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Yang R, Zhang H, Marfavi Z, Lv Q, Han Y, Sun K, Yuan C, Tao K. Infiltrating Perfluorocarbon Nanoemulsion and Sensitizing Ultrasound Cavitation to Eradicate Biofilms. ACS APPLIED MATERIALS & INTERFACES 2024; 16:3126-3138. [PMID: 38191301 DOI: 10.1021/acsami.3c15167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
Developing strategies for the treatment of bacterial biofilms is challenging due to their complex and resilient structure, low permeability to therapeutics, and ability to protect resident pathogens. Herein, we demonstrate that a polylysine-stabilized perfluorocarbon nanoemulsion is favored for penetrating biofilms and sensitizing the cavitation effect of low-intensity ultrasound, resulting in the dispersal of extracellular polymeric substances and killing of the protected cells. Through experiments, we observed a complete penetration of the nanoemulsion in a 40 μm Pseudomonas aeruginosa biofilm and demonstrated that it was induced by the fluidic perfluorocarbon, possibly attributing to its low surface tension. Furthermore, we presented an almost complete antibiofilm effect with a low-intensity ultrasound (1 MHz, 0.75 W/cm2, 5 min) in diverse cases, including cultured biofilms, colonized urinary catheters, and chronic wounds. During the treatment process, the perfluorocarbon phase enhanced the number and imploding energy of ultrasound cavities, thoroughly divided the biofilm structure, prevented biofilm self-healing, and sterilized the resident pathogens. Thus, the penetration and sensitization of the nanoemulsion might serve as a facile and potent strategy for eradicating biofilms in various applications.
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Affiliation(s)
- Ruihao Yang
- State Key Lab of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Haoran Zhang
- Shanghai Key Laboratory of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Zeinab Marfavi
- State Key Lab of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Quanjie Lv
- State Key Lab of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Yijun Han
- State Key Lab of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Kang Sun
- State Key Lab of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Congli Yuan
- Shanghai Key Laboratory of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Ke Tao
- State Key Lab of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
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Krishna SS, Sudheesh MS, Viswanad V. Liposomal drug delivery to the lungs: a post covid-19 scenario. J Liposome Res 2023; 33:410-424. [PMID: 37074963 DOI: 10.1080/08982104.2023.2199068] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 03/10/2023] [Indexed: 04/20/2023]
Abstract
High local delivery of anti-infectives to the lungs is required for activity against infections of the lungs. The present pandemic has highlighted the potential of pulmonary delivery of anti-infective agents as a viable option for infections like Covid-19, which specifically causes lung infections and mortality. To prevent infections of such type and scale in the future, target-specific delivery of drugs to the pulmonary region is a high-priority area in the field of drug delivery. The suboptimal effect of oral delivery of anti-infective drugs to the lungs due to the poor biopharmaceutical property of the drugs makes this delivery route very promising for respiratory infections. Liposomes have been used as an effective delivery system for drugs due to their biocompatible and biodegradable nature, which can be used effectively for target-specific drug delivery to the lungs. In the present review, we focus on the use of liposomal drug delivery of anti-infectives for the acute management of respiratory infections in the wake of Covid-19 infection.
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Affiliation(s)
- S Swathi Krishna
- Department of Pharmaceutics, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS, Kochi, India
| | - M S Sudheesh
- Department of Pharmaceutics, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS, Kochi, India
| | - Vidya Viswanad
- Department of Pharmaceutics, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS, Kochi, India
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Jin Z, Gao Q, Wu K, Ouyang J, Guo W, Liang XJ. Harnessing inhaled nanoparticles to overcome the pulmonary barrier for respiratory disease therapy. Adv Drug Deliv Rev 2023; 202:115111. [PMID: 37820982 DOI: 10.1016/j.addr.2023.115111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Revised: 09/22/2023] [Accepted: 10/08/2023] [Indexed: 10/13/2023]
Abstract
The lack of effective treatments for pulmonary diseases presents a significant global health burden, primarily due to the challenges posed by the pulmonary barrier that hinders drug delivery to the lungs. Inhaled nanomedicines, with their capacity for localized and precise drug delivery to specific pulmonary pathologies through the respiratory route, hold tremendous promise as a solution to these challenges. Nevertheless, the realization of efficient and safe pulmonary drug delivery remains fraught with multifaceted challenges. This review summarizes the delivery barriers associated with major pulmonary diseases, the physicochemical properties and drug formulations affecting these barriers, and emphasizes the design advantages and functional integration of nanomedicine in overcoming pulmonary barriers for efficient and safe local drug delivery. The review also deliberates on established nanocarriers and explores drug formulation strategies rooted in these nanocarriers, thereby furnishing essential guidance for the rational design and implementation of pulmonary nanotherapeutics. Finally, this review cast a forward-looking perspective, contemplating the clinical prospects and challenges inherent in the application of inhaled nanomedicines for respiratory diseases.
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Affiliation(s)
- Zhaokui Jin
- School of Biomedical Engineering, Guangzhou Medical University, Guangzhou 511436, PR China
| | - Qi Gao
- School of Biomedical Engineering, Guangzhou Medical University, Guangzhou 511436, PR China
| | - Keke Wu
- School of Biomedical Engineering, Guangzhou Medical University, Guangzhou 511436, PR China
| | - Jiang Ouyang
- School of Biomedical Engineering, Guangzhou Medical University, Guangzhou 511436, PR China
| | - Weisheng Guo
- School of Biomedical Engineering, Guangzhou Medical University, Guangzhou 511436, PR China.
| | - Xing-Jie Liang
- School of Biomedical Engineering, Guangzhou Medical University, Guangzhou 511436, PR China; CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China, No. 11, First North Road, Zhongguancun, Beijing 100190, PR China.
