University School of Public Health, Boston University, Boston, MA, USA
| | - Laura A Novotny
- The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Laura L Hammitt
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Arwa Kurabi
- Division of Otolaryngology, Department of Surgery, University of California, San Diego, CA, USA
| | - Jian-Dong Li
- Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences, Georgia State University, GA, USA
| | - Ruth B Thornton
- School of Biomedical Sciences, University of Western Australia, Australia and Wesfarmers Centre for Vaccines and Infectious Diseases Research, Telethon Kids Institute, Perth, Australia
| | - Lea-Ann S Kirkham
- Wesfarmers Centre for Vaccines and Infectious Diseases Research, Telethon Kids Institute, Australia and Centre for Child Health Research, University of Western Australia, Perth, Australia
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Vestby LK, Grønseth T, Simm R, Nesse LL. Bacterial Biofilm and its Role in the Pathogenesis of Disease. Antibiotics (Basel) 2020; 9:E59. [PMID: 32028684 PMCID: PMC7167820 DOI: 10.3390/antibiotics9020059] [Citation(s) in RCA: 523] [Impact Index Per Article: 104.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/28/2020] [Accepted: 01/29/2020] [Indexed: 12/31/2022] Open
Abstract
Recognition of the fact that bacterial biofilm may play a role in the pathogenesis of disease has led to an increased focus on identifying diseases that may be biofilm-related. Biofilm infections are typically chronic in nature, as biofilm-residing bacteria can be resilient to both the immune system, antibiotics, and other treatments. This is a comprehensive review describing biofilm diseases in the auditory, the cardiovascular, the digestive, the integumentary, the reproductive, the respiratory, and the urinary system. In most cases reviewed, the biofilms were identified through various imaging technics, in addition to other study approaches. The current knowledge on how biofilm may contribute to the pathogenesis of disease indicates a number of different mechanisms. This spans from biofilm being a mere reservoir of pathogenic bacteria, to playing a more active role, e.g., by contributing to inflammation. Observations also indicate that biofilm does not exclusively occur extracellularly, but may also be formed inside living cells. Furthermore, the presence of biofilm may contribute to development of cancer. In conclusion, this review shows that biofilm is part of many, probably most chronic infections. This is important knowledge for development of effective treatment strategies for such infections.
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Affiliation(s)
- Lene K. Vestby
- Department of Immunology and Virology, Norwegian Veterinary Institute, P.O. Box 750 Sentrum, N-0106 Oslo, Norway;
| | - Torstein Grønseth
- Department of Otolaryngology, Head and Neck Surgery, Oslo University Hospital HF, Postboks 4950 Nydalen, 0424 Oslo, Norway;
| | - Roger Simm
- Institute of Oral Biology, University of Oslo, P.O. Box 1052, Blindern, 0316 Oslo, Norway;
| | - Live L. Nesse
- Department of Food Safety and Animal Health Research, Norwegian Veterinary Institute, P.O. Box 750 Sentrum, N-0106 Oslo, Norway
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The extracellular DNA lattice of bacterial biofilms is structurally related to Holliday junction recombination intermediates. Proc Natl Acad Sci U S A 2019; 116:25068-25077. [PMID: 31767757 DOI: 10.1073/pnas.1909017116] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Extracellular DNA (eDNA) is a critical component of the extracellular matrix of bacterial biofilms that protects the resident bacteria from environmental hazards, which includes imparting significantly greater resistance to antibiotics and host immune effectors. eDNA is organized into a lattice-like structure, stabilized by the DNABII family of proteins, known to have high affinity and specificity for Holliday junctions (HJs). Accordingly, we demonstrated that the branched eDNA structures present within the biofilms formed by NTHI in the middle ear of the chinchilla in an experimental otitis media model, and in sputum samples recovered from cystic fibrosis patients that contain multiple mixed bacterial species, possess an HJ-like configuration. Next, we showed that the prototypic Escherichia coli HJ-specific DNA-binding protein RuvA could be functionally exchanged for DNABII proteins in the stabilization of biofilms formed by 3 diverse human pathogens, uropathogenic E. coli, nontypeable Haemophilus influenzae, and Staphylococcus epidermidis Importantly, while replacement of DNABII proteins within the NTHI biofilm matrix with RuvA was shown to retain similar mechanical properties when compared to the control NTHI biofilm structure, we also demonstrated that biofilm eDNA matrices stabilized by RuvA could be subsequently undermined upon addition of the HJ resolvase complex, RuvABC, which resulted in significant biofilm disruption. Collectively, our data suggested that nature has recapitulated a functional equivalent of the HJ recombination intermediate to maintain the structural integrity of bacterial biofilms.
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Jun Y, Youn CK, Jo ER, Cho SI. In vitro inhibitory activity of N-acetylcysteine on tympanostomy tube biofilms from methicillin-resistant Staphylococcus aureus and quinolone-resistant Pseudomonas aeruginosa. Int J Pediatr Otorhinolaryngol 2019; 126:109622. [PMID: 31404783 DOI: 10.1016/j.ijporl.2019.109622] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 07/05/2019] [Accepted: 08/01/2019] [Indexed: 12/20/2022]
Abstract
OBJECTIVES Biofilm formation in tympanostomy tubes causes persistent and refractory otorrhea. In the present study, we investigated the in vitro antibiofilm activity of N-acetylcysteine (NAC) against biofilm formation by methicillin-resistant Staphylococcus aureus (MRSA) and quinolone-resistant Pseudomonas aeruginosa (QRPA). METHODS We examined the antibiofilm activity of NAC against biofilms produced by MRSA and QRPA strains using in vitro biofilm formation assay, adhesion assay, and biofilm eradication assay. Additionally, the antibiofilm activity of different concentrations of NAC against tympanostomy-tube biofilms from MRSA and QRPA strains was compared using a scanning electron microscope. RESULTS The adhesion of MRSA and QRPA strains decreased significantly in a concentration-dependent manner after treatment with varying amounts of NAC. Treatment with NAC inhibited biofilm formation of both MRSA and QRPA strains and increased eradication of preformed mature biofilm produced by MRSA and QRPA. Besides, NAC exhibited significant eradication-activity against tympanostomy-tube biofilms produced by MRSA and QRPA strains. CONCLUSIONS Our results show potent inhibition of MRSA and QRPA biofilm after treatment with NAC. NAC shows potential for the treatment of biofilms and refractory post-tympanostomy tube otorrhea resulting from MRSA and QRPA infection.
