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Top Hartmann K, Lund Nielsen R, Mikkelsen FC, Aalbæk B, Lichtenberg M, Holm Jakobsen T, Bjarnsholt T, Kvich L, Ingmer H, Odgaard A, Elvang Jensen H, Kruse Jensen L. Bacterial micro-aggregates as inoculum in animal models of implant-associated infections. Biofilm 2024; 7:100200. [PMID: 38803605 PMCID: PMC11128829 DOI: 10.1016/j.bioflm.2024.100200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 05/07/2024] [Accepted: 05/07/2024] [Indexed: 05/29/2024] Open
Abstract
Is it time to rethink the inoculum of animal models of implant-associated infections (IAI)? Traditionally, animal models of IAI are based on inoculation with metabolically active overnight cultures of planktonic bacteria or pre-grown surface-attached biofilms. However, such inoculums do not mimic the clinical initiation of IAI. Therefore, the present study aimed to develop a clinically relevant inoculum of low metabolic micro-aggregated bacteria. The porcine Staphylococcus aureus strain S54F9 was cultured in Tryptone Soya Broth (TSB) for seven days to facilitate the formation of low metabolic micro-aggregates. Subsequently, the aggregated culture underwent filtration using cell strainers of different pore sizes to separate micro-aggregates. Light microscopy was used to evaluate the aggregate formation and size in the different fractions, while isothermal microcalorimetry was used to disclose a low metabolic activity. The micro-aggregate fraction obtained with filter size 5-15 μm (actual measured mean size 32 μm) was used as inoculum in a porcine implant-associated osteomyelitis (IAO) model and compared to a standard overnight planktonic inoculum and a sham inoculum of 0.9 % saline. The micro-aggregate and planktonic inoculums caused IAO with the re-isolation of S. aureus from soft tissues, bones, and implants. However, compared to their planktonic counterpart, neither of the micro-aggregate inoculated animals showed signs of osteomyelitis, i.e., sequester, osteolysis, and pus at gross inspection. Furthermore, inoculation with low metabolic micro-aggregates resulted in a strong healing response with pronounced osteoid formation, comparable to sham animals. In conclusion, the formation and separation of low metabolic bacterial micro-aggregates into various size fractions is possible, however, planktonic bacteria were still seen in all size fractions. Inoculation with micro-aggregates caused a less-aggressive osteomyelitis i.e. combination of infected tissue and strong healing response. Therefore, the use of low metabolic micro-aggregates could be a relevant inoculum for animal models of less-aggressive and thereby slower developing IAI and add in to our understanding of the host-implant-bacteria interactions in slow-onset low-grade infections.
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Affiliation(s)
- Katrine Top Hartmann
- Department of Veterinary- and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark
| | - Regitze Lund Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Freja Cecilie Mikkelsen
- Department of Veterinary- and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark
| | - Bent Aalbæk
- Department of Veterinary- and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark
| | - Mads Lichtenberg
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Tim Holm Jakobsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Thomas Bjarnsholt
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
- Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen, Denmark
| | - Lasse Kvich
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Hanne Ingmer
- Department of Veterinary- and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark
| | - Anders Odgaard
- Department of Orthopedic Surgery, Copenhagen University Hospital, Rigshospitalet, Inge Lehmanns vej 6, 2100, Copenhagen, Denmark
| | - Henrik Elvang Jensen
- Department of Veterinary- and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark
| | - Louise Kruse Jensen
- Department of Veterinary- and Animal Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870, Frederiksberg C, Denmark
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Jensen N, Jensen HE, Aalbaek B, Blirup-Plum SA, Soto SM, Cepas V, López Y, Gabasa Y, Gutiérrez-del-Río I, Villar CJ, Lombó F, Iglesias MJ, Soengas R, López Ortiz F, Jensen LK. Synthesis of the cyanobacterial halometabolite Chlorosphaerolactylate B and demonstration of its antimicrobial effect in vitro and in vivo. Front Microbiol 2022; 13:950855. [PMID: 36246241 PMCID: PMC9557163 DOI: 10.3389/fmicb.2022.950855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 08/18/2022] [Indexed: 12/02/2022] Open
Abstract