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Afrasiabi S, Chiniforush N. Antibacterial potential of riboflavin mediated blue diode laser photodynamic inactivation against Enterococcus faecalis: A laboratory investigation. Photodiagnosis Photodyn Ther 2023; 41:103291. [PMID: 36642284 DOI: 10.1016/j.pdpdt.2023.103291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 01/11/2023] [Accepted: 01/11/2023] [Indexed: 01/15/2023]
Abstract
OBJECTIVES This study aimed to evaluate the inactivation potency of riboflavin-mediated blue diode laser photodynamic inactivation (PDI) against Enterococcus faecalis at planktonic and biofilm stages and also investigated its effect on the tooth color change. MATERIALS AND METHODS The antibacterial and antibiofilm activities of riboflavin mediated PDI against E. faecalis were investigated. The numbers of colony-forming units (CFUs)/mL were calculated. Teeth discoloration were evaluated using the CIE L*a*b* based color difference (ΔE). RESULTS Antibacterial analysis indicated that the blue diode laser irradiation at 12, 18, 24, and 30 J/cm2 alone and different concentrations of riboflavin solution (6.25 to 100 μM) reduced the number of CFU/mL of E. faecalis, but the reduction was not statistically significant (P > 0.05). Depending on the riboflavin concentration and the light dose, there can be as much as a 1-log effect on CFU/mL. In addition, E. faecalis biofilm was more affected with 30 J/cm2 irradiation dosage and 100 μM riboflavin than other groups. Meanwhile, bacterial suspensions treated with 5.25% sodium hypochlorite (NaOCl) showed maximum biofilm inhibition and colony number reduction, compared with the control. The teeth exhibited clinically acceptable color change after riboflavin treatment at concentration ranging from 6.25 to 50 μM (ΔE < 3.7). CONCLUSIONS The riboflavin mediated PDI process is somewhat less effective than NaOCl but perhaps less toxic to tissues. It might be feasible to repeat the riboflavin + light treatment to further promote efficacy.
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Affiliation(s)
- Shima Afrasiabi
- Laser Research Center of Dentistry, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Nasim Chiniforush
- Laser Research Center of Dentistry, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
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Bernardi S, Anderson A, Macchiarelli G, Hellwig E, Cieplik F, Vach K, Al-Ahmad A. Subinhibitory Antibiotic Concentrations Enhance Biofilm Formation of Clinical Enterococcus faecalis Isolates. Antibiotics (Basel) 2021; 10:antibiotics10070874. [PMID: 34356795 PMCID: PMC8300655 DOI: 10.3390/antibiotics10070874] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 07/08/2021] [Accepted: 07/14/2021] [Indexed: 12/15/2022] Open
Abstract
Enterococcus faecalis is a microorganism that can be found in the oral cavity, especially in secondary endodontic infections, with a prevalence ranging from 24-70%. The increase in the ability to form biofilms in the presence of subinhibitory antibiotic concentrations is a phenomenon that is observed for a wide variety of bacterial pathogens and is associated with increased resistance. In this study, therefore, six E. faecalis isolates from an endodontic environment and two control strains were exposed to subinhibitory concentrations of Penicillin G, Amoxicillin, Doxycycline, Fosfomycin, Tetracycline and Vancomycin and examined for their biofilm formation abilities. The minimum inhibitory concentration (MIC) was determined for all E. faecalis isolates. A culture of the isolate was mixed with a serial dilution series of the respective antibiotic, incubated overnight and the biofilm formation was analyzed using a microtiter plate assay. All isolates were able to form biofilms in the absence of an antibiotic. A significant increase in biofilm formation of up to more than 50% was found in the isolates exposed to subinhibitory concentrations of various antibiotics. Most isolates showed a significant increase in Fosfomycin (7/8), Doxycycline (6/8) and Tetracycline (6/8). Three endodontic isolates showed a significant increase in five of the antibiotics examined at the same time. On exposure to Vancomycin, three endodontic isolates and the two control strains showed an increase. The increase in the ability to form biofilms extended over a concentration range from 1/2 to 1/64 of the MIC concentration. Antibiotics may reach certain niches in the oral cavity at subinhibitory concentrations only. This can increase the biofilm formation by enterococci, and in turn lead to decreased susceptibility of these taxa to antibiotics.
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Affiliation(s)
- Sara Bernardi
- Department of Life, Health and Environmental Sciences, University of L'Aquila, 67100 L'Aquila, Italy
- Centre of Microscopy, University of L'Aquila, 67100 L'Aquila, Italy
| | - Annette Anderson
- Department of Operative Dentistry & Periodontology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Guido Macchiarelli
- Department of Life, Health and Environmental Sciences, University of L'Aquila, 67100 L'Aquila, Italy
| | - Elmar Hellwig
- Department of Operative Dentistry & Periodontology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Fabian Cieplik
- Department of Conservative Dentistry and Periodontology, University Hospital Regensburg, 93053 Regensburg, Germany
| | - Kirstin Vach
- Institute of Medical Biometry and Statistics, Faculty of Medicine, 79104 Freiburg, Germany
| | - Ali Al-Ahmad
- Department of Operative Dentistry & Periodontology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
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Elliott RO, He M. Unlocking the Power of Exosomes for Crossing Biological Barriers in Drug Delivery. Pharmaceutics 2021; 13:pharmaceutics13010122. [PMID: 33477972 PMCID: PMC7835896 DOI: 10.3390/pharmaceutics13010122] [Citation(s) in RCA: 110] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/12/2021] [Accepted: 01/14/2021] [Indexed: 12/25/2022] Open
Abstract
Since the 2013 Nobel Prize was awarded for the discovery of vesicle trafficking, a subgroup of nanovesicles called exosomes has been driving the research field to a new regime for understanding cellular communication. This exosome-dominated traffic control system has increased understanding of many diseases, including cancer metastasis, diabetes, and HIV. In addition to the important diagnostic role, exosomes are particularly attractive for drug delivery, due to their distinctive properties in cellular information transfer and uptake. Compared to viral and non-viral synthetic systems, the natural, cell-derived exosomes exhibit intrinsic payload and bioavailability. Most importantly, exosomes easily cross biological barriers, obstacles that continue to challenge other drug delivery nanoparticle systems. Recent emerging studies have shown numerous critical roles of exosomes in many biological barriers, including the blood–brain barrier (BBB), blood–cerebrospinal fluid barrier (BCSFB), blood–lymph barrier (BlyB), blood–air barrier (BAB), stromal barrier (SB), blood–labyrinth barrier (BLaB), blood–retinal barrier (BRB), and placental barrier (PB), which opens exciting new possibilities for using exosomes as the delivery platform. However, the systematic reviews summarizing such discoveries are still limited. This review covers state-of-the-art exosome research on crossing several important biological barriers with a focus on the current, accepted models used to explain the mechanisms of barrier crossing, including tight junctions. The potential to design and engineer exosomes to enhance delivery efficacy, leading to future applications in precision medicine and immunotherapy, is discussed.