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Affiliation(s)
- Yonghyun Jun
- Department of Anatomy, Chosun University College of Medicine, Gwangju, South Korea
| | - Cha Kyung Youn
- Department of Premedical Science, Chosun University College of Medicine, Gwangju, South Korea
| | - Eu-Ri Jo
- Department of Otolaryngology-Head and Neck Surgery, Chosun University College of Medicine, Gwangju, South Korea
| | - Sung Il Cho
- Department of Otolaryngology-Head and Neck Surgery, Chosun University College of Medicine, Gwangju, South Korea.
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Novotny LA, Goodman SD, Bakaletz LO. Redirecting the immune response towards immunoprotective domains of a DNABII protein resolves experimental otitis media. NPJ Vaccines 2019; 4:43. [PMID: 31632744 PMCID: PMC6791836 DOI: 10.1038/s41541-019-0137-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 09/13/2019] [Indexed: 12/18/2022] Open
Abstract
The chronicity and recurrence of many bacterial diseases is largely attributable to the presence of a biofilm, and eradication of these structures is confounded by an extracellular DNA-rich matrix. DNABII proteins, including integration host factor (IHF), are critical components of the matrix formed by all human pathogens tested to date. Whereas the natural adaptive immune response to IHF is against non-protective epitopes within the carboxyl-terminal region, antibodies against the DNA-binding “tips” induce biofilm collapse. We designed a “tip-chimer” immunogen to mimic the DNA-binding regions within the α-subunit and β-subunit of IHF from nontypeable Haemophilus influenzae (IHFNTHi). Re-direction of the natural adaptive immune response toward immunoprotective domains disrupted NTHi biofilms in vitro and in an experimental model of otitis media. Our data support the rational design of a powerful therapeutic approach, and also that of a DNABII-directed vaccine antigen that would avoid augmentation of any pre-existing natural, but nonprotective, immune response. Bacterial biofilms are characterized by the presence of a protective extracellular polymeric substance (EPS) that incorporates both eDNA and members of the DNABII family of bacterial DNA-binding proteins. Antibodies against the “tips” of these DNA binding-domains can cause biofilm collapse, but these epitopes are masked from the host adaptive immune system when bound to eDNA, making biofilm eradication difficult. Here, the team led by Lauren Bakaletz used a chimeric peptide to generate tip-specific antibodies against nontypeable Haemophilus influenzae to treat biofilms in vitro and in vivo. The “tip-chimer” contained the immunoprotective domains from the DNA-binding tips of a DNABII protein, integration host factor (IHF), expressed by nontypeable Haemophilus influenzae. The consequent antibodies disrupted H. influenzae biofilms in vitro and were used to treat a chinchilla model of experimental otitis media when inoculated directly into the middle ear, resulting in reduced bacterial load and clearance of already established mucosal biofilms. These findings suggest that redirecting the host adaptive immune response towards the immunoprotective tips of DNABII proteins could provide a strategy to eradicate biofilms caused by various pathogens that produce these proteins.
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Affiliation(s)
- L A Novotny
- 1Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH 43205 USA
| | - S D Goodman
- 1Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH 43205 USA.,2The Ohio State University College of Medicine, Columbus, OH 43210 USA
| | - L O Bakaletz
- 1Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH 43205 USA.,2The Ohio State University College of Medicine, Columbus, OH 43210 USA
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van den Broek MFL, De Boeck I, Kiekens F, Boudewyns A, Vanderveken OM, Lebeer S. Translating Recent Microbiome Insights in Otitis Media into Probiotic Strategies. Clin Microbiol Rev 2019; 32:e00010-18. [PMID: 31270125 PMCID: PMC6750133 DOI: 10.1128/cmr.00010-18] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The microbiota of the upper respiratory tract (URT) protects the host from bacterial pathogenic colonization by competing for adherence to epithelial cells and by immune response regulation that includes the activation of antimicrobial and (anti-)inflammatory components. However, environmental or host factors can modify the microbiota to an unstable community that predisposes the host to infection or inflammation. One of the URT diseases most often encountered in children is otitis media (OM). The role of pathogenic bacteria like Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis in the pathogenesis of OM is well documented. Results from next-generation-sequencing (NGS) studies reveal other bacterial taxa involved in OM, such as Turicella and Alloiococcus Such studies can also identify bacterial taxa that are potentially protective against URT infections, whose beneficial action needs to be substantiated in relevant experimental models and clinical trials. Of note, lactic acid bacteria (LAB) are members of the URT microbiota and associated with a URT ecosystem that is deemed healthy, based on NGS and some experimental and clinical studies. These observations have formed the basis of this review, in which we describe the current knowledge of the molecular and clinical potential of LAB in the URT, which is currently underexplored in microbiome and probiotic research.