Chlorosphaerolactylate B, a newly discovered antimicrobial halometabolite from the cyanobacterium Sphaerospermopsis sp. LEGE 00249 has been synthesized in three steps by using 12-bromododecanoic acid as starting material. A total of 0.5 g was produced for in vitro and in vivo antimicrobial efficacy testing. In vitro, the minimal inhibitory concentration (MIC) was estimated to be 256 mg/L for Staphylococcus aureus, while the minimal biofilm inhibitory concentration (MBIC) was estimated to be 74 mg/L. The in vivo study utilized a porcine model of implant-associated osteomyelitis. In total, 12 female pigs were allocated into 3 groups based on inoculum (n = 4 in each group). An implant cavity (IC) was drilled in the right tibia and followed by inoculation and insertion of a steel implant. All pigs were inoculated with 10 μL containing either: 11.79 mg synthetic Chlorosphaerolactylate B + 104 CFU of S. aureus (Group A), 104 CFU of S. aureus (Group B), or pure saline (Group C), respectively. Pigs were euthanized five days after inoculation. All Group B animals showed macroscopic and microscopic signs of bone infection and both tissue and implant harbored S. aureus bacteria (mean CFU on implants = 1.9 × 105). In contrast, S. aureus could not be isolated from animals inoculated with saline. In Group A, two animals had a low number of S. aureus (CFU = 6.7 × 101 and 3.8 × 101, respectively) on the implants, otherwise all Group A animals were similar to Group C animals. In conclusion, synthetic Chlorosphaerolactylate B holds potential to be a novel antimicrobial and antibiofilm compound.
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Affiliation(s)
- Nikoline Jensen
- Section for Pathobiological Sciences, Department of Veterinary and Animal Science, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Elvang Jensen
- Section for Pathobiological Sciences, Department of Veterinary and Animal Science, University of Copenhagen, Copenhagen, Denmark
| | - Bent Aalbaek
- Section for Pathobiological Sciences, Department of Veterinary and Animal Science, University of Copenhagen, Copenhagen, Denmark
| | - Sophie Amalie Blirup-Plum
- Section for Pathobiological Sciences, Department of Veterinary and Animal Science, University of Copenhagen, Copenhagen, Denmark
| | - Sara M. Soto
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
- CIBER Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Virginio Cepas
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Yuly López
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Yaiza Gabasa
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Ignacio Gutiérrez-del-Río
- Biotechnology in Nutraceuticals and Bioactive Compounds-BIONUC, Department of Functional Biology, University of Oviedo, Oviedo, Spain
- Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - Claudio J. Villar
- Biotechnology in Nutraceuticals and Bioactive Compounds-BIONUC, Department of Functional Biology, University of Oviedo, Oviedo, Spain
- Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - Felipe Lombó
- Biotechnology in Nutraceuticals and Bioactive Compounds-BIONUC, Department of Functional Biology, University of Oviedo, Oviedo, Spain
- Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - María José Iglesias
- Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - Raquel Soengas
- Área de Química Orgánica, Centro de Investigación CIAIMBITAL, Universidad de Almería, Almería, Spain
| | - Fernando López Ortiz
- Área de Química Orgánica, Centro de Investigación CIAIMBITAL, Universidad de Almería, Almería, Spain
- *Correspondence: Fernando López Ortiz,
| | - Louise Kruse Jensen
- Section for Pathobiological Sciences, Department of Veterinary and Animal Science, University of Copenhagen, Copenhagen, Denmark
- Louise Kruse Jensen,
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Marx C, Gardner S, Harman RM, Wagner B, Van de Walle GR. Mesenchymal stromal cell-secreted CCL2 promotes antibacterial defense mechanisms through increased antimicrobial peptide expression in keratinocytes. Stem Cells Transl Med 2021; 10:1666-1679. [PMID: 34528765 PMCID: PMC8641085 DOI: 10.1002/sctm.21-0058] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 06/29/2021] [Accepted: 08/11/2021] [Indexed: 12/28/2022] Open
Abstract