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Affiliation(s)
- Rebekah Omarkhail Elliott
- Department of Chemical and Petroleum Engineering, Bioengineering Program, University of Kansas, Lawrence, KS 66045, USA;
| | - Mei He
- Department of Chemical and Petroleum Engineering, Bioengineering Program, University of Kansas, Lawrence, KS 66045, USA;
- Department of Chemistry, University of Kansas, Lawrence, KS 66045, USA
- Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, FL 32610, USA
- Correspondence:
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Castelo-Branco DDSCM, Amando BR, Ocadaque CJ, Aguiar LD, Paiva DDDQ, Diógenes EM, Guedes GMDM, Costa CL, Santos-Filho ASP, Andrade ARCD, Cordeiro RDA, Rocha MFG, Sidrim JJC. Mini-review: from in vitro to ex vivo studies: an overview of alternative methods for the study of medical biofilms. BIOFOULING 2020; 36:1129-1148. [PMID: 33349038 DOI: 10.1080/08927014.2020.1859499] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 11/23/2020] [Accepted: 11/29/2020] [Indexed: 06/12/2023]
Abstract
Microbial biofilms are a natural adaptation of microorganisms, typically composed of multiple microbial species, exhibiting complex community organization and cooperation. Biofilm dynamics and their complex architecture are challenging for basic analyses, including the number of viable cells, biomass accumulation, biofilm morphology, among others. The methods used to study biofilms range from in vitro techniques to complex in vivo models. However, animal welfare has become a major concern, not only in society, but also in the academic and scientific field. Thus, the pursuit for alternatives to in vivo biofilm analyses presenting characteristics that mimic in vivo conditions has become essential. In this context, the present review proposes to provide an overview of strategies to study biofilms of medical interest, with emphasis on alternatives that approximate experimental conditions to host-associated environments, such as the use of medical devices as substrata for biofilm formation, microcosm and ex vivo models.
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Affiliation(s)
- Débora de Souza Collares Maia Castelo-Branco
- Department of Pathology and Legal Medicine, Postgraduate Program in Medical Microbiology, Group of Applied Medical Microbiology, Federal University of Ceará, Fortaleza, Brazil
- Department of Pathology and Legal Medicine, Postgraduate Program in Medical Microbiology, Specialized Medical Mycology Center, Federal University of Ceará, Fortaleza, Brazil
| | - Bruno Rocha Amando
- Department of Pathology and Legal Medicine, Postgraduate Program in Medical Microbiology, Group of Applied Medical Microbiology, Federal University of Ceará, Fortaleza, Brazil
| | - Crister José Ocadaque
- Department of Pathology and Legal Medicine, Postgraduate Program in Medical Microbiology, Group of Applied Medical Microbiology, Federal University of Ceará, Fortaleza, Brazil
| | - Lara de Aguiar
- Department of Pathology and Legal Medicine, Postgraduate Program in Medical Microbiology, Specialized Medical Mycology Center, Federal University of Ceará, Fortaleza, Brazil
- Postgraduate Program in Veterinary Sciences, College of Veterinary, State University of Ceará, Fortaleza, Brazil
| | - Débora Damásio de Queiroz Paiva
- Department of Pathology and Legal Medicine, Postgraduate Program in Medical Microbiology, Group of Applied Medical Microbiology, Federal University of Ceará, Fortaleza, Brazil
| | - Expedito Maia Diógenes
- Department of Pathology and Legal Medicine, Postgraduate Program in Medical Microbiology, Group of Applied Medical Microbiology, Federal University of Ceará, Fortaleza, Brazil
| | - Glaucia Morgana de Melo Guedes
- Department of Pathology and Legal Medicine, Postgraduate Program in Medical Microbiology, Group of Applied Medical Microbiology, Federal University of Ceará, Fortaleza, Brazil
- Department of Pathology and Legal Medicine, Postgraduate Program in Medical Microbiology, Specialized Medical Mycology Center, Federal University of Ceará, Fortaleza, Brazil
| | - Cecília Leite Costa
- Department of Pathology and Legal Medicine, Postgraduate Program in Medical Microbiology, Group of Applied Medical Microbiology, Federal University of Ceará, Fortaleza, Brazil
| | - Anísio Silvestre Pinheiro Santos-Filho
- Department of Pathology and Legal Medicine, Postgraduate Program in Medical Microbiology, Group of Applied Medical Microbiology, Federal University of Ceará, Fortaleza, Brazil
| | - Ana Raquel Colares de Andrade
- Department of Pathology and Legal Medicine, Postgraduate Program in Medical Microbiology, Specialized Medical Mycology Center, Federal University of Ceará, Fortaleza, Brazil
| | - Rossana de Aguiar Cordeiro
- Department of Pathology and Legal Medicine, Postgraduate Program in Medical Microbiology, Specialized Medical Mycology Center, Federal University of Ceará, Fortaleza, Brazil
| | - Marcos Fábio Gadelha Rocha
- Department of Pathology and Legal Medicine, Postgraduate Program in Medical Microbiology, Specialized Medical Mycology Center, Federal University of Ceará, Fortaleza, Brazil
- Postgraduate Program in Veterinary Sciences, College of Veterinary, State University of Ceará, Fortaleza, Brazil
| | - José Júlio Costa Sidrim
- Department of Pathology and Legal Medicine, Postgraduate Program in Medical Microbiology, Specialized Medical Mycology Center, Federal University of Ceará, Fortaleza, Brazil
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Mountcastle SE, Cox SC, Sammons RL, Jabbari S, Shelton RM, Kuehne SA. A review of co-culture models to study the oral microenvironment and disease. J Oral Microbiol 2020; 12:1773122. [PMID: 32922679 PMCID: PMC7448840 DOI: 10.1080/20002297.2020.1773122] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 04/25/2020] [Accepted: 05/19/2020] [Indexed: 12/19/2022] Open
Abstract
Co-cultures allow for the study of cell-cell interactions between different eukaryotic species or with bacteria. Such an approach has enabled researchers to more closely mimic complex tissue structures. This review is focused on co-culture systems modelling the oral cavity, which have been used to evaluate this unique cellular environment and understand disease progression. Over time, these systems have developed significantly from simple 2D eukaryotic cultures and planktonic bacteria to more complex 3D tissue engineered structures and biofilms. Careful selection and design of the co-culture along with critical parameters, such as seeding density and choice of analysis method, have resulted in several advances. This review provides a comparison of existing co-culture systems for the oral environment, with emphasis on progression of 3D models and the opportunity to harness techniques from other fields to improve current methods. While filling a gap in navigating this literature, this review ultimately supports the development of this vital technique in the field of oral biology.
