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Loeffler H, Waletzko-Hellwig J, Fischer RJ, Basen M, Frank M, Jonitz-Heincke A, Bader R, Klinder A. Systematic enhancement of microbial decontamination efficiency in bone graft processing by means of high hydrostatic pressure using Escherichia coli as a model organism. J Biomed Mater Res B Appl Biomater 2024; 112:e35383. [PMID: 38345152 DOI: 10.1002/jbm.b.35383] [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: 06/21/2023] [Revised: 10/30/2023] [Accepted: 01/27/2024] [Indexed: 02/15/2024]
Abstract
To obtain bone allografts that are safe for transplantation, several processing steps for decellularization and decontamination have to be applied. Currently available processing methods, although well-established, may interfere with the biomechanical properties of the bone. High hydrostatic pressure (HHP) is known to devitalize tissues effectively while leaving the extracellular matrix intact. However, little is known about the inactivation of the contaminating microorganisms by HHP. This study aims to investigate the ability of high-pressure decontamination and to establish a treatment protocol that is able to successfully inactivate microorganisms with the final goal to sterilize bone specimens. Using Escherichia coli (E. coli) as a model organism, HHP treatment parameters like temperature and duration, pressurization medium, and the number of treatment cycles were systematically adjusted to maximize the efficiency of inactivating logarithmic and stationary phase bacteria. Towards that we quantified colony-forming units (cfu) after treatment and investigated morphological changes via Field Emission Scanning Electron Microscopy (FESEM). Additionally, we tested the decontamination efficiency of HHP in bovine cancellous bone blocks that were contaminated with bacteria. Finally, two further model organisms were evaluated, namely Pseudomonas fluorescens as a Gram-negative microorganism and Micrococcus luteus as a Gram-positive representative. A HHP protocol, using 350 MPa, was able to sterilize a suspension of stationary phase E. coli, leading to a logarithmic reduction factor (log RF) of at least -7.99 (±0.43). The decontamination of bone blocks was less successful, indicating a protective effect of the surrounding tissue. Sterilization of 100% of the samples was achieved when a protocol optimized in terms of treatment temperature, duration, pressurization medium, and number and/or interval of cycles, respectively, was applied to bone blocks artificially contaminated with a suspension containing 104 cfu/mL. Hence, we here successfully established protocols for inactivating Gram-negative model microorganisms by HHP of up to 350 MPa, while pressure levels of 600 MPa were needed to inactivate the Gram-positive model organism. Thus, this study provides a basis for further investigations on different pathogenic bacteria that could enable the use of HHP in the decontamination of bone grafts intended for transplantation.
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Affiliation(s)
- Henrike Loeffler
- Biomechanics and Implant Technology Research Laboratory, Department of Orthopedics, Rostock University Medical Center, Rostock, Germany
| | - Janine Waletzko-Hellwig
- Biomechanics and Implant Technology Research Laboratory, Department of Orthopedics, Rostock University Medical Center, Rostock, Germany
| | - Ralf-Joerg Fischer
- Microbiology, Institute of Biological Sciences, University of Rostock, Rostock, Germany
| | - Mirko Basen
- Microbiology, Institute of Biological Sciences, University of Rostock, Rostock, Germany
- Department Maritime Systems, Faculty of Interdisciplinary Research, University of Rostock, Rostock, Germany
| | - Marcus Frank
- Medical Biology and Electron Microscopy Center, Rostock University Medical Center, Rostock, Germany
- Department Life, Light and Matter, Faculty for Interdisciplinary Research, University of Rostock, Rostock, Germany
| | - Anika Jonitz-Heincke
- Biomechanics and Implant Technology Research Laboratory, Department of Orthopedics, Rostock University Medical Center, Rostock, Germany
| | - Rainer Bader
- Biomechanics and Implant Technology Research Laboratory, Department of Orthopedics, Rostock University Medical Center, Rostock, Germany
| | - Annett Klinder
- Biomechanics and Implant Technology Research Laboratory, Department of Orthopedics, Rostock University Medical Center, Rostock, Germany