Mesenchymal stromal cells (MSCs) from both humans and horses, which represent a clinically relevant translation animal model for human cutaneous wound healing, were recently found to possess antimicrobial properties against planktonic bacteria, and in the case of equine MSCs, also against biofilms. This, together with previous findings that human and equine MSCs promote angiogenesis and wound healing, makes these cells an attractive approach to treat infected cutaneous wounds in both species. The anti-biofilm activities of equine MSC, via secretion of cysteine proteases, have only been demonstrated in vitro, thus lacking information about in vivo relevance. Moreover, the effects of the equine MSC secretome on resident skin cells have not yet been explored. The goals of this study were to (a) test the efficacy of the MSC secretome in a physiologically relevant ex vivo equine skin biofilm explant model and (b) explore the impact of the MSC secretome on the antimicrobial defense mechanisms of resident skin cells. Our salient findings were that secreted factors from equine MSCs significantly decreased viability of methicillin-resistant Staphylococcus aureus bacteria in mature biofilms in this novel skin biofilm explant model. Moreover, we demonstrated that equine MSCs secrete CCL2 that increases the antimicrobial activity of equine keratinocytes by stimulating expression of antimicrobial peptides. Collectively, these data contribute to our understanding of the MSC secretome's antimicrobial properties, both directly by killing bacteria and indirectly by stimulating immune responses of surrounding resident skin cells, thus further supporting the value of MSC secretome-based treatments for infected wounds.
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Affiliation(s)
- Charlotte Marx
- Baker Institute for Animal HealthCollege of Veterinary Medicine, Cornell UniversityIthacaNew YorkUSA
| | - Sophia Gardner
- Baker Institute for Animal HealthCollege of Veterinary Medicine, Cornell UniversityIthacaNew YorkUSA
| | - Rebecca M. Harman
- Baker Institute for Animal HealthCollege of Veterinary Medicine, Cornell UniversityIthacaNew YorkUSA
| | - Bettina Wagner
- Department of Population Medicine and Diagnostic SciencesCollege of Veterinary Medicine, Cornell UniversityIthacaNew YorkUSA
| | - Gerlinde R. Van de Walle
- Baker Institute for Animal HealthCollege of Veterinary Medicine, Cornell UniversityIthacaNew YorkUSA
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Perry TW. Cutaneous microbial biofilm formation as an underlying cause of red scrotum syndrome. Eur J Med Res 2021; 26:95. [PMID: 34412706 PMCID: PMC8375042 DOI: 10.1186/s40001-021-00569-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 08/09/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Red scrotum syndrome is typically described as well-demarcated erythema of the anterior scrotum accompanied by persistent itching and burning. It is chronic and difficult to treat and contributes to significant psychological distress and reduction in quality of life. The medical literature surrounding the condition is sparse, with the prevalence likely under-recognized and the pathophysiology remaining poorly understood. Formation of a cutaneous microbial biofilm has not been proposed as an underlying etiology. Microbial biofilms can form whenever microorganisms are suspended in fluid on a surface for a prolonged time and are becoming increasingly recognized as important contributors to medical disease (e.g., chronic wounds). CASE PRESENTATION A 26-year-old man abruptly developed well-demarcated erythema of the bilateral scrotum after vaginal secretions were left covering the scrotum overnight. For 14 months, the patient experienced daily scrotal itching and burning while seeking care from multiple physicians and attempting numerous failed therapies. He eventually obtained complete symptomatic relief with the twice daily application of 0.8% menthol powder. Findings in support of a cutaneous microbial biofilm as the underlying etiology include: (1) the condition began following a typical scenario that would facilitate biofilm formation; (2) the demarcation of erythema precisely follows the scrotal hairline, suggesting that hair follicles acted as scaffolding during biofilm formation; (3) despite resolution of symptoms, the scrotal erythema has persisted, unchanged in boundary 15 years after the condition began; and (4) the erythematous skin demonstrates prolonged retention of gentian violet dye in comparison with adjacent unaffected skin, suggesting the presence of dye-avid material on the skin surface. CONCLUSION The probability that microorganisms, under proper conditions, can form biofilm on intact skin is poorly recognized. This case presents a compelling argument for a cutaneous microbial biofilm as the underlying cause of red scrotum syndrome in one patient, and a review of similarities with other reported cases suggests the same etiology is likely responsible for a significant portion of the total disease burden. This etiology may also be a significant contributor to the disease burden of vulvodynia, a condition with many similarities to red scrotum syndrome.