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Affiliation(s)
- Sophie E Mountcastle
- EPSRC Centre for Doctoral Training in Physical Sciences for Health, University of Birmingham, Birmingham, UK
- School of Dentistry, University of Birmingham, Birmingham, UK
| | - Sophie C Cox
- School of Chemical Engineering, University of Birmingham, Birmingham, UK
| | | | - Sara Jabbari
- School of Mathematics, University of Birmingham, Birmingham, UK
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| | | | - Sarah A Kuehne
- School of Dentistry, University of Birmingham, Birmingham, UK
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
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Small Molecules Produced by Commensal Staphylococcus epidermidis Disrupt Formation of Biofilms by Staphylococcus aureus. Appl Environ Microbiol 2020; 86:AEM.02539-19. [PMID: 31862721 DOI: 10.1128/aem.02539-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 12/16/2019] [Indexed: 11/20/2022] Open
Abstract
The microbiota influences host health through several mechanisms, including protecting it from pathogen colonization. Staphylococcus epidermidis is one of the most frequently found species in the skin microbiota, and its presence can limit the development of pathogens such as Staphylococcus aureus S. aureus causes diverse types of infections ranging from skin abscesses to bloodstream infections. Given the increasing prevalence of S. aureus drug-resistant strains, it is imperative to search for new strategies for treatment and prevention. Thus, we investigated the activity of molecules produced by a commensal S. epidermidis isolate against S. aureus biofilms. We showed that molecules present in S. epidermidis cell-free conditioned media (CFCM) caused a significant reduction in biofilm formation in most S. aureus clinical isolates, including all 4 agr types and agr-defective strains, without any impact on growth. S. epidermidis molecules also disrupted established S. aureus biofilms and reduced the antibiotic concentration required to eliminate them. Preliminary characterization of the active compound showed that its activity is resistant to heat, protease inhibitors, trypsin, proteinase K, and sodium periodate treatments, suggesting that it is not proteinaceous. RNA sequencing revealed that S. epidermidis-secreted molecules modulate the expression of hundreds of S. aureus genes, some of which are associated with biofilm production. Biofilm formation is one of the main virulence factors of S. aureus and has been associated with chronic infections and antimicrobial resistance. Therefore, molecules that can counteract this virulence factor may be promising alternatives as novel therapeutic agents to control S. aureus infections.IMPORTANCE S. aureus is a leading agent of infections worldwide, and its main virulence characteristic is the ability to produce biofilms on surfaces such as medical devices. Biofilms are known to confer increased resistance to antimicrobials and to the host immune responses, requiring aggressive antibiotic treatment and removal of the infected surface. Here, we investigated a new source of antibiofilm compounds, the skin microbiome. Specifically, we found that a commensal strain of S. epidermidis produces molecules with antibiofilm activity, leading to a significant decrease of S. aureus biofilm formation and to a reduction of previously established biofilms. The molecules potentiated the activity of antibiotics and affected the expression of hundreds of S. aureus genes, including those associated with biofilm formation. Our research highlights the search for compounds that can aid us in the fight against S. aureus infections.
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Hashemi MM, Rovig J, Holden BS, Taylor MF, Weber S, Wilson J, Hilton B, Zaugg AL, Ellis SW, Yost CD, Finnegan PM, Kistler CK, Berkow EL, Deng S, Lockhart SR, Peterson M, Savage PB. Ceragenins are active against drug-resistant Candida auris clinical isolates in planktonic and biofilm forms. J Antimicrob Chemother 2019; 73:1537-1545. [PMID: 29635279 DOI: 10.1093/jac/dky085] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 02/20/2018] [Indexed: 12/16/2022] Open
Abstract
Background Candida auris has emerged as a serious threat to human health. Of particular concern are the resistance profiles of many clinical isolates, with some being resistant to multiple classes of antifungals. Objectives Measure susceptibilities of C. auris isolates, in planktonic and biofilm forms, to ceragenins (CSAs). Determine the effectiveness of selected ceragenins in gel and cream formulations in eradicating fungal infections in tissue explants. Materials and methods A collection of 100 C. auris isolates available at CDC was screened for susceptibility to a lead ceragenin. A smaller collection was used to characterize antifungal activities of other ceragenins against organisms in planktonic and biofilm forms. Effects of ceragenins on fungal cells and biofilms were observed via microscopy. An ex vivo model of mucosal fungal infection was used to evaluate formulated forms of lead ceragenins. Results Lead ceragenins displayed activities comparable to those of known antifungal agents against C. auris isolates with MICs of 0.5-8 mg/L and minimum fungicidal concentrations (MFCs) of 2-64 mg/L. No cross-resistance with other antifungals was observed. Fungal cell morphology was altered in response to ceragenin treatment. Ceragenins exhibited activity against sessile organisms in biofilms. Gel and cream formulations including 2% CSA-44 or CSA-131 resulted in reductions of over 4 logs against established fungal infections in ex vivo mucosal tissues. Conclusions Ceragenins demonstrated activity against C. auris, suggesting that these compounds warrant further study to determine whether they can be used for topical applications to skin and mucosal tissues for treatment of infections with C. auris and other fungi.