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Maletzki C, Freiin Grote V, Kalle F, Kleitke T, Zimpfer A, Becker AS, Bergmann-Ewert W, Jonitz-Heincke A, Bader R, Vollmar B, Hackenberg S, Scherzad A, Mlynski R, Strüder D. Establishing safe high hydrostatic pressure devitalization thresholds for autologous head and neck cancer vaccination and reconstruction. Cell Death Discov 2023; 9:390. [PMID: 37872173 PMCID: PMC10593744 DOI: 10.1038/s41420-023-01671-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 09/13/2023] [Accepted: 10/03/2023] [Indexed: 10/25/2023] Open
Abstract
High hydrostatic pressure specifically devitalizes cells and tissues without major changes in their molecular structure. Hence, high hydrostatic pressure may enhance the development of whole-cell anti-tumor vaccines, representing tumor heterogeneity and thus (neo-) antigen diversity. Moreover, safe devitalization of tumor-infiltrated supporting tissue may facilitate reimplantation for functional reconstruction. However, precise high hydrostatic pressure thresholds for safe cancer cell killing are unknown. Here, we show that high hydrostatic pressure of at least 450 MPa is necessary to safely devitalize head and neck squamous cell cancer. A pressure of 300 MPa, which has been used frequently in cancer vaccine preparation, resulted in partial devitalization with 27% live cells in flow cytometry and 4% remaining autofluorescence in cell culture after one week. The remaining cells could form vital tumors in the chorioallantoic membrane assay. In contrast, 450 MPa killed all cells in vitro and prevented tumor outgrowth in ovo. The effectiveness of 450 MPa was attributed to the induction of DNA double-strand breaks, independent of apoptosis, autophagy, or methuosis. Furthermore, 450 MPa continued to induce immunogenic cell death. Our results demonstrate that 450 MPa of high hydrostatic pressure induces safe and sustained devitalization of head and neck cancer cells and tissues. Because of the heterogeneity in pressure resistance, we propose our approach as a starting point for determining the precise thresholds for other cancer entities. Further studies on head and neck cancer should focus on immunological co-cultures, combinations of immune checkpoint inhibition, and accurate anatomical reconstruction with pressure-treated autografts.
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Affiliation(s)
- Claudia Maletzki
- Department of Internal Medicine, Medical Clinic III - Hematology, Oncology, Palliative Medicine, Rostock University Medical Center, Rostock, Germany
| | - Vivica Freiin Grote
- Research Laboratory for Biomechanics and Implant Technology, Department of Orthopedics, Rostock University Medical Centre, Rostock, Germany
| | - Friederike Kalle
- Department of Otorhinolaryngology, Head and Neck Surgery "Otto Körner", Rostock University Medical Center, Rostock, Germany
| | - Thoralf Kleitke
- Department of Otorhinolaryngology, Head and Neck Surgery "Otto Körner", Rostock University Medical Center, Rostock, Germany
| | - Annette Zimpfer
- Institute of Pathology, Rostock University Medical Center, Rostock, Germany
| | - Anne-Sophie Becker
- Institute of Pathology, Rostock University Medical Center, Rostock, Germany
| | - Wendy Bergmann-Ewert
- Core Facility for Cell Sorting and Cell Analysis, University Medical Center Rostock, Rostock, Germany
| | - Anika Jonitz-Heincke
- Research Laboratory for Biomechanics and Implant Technology, Department of Orthopedics, Rostock University Medical Centre, Rostock, Germany
| | - Rainer Bader
- Research Laboratory for Biomechanics and Implant Technology, Department of Orthopedics, Rostock University Medical Centre, Rostock, Germany
| | - Brigitte Vollmar
- Institute for Experimental Surgery, Rostock University Medical Center, Rostock, Germany
| | - Stephan Hackenberg
- Department of Otorhinolaryngology-Head and Neck Surgery, RWTH Aachen University Hospital, Aachen, Germany
| | - Agmal Scherzad
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery, University of Wuerzburg, Wuerzburg, Germany
| | - Robert Mlynski
- Department of Otorhinolaryngology, Head and Neck Surgery "Otto Körner", Rostock University Medical Center, Rostock, Germany
| | - Daniel Strüder
- Department of Otorhinolaryngology, Head and Neck Surgery "Otto Körner", Rostock University Medical Center, Rostock, Germany.