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Affiliation(s)
- Theodore W Perry
- Fee-Basis Hospitalist, North Texas VA Medical Center, 4500 South Lancaster Road, TX, 75216, Dallas, USA.
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Parnell-Turner H, Griffin CE, Rosenkrantz WS, Kelly Keating M, Bidot WA. Evaluation of the use of paired modified Wright's and periodic acid Schiff stains to identify microbial aggregates on cytological smears of dogs with microbial otitis externa and suspected biofilm. Vet Dermatol 2021; 32:448-e122. [PMID: 34351013 DOI: 10.1111/vde.13009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 05/10/2021] [Accepted: 06/03/2021] [Indexed: 12/31/2022]
Abstract
BACKGROUND Micro-organisms associated with canine otitis externa (OE) may cause biofilm-associated infections (BAI). A key component of biofilm is microbial aggregate and extracellular polymeric substance (EPS). Periodic acid Schiff (PAS) can stain polysaccharide EPS in human otitis media with effusion, but this has not been tested in canine OE. There is no cytological definition for microbial aggregate, and definitive methods for identifying BAI in a clinical setting in canine OE have not been defined. OBJECTIVES To establish whether PAS stain can identify polysaccharide matrix on cytological smears; and to determine the reproducibility of identification of microbial aggregates within a discrete area of stained matrix, using paired modified Wright's and PAS-stained smears. ANIMALS Forty privately-owned dogs presenting to a dermatological referral practice. METHODS AND MATERIALS In this prospective, cross-sectional study, three investigators independently and blindly classified 40 paired modified Wright's-PAS slide sets into groups: aggregate-associated infection (AAI) and non-AAI (n = 27); and control (n = 13). Agreement between investigators for presence of AAI was measured using Fleiss' kappa statistic (FK). Agreement between investigators and dermatologists for presence of AAI upon cytological evaluation, and suspected BAI based on clinical examination, was measured using Cohen's kappa statistic. RESULTS The matrix was confirmed to stain PAS-positive. Interinvestigator agreement for AAI was very good using PAS (0.82 FK) and fair using modified-Wright's (MW) (0.33 FK). Reproducible cytological features associated with AAI were the presence of: three or more distinct aggregates (0.76 FK); discrete areas of PAS-positive matrix (0.70 FK); and the presence of high-density material (0.70 FK) using PAS stain. CONCLUSION PAS can stain the extracellular matrix on otic smears, and a novel protocol for reproducible identification of cytological features such as microbial aggregates has been established.
