Závěrečná zpráva o řešení grantu Agentury pro zdravotnický výzkum MZ ČR
nestr.
Biofilm-related infections (BRI) are an overwhelming issue for health care systems in Europe and worldwide. BRIs are characterized by a chronic behavior or frequent recurrences, antibiotic resistance, complex and prolonged treatment, poor prognosis, high social and economical costs and difficult diagnosis. Demand in implantable biomedical microsystems, which are used for early detection and diagnosis of diseases is increased and lead to intensive research and innovation in such area. However, there a lack of reliable implantable sensors for detection of onset of bacterial infection. Based on the previous knowledge of research team members and preliminary tests, we will design new type of implantable sensors based either on physical or chemical principles of early biofilm detection.
Infekce spojené s tvorbou biofilmu (BRI) jsou zásadním problémem pro zdravotnictví v Evropě i v celosvětovém měřítku. BRI se vyznačují chronickým chováním nebo častými recidivami, rezistencí na antibiotika, komplexní a dlouhodobou léčbou, špatnou prognózou, vysokými sociálními a ekonomickými náklady a obtížnou diagnózou. Požadavky na implantabilní biomedicínské mikrosystémy, které se používají pro včasné odhalení a diagnostiku nemocí, se zvyšují a vedou k jejich intenzivnímu výzkumu a inovacím. Existuje však nedostatek spolehlivých implantabilních senzorů pro včasnou detekci nástupu bakteriální infekce. Na základě předchozích znalostí členů výzkumných týmů a předběžných zkoušek bude navržen nový typ implantabilních senzorů založených buď na fyzikálních, nebo chemických principech včasné detekce vzniku biofilmu.
- Klíčová slova
- detekce biofilmu, implantable biosensors, detection of colonization, detekce infekce, detection of infection, implantovatelný biosenzory,
- NLK Publikační typ
- závěrečné zprávy o řešení grantu AZV MZ ČR
Lyme arthritis, one of the possible late manifestations of Lyme borreliosis, predominantly affects the supporting joints and in adults most often occurs in the form of monoarthritis of the knee. Early diagnosis is based on clinical findings and serology. PCR detection of Borrelia in synovial fluid has become an integral part of the laboratory testing algorithm. The clinical presentation and inflammatory markers in Lyme arthritis can resemble septic arthritis. Determining the levels of alpha-defensins (human neutrophil peptide (HNP 1-3)) in synovial fluid by liquid chromatography is a highly sensitive method revealing the presence of inflammatory process. Between 2020 and 2022, we examined eleven patients with Lyme arthritis of the knee. We measured levels of HNP 1-3 from synovial fluid by HPLC in patients, and we compared it with the corresponding C-reactive protein (CRP) levels in paired serum samples. In patients diagnosed with Lyme arthritis, HNP 1-3 levels in synovial fluid ranged from 2.5 to 261 mg/L, with a median of 46.5 mg/L. Average serum CRP was 43 mg/L. The results show that elevated HNP 1-3 can be consistent with not only septic arthritis or systemic disease, but also with Lyme arthritis, especially in patients with negative culture and 16S PCR from synovial fluid. Final diagnosis must be verified by examination for anti-Borrelia antibodies from serum and synovial fluid. The aim of this work is to introduce an HPLC method for the determination of alpha-defensins as one of the possible diagnostic markers.