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Hiemer B, Genz B, Ostwald J, Jonitz-Heincke A, Wree A, Lindner T, Tischer T, Dommerich S, Bader R. Repair of cartilage defects with devitalized osteochondral tissue: A pilot animal study. J Biomed Mater Res B Appl Biomater 2019; 107:2354-2364. [PMID: 30701676 DOI: 10.1002/jbm.b.34329] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 10/23/2018] [Accepted: 12/23/2018] [Indexed: 12/23/2022]
Abstract
Devitalization using high hydrostatic pressure (HHP) treatment inactivates cells while matrix structure and biomechanical properties are maintained. Because of strong chondroinductive potential of HHP-devitalized cartilage matrix, it may be used as scaffold for reconstruction of (osteo-)chondral lesions. In this pilot study, we evaluated the feasibility of HHP-devitalized osteochondral tissue to repair osteochondral defects in a rabbit model. Removal and reimplantation of osteochondral plugs were performed in 12 female New Zealand White rabbits. From the knee joint of each animal, osteochondral plugs (diameter = 4 mm; depth = 2.5 mm) were harvested and devitalized by HHP (452 MPa for 10 min). Afterward, the plugs were reimplanted into the respective cavity, from where they were taken. Animals were sacrificed 12 weeks postoperatively and the integration of osteochondral plugs was examined using μ-CT, MRI, and histological staining. Furthermore, revitalization of HHP-treated osteochondral plugs was characterized by gene expression analyses. Macroscopic evaluation of tissue repair at implantation sites of HHP-treated osteochondral plugs showed an adequate defect filling 12 weeks after implantation. Plug margins were hardly detectable indicating successful tissue integration. Additionally, gene expression analyses demonstrated initial revitalization of the HHP-treated tissue 12 weeks postoperatively. Our preliminary data revealed that HHP-treated osteochondral plugs could be used to refill osteochondral defects in the knee joint and promote cell migration into defect site. Data indicated that HHP-treated tissue has the potential to act as functional scaffolds for reconstruction of cartilage defects. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2354-2364, 2019.
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Affiliation(s)
- Bettina Hiemer
- Department of Orthopaedics, Biomechanics and Implant Technology Research Laboratory, Rostock University Medical Center, Rostock, Germany
| | - Berit Genz
- Department of Otorhinolaryngology, Rostock University Medical Center, Rostock, Germany.,Hepatic Fibrosis Lab, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Jürgen Ostwald
- Department of Otorhinolaryngology, Rostock University Medical Center, Rostock, Germany
| | - Anika Jonitz-Heincke
- Department of Orthopaedics, Biomechanics and Implant Technology Research Laboratory, Rostock University Medical Center, Rostock, Germany
| | - Andreas Wree
- Department of Anatomy, Rostock University Medical Center, Rostock, Germany
| | - Tobias Lindner
- Core Facility Multimodal Small Animal Imaging, Rostock University Medical Center, Rostock, Germany
| | - Thomas Tischer
- Department of Orthopaedics, Biomechanics and Implant Technology Research Laboratory, Rostock University Medical Center, Rostock, Germany
| | - Steffen Dommerich
- Department of Otorhinolaryngology, Charité Berlin University Medical Center, Berlin, Germany
| | - Rainer Bader
- Department of Orthopaedics, Biomechanics and Implant Technology Research Laboratory, Rostock University Medical Center, Rostock, Germany
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Yamin M, Souza AR, Castelucci BG, Mattoso JG, Bonafe CFS. Synergism between high hydrostatic pressure and glutaraldehyde for the inactivation of Staphylococcus aureus at moderate temperature. Appl Microbiol Biotechnol 2018; 102:8341-8350. [PMID: 30091042 DOI: 10.1007/s00253-018-9270-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 07/04/2018] [Accepted: 07/24/2018] [Indexed: 10/28/2022]
Abstract
The sterilization of transplant and medical devices should be effective but not detrimental to the structural properties of the materials used. In this study, we examined the effectiveness of chemical and physical agents for inactivating Staphylococcus aureus, a gram-positive bacterium and important cause of infections and biofilm production. The treatment conditions in this work were chosen to facilitate their subsequent use with sensitive materials. The effects of temperature, high hydrostatic pressure, and glutaraldehyde disinfectant on the growth of two strains of S. aureus (ATCC 25923 and BEC 9393) were investigated individually and/or in combinations. A low concentration of glutaraldehyde (0.5 mM), high hydrostatic pressure (300 MPa for 10 min), and moderate temperature (50 °C), when used in combination, significantly potentiated the inactivation of both bacterial strains by > 8 orders of magnitude. Transmission electron microscopy revealed structural damage and changes in area that correlated with the use of pressure in the presence of glutaraldehyde at room temperature in both strains. Biofilm from strain ATCC 25923 was particularly susceptible to inactivation. The conditions used here provided effective sterilization that can be applied to sensitive surgical devices and biomaterials, with negligible damage. The use of this experimental approach to investigate other pathogens could lead to the adoption of this procedure for sterilizing sensitive materials.