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Affiliation(s)
| | - Craig E Griffin
- Animal Dermatology Clinic, 5610 Kearny Mesa Road, San Diego, CA, 92111, USA
| | | | - M Kelly Keating
- Animal Dermatology Clinic, 2965 Edinger Avenue, Tustin, CA, 92780, USA
| | - Willie A Bidot
- Office of Animal Resources, Western University of Health Sciences, Pomona, CA, 91766, USA
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Domnin P, Arkhipova A, Petrov S, Sysolyatina E, Parfenov V, Karalkin P, Mukhachev A, Gusarov A, Moisenovich M, Khesuani Y, Ermolaeva S. An In Vitro Model of Nonattached Biofilm-Like Bacterial Aggregates Based on Magnetic Levitation. Appl Environ Microbiol 2020; 86:e01074-20. [PMID: 32680859 PMCID: PMC7480373 DOI: 10.1128/aem.01074-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 07/10/2020] [Indexed: 12/27/2022] Open
Abstract
Chronic infections are associated with the formation of nonattached biofilm-like aggregates. In vitro models of surface-attached biofilms do not always accurately mimic these processes. Here, we tested a new approach to create in vitro nonattached bacterial aggregates using the principle of magnetic levitation of biological objects placed into a magnetic field gradient. Bacteria grown under magnetic levitation conditions formed nonattached aggregates that were studied with confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) and characterized quantitatively. Nonattached aggregates consisted of bacteria submerged into an extracellular matrix and demonstrated features characteristic of biofilms, such as a polymeric matrix that binds Ruby Red and Congo red dyes, a prerequisite of bacterial growth, and increased resistance to gentamicin. Three quantitative parameters were explored to characterize strain-specific potential to form nonattached aggregates: geometric sizes, relative quantities of aggregated and free-swimming bacteria, and Congo red binding. Among three tested Escherichia coli strains, one strain formed nonattached aggregates poorly, and for this strain, all three of the considered parameters were different from those of the other two strains (P < 0.05). Further, we characterized biofilm formation on plastic and agar surfaces by these strains and found that good biofilm formation ability does not necessarily indicate good nonattached aggregate formation ability, and vice versa. The model and quantitative methods can be applied for in vitro studies of nonattached aggregates and modeling bacterial behavior in chronic infections, as it is important to increase our understanding of the role that nonattached bacterial aggregates play in the pathogenesis of chronic diseases.IMPORTANCE An increasing amount of evidence indicates that chronic infections are associated with nonattached biofilm-like aggregates formed by pathogenic bacteria. These aggregates differ from biofilms because they form under low-shear conditions within the volume of biological fluids and they do not attach to surfaces. Here, we describe an in vitro model that provides nonattached aggregate formation within the liquid volume due to magnetic levitation. Using this model, we demonstrated that despite morphological and functional similarities of nonattached aggregates and biofilms, strains that exhibit good biofilm formation might exhibit poor nonattached aggregate formation, suggesting that mechanisms underlying the formation of biofilms and nonattached aggregates are not identical. The magnetic levitation approach can be useful for in vitro studies of nonattached aggregate formation and simulation of bacterial behavior in chronic infections.
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Affiliation(s)
- Pavel Domnin
- Gamaleya Research Centre of Epidemiology and Microbiology, Moscow, Russia
- Lomonosov Moscow State University, Moscow, Russia
| | | | | | - Elena Sysolyatina
- Gamaleya Research Centre of Epidemiology and Microbiology, Moscow, Russia
| | | | | | - Andrey Mukhachev
- Gamaleya Research Centre of Epidemiology and Microbiology, Moscow, Russia
| | - Alexey Gusarov
- Gamaleya Research Centre of Epidemiology and Microbiology, Moscow, Russia
| | | | | | - Svetlana Ermolaeva
- Gamaleya Research Centre of Epidemiology and Microbiology, Moscow, Russia
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Lüthje FL, Skovgaard K, Jensen HE, Blirup-Plum SA, Henriksen NL, Aalbæk B, Jensen LK. Receptor Activator of Nuclear Factor kappa-B Ligand is Not Regulated During Chronic Osteomyelitis in Pigs. J Comp Pathol 2020; 179:7-24. [PMID: 32958151 DOI: 10.1016/j.jcpa.2020.06.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/30/2020] [Accepted: 06/17/2020] [Indexed: 01/12/2023]
Abstract
Bone loss is a major complication of osteomyelitis and from numerous in-vitro studies, it has been concluded that the bone lysis is caused by elevated expression of the receptor activator of nuclear factor κB ligand (RANKL), leading to increased osteoclast activity. However, we failed to find any relationship between bone loss and osseous RANKL expression in a porcine model of acute and chronic implant-associated osteomyelitis (IAO) due to Staphylococcus aureus or in chronic osteomyelitis lesions in slaughter pigs. Surprisingly, we found that the expression of RANKL was reduced during chronic bone infections. This is in line with the few studies conducted on human samples. A significant bone loss was observed in IAO lesions and in lesions from slaughter pigs, but with no indication of osteoclast involvement using histochemistry, immunohistochemistry for RANKL, receptor activator of nuclear factor kappa-B, osteoprotegerin and cathepsin K, and high-throughput quantitative real-time polymerase chain reaction on bone tissue from osteomyelitic lesions. A strong inflammatory response was seen in the infected animals and, therefore, we propose proteolytic enzymes induced by inflammation to be a major component of the bone loss. Furthermore, we found a significant upregulation of the IL26 gene in infected animals, which can inhibit RANKL-induced osteoclastogenesis, but has no homologue in mice. This finding emphasises that neither murine models nor in-vitro studies can mirror human disease development completely. The present study emphasises that the interactions between microorganisms, the immune system and bone cells in osteomyelitis are too complex to be accurately represented by an in-vitro model.