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Affiliation(s)
- Marianne F L van den Broek
- Environmental Ecology and Applied Microbiology Research Group, Department of Bioscience Engineering, University of Antwerp, Antwerp, Belgium
| | - Ilke De Boeck
- Environmental Ecology and Applied Microbiology Research Group, Department of Bioscience Engineering, University of Antwerp, Antwerp, Belgium
| | - Filip Kiekens
- Laboratory of Pharmaceutical Technology and Biopharmacy, Department of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Wilrijk, Belgium
| | - An Boudewyns
- Department of Otorhinolaryngology, Head and Neck Surgery, Antwerp University Hospital, Edegem, Belgium
| | - Olivier M Vanderveken
- Department of Otorhinolaryngology, Head and Neck Surgery, Antwerp University Hospital, Edegem, Belgium
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Sarah Lebeer
- Environmental Ecology and Applied Microbiology Research Group, Department of Bioscience Engineering, University of Antwerp, Antwerp, Belgium
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Martyn L, Sethia R, Chon R, Novotny L, Goodman SD, Elmaraghy C, Bakaletz LO. Antibodies against the DNABII protein integration host factor (IHF) inhibit sinus implant biofilms. Laryngoscope 2019; 130:1364-1371. [PMID: 31314141 DOI: 10.1002/lary.28188] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 06/24/2019] [Accepted: 06/27/2019] [Indexed: 11/10/2022]
Abstract
OBJECTIVES Chronic rhinosinusitis is a common, costly condition often treated with endoscopic sinus surgery and intraoperative placement of intranasal sinus implant materials. Whereas these materials aid in postoperative healing, they also support bacterial biofilm formation and thus contribute to negative outcomes. This study examined pretreatment of sinus implant materials with antibody against an essential bacterial biofilm structural component, the DNABII family of DNA-binding proteins, as a strategy to prevent biofilm formation. METHODS Sinus implant materials were equilibrated in immunoglobulin G (IgG)-enriched antiserum against the DNABII protein integration host factor (IHF), individually or in combination with amoxicillin-clavulanate prior to inoculation with nontypeable Haemophilus influenzae (NTHI), a predominant pathogen of chronic rhinosinusitis. After 16 hours, the bacterial burden was quantitated and compared to pretreatment with saline, IgG-enriched naive serum, or amoxicillin-clavulanate alone. RESULTS NTHI readily formed biofilms on all three materials in vitro. However, pretreatment of each material with IgG-enriched anti-IHF resulted in a significant decrease in bacterial burden compared to controls (P ≤ 0.05). Moreover, a significant and synergistic outcome was achieved with a cocktail of anti-IHF plus amoxicillin-clavulanate (P ≤ 0.05) with complete inhibition of NTHI biofilm formation on all three materials. CONCLUSIONS Biofilm formation was well supported in vitro on three sinus implant materials that vary in composition and resorption characteristics; however, pretreatment of each with DNABII protein targeted antibodies in combination with a previously ineffective antibiotic was highly effective to prevent the formation NTHI biofilms. These data demonstrate the potential for clinical utility of pretreatment of sinus implant and additional surgical materials with anti-DNABII antibodies. LEVEL OF EVIDENCE NA Laryngoscope, 130:1364-1371, 2020.
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Affiliation(s)
- Lauren Martyn
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, U.S.A
| | - Rishabh Sethia
- Department of Pediatric Otolaryngology, Nationwide Children's Hospital, Columbus, Ohio, U.S.A.,The Ohio State University College of Medicine, Columbus, Ohio, U.S.A
| | - Rachel Chon
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, U.S.A
| | - Laura Novotny
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, U.S.A
| | - Steven D Goodman
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, U.S.A.,The Ohio State University College of Medicine, Columbus, Ohio, U.S.A
| | - Charles Elmaraghy
- Department of Pediatric Otolaryngology, Nationwide Children's Hospital, Columbus, Ohio, U.S.A.,The Ohio State University College of Medicine, Columbus, Ohio, U.S.A.,Department of Otolaryngology-Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio, U.S.A
| | - Lauren O Bakaletz
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, U.S.A.,The Ohio State University College of Medicine, Columbus, Ohio, U.S.A.,Department of Otolaryngology-Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio, U.S.A
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25
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Wong SM, Jackson MD, Akerley BJ. Suppression of Alternative Lipooligosaccharide Glycosyltransferase Activity by UDP-Galactose Epimerase Enhances Murine Lung Infection and Evasion of Serum IgM. Front Cell Infect Microbiol 2019; 9:160. [PMID: 31157175 PMCID: PMC6530457 DOI: 10.3389/fcimb.2019.00160] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 04/29/2019] [Indexed: 01/17/2023] Open
Abstract
In pathogens that produce lipooligosaccharide (LOS), sugar residues within the surface-exposed LOS outer core mediate interactions with components of the host immune system, promoting bacterial infection. Many LOS structures are controlled by phase variation mediated by random slipped-strand base mispairing, which can reversibly switch gene expression on or off. Phase variation diversifies the LOS, however its adaptive role is not well-understood. Nontypeable Haemophilus influenzae (NTHi) is an important pathogen that causes a range of illnesses in the upper and lower respiratory tract. In NTHi a phase variable galactosyltransferase encoded by lic2A initiates galactose chain extension of the LOS outer core. The donor substrate for Lic2A, UDP-galactose, is generated from UDP-glucose by UDP-galactose epimerase encoded by galE. Our previous fitness profiling of H. influenzae mutants in a murine lung model showed that the galE mutant had a severe survival defect, while the lic2A mutant's defect was modest, leading us to postulate that unidentified factors act as suppressors of potential defects in a lic2A mutant. Herein we conducted a genome-wide genetic interaction screen to identify genes epistatic on lic2A for survival in the murine lung. An unexpected finding was that galE mutants exhibited restored virulence properties in a lic2A mutant background. We identified an alternative antibody epitope generated by Lic2A in the galE mutant that increased sensitivity to classical complement mediated killing in human serum. Deletion of lic2A or restoration of UDP-galactose synthesis alleviated the galE mutant's virulence defects. These studies indicate that when deprived of its galactosyl substrate, Lic2A acquires an alternative activity leading to increased recognition of NTHi by IgM and decreased survival in the lung model. Biofilm formation was increased by deletion of galE and by increased availability of UDP-GlcNAc precursors that can compete with UDP-galactose production. NTHi's ability to reversibly inactivate lic2A by phase-variation may influence survival in niches of infection in which UDP-Galactose levels are limiting.