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Affiliation(s)
- Marriam Yamin
- Laboratory of Protein Thermodynamics, Departament of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Ancelmo R Souza
- Laboratory of Protein Thermodynamics, Departament of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Bianca G Castelucci
- Electron Microscopy Center, Institute of Biology, State University of Campinas (UNICAMP), Rua Monteiro Lobato, 255, Campinas, SP, 13083-970, Brazil
| | - Juliana G Mattoso
- Laboratory of Protein Thermodynamics, Departament of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Carlos Francisco Sampaio Bonafe
- Laboratory of Protein Thermodynamics, Departament of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil.
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Šarc A, Kosel J, Stopar D, Oder M, Dular M. Removal of bacteria Legionella pneumophila, Escherichia coli, and Bacillus subtilis by (super)cavitation. ULTRASONICS SONOCHEMISTRY 2018; 42:228-236. [PMID: 29429664 DOI: 10.1016/j.ultsonch.2017.11.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 09/27/2017] [Accepted: 11/01/2017] [Indexed: 05/07/2023]
Abstract
In sufficient concentrations, the pathogenic bacteria L. pneumophila can cause a respiratory illness that is known as the "Legionnaires" disease. Moreover, toxic Shiga strains of bacteria E. coli can cause life-threatening hemolytic-uremic syndrome. Because of the recent restrictions imposed on the usage of chlorine, outbreaks of these two bacterial species have become more common. In this study we have developed a novel rotation generator and its effectiveness against bacteria Legionella pneumophila and Escherichia coli was tested for various types of hydrodynamic cavitation (attached steady cavitation, developed unsteady cavitation and supercavitation). The results show that the supercavitation was the only effective form of cavitation. It enabled more than 3 logs reductions for both bacterial species and was also effective against a more persistent Gram positive bacteria, B. subtilis. The deactivation mechanism is at present unknown. It is proposed that when bacterial cells enter a supercavitation cavity, an immediate pressure drop occurs and this results in bursting of the cellular membrane. The new rotation generator that induced supercavitation proved to be economically and microbiologically far more effective than the classical Venturi section (super)cavitation.
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Affiliation(s)
- Andrej Šarc
- University of Ljubljana, Faculty of Mechanical Engineering, Askerceva 6, 1000 Ljubljana, Slovenia
| | - Janez Kosel
- University of Ljubljana, Faculty of Mechanical Engineering, Askerceva 6, 1000 Ljubljana, Slovenia
| | - David Stopar
- University of Ljubljana, Biotechnical Faculty, Večna pot 111, 1000 Ljubljana, Slovenia
| | - Martina Oder
- University of Ljubljana, Faculty of Health Sciences, Zdravstvena pot 5, 1000 Ljubljana, Slovenia
| | - Matevž Dular
- University of Ljubljana, Faculty of Mechanical Engineering, Askerceva 6, 1000 Ljubljana, Slovenia.
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Hiemer B, Genz B, Jonitz-Heincke A, Pasold J, Wree A, Dommerich S, Bader R. Devitalisation of human cartilage by high hydrostatic pressure treatment: Subsequent cultivation of chondrocytes and mesenchymal stem cells on the devitalised tissue. Sci Rep 2016; 6:33747. [PMID: 27671122 PMCID: PMC5037397 DOI: 10.1038/srep33747] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 08/31/2016] [Indexed: 01/08/2023] Open
Abstract
The regeneration of cartilage lesions still represents a major challenge. Cartilage has a tissue-specific architecture, complicating recreation by synthetic biomaterials. A novel approach for reconstruction is the use of devitalised cartilage. Treatment with high hydrostatic pressure (HHP) achieves devitalisation while biomechanical properties are remained. Therefore, in the present study, cartilage was devitalised using HHP treatment and the potential for revitalisation with chondrocytes and mesenchymal stem cells (MSCs) was investigated. The devitalisation of cartilage was performed by application of 480 MPa over 10 minutes. Effective cellular inactivation was demonstrated by the trypan blue exclusion test and DNA quantification. Histology and electron microscopy examinations showed undamaged cartilage structure after HHP treatment. For revitalisation chondrocytes and MSCs were cultured on devitalised cartilage without supplementation of chondrogenic growth factors. Both chondrocytes and MSCs significantly increased expression of cartilage-specific genes. ECM stainings showed neocartilage-like structure with positive AZAN staining as well as collagen type II and aggrecan deposition after three weeks of cultivation. Our results showed that HHP treatment caused devitalisation of cartilage tissue. ECM proteins were not influenced, thus, providing a scaffold for chondrogenic differentiation of MSCs and chondrocytes. Therefore, using HHP-treated tissue might be a promising approach for cartilage repair.