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Affiliation(s)
- Marjan M Hashemi
- Department of Chemistry and Biochemistry, Brigham Young University, C100 BNSN, Provo, UT 84602, USA
| | - John Rovig
- Department of Chemistry and Biochemistry, Brigham Young University, C100 BNSN, Provo, UT 84602, USA
| | - Brett S Holden
- Department of Chemistry and Biochemistry, Brigham Young University, C100 BNSN, Provo, UT 84602, USA
| | - Maddison F Taylor
- Department of Chemistry and Biochemistry, Brigham Young University, C100 BNSN, Provo, UT 84602, USA
| | - Scott Weber
- Department of Chemistry and Biochemistry, Brigham Young University, C100 BNSN, Provo, UT 84602, USA
| | - John Wilson
- Department of Chemistry and Biochemistry, Brigham Young University, C100 BNSN, Provo, UT 84602, USA
| | - Brian Hilton
- Department of Chemistry and Biochemistry, Brigham Young University, C100 BNSN, Provo, UT 84602, USA
| | - Aaron L Zaugg
- Department of Chemistry and Biochemistry, Brigham Young University, C100 BNSN, Provo, UT 84602, USA
| | - Samuel W Ellis
- Department of Chemistry and Biochemistry, Brigham Young University, C100 BNSN, Provo, UT 84602, USA
| | - Connor D Yost
- Department of Chemistry and Biochemistry, Brigham Young University, C100 BNSN, Provo, UT 84602, USA
| | | | | | - Elizabeth L Berkow
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Shenglou Deng
- Department of Chemistry and Biochemistry, Brigham Young University, C100 BNSN, Provo, UT 84602, USA
| | - Shawn R Lockhart
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - Paul B Savage
- Department of Chemistry and Biochemistry, Brigham Young University, C100 BNSN, Provo, UT 84602, USA
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Ho DK, Nichols BLB, Edgar KJ, Murgia X, Loretz B, Lehr CM. Challenges and strategies in drug delivery systems for treatment of pulmonary infections. Eur J Pharm Biopharm 2019; 144:110-124. [PMID: 31493510 DOI: 10.1016/j.ejpb.2019.09.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 08/23/2019] [Accepted: 09/03/2019] [Indexed: 01/08/2023]
Abstract
Inhalation therapy has been reported as the most effective treatment for respiratory bacterial infections due to the increasing relevance of drug bioavailability. Drug delivery systems (DDS) have the capacity to overcome pulmonary biological barriers limiting the bioavailability of inhaled anti-infectives. This is important to eradicate bacterial infections and to prevent the development of bacterial resistance. Despite substantial efforts in the field, the current state-of-the-art often fails to achieve those goals, and we still observe increasing bacterial resistance. We give a brief insight on benefits and challenges in pulmonary delivery of anti-infectives. In the context of drug delivery development for pulmonary infections, particularly focusing on Pseudomonas aeruginosa (PA) infections, this mini review will critically discuss the main requirements, as well as the recent strategies of drug delivery system synthesis and preparation. Finally, interaction of DDS with crucial pulmonary biological barriers will be of great importance for the success of future applications of the developed DDS.
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Affiliation(s)
- Duy-Khiet Ho
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research (HZI), Saarland University, D-66123 Saarbrücken, Germany
| | - Brittany L B Nichols
- Department of Chemistry, Virginia Tech, Blacksburg, VA 24061, United States; Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA 24061, United States
| | - Kevin J Edgar
- Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA 24061, United States; Department of Sustainable Biomaterials, Virginia Tech, Blacksburg, VA 24061, United States
| | - Xabier Murgia
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research (HZI), Saarland University, D-66123 Saarbrücken, Germany
| | - Brigitta Loretz
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research (HZI), Saarland University, D-66123 Saarbrücken, Germany.
| | - Claus-Michael Lehr
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research (HZI), Saarland University, D-66123 Saarbrücken, Germany; Department of Pharmacy, Saarland University, D-66123 Saarbrücken, Germany
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12
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Nosetti L, Piacentini G, Macchi A, De Bernardi F, Simoncini D, Nicoloso M, Agosti M, Zaffanello M. Nasal cytology in children with primary snoring and obstructive sleep apnoea syndrome. Int J Pediatr Otorhinolaryngol 2019; 122:133-137. [PMID: 31022683 DOI: 10.1016/j.ijporl.2019.04.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 04/10/2019] [Accepted: 04/12/2019] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Rhinitis is an acute or chronic inflammatory condition due to several causes (i.e. infections, allergens). There are controversial results that point out the role of nasal inflammation in primary snoring and obstructive sleep apnoea syndrome (OSAS). METHODS The aim of the present investigation is to study the nasal cytology in 58 children aged from 1 to 15 affected by sleep disordered breathing. RESULTS Inflammation of the nasal mucous was found in 88% of children. The most frequent problems were infectious rhinitis (36%), followed by non-allergic rhinitis (28%) and allergic rhinitis (21%). Infectious rhinitis was found in 31% of children with primary snoring and 41% with OSAS. Allergic rhinitis was found in 35% of children with primary snoring, and 6% with OSAS. Non-allergic rhinitis was found in 19% of children with primary snoring, and 34% with OSAS. Bacteria was found in 59% of children with OSAS and 46% in children with primary snoring. CONCLUSION the most prevalent forms of rhinitis in primary snoring were the allergic rhinitis, and in OSAS group were the non-allergic rhinitis. Bacteria were equally distributed in primary snoring and OSAS children. The nasal cytology provided interesting information that can be used to plan possible treatment strategies.
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Affiliation(s)
- Luana Nosetti
- Division of Pediatrics, "F. Del Ponte" Hospital, University of Insubria, Varese, Italy.
| | - Giorgio Piacentini
- Department of Surgical Sciences, Dentistry, Gynecology and Pediatrics, University of Verona, Verona, Italy.
| | - Alberto Macchi
- Department of Otolaryngology, University of Insubria and ASST Laghi, Ospedale di Circolo, Varese, Italy.
| | - Francesca De Bernardi
- Department of Otolaryngology, University of Insubria and ASST Laghi, Ospedale di Circolo, Varese, Italy.
| | - Daniela Simoncini
- Division of Pediatrics, "F. Del Ponte" Hospital, University of Insubria, Varese, Italy.
| | - Martina Nicoloso
- Division of Pediatrics, "F. Del Ponte" Hospital, University of Insubria, Varese, Italy.
| | - Massimo Agosti
- Division of Neonatology and Neonatal Intensive Care Unit, "F. Del Ponte" Hospital, Varese, Italy.
| | - Marco Zaffanello
- Department of Surgical Sciences, Dentistry, Gynecology and Pediatrics, University of Verona, Verona, Italy.