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Affiliation(s)
- Sandy M Wong
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, MS, United States
| | - Mary Darby Jackson
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, MS, United States
| | - Brian J Akerley
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, MS, United States
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26
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Parrish JM, Soni M, Mittal R. Subversion of host immune responses by otopathogens during otitis media. J Leukoc Biol 2019; 106:943-956. [PMID: 31075181 PMCID: PMC7166519 DOI: 10.1002/jlb.4ru0119-003r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 03/11/2019] [Accepted: 04/05/2019] [Indexed: 12/26/2022] Open
Abstract
Otitis media (OM) is one of the most common ear diseases affecting humans. Children are at greater risk and suffer most frequently from OM, which can cause serious deterioration in the quality of life. OM is generally classified into two main types: acute and chronic OM (AOM and COM). AOM is characterized by tympanic membrane swelling or otorrhea and is accompanied by signs or symptoms of ear infection. In COM, there is a tympanic membrane perforation and purulent discharge. The most common pathogens that cause AOM are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis whereas Pseudomonas aeruginosa and Staphylococcus aureus are commonly associated with COM. Innate and adaptive immune responses provide protection against OM. However, pathogens employ a wide arsenal of weapons to evade potent immune responses and these mechanisms likely contribute to AOM and COM. Immunologic evasion is multifactorial, and involves damage to host mucociliary tract, genetic polymorphisms within otopathogens, the number and variety of different otopathogens in the nasopharynx as well as the interaction between the host's innate and adaptive immune responses. Otopathogens utilize host mucin production, phase variation, biofilm production, glycans, as well as neutrophil and eosinophilic extracellular traps to induce OM. The objective of this review article is to discuss our current understanding about the mechanisms through which otopathogens escape host immunity to induce OM. A better knowledge about the molecular mechanisms leading to subversion of host immune responses will provide novel clues to develop effective treatment modalities for OM.
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Affiliation(s)
- James M Parrish
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Manasi Soni
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Rahul Mittal
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida, USA
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27
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Barron CL, Kamel-Abusalha LB, Sethia R, Goodman SD, Elmaraghy CA, Bakaletz LO. Identification of essential biofilm proteins in middle ear fluids of otitis media with effusion patients. Laryngoscope 2019; 130:806-811. [PMID: 31021431 DOI: 10.1002/lary.28011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 02/14/2019] [Accepted: 04/02/2019] [Indexed: 11/09/2022]
Abstract
OBJECTIVES Otitis media with effusion (OME) is a common disease of childhood that is largely asymptomatic. However, middle ear fluid can persist for months and negatively impact a child's quality of life. Many cases of OME remain chronic and require surgical intervention. Because biofilms are known to contribute to the persistence of many diseases, this study examined effusions collected from children with chronic OME for the presence of essential biofilm structural components, members of the DNABII family of bacterial DNA-binding proteins. METHODS Middle ear effusions were recovered from 38 children with chronic OME at the time of tympanostomy tube insertion. A portion of each specimen was submitted for microbiology culture. The remaining material was assessed by immunoblot to quantitate individual DNABII proteins, integration host factor (IHF), and histone-like protein (HU). RESULTS Sixty-five percent of effusions (24 of 37) were culture-positive for bacterial species or yeast, whereas 35% (13 of 37) were culture-negative. IHF was detected in 95% (36 of 38) at concentrations from 2 to 481 ng/μL effusion. HU was detected in 95% (36 of 38) and quantitated from 13 to 5,264 ng/μL effusion (P ≤ 0.05 compared to IHF). CONCLUSION Because DNABII proteins are essential structural components of bacterial biofilms, these data lend further support to our understanding that biofilms are present in the vast majority of chronic middle ear effusions, despite negative culture results. The presence and ubiquity of DNABII proteins in OME specimens indicated that these proteins can serve as an important clinical target for our novel DNABII-directed strategy to treat biofilm diseases such as chronic OME. LEVEL OF EVIDENCE NA Laryngoscope, 130:806-811, 2020.
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Affiliation(s)
- Christine L Barron
- Center for Microbial Pathogenesis, Nationwide Children's Hospital, Columbus, Ohio, U.S.A.,Department of Pediatric Otolaryngology-Head and Neck Surgery, Nationwide Children's Hospital, Columbus, Ohio, U.S.A.,The Ohio State University College of Medicine, Columbus, Ohio, U.S.A
| | - Louie B Kamel-Abusalha
- Center for Microbial Pathogenesis, Nationwide Children's Hospital, Columbus, Ohio, U.S.A.,Department of Pediatric Otolaryngology-Head and Neck Surgery, Nationwide Children's Hospital, Columbus, Ohio, U.S.A
| | - Rishabh Sethia
- Center for Microbial Pathogenesis, Nationwide Children's Hospital, Columbus, Ohio, U.S.A.,Department of Pediatric Otolaryngology-Head and Neck Surgery, Nationwide Children's Hospital, Columbus, Ohio, U.S.A.,The Ohio State University College of Medicine, Columbus, Ohio, U.S.A
| | - Steven D Goodman
- Center for Microbial Pathogenesis, Nationwide Children's Hospital, Columbus, Ohio, U.S.A.,The Ohio State University College of Medicine, Columbus, Ohio, U.S.A
| | - Charles A Elmaraghy
- Department of Pediatric Otolaryngology-Head and Neck Surgery, Nationwide Children's Hospital, Columbus, Ohio, U.S.A.,The Ohio State University College of Medicine, Columbus, Ohio, U.S.A
| | - Lauren O Bakaletz
- Center for Microbial Pathogenesis, Nationwide Children's Hospital, Columbus, Ohio, U.S.A.,The Ohio State University College of Medicine, Columbus, Ohio, U.S.A
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Ajdnik U, Zemljič LF, Bračič M, Maver U, Plohl O, Rebol J. Functionalisation of Silicone by Drug-Embedded Chitosan Nanoparticles for Potential Applications in Otorhinolaryngology. MATERIALS (BASEL, SWITZERLAND) 2019; 12:E847. [PMID: 30871195 PMCID: PMC6471903 DOI: 10.3390/ma12060847] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 03/07/2019] [Accepted: 03/08/2019] [Indexed: 12/16/2022]
Abstract
Silicones are widely used medical materials that are also applied for tympanostomy tubes with a trending goal to functionalise the surface of the latter to enhance the healing of ear inflammations and other ear diseases, where such medical care is required. This study focuses on silicone surface treatment with various antimicrobial coatings. Polysaccharide coatings in the form of chitosan nanoparticles alone, or with an embedded drug mixture composed of amoxicillin/clavulanic acid (co-amoxiclav) were prepared and applied onto silicone material. Plasma activation was also used as a pre-treatment for activation of the material's surface for better adhesion of the coatings. The size of the nanoparticles was measured using the DLS method (Dynamic Light Scattering), stability of the dispersion was determined with zeta potential measurements, whilst the physicochemical properties of functionalised silicone materials were examined using the UV-Vis method (Ultraviolet-Visible Spectroscopy), SEM (Scanning Electron Microscopy), XPS (X-Ray Photoelectron Spectroscopy). Moreover, in vitro drug release testing was used to follow the desorption kinetics and antimicrobial properties were tested by a bacterial cell count reduction assay using the standard gram-positive bacteria Staphylococcus aureus. The results show silicone materials as suitable materials for tympanostomy tubes, with the coating developed in this study showing excellent antimicrobial and biofilm inhibition properties. This implies a potential for better healing of ear inflammation, making the newly developed approach for the preparation of functionalised tympanostomy tubes promising for further testing towards clinical applications.