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Affiliation(s)
- B. Hiemer
- Rostock University Medical Center, Department of Orthopaedics, Biomechanics and Implant Technology Research Laboratory, Doberaner Strasse 142, 18057 Rostock, Germany
| | - B. Genz
- Rostock University Medical Center, Department of Otorhinolaryngology, Doberaner Strasse 137–139, 18057 Rostock, Germany
| | - A. Jonitz-Heincke
- Rostock University Medical Center, Department of Orthopaedics, Biomechanics and Implant Technology Research Laboratory, Doberaner Strasse 142, 18057 Rostock, Germany
| | - J. Pasold
- Rostock University Medical Center, Department of Orthopaedics, Biomechanics and Implant Technology Research Laboratory, Doberaner Strasse 142, 18057 Rostock, Germany
| | - A. Wree
- Rostock University Medical Center, Department of Anatomy, Gertrudenstraße 9, 18057 Rostock, Germany
| | - S. Dommerich
- Charité Berlin University Medical Center, Department of Otorhinolaryngology, Chariteplatz 1, 10117 Berlin, Germany
| | - R. Bader
- Rostock University Medical Center, Department of Orthopaedics, Biomechanics and Implant Technology Research Laboratory, Doberaner Strasse 142, 18057 Rostock, Germany
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Impact of Staphylococcus epidermidis lysates on middle ear epithelial proinflammatory and mucogenic response. J Investig Med 2015; 63:258-66. [PMID: 25503091 DOI: 10.1097/jim.0000000000000127] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Chronic otitis media with effusion (COME) develops after sustained inflammation and is characterized by secretory middle ear epithelial metaplasia and effusion, most frequently mucoid. Staphylococcus epidermidis, typically considered a commensal organism, is very frequently recovered in chronic middle ear fluid and in middle ear biofilms. Although it has been shown to drive inflammation in sinonasal epithelium, the impact of S. epidermidis on COME is markedly understudied. The goal of this study was to examine the in vitro effects of S. epidermidis lysates on murine and human middle ear epithelial cells. METHODS Staphylococcus epidermidis lysates were generated and used to stimulate submerged and differentiated human and murine epithelial cells (MEECs) for 24 to 48 hours. Quantitative real time-polymerase chain reaction, Western blot, enzyme-linked immunosorbent assay, and immunocytochemistry techniques were performed to interrogate the mucin gene MUC5AC and MUC5B expression and protein production, chemokine response, as well as NF-κB activation. Luciferase reporter assays were performed to further evaluate nuclear factor κB (NF-κB) activation and query specific promoter responses after S. epidermidis exposure. RESULTS Staphylococcus epidermidis induced a time- and dose-dependent MUC5AC and MUC5B overexpression along with a parallel overexpression of Cxcl2 in mouse MEEC and IL-8 in human MEEC. Further investigations in mMEEC showed a 1.3 to 1.5 induction of the MUC5AC and MUC5B promoters. As potential mechanisms for these responses, induction of an oxidative stress marker, along with early nuclear translocation and activation of NF-κB, was found. Finally, chronic exposure induced marked epithelial thickening of cells differentiated at the air liquid interface. CONCLUSIONS Staphylococcus epidermidis lysates activate a proinflammatory response in MEEC, including mucin gene expression and protein production. Although typically considered a nonpathogenic commensal organism in the ear, these results suggest that they may play a role in the perpetuation of an inflammatory and mucogenic response in COME.
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Infectious causes of cholesteatoma and treatment of infected ossicles prior to reimplantation by hydrostatic high-pressure inactivation. BIOMED RESEARCH INTERNATIONAL 2015; 2015:761259. [PMID: 25705686 PMCID: PMC4330946 DOI: 10.1155/2015/761259] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 01/20/2015] [Indexed: 11/26/2022]
Abstract
Chronic inflammation, which is caused by recurrent infections, is one of the factors contributing to the pathogenesis of cholesteatoma. If reimplantation of autologous ossicles after a surgical intervention is intended, inactivation of planktonic bacteria and biofilms is desirable. High hydrostatic pressure treatment is a procedure, which has been used to inactivate cholesteatoma cells on ossicles. Here we discuss the potential inactivating effect of high hydrostatic pressure on microbial pathogens including biofilms. Recent experimental data suggest an incomplete inactivation at a pressure level, which is tolerable for the bone substance of ossicles and results at least in a considerable reduction of pathogen load. Further studies are necessary to access how far this quantitative reduction of pathogens is sufficient to prevent ongoing chronic infections, for example, due to forming of biofilms.