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Rahimi C, Rahimi B, Padova D, Rooholghodos SA, Bienek DR, Luo X, Kaufman G, Raub CB. Oral mucosa-on-a-chip to assess layer-specific responses to bacteria and dental materials. BIOMICROFLUIDICS 2018; 12:054106. [PMID: 30310527 PMCID: PMC6158033 DOI: 10.1063/1.5048938] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 09/06/2018] [Indexed: 05/24/2023]
Abstract
The human oral mucosa hosts a diverse microbiome and is exposed to potentially toxic biomaterials from dental restoratives. Mucosal health is partly determined by cell and tissue responses to challenges such as dental materials and pathogenic bacteria. An in vitro model to rapidly determine potential layer-specific responses would lead to a better understanding of mucosal homeostasis and pathology. Therefore, this study aimed to develop a co-cultured microfluidic mucosal model on-a-chip to rapidly assess mucosal remodeling and the responses of epithelial and subepithelial layers to challenges typically found in the oral environment. A gingival fibroblast-laden collagen hydrogel was assembled in the central channel of a three-channel microfluidic chamber with interconnecting pores, followed by a keratinocyte layer attached to the collagen exposed in the pores. This configuration produced apical and subepithelial side channels capable of sustaining flow. Keratinocyte, fibroblast, and collagen densities were optimized to create a co-culture tissue-like construct stable over one week. Cells were stained and imaged with epifluorescence microscopy to confirm layer characteristics. As proof-of-concept, the mucosal construct was exposed separately to a dental monomer, 2-hydroxylethyl methacrylate (HEMA), and the oral bacteria Streptococcus mutans. Exposure to HEMA lowered mucosal cell viability, while exposure to the bacteria lowered trans-epithelial electrical resistance. These findings suggest that the oral mucosa-on-a-chip is useful for studying oral mucosal interactions with bacteria and biomaterials with a histology-like view of the tissue layers.
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Affiliation(s)
- Christopher Rahimi
- Department of Biomedical Engineering, The Catholic University of America, 620 Michigan Avenue NE, Washington, District of Columbia 20064, USA
| | - Benjamin Rahimi
- Department of Biomedical Engineering, The Catholic University of America, 620 Michigan Avenue NE, Washington, District of Columbia 20064, USA
| | - Dominic Padova
- Department of Biomedical Engineering, The Catholic University of America, 620 Michigan Avenue NE, Washington, District of Columbia 20064, USA
| | - Seyed A. Rooholghodos
- Department of Mechanical Engineering, The Catholic University of America, 620 Michigan Avenue NE, Washington, District of Columbia 20064, USA
| | - Diane R. Bienek
- ADA Foundation, Volpe Research Center, 100 Bureau Drive, Stop #8546, Gaithersburg, Maryland 20899, USA
| | - Xiaolong Luo
- Department of Mechanical Engineering, The Catholic University of America, 620 Michigan Avenue NE, Washington, District of Columbia 20064, USA
| | - Gili Kaufman
- ADA Foundation, Volpe Research Center, 100 Bureau Drive, Stop #8546, Gaithersburg, Maryland 20899, USA
| | - Christopher B. Raub
- Department of Biomedical Engineering, The Catholic University of America, 620 Michigan Avenue NE, Washington, District of Columbia 20064, USA
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Nie S, Lu X, Hu YW, Zheng L, Wang Q. Influence of environmental and genotypic factors on biofilm formation by clinical isolates of group B streptococci. Microb Pathog 2018; 121:45-50. [DOI: 10.1016/j.micpath.2018.05.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 04/16/2018] [Accepted: 05/11/2018] [Indexed: 12/13/2022]
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Alpha-Toxin Contributes to Biofilm Formation among Staphylococcus aureus Wound Isolates. Toxins (Basel) 2018; 10:toxins10040157. [PMID: 29659477 PMCID: PMC5923323 DOI: 10.3390/toxins10040157] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 04/03/2018] [Accepted: 04/04/2018] [Indexed: 01/03/2023] Open
Abstract
Biofilms complicate treatment of Staphylococcus aureus (SA) wound infections. Previously, we determined alpha-toxin (AT)-promoted SA biofilm formation on mucosal tissue. Therefore, we evaluated SA wound isolates for AT production and biofilm formation on epithelium and assessed the role of AT in biofilm formation. Thirty-eight wound isolates were molecularly typed by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (ST), and spa typing. We measured biofilm formation of these SA isolates in vitro and ex vivo and quantified ex vivo AT production. We also investigated the effect of an anti-AT monoclonal antibody (MEDI4893*) on ex vivo biofilm formation by methicillin-resistant SA (USA 300 LAC) and tested whether purified AT rescued the biofilm defect of hla mutant SA strains. The predominant PFGE/ST combinations were USA100/ST5 (50%) and USA300/ST8 (33%) for methicillin-resistant SA (MRSA, n = 18), and USA200/ST30 (20%) for methicillin-susceptible SA (MSSA, n = 20). Ex vivo AT production correlated significantly with ex vivo SA wound isolate biofilm formation. Anti-alpha-toxin monoclonal antibody (MEDI4893*) prevented ex vivo biofilm formation by MRSA USA300 strain LAC. Wild-type AT rescued the ex vivo biofilm defect of non-AT producing SA strains. These findings provide evidence that AT plays a role in SA biofilm formation on epithelial surfaces and suggest that neutralization of AT may be useful in preventing and treating SA infections.
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Abstract
Ceragenins were designed as non-peptide mimics of endogenous antimicrobial peptides, and they display broad-spectrum antibacterial and antifungal activities, including the ability to eradicate established biofilms. These features of ceragenins make them attractive potential therapeutics for persistent infections in the lung, including those associated with cystic fibrosis. A characteristic of an optimal therapeutic for use in the lungs and trachea is the exertion of potent antimicrobial activities without damaging the cilia that play a critical role in these tissues. In previous work, potent antimicrobial activities of ceragenin CSA-131 have been reported; however, we found in ex vivo studies that this ceragenin, at concentrations necessary to eradicate established biofilms, also causes loss of cilia function. By formulating CSA-131 in poloxamer micelles, cilia damage was eliminated and antimicrobial activity was unaffected. The ability of CSA-131, formulated with a poloxamer, to reduce the populations of fungal pathogens in tracheal and lung tissue was also observed in ex vivo studies. These findings suggest that CSA-131, formulated in micelles, may act as a potential therapeutic for polymicrobial and biofilm-related infections in the lung and trachea.