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Affiliation(s)
- Urban Ajdnik
- University of Maribor, Faculty of Mechanical Engineering, Institute for Engineering Materials and Design, Smetanova 17, 2000 Maribor, Slovenia.
| | - Lidija Fras Zemljič
- University of Maribor, Faculty of Mechanical Engineering, Institute for Engineering Materials and Design, Smetanova 17, 2000 Maribor, Slovenia.
| | - Matej Bračič
- University of Maribor, Faculty of Mechanical Engineering, Institute for Engineering Materials and Design, Smetanova 17, 2000 Maribor, Slovenia.
| | - Uroš Maver
- Faculty of Medicine, Institute of Biomedical Sciences, University of Maribor, Taborska ulica 8, 2000 Maribor, Slovenia.
| | - Olivija Plohl
- University of Maribor, Faculty of Mechanical Engineering, Institute for Engineering Materials and Design, Smetanova 17, 2000 Maribor, Slovenia.
| | - Janez Rebol
- University Medical Centre Maribor, Department of Otorhinolaryngology, Cervical and Maxillofacial Surgery, Ljubljanska ulica 5, 2000 Maribor, Slovenia.
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29
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Novotny LA, Brockman KL, Mokrzan EM, Jurcisek JA, Bakaletz LO. Biofilm biology and vaccine strategies for otitis media due to nontypeable Haemophilus influenzae. J PEDIAT INF DIS-GER 2019; 14:69-77. [PMID: 30853830 PMCID: PMC6402341 DOI: 10.1055/s-0038-1660818] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Otitis media (OM) is one of the most common diseases of childhood, and nontypeable Haemophilus influenzae (NTHI) is the predominant causative agent of chronic and recurrent OM, as well as OM for which treatment has failed. Moreover, NTHI is now as important a causative agent of acute OM as the pneumococcus. NTHI colonizes the human nasopharynx asymptomatically. However, upon perturbation of the innate and physical defenses of the airway by upper respiratory tract viral infection, NTHI can replicate, ascend the Eustachian tube, gain access to the normally sterile middle ear space, and cause disease. Bacterial biofilms within the middle ear, including those formed by NTHI, contribute to the chronic and recurrent nature of this disease. These multicomponent structures are highly resistant to clearance by host defenses and elimination by traditional antimicrobial therapies. Herein, we review several strategies utilized by NTHI in order to persist within the human host and interventions currently under investigation to prevent and/or resolve NTHI-induced diseases of the middle ear and uppermost airway.
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Affiliation(s)
- Laura A Novotny
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital and The Ohio State University College of Medicine, Columbus, OH, USA
| | - Kenneth L Brockman
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital and The Ohio State University College of Medicine, Columbus, OH, USA
| | - Elaine M Mokrzan
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital and The Ohio State University College of Medicine, Columbus, OH, USA
| | - Joseph A Jurcisek
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital and The Ohio State University College of Medicine, Columbus, OH, USA
| | - Lauren O Bakaletz
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital and The Ohio State University College of Medicine, Columbus, OH, USA
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30
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Tympanostomy tube otorrhea in children: prevention and treatment. Curr Opin Otolaryngol Head Neck Surg 2018; 26:437-440. [DOI: 10.1097/moo.0000000000000493] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Comparative efficacies of topical antiseptic eardrops against biofilms from methicillin-resistant Staphylococcus aureus and quinolone-resistant Pseudomonas aeruginosa. The Journal of Laryngology & Otology 2018; 132:519-522. [PMID: 29909794 DOI: 10.1017/s0022215118000932] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE The present study aimed to compare the anti-biofilm activities of four commonly available antiseptic eardrops against biofilms from methicillin-resistant Staphylococcus aureus and quinolone-resistant Pseudomonas aeruginosa in vitro. METHODS The anti-biofilm activities of 50 per cent Burow's solution, vinegar with water (1:1), 2 per cent acetic acid solution, and 4 per cent boric acid solution were evaluated using biofilm assays. Additionally, the anti-biofilm activities of the four antiseptic solutions against tympanostomy tube biofilms were compared using a scanning electron microscope. RESULTS The inhibition of biofilm formation from methicillin-resistant S aureus and quinolone-resistant P aeruginosa occurred after treatment with 4 per cent boric acid solution, 2 per cent acetic acid solution, and vinegar with water (1:1). However, 50 per cent Burow's solution did not exhibit effective anti-biofilm activity. CONCLUSION The results indicate that 4 per cent boric acid solution and vinegar with water (1:1) are potent inhibitors of biofilms from methicillin-resistant S aureus and quinolone-resistant P aeruginosa, and provide safe pH levels for avoiding ototoxicity.