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Frickmann H, Podbielski A, Essig A, Schwarz NG, Zautner AE. Difficulties in species identification within the genus Haemophilus - A pilot study addressing a significant problem for routine diagnostics. Eur J Microbiol Immunol (Bp) 2014; 4:99-105. [PMID: 24883195 DOI: 10.1556/eujmi.4.2014.2.2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 02/06/2014] [Indexed: 11/19/2022] Open
Abstract
Diagnostic misidentifications of commensalic Haemophilus haemolyticus as pathogenic Haemophilus influenzae are frequent. This pilot study evaluates whether isolations of H. haemolyticus are frequent enough in Germany to cause a relevant diagnostic problem, considering the fact that even H. influenzae is a mere colonizer in about 30% of isolations. In microbiological laboratories of two hospitals located in Northern and Southern Germany, the distribution of Haemophilus spp. was analyzed during a six-month-period. Site of infection, sex, and age of the patients was taken into consideration. A total of 77 Haemophilus spp. isolates was acquired and discriminated on species level, comprising: 48 H. influenzae, 25 Haemophilus parainfluenzae, 3 H. haemolyticus, and 1 Haemophilus parahaemolyticus. The proportion of H. haemolyticus was calculated to range between 1.2% and 16.2 % within the 95% confidence limits. Commensalic Haemophilus spp. were isolated from oropharynx-associated sites only. H. influenzae, in contrast, was detected in clinically relevant materials like lower respiratory materials and conjunctiva swabs. Altogether, there was a low proportion of clinical H. haemolyticus isolates. Accordingly, the problem of unnecessary antibiotic therapies due to misidentifications of H. haemolyticus as H. influenzae is quantitatively negligible compared with the risk of confusing H. influenzae colonizations with infections.
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Frickmann H, Christner M, Donat M, Berger A, Essig A, Podbielski A, Hagen RM, Poppert S. Rapid discrimination of Haemophilus influenzae, H. parainfluenzae, and H. haemolyticus by fluorescence in situ hybridization (FISH) and two matrix-assisted laser-desorption-ionization time-of-flight mass spectrometry (MALDI-TOF-MS) platforms. PLoS One 2013; 8:e63222. [PMID: 23646201 PMCID: PMC3639997 DOI: 10.1371/journal.pone.0063222] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 04/01/2013] [Indexed: 12/12/2022] Open
Abstract
Background Due to considerable differences in pathogenicity, Haemophilus influenzae, H. parainfluenzae and H. haemolyticus have to be reliably discriminated in routine diagnostics. Retrospective analyses suggest frequent misidentifications of commensal H. haemolyticus as H. influenzae. In a multi-center approach, we assessed the suitability of fluorescence in situ hybridization (FISH) and matrix-assisted laser-desorption-ionization time-of-flight mass-spectrometry (MALDI-TOF-MS) for the identification of H. influenzae, H. parainfluenzae and H. haemolyticus to species level. Methodology A strain collection of 84 Haemophilus spp. comprising 50 H. influenzae, 25 H. parainfluenzae, 7 H. haemolyticus, and 2 H. parahaemolyticus including 77 clinical isolates was analyzed by FISH with newly designed DNA probes, and two different MALDI-TOF-MS systems (Bruker, Shimadzu) with and without prior formic acid extraction. Principal Findings Among the 84 Haemophilus strains analyzed, FISH led to 71 correct results (85%), 13 uninterpretable results (15%), and no misidentifications. Shimadzu MALDI-TOF-MS resulted in 59 correct identifications (70%), 19 uninterpretable results (23%), and 6 misidentifications (7%), using colony material applied directly. Bruker MALDI-TOF-MS with prior formic acid extraction led to 74 correct results (88%), 4 uninterpretable results (5%) and 6 misidentifications (7%). The Bruker MALDI-TOF-MS misidentifications could be resolved by the addition of a suitable H. haemolyticus reference spectrum to the system's database. In conclusion, no analyzed diagnostic procedure was free of errors. Diagnostic results have to be interpreted carefully and alternative tests should be applied in case of ambiguous test results on isolates from seriously ill patients.
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Affiliation(s)
- Hagen Frickmann
- Department of Tropical Medicine at the Bernhard Nocht Institute, German Armed Forces Hospital of Hamburg, Hamburg, Germany.
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