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Bone & Joint Research
Vol. 13, Issue 11 | Pages 632 - 646
7 Nov 2024
Diaz Dilernia F Watson D Heinrichs DE Vasarhelyi E

Aims

The mechanism by which synovial fluid (SF) kills bacteria has not yet been elucidated, and a better understanding is needed. We sought to analyze the antimicrobial properties of exogenous copper in human SF against Staphylococcus aureus.

Methods

We performed in vitro growth and viability assays to determine the capability of S. aureus to survive in SF with the addition of 10 µM of copper. We determined the minimum bactericidal concentration of copper (MBC-Cu) and evaluated its sensitivity to killing, comparing wild type (WT) and CopAZB-deficient USA300 strains.


Bone & Joint Research
Vol. 13, Issue 1 | Pages 40 - 51
11 Jan 2024
Lin J Suo J Bao B Wei H Gao T Zhu H Zheng X

Aims

To investigate the efficacy of ethylenediaminetetraacetic acid-normal saline (EDTA-NS) in dispersing biofilms and reducing bacterial infections.

Methods

EDTA-NS solutions were irrigated at different durations (1, 5, 10, and 30 minutes) and concentrations (1, 2, 5, 10, and 50 mM) to disrupt Staphylococcus aureus biofilms on Matrigel-coated glass and two materials widely used in orthopaedic implants (Ti-6Al-4V and highly cross-linked polyethylene (HXLPE)). To assess the efficacy of biofilm dispersion, crystal violet staining biofilm assay and colony counting after sonification and culturing were performed. The results were further confirmed and visualized by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). We then investigated the efficacies of EDTA-NS irrigation in vivo in rat and pig models of biofilm-associated infection.


Bone & Joint Research
Vol. 12, Issue 2 | Pages 113 - 120
1 Feb 2023
Cai Y Liang J Chen X Zhang G Jing Z Zhang R Lv L Zhang W Dang X

Aims

This study aimed to explore the diagnostic value of synovial fluid neutrophil extracellular traps (SF-NETs) in periprosthetic joint infection (PJI) diagnosis, and compare it with that of microbial culture, serum ESR and CRP, synovial white blood cell (WBC) count, and polymorphonuclear neutrophil percentage (PMN%).

Methods

In a single health centre, patients with suspected PJI were enrolled from January 2013 to December 2021. The inclusion criteria were: 1) patients who were suspected to have PJI; 2) patients with complete medical records; and 3) patients from whom sufficient synovial fluid was obtained for microbial culture and NET test. Patients who received revision surgeries due to aseptic failure (AF) were selected as controls. Synovial fluid was collected for microbial culture and SF-WBC, SF-PNM%, and SF-NET detection. The receiver operating characteristic curve (ROC) of synovial NET, WBC, PMN%, and area under the curve (AUC) were obtained; the diagnostic efficacies of these diagnostic indexes were calculated and compared.


Bone & Joint Research
Vol. 11, Issue 2 | Pages 73 - 81
22 Feb 2022
Gao T Lin J Wei H Bao B Zhu H Zheng X

Aims

Trained immunity confers non-specific protection against various types of infectious diseases, including bone and joint infection. Platelets are active participants in the immune response to pathogens and foreign substances, but their role in trained immunity remains elusive.

Methods

We first trained the innate immune system of C57BL/6 mice via intravenous injection of two toll-like receptor agonists (zymosan and lipopolysaccharide). Two, four, and eight weeks later, we isolated platelets from immunity-trained and control mice, and then assessed whether immunity training altered platelet releasate. To better understand the role of immunity-trained platelets in bone and joint infection development, we transfused platelets from immunity-trained mice into naïve mice, and then challenged the recipient mice with Staphylococcus aureus or Escherichia coli.


Bone & Joint Research
Vol. 11, Issue 2 | Pages 112 - 120
16 Feb 2022
Vittrup SØ Hanberg P Knudsen MB Tøstesen SK Kipp JO Hansen J Jørgensen NP Stilling M Bue M

Aims

Prompt and sufficient broad-spectrum empirical antibiotic treatment is key to preventing infection following open tibial fractures. Succeeding co-administration, we dynamically assessed the time for which vancomycin and meropenem concentrations were above relevant epidemiological cut-off (ECOFF) minimal inhibitory concentrations (T > MIC) in tibial compartments for the bacteria most frequently encountered in open fractures. Low and high MIC targets were applied: 1 and 4 µg/ml for vancomycin, and 0.125 and 2 µg/ml for meropenem.

Methods

Eight pigs received a single dose of 1,000 mg vancomycin and 1,000 mg meropenem simultaneously over 100 minutes and 10 minutes, respectively. Microdialysis catheters were placed for sampling over eight hours in tibial cancellous bone, cortical bone, and adjacent subcutaneous adipose tissue. Venous blood samples were collected as references.


Bone & Joint Research
Vol. 9, Issue 5 | Pages 236 - 241
1 May 2020
Li R Wang C Ji X Zheng Q Li X Ni M Zhang G Chen J

Aims

The purpose of this study was to validate our hypothesis that centrifugation may eliminate false-positive leucocyte esterase (LE) strip test results caused by autoimmune diseases in the diagnosis of knee infection.

Methods

Between January 2016 and May 2019, 83 cases, including 33 cases of septic arthritis and 50 cases of aseptic arthritis, were enrolled in this study. To further validate our hypothesis, another 34 cases of inflammatory arthritis from the Department of Rheumatology of our institution were also included. After aspiration, one drop of synovial fluid was applied to LE strips before and after centrifugation. The results were recorded after approximately three minutes according to the different colour grades on the colour chart. The differences of LE results between each cohort were analyzed.


Bone & Joint Research
Vol. 8, Issue 1 | Pages 3 - 10
1 Jan 2019
Hernandez P Sager B Fa A Liang T Lozano C Khazzam M

Objectives

The purpose of this study was to examine the bactericidal efficacy of hydrogen peroxide (H2O2) on Cutibacterium acnes (C. acnes). We hypothesize that H2O2 reduces the bacterial burden of C. acnes.

Methods

The effect of H2O2 was assessed by testing bactericidal effect, time course analysis, growth inhibition, and minimum bactericidal concentration. To assess the bactericidal effect, bacteria were treated for 30 minutes with 0%, 1%, 3%, 4%, 6%, 8%, or 10% H2O2 in saline or water and compared with 3% topical H2O2 solution. For time course analysis, bacteria were treated with water or saline (controls), 3% H2O2 in water, 3% H2O2 in saline, or 3% topical solution for 5, 10, 15, 20, and 30 minutes. Results were analyzed with a two-way analysis of variance (ANOVA) (p < 0.05).