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32
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Yankey H, Isaacson G. Efficacy of topical 2% mupirocin ointment for treatment of tympanostomy tube otorrhea caused by community-acquired methicillin resistant Staphylococcus aureus. Int J Pediatr Otorhinolaryngol 2018; 109:36-39. [PMID: 29728181 DOI: 10.1016/j.ijporl.2018.03.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 03/17/2018] [Accepted: 03/21/2018] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To demonstrate the safety and effectiveness of topical 2% mupirocin ointment as an adjunctive therapy for tympanostomy tube otorrhea (TTO) caused by methicillin-resistant Staphylococcus aureus (MRSA). METHODS We treated children with community-acquired MRSA TTO by aural suctioning and culture-directed systemic antibiotics (+/- ototopical drops) alone (control group) or with the addition of single 1 ml dose of mupirocin ointment applied to the tube and ear canal (mupirocin group). Patient age, laterality, response to treatment, associate hearing loss, duration of follow-up, and recurrence of infection by MRSA or by other organisms were compared. RESULTS 29 children (37 ears) with MRSA TTO were included. 8 children (12 ears) received adjunctive topical mupirocin ointment - 21 children (25 ears) did not. 8 of 12 ears in the mupirocin group received concomitant systemic antibiotics - 4 ears were treated with topical mupirocin alone. The mean duration of follow-up of the mupirocin group was 7 months (with 95% C.I of 7 ± 7). The control group was 24 months (with 95% C.I of 24 ± 9). Recurrence of MRSA TTO in the mupirocin and control groups were 0/12; 0% and 10/25; 40%, by ear, respectively (p = 0.015). Recurrence of non-MRSA TTO in the mupirocin and control groups were 6/12; 50% and 9/25; 36%, by ear, respectively (p = 1.0). There were no sensorineural hearing losses in the mupirocin-treated children. CONCLUSION In this small series, a single application of topical mupirocin in combination with mechanical debridement, controlled infection by CA-MRSA without evidence of local reaction or subsequent hearing loss. Its role in treatment of MRSA TTO merits further investigation.
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Affiliation(s)
- Hilary Yankey
- Department of Otolaryngology - Head & Neck Surgery, Lewis Katz School of Medicine at Temple University, USA
| | - Glenn Isaacson
- Department of Otolaryngology - Head & Neck Surgery, Lewis Katz School of Medicine at Temple University, USA; Department of Pediatrics, Lewis Katz School of Medicine at Temple University, USA.
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33
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Devaraj A, Buzzo J, Rocco CJ, Bakaletz LO, Goodman SD. The DNABII family of proteins is comprised of the only nucleoid associated proteins required for nontypeable Haemophilus influenzae biofilm structure. Microbiologyopen 2017; 7:e00563. [PMID: 29230970 PMCID: PMC6011942 DOI: 10.1002/mbo3.563] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/23/2017] [Accepted: 10/30/2017] [Indexed: 11/20/2022] Open
Abstract
Biofilms play a central role in the pathobiology of otitis media (OM), bronchitis, sinusitis, conjunctivitis, and pneumonia caused by nontypeable Haemophilus influenzae (NTHI). Our previous studies show that extracellular DNA (eDNA) and DNABII proteins are essential components of biofilms formed by NTHI. The DNABII protein family includes integration host factor (IHF) and the histone‐like protein HU and plays a central role in NTHI biofilm structural integrity. We demonstrated that immunological targeting of these proteins during NTHI‐induced experimental OM in a chinchilla model caused rapid clearance of biofilms from the middle ear. Given the essential role of DNABII proteins in maintaining the structure of an NTHI biofilm, we investigated whether any of the other nucleoid associated proteins (NAPs) expressed by NTHI might play a similar role, thereby serving as additional target(s) for intervention. We demonstrated that although several NAPs including H‐NS, CbpA, HfQ and Dps are present within the biofilm extracellular matrix, only the DNABII family of proteins is critical for the structural integrity of the biofilms formed by NTHI. We have also demonstrated that IHF and HU are located at distinct regions within the extracellular matrix of NTHI biofilms formed in vitro, indicative of independent functions of these two proteins.
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Affiliation(s)
- Aishwarya Devaraj
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital and The Ohio State University College of Medicine, Columbus, OH, USA
| | - John Buzzo
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital and The Ohio State University College of Medicine, Columbus, OH, USA
| | - Christopher J Rocco
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital and The Ohio State University College of Medicine, Columbus, OH, USA
| | - Lauren O Bakaletz
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital and The Ohio State University College of Medicine, Columbus, OH, USA
| | - Steven D Goodman
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital and The Ohio State University College of Medicine, Columbus, OH, USA
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Jurcisek JA, Brockman KL, Novotny LA, Goodman SD, Bakaletz LO. Nontypeable Haemophilus influenzae releases DNA and DNABII proteins via a T4SS-like complex and ComE of the type IV pilus machinery. Proc Natl Acad Sci U S A 2017; 114:E6632-E6641. [PMID: 28696280 PMCID: PMC5559034 DOI: 10.1073/pnas.1705508114] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Biofilms formed by nontypeable Haemophilus influenzae (NTHI) are central to the chronicity, recurrence, and resistance to treatment of multiple human respiratory tract diseases including otitis media, chronic rhinosinusitis, and exacerbations of both cystic fibrosis and chronic obstructive pulmonary disease. Extracellular DNA (eDNA) and associated DNABII proteins are essential to the overall architecture and structural integrity of biofilms formed by NTHI and all other bacterial pathogens tested to date. Although cell lysis and outer-membrane vesicle extrusion are possible means by which these canonically intracellular components might be released into the extracellular environment for incorporation into the biofilm matrix, we hypothesized that NTHI additionally used a mechanism of active DNA release. Herein, we describe a mechanism whereby DNA and associated DNABII proteins transit from the bacterial cytoplasm to the periplasm via an inner-membrane pore complex (TraC and TraG) with homology to type IV secretion-like systems. These components exit the bacterial cell through the ComE pore through which the NTHI type IV pilus is expressed. The described mechanism is independent of explosive cell lysis or cell death, and the release of DNA is confined to a discrete subpolar location, which suggests a novel form of DNA release from viable NTHI. Identification of the mechanisms and determination of the kinetics by which critical biofilm matrix-stabilizing components are released will aid in the design of novel biofilm-targeted therapeutic and preventative strategies for diseases caused by NTHI and many other human pathogens known to integrate eDNA and DNABII proteins into their biofilm matrix.