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Gillman AN, Breshears LM, Kistler CK, Finnegan PM, Torres VJ, Schlievert PM, Peterson ML. Epidermal Growth Factor Receptor Signaling Enhances the Proinflammatory Effects of Staphylococcus aureus Gamma-Toxin on the Mucosa. Toxins (Basel) 2017; 9:toxins9070202. [PMID: 28657583 PMCID: PMC5535149 DOI: 10.3390/toxins9070202] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 06/02/2017] [Accepted: 06/09/2017] [Indexed: 12/27/2022] Open
Abstract
Staphylococcus aureus (S. aureus) produces many different exotoxins including the gamma-toxins, HlgAB and HlgCB. Gamma-toxins form pores in both leukocyte and erythrocyte membranes, resulting in cell lysis. The genes encoding gamma-toxins are present in most strains of S. aureus, and are commonly expressed in clinical isolates recovered from menstrual Toxic Shock Syndrome (mTSS) patients. This study set out to investigate the cytotoxic and proinflammatory effects of gamma-toxins on vaginal epithelial surfaces. We found that both HlgAB and HlgCB were cytotoxic to cultured human vaginal epithelial cells (HVECs) and induced cytokine production at sub-cytotoxic doses. Cytokine production induced by gamma-toxin treatment of HVECs was found to involve epidermal growth factor receptor (EGFR) signaling and mediated by shedding of EGFR ligands from the cell surface. The gamma-toxin subunits displayed differential binding to HVECs (HlgA 93%, HlgB 97% and HlgC 28%) with both components (HlgAB or HlgCB) required for maximum detectable binding and significant stimulation of cytokine production. In studies using full thickness ex vivo porcine vaginal mucosa, HlgAB or HlgCB stimulated a dose-dependent cytokine response, which was reduced significantly by inhibition of EGFR signaling. The effects of gamma-toxins on porcine vaginal tissue and cultured HVECs were validated using ex vivo human ectocervical tissue. Collectively, these studies have identified the EGFR-signaling pathway as a key component in gamma-toxin-induced proinflammatory changes at epithelial surfaces and highlight a potential therapeutic target to diminish toxigenic effects of S. aureus infections.
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Affiliation(s)
- Aaron N Gillman
- Department of Pharmacy, University of Tromsø, Tromsø 9019, Troms, Norway.
- Department of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Laura M Breshears
- Department of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, MN 55455, USA.
| | | | | | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA.
| | - Patrick M Schlievert
- Department of Microbiology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA.
| | - Marnie L Peterson
- Department of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, MN 55455, USA.
- Extherid Biosciences, LLC., Jackson, WY 83001, USA.
- School of Pharmacy, University of Wyoming, Laramie, WY 82071, USA.
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The Acinetobacter baumannii Two-Component System AdeRS Regulates Genes Required for Multidrug Efflux, Biofilm Formation, and Virulence in a Strain-Specific Manner. mBio 2016; 7:e00430-16. [PMID: 27094331 PMCID: PMC4850262 DOI: 10.1128/mbio.00430-16] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The opportunistic pathogen Acinetobacter baumannii is able to persist in the environment and is often multidrug resistant (MDR), causing difficulties in the treatment of infections. Here, we show that the two-component system AdeRS, which regulates the production of the AdeABC multidrug resistance efflux pump, is required for the formation of a protective biofilm in an ex vivo porcine mucosal model, which mimics a natural infection of the human epithelium. Interestingly, deletion of adeB impacted only on the ability of strain AYE to form a biofilm on plastic and only on the virulence of strain Singapore 1 for Galleria mellonella. RNA-Seq revealed that loss of AdeRS or AdeB significantly altered the transcriptional landscape, resulting in the changed expression of many genes, notably those associated with antimicrobial resistance and virulence interactions. For example, A. baumannii lacking AdeRS displayed decreased expression of adeABC, pil genes, com genes, and a pgaC-like gene, whereas loss of AdeB resulted in increased expression of pil and com genes and decreased expression of ferric acinetobactin transport system genes. These data define the scope of AdeRS-mediated regulation, show that changes in the production of AdeABC mediate important phenotypes controlled by AdeRS, and suggest that AdeABC is a viable target for antimicrobial drug and antibiofilm discovery. Acinetobacter baumannii is a nosocomial pathogen and is an increasing problem in hospitals worldwide. This organism is often multidrug resistant, can persist in the environment, and forms a biofilm on environmental surfaces and wounds. Overproduction of efflux pumps can allow specific toxic compounds to be pumped out of the cell and can lead to multidrug resistance. This study demonstrates the role of the A. baumannii efflux pump AdeB, and its regulator AdeRS, in multidrug resistance, epithelial cell killing, and biofilm formation. Deletion of the genes encoding these systems led to increased susceptibility to antibiotics, decreased biofilm formation on biotic and abiotic surfaces, and decreased virulence. Our data suggest that inhibition of AdeB could prevent biofilm formation or colonization in patients by A. baumannii and provides a good target for drug discovery.