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Affiliation(s)
- F L Lüthje
- Department of Veterinary and Animal Science, University of Copenhagen, Frederiksberg C, Denmark; Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - K Skovgaard
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - H E Jensen
- Department of Veterinary and Animal Science, University of Copenhagen, Frederiksberg C, Denmark
| | - S A Blirup-Plum
- Department of Veterinary and Animal Science, University of Copenhagen, Frederiksberg C, Denmark
| | - N L Henriksen
- Department of Veterinary and Animal Science, University of Copenhagen, Frederiksberg C, Denmark
| | - B Aalbæk
- Department of Veterinary and Animal Science, University of Copenhagen, Frederiksberg C, Denmark
| | - L K Jensen
- Department of Veterinary and Animal Science, University of Copenhagen, Frederiksberg C, Denmark.
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Blirup-Plum SA, Bjarnsholt T, Jensen HE, Kragh KN, Aalbæk B, Gottlieb H, Bue M, Jensen LK. Pathological and microbiological impact of a gentamicin-loaded biocomposite following limited or extensive debridement in a porcine model of osteomyelitis. Bone Joint Res 2020; 9:394-401. [PMID: 32793334 PMCID: PMC7393185 DOI: 10.1302/2046-3758.97.bjr-2020-0007.r1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Aims CERAMENT|G is an absorbable gentamicin-loaded biocomposite used as an on-site vehicle of antimicrobials for the treatment of chronic osteomyelitis. The purpose of the present study was to investigate the sole effect of CERAMENT|G, i.e. without additional systemic antimicrobial therapy, in relation to a limited or extensive debridement of osteomyelitis lesions in a porcine model. Methods Osteomyelitis was induced in nine pigs by inoculation of 104 colony-forming units (CFUs) of Staphylococcus aureus into a drill hole in the right tibia. After one week, the pigs were allocated into three groups. Group A (n = 3) received no treatment during the study period (19 days). Groups B (n = 3) and C (n = 3) received limited or extensive debridement seven days postinoculation, respectively, followed by injection of CERAMENT|G into the bone voids. The pigs were euthanized ten (Group C) and 12 (Group B) days after the intervention. Results All animals presented confirmatory signs of bone infection post-mortem. The estimated amount of inflammation was substantially greater in Groups A and B compared to Group C. In both Groups B and C, peptide nucleic acid fluorescence in situ hybridization (PNA FISH) of CERAMENT|G and surrounding bone tissue revealed bacteria embedded in an opaque matrix, i.e. within biofilm. In addition, in Group C, the maximal measured post-mortem gentamicin concentrations in CERAMENT|G and surrounding bone tissue samples were 16.6 μg/ml and 6.2 μg/ml, respectively. Conclusion The present study demonstrates that CERAMENT|G cannot be used as a standalone alternative to extensive debridement or be used without the addition of systemic antimicrobials. Cite this article: Bone Joint Res 2020;9(7):394–401.
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Affiliation(s)
- Sophie A Blirup-Plum
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Bjarnsholt
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Microbiology, Copenhagen University Hospital, Copenhagen, Denmark
| | - Henrik E Jensen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kasper N Kragh
- Costerton Biofilm Center, Department of Immunology and Microbiology, Copenhagen, Copenhagen, Denmark
| | - Bent Aalbæk
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hans Gottlieb
- Department of Orthopedic Surgery, Herlev Hospital, Herlev, Denmark
| | - Mats Bue
- Orthopaedic Research Unit, Aarhus University Hospital, Aarhus, Denmark
| | - Louise K Jensen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
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