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Affiliation(s)
- Joseph A Jurcisek
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205
| | - Kenneth L Brockman
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH 43210
| | - Laura A Novotny
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205
| | - Steven D Goodman
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH 43210
| | - Lauren O Bakaletz
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205;
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH 43210
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Steele DW, Adam GP, Di M, Halladay CW, Balk EM, Trikalinos TA. Prevention and Treatment of Tympanostomy Tube Otorrhea: A Meta-analysis. Pediatrics 2017; 139:peds.2017-0667. [PMID: 28562289 DOI: 10.1542/peds.2017-0667] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/15/2017] [Indexed: 11/24/2022] Open
Abstract
CONTEXT Children with tympanostomy tubes often develop ear discharge. OBJECTIVE Synthesize evidence about the need for water precautions (ear plugs or swimming avoidance) and effectiveness of topical versus oral antibiotic treatment of otorrhea in children with tympanostomy tubes. DATA SOURCES Searches in Medline, the Cochrane Central Trials Registry and Cochrane Database of Systematic Reviews, Excerpta Medica Database, and the Cumulative Index to Nursing and Allied Health Literature. STUDY SELECTION Abstracts and full-text articles independently screened by 2 investigators. DATA EXTRACTION 25 articles were included. RESULTS One randomized controlled trial (RCT) in children assigned to use ear plugs versus no precautions reported an odds ratio (OR) of 0.68 (95% confidence interval, 0.37-1.25) for >1 episode of otorrhea. Another RCT reported an OR of 0.71 (95% confidence interval, 0.29-1.76) for nonswimmers versus swimmers. Network meta-analyses suggest that, relative to oral antibiotics, topical antibiotic-glucocorticoid drops were more effective: OR 5.3 (95% credible interval, 1.2-27). The OR for antibiotic-only drops was 3.3 (95% credible interval, 0.74-16). Overall, the topical antibiotic-glucocorticoid and antibiotic-only preparations have the highest probabilities, 0.77 and 0.22 respectively, of being the most effective therapies. LIMITATIONS Sparse randomized evidence (2 RCTs) and high risk of bias for nonrandomized comparative studies evaluating water precautions. Otorrhea treatments include non-US Food and Drug Administration approved, off-label, and potentially ototoxic antibiotics. CONCLUSIONS No compelling evidence of a need for water precautions exists. Cure rates are higher for topical drops than oral antibiotics.
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Affiliation(s)
- Dale W Steele
- Evidence-Based Practice Center, Center for Evidence Synthesis in Health, and .,Departments of Health Services, Policy and Practice, School of Public Health.,Emergency Medicine, Section of Pediatrics-Hasbro Children's Hospital, and.,Pediatrics, Alpert Medical School, Brown University, Providence, Rhode Island
| | - Gaelen P Adam
- Evidence-Based Practice Center, Center for Evidence Synthesis in Health, and
| | - Mengyang Di
- Evidence-Based Practice Center, Center for Evidence Synthesis in Health, and
| | | | - Ethan M Balk
- Evidence-Based Practice Center, Center for Evidence Synthesis in Health, and.,Departments of Health Services, Policy and Practice, School of Public Health
| | - Thomas A Trikalinos
- Evidence-Based Practice Center, Center for Evidence Synthesis in Health, and.,Departments of Health Services, Policy and Practice, School of Public Health
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Ahearn CP, Gallo MC, Murphy TF. Insights on persistent airway infection by non-typeable Haemophilus influenzae in chronic obstructive pulmonary disease. Pathog Dis 2017; 75:3753446. [PMID: 28449098 PMCID: PMC5437125 DOI: 10.1093/femspd/ftx042] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 04/28/2017] [Indexed: 12/21/2022] Open
Abstract
Non-typeable Haemophilus influenzae (NTHi) is the most common bacterial cause of infection of the lower airways in adults with chronic obstructive pulmonary disease (COPD). Infection of the COPD airways causes acute exacerbations, resulting in substantial morbidity and mortality. NTHi has evolved multiple mechanisms to establish infection in the hostile environment of the COPD airways, allowing the pathogen to persist in the airways for months to years. Persistent infection of the COPD airways contributes to chronic airway inflammation that increases symptoms and accelerates the progressive loss of pulmonary function, which is a hallmark of the disease. Persistence mechanisms of NTHi include the expression of multiple redundant adhesins that mediate binding to host cellular and extracellular matrix components. NTHi evades host immune recognition and clearance by invading host epithelial cells, forming biofilms, altering gene expression and displaying surface antigenic variation. NTHi also binds host serum factors that confer serum resistance. Here we discuss the burden of COPD and the role of NTHi infections in the course of the disease. We provide an overview of NTHi mechanisms of persistence that allow the pathogen to establish a niche in the hostile COPD airways.