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Breshears LM, Edwards VL, Ravel J, Peterson ML. Lactobacillus crispatus inhibits growth of Gardnerella vaginalis and Neisseria gonorrhoeae on a porcine vaginal mucosa model. BMC Microbiol 2015; 15:276. [PMID: 26652855 PMCID: PMC4675025 DOI: 10.1186/s12866-015-0608-0] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 11/30/2015] [Indexed: 02/07/2023] Open
Abstract
Background The vaginal microbiota can impact the susceptibility of women to bacterial vaginosis (BV) and sexually transmitted infections (STIs). BV is characterized by depletion of Lactobacillus spp., an overgrowth of anaerobes (often dominated by Gardnerella vaginalis) and a pH > 4.5. BV is associated with an increased risk of acquiring STIs such as chlamydia and gonorrhea. While these associations have been identified, the molecular mechanism(s) driving the risk of infections are unknown. An ex vivo porcine vaginal mucosal model (PVM) was developed to explore the mechanistic role of Lactobacillus spp. in affecting colonization by G. vaginalis and Neisseria gonorrhoeae. Results The data presented here demonstrate that all organisms tested can colonize and grow on PVM to clinically relevant densities. Additionally, G. vaginalis and N. gonorrhoeae form biofilms on PVM. It was observed that lactic acid, acetic acid, and hydrochloric acid inhibit the growth of G. vaginalis on PVM in a pH-dependent manner. N. gonorrhoeae grows best in the presence of lactic acid at pH 5.5, but did not grow well at this pH in the presence of acetic acid. Finally, a clinical Lactobacillus crispatus isolate (24-9-7) produces lactic acid and inhibits growth of both G. vaginalis and N. gonorrhoeae on PVM. Conclusions These data reveal differences in the effects of pH, various acids and L. crispatus on the growth of G. vaginalis and N. gonorrhoeae on a live vaginal mucosal surface. The PVM is a useful model for studying the interactions of commensal vaginal microbes with pathogens and the mechanisms of biofilm formation on the vaginal mucosa.
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Affiliation(s)
- Laura M Breshears
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, 4-442 McGuire Translational Research Facility, 2001 6th St. SE, Minneapolis, MN, 55455, USA.
| | - Vonetta L Edwards
- Institute for Genome Sciences, University of Maryland, School of Medicine, Bio Park II, 6th Floor, 801 West Baltimore St., Baltimore, MD, 21201, USA.
| | - Jacques Ravel
- Institute for Genome Sciences, University of Maryland, School of Medicine, Bio Park II, 6th Floor, 801 West Baltimore St., Baltimore, MD, 21201, USA.
| | - Marnie L Peterson
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, 4-442 McGuire Translational Research Facility, 2001 6th St. SE, Minneapolis, MN, 55455, USA.
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Batoni G, Maisetta G, Esin S. Antimicrobial peptides and their interaction with biofilms of medically relevant bacteria. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1858:1044-60. [PMID: 26525663 DOI: 10.1016/j.bbamem.2015.10.013] [Citation(s) in RCA: 225] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 10/16/2015] [Accepted: 10/18/2015] [Indexed: 02/07/2023]
Abstract
Biofilm-associated infections represent one of the major threats of modern medicine. Biofilm-forming bacteria are encased in a complex mixture of extracellular polymeric substances (EPS) and acquire properties that render them highly tolerant to conventional antibiotics and host immune response. Therefore, there is a pressing demand of new drugs active against microbial biofilms. In this regard, antimicrobial peptides (AMPs) represent an option taken increasingly in consideration. After dissecting the peculiar biofilm features that may greatly affect the development of new antibiofilm drugs, the present article provides a general overview of the rationale behind the use of AMPs against biofilms of medically relevant bacteria and on the possible mechanisms of AMP-antibiofilm activity. An analysis of the interactions of AMPs with biofilm components, especially those constituting the EPS, and the obstacles and/or opportunities that may arise from such interactions in the development of new AMP-based antibiofilm strategies is also presented and discussed. This article is part of a Special Issue entitled: Antimicrobial Peptides edited by Karl Lohner and Kai Hilpert.
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Affiliation(s)
- Giovanna Batoni
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy.
| | - Giuseppantonio Maisetta
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Semih Esin
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
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Gu Q, Sun T, Wu G, Li M, Qiu W. Influence of carrier filling ratio on the performance of moving bed biofilm reactor in treating coking wastewater. BIORESOURCE TECHNOLOGY 2014; 166:72-78. [PMID: 24907566 DOI: 10.1016/j.biortech.2014.05.026] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Revised: 05/09/2014] [Accepted: 05/11/2014] [Indexed: 06/03/2023]
Abstract
This study aims to evaluate the effect of carrier filling ratio on the performance of a moving bed biofilm reactor in degrading chemical oxygen demand, phenol, thiocyanate, and ammonia from coking wastewater at 20h of hydraulic retention time. The operational experiments under different carrier filling ratios ranging from 20% to 60% were investigated. The maximum removal efficiency of 89%, 99% and 99% for COD, phenol and thiocyanate, and minimum sensitivity to the increasing contaminants concentration in the influent were achieved at 50% carrier filling ratio. The Haldane competitive substrate inhibition kinetics model was used to describe the relationship between the oxygen uptake rate of ammonium oxidizers and the concentration of free ammonium. The highest biofilm microbial community functional diversity (Shannon's diversity index, H') and evenness (Shannon's evenness index, E') were obtained at 50% carrier filling ratio in all runs using a Biolog ECO microplate.
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Affiliation(s)
- Qiyuan Gu
- School of Civil and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China.
| | - Tichang Sun
- School of Civil and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China.
| | - Gen Wu
- Basic Research Service, Ministry of Science and Technology of the People's Republic of China, Beijing 100862, China.
| | - Mingyue Li
- School of Civil and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China.
| | - Wei Qiu
- State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, China; School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
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Thomas NM, Brook I. Otitis media: an update on current pharmacotherapy and future perspectives. Expert Opin Pharmacother 2014; 15:1069-83. [PMID: 24793547 DOI: 10.1517/14656566.2014.903920] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
INTRODUCTION Acute otitis media (AOM) is the most common childhood bacterial infection and also the leading cause of conductive hearing loss in children. Currently, there is an urgent need for developing novel therapeutic agents for treating AOM. AREAS COVERED Structured search of current literature. PubMed was searched for published literature in areas of pharmacotherapeutics, preventive therapies and complementary treatments for OM. The intent of this review is to provide a comprehensive evaluation of therapeutics for AOM, including preventive modalities and complementary medicine. EXPERT OPINION the management of AOM in young children is still evolving and depends on patterns of bacterial colonization and antimicrobial resistance in the community. The introduction of vaccinations against potential respiratory tract pathogens has altered the frequency of recovery of pathogens causing ear infections in children. Even though not all patients require antimicrobial therapy to overcome their infection, these agents improve symptoms faster and lead to fewer treatment failures. Further studies are warranted to evaluate which patients would best benefit from antimicrobial therapy.
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Affiliation(s)
- Nicole M Thomas
- Uniformed Services University of the Health Sciences, Department of Pediatrics , Bethesda, MD , USA
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