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Affiliation(s)
- Christian P. Ahearn
- Department of Microbiology and Immunology, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
- Clinical and Translational Research Center, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
| | - Mary C. Gallo
- Department of Microbiology and Immunology, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
- Clinical and Translational Research Center, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
| | - Timothy F. Murphy
- Department of Microbiology and Immunology, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
- Clinical and Translational Research Center, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
- Division of Infectious Disease, Department of Medicine, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
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Novotny LA, Jurcisek JA, Goodman SD, Bakaletz LO. Monoclonal antibodies against DNA-binding tips of DNABII proteins disrupt biofilms in vitro and induce bacterial clearance in vivo. EBioMedicine 2016; 10:33-44. [PMID: 27342872 PMCID: PMC5006588 DOI: 10.1016/j.ebiom.2016.06.022] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 06/13/2016] [Accepted: 06/15/2016] [Indexed: 12/23/2022] Open
Abstract
The vast majority of chronic and recurrent bacterial diseases are attributed to the presence of a recalcitrant biofilm that contributes significantly to pathogenesis. As such, these diseases will require an innovative therapeutic approach. We targeted DNABII proteins, an integral component of extracellular DNA (eDNA) which is universally found as part of the pathogenic biofilm matrix to develop a biofilm disrupting therapeutic. We show that a cocktail of monoclonal antibodies directed against specific epitopes of a DNABII protein is highly effective to disrupt diverse biofilms in vitro as well as resolve experimental infection in vivo, in both a chinchilla and murine model. Combining this monoclonal antibody cocktail with a traditional antibiotic to kill bacteria newly released from the biofilm due to the action of the antibody cocktail was highly effective. Our results strongly support these monoclonal antibodies as attractive candidates for lead optimization as a therapeutic for resolution of bacterial biofilm diseases. Monoclonal antibodies (MAbs) against protective epitopes of a DNABII protein disrupted diverse bacterial biofilms in vitro. Delivery of these MAbs also provided therapeutic efficacy in two animal models of biofilm infection. Bacteria newly released from the biofilm by the action of the MAbs were susceptible to host-mediated clearance and tobramycin.
Research In Context The bacteria which cause the vast majority of chronic and recurrent diseases characteristically form ‘biofilms’. Biofilms are communities of bacteria with many unique properties, including being highly resistant to antibiotics and the body's immune response. To develop an effective therapeutic for biofilm infections, we targeted the DNABII proteins, a universal biofilm component that provides structural integrity. Monoclonal antibodies against domains of the DNABII proteins induced complete collapse of diverse biofilms with release of resident bacteria that were highly susceptible to killing by host immune effectors and traditional antibiotics. This therapeutic also mediated resolution of infection in two experimental animal models.
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Affiliation(s)
- Laura A Novotny
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205, USA; The Ohio State University College of Medicine, Department of Pediatrics, 700 Children's Drive, Columbus, OH, 43205, USA.
| | - Joseph A Jurcisek
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205, USA; The Ohio State University College of Medicine, Department of Pediatrics, 700 Children's Drive, Columbus, OH, 43205, USA.
| | - Steven D Goodman
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205, USA; The Ohio State University College of Medicine, Department of Pediatrics, 700 Children's Drive, Columbus, OH, 43205, USA.
| | - Lauren O Bakaletz
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205, USA; The Ohio State University College of Medicine, Department of Pediatrics, 700 Children's Drive, Columbus, OH, 43205, USA.
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Freire MO, Devaraj A, Young A, Navarro JB, Downey JS, Chen C, Bakaletz LO, Zadeh HH, Goodman SD. A bacterial-biofilm-induced oral osteolytic infection can be successfully treated by immuno-targeting an extracellular nucleoid-associated protein. Mol Oral Microbiol 2016; 32:74-88. [PMID: 26931773 DOI: 10.1111/omi.12155] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/28/2016] [Indexed: 02/06/2023]
Abstract
Periodontal disease exemplifies a chronic and recurrent infection with a necessary biofilm component. Mucosal inflammation is a hallmark response of the host seen in chronic diseases, such as colitis, gingivitis, and periodontitis (and the related disorder peri-implantitis). We have taken advantage of our recently developed rat model of human peri-implantitis that recapitulates osteolysis, the requirement of biofilm formation, and the perpetuation of the bona fide disease state, to test a new therapeutic modality with two novel components. First we used hyperimmune antiserum directed against the DNABII family of proteins, now known to be a critical component of the extracellular matrix of bacterial biofilms. Second we delivered the antiserum as cargo in biodegradable microspheres to the site of the biofilm infection. We demonstrated that delivery of a single dose of anti-DNABII in poly(lactic-co-glycolic acid) (PLGA) microspheres induced significant resolution of experimental peri-implantitis, including marked reduction of inflammation. These data support the continued development of a DNABII protein-targeted therapeutic for peri-implantitis and other chronic inflammatory pathologies of the oral cavity in animals and humans.
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Affiliation(s)
- M O Freire
- Department of Applied Oral Sciences, The Forsyth Institute, Cambridge, MA, USA.,Department of Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - A Devaraj
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, and The Ohio State University College of Medicine, Columbus, OH, USA
| | - A Young
- Division of Periodontology, Diagnostic Sciences & Dental Hygiene Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
| | - J B Navarro
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, and The Ohio State University College of Medicine, Columbus, OH, USA
| | - J S Downey
- Division of Periodontology, Diagnostic Sciences & Dental Hygiene Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
| | - C Chen
- Division of Periodontology, Diagnostic Sciences & Dental Hygiene Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
| | - L O Bakaletz
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, and The Ohio State University College of Medicine, Columbus, OH, USA
| | - H H Zadeh
- Division of Periodontology, Diagnostic Sciences & Dental Hygiene Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA.,Laboratory for Immunoregulation and Tissue Engineering (LITE), University of Southern California, Los Angeles, CA, USA
| | - S D Goodman
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, and The Ohio State University College of Medicine, Columbus, OH, USA
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