- MeSH
- alfa-defensiny * metabolismus analýza MeSH
- biologické markery * analýza MeSH
- C-reaktivní protein analýza MeSH
- dospělí MeSH
- infekční artritida mikrobiologie diagnóza imunologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- lymeská nemoc * diagnóza imunologie mikrobiologie MeSH
- senioři MeSH
- synoviální tekutina * chemie imunologie mikrobiologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: The diagnosis of joint replacement infection is a difficult clinical challenge that often occurs when the implant cannot be salvaged. We hypothesize that the pH value of synovial fluid could be an important indicator of the inflammatory status of the joint. However, in the literature, there is a lack of data on the pH changes in hip and knee joint replacements and their relation to infection and implant failure. In this study, we aimed to measure the pH levels of synovial fluid in patients with hip and knee joint replacements. We also investigated the potential of pH measurement as a diagnostic tool for joint replacement infection. In this study, we recorded the pH values to be 7.55 and 7.46 in patients where Pseudomonas aeruginosa was identified as the cause of the prosthetic joint infection. We attribute this to the different environments created by this specific bacterium. In other cases where the pH was higher, chronic mitigated infections were diagnosed, caused by strains of Staphylococcus aureus, Streptococcus agalactiase, and coagulase negative staphylococcus. MATERIALS AND METHODS: In our cohort of 155 patients with implanted hip (THA; n = 85) or knee (TKA; n = 70) joint replacements, we conducted a prospective study with a pH measurement. Out of the whole cohort, 44 patients had confirmed joint replacement infection (28.4%) (44/155). In 111 patients, infection was ruled out (71.6%) (111/155). Joint replacement infection was classified according to the criteria of the Musculoskeletal Infection Society (MSIS) from 2018. Based on the measured values, we determined the cut-off level for the probability of ongoing inflammation. We also determined the sensitivity and specificity of the measurement. RESULTS: The group of patients with infection (n = 44) had a significantly lower synovial fluid pH (pH = 6.98 ± 0.48) than the group of patients with no infection (n = 111, pH = 7.82 ± 0.29, p < 0.001). The corresponding median pH values were 7.08 for the patients with infection and 7.83 for the patients with no infection. When we determined the cut-off level of pH 7.4, the sensitivity level of infected replacements was 88.6%, and the specificity level of the measurement was 95.5%. The predictive value of a positive test was 88.6%, and the predictive value of a negative test was 95.5%. CONCLUSIONS: Our results confirm that it is appropriate to include a pH measurement in the diagnostic spectrum of hip and knee replacements. This diagnostic approach has the potential to provide continuous in vivo feedback, facilitated by specialized biosensors. The advantage of this method is the future incorporation of a pH-detecting sensor into intelligent knee and hip replacements that will assess pH levels over time. By integrating these biosensors into intelligent implants, the early detection of joint replacement infections could be achieved, enhancing proactive intervention strategies.
- Publikační typ
- časopisecké články MeSH
Závěrečná zpráva o řešení grantu Agentury pro zdravotnický výzkum MZ ČR
nestr.
Solution of bone defects is not always easy medical procedure, especially in the field of osteomyelitis, or near joint replacements on the surface of the attritor granuloma. In these cases, the "dead space" occurs, which not only locally weakens the bone with the risk of fracture, but as well becomes a suitable place to form or exacerbate osteomyelitis. In the present project we will newly utilize resorbable, injectable self-hardening bone substitute material consisting of calcium phosphate, thermosensitive thixotropic copolymer and short biodegradable nanofibers improving rheology and ductility of osteoinductive cement. The advantage of this cement is the choice of porosity enabling fixation of the implants and the selection of bone substitute according to the type and location of bone defect in the body. This porous cement will be saturated with antibiotics and tested in-vitro, ex-vivo and in-vivo on animal models for the treatment or prevention of osteomyelitis. The bioactive cement is expected to resorb within the healing process along with gradual remodelling by new bone.
Řešení kostních defektů nebývá vždy snadným léčebným postupem, obzvláště v terénu osteomyelitidy nebo v místě kloubních náhrad na podkladě otěrového granulomu. V těchto případech vzniká „mrtvý prostor“, který nejenže v daném místě oslabuje kost s rizikem vzniku zlomeniny, ale také bývá místem vhodným k vytvoření nebo exacerbaci osteomyelitidy. V předloženém projektu nově použijeme resobovatelný, injekčně aplikovatelný, samotuhnoucí materiál náhrady kostní tkáně složený z fosforečnanu vápenatého, termocitlivého tixotropního kopolymeru a krátkých biodegradabilních nanovláken zlepšující reologii a tažnost osteoindukčního cementu. Výhodou tohoto cementu je možnost výběru porozity, umožňující fixaci implantátů a volbu náhrady kostní tkáně podle typu a lokalizace kostního defektu v organizmu. Tento porézní cement bude navíc sycen antibiotiky a testován in-vitro, ex-vivo i in-vivo na zvířecích modelech pro léčbu nebo prevenci osteomyelitidy. Očekává se, že během hojení bude bioaktivní cement resorbován a postupně přestaven novou kostí.
- Klíčová slova
- injektabilní kostní cement, infikované kostní defekty, osteomyelitida, osteointegrace, injectable bone cement, infected bone defects, osteomyelitis, osteointegration,
- NLK Publikační typ
- závěrečné zprávy o řešení grantu AZV MZ ČR
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Polymethylmethacrylate (PMMA) bone cement mixed with antibiotics is used in orthopedic surgery to cope with implant-related infections which are typically associated with the formation of bacterial biofilms. Taking into account the growing bacterial resistance to current antibiotics, we examined here the efficacy of a selected antimicrobial peptide (AMP) mixed into the bone cement to inhibit bacterial adhesion and the consequent biofilm formation on its surface. In particular, we followed the formation of bacterial biofilms of methicillin-resistant Staphylococcus aureus (MRSA) on implants made from PMMA bone cement loaded with AMP composed of 12 amino acid residues. This was evaluated by CFU counting of bacteria released by sonication from the biofilms formed on their surfaces after these implants were retrieved from the infected murine femoral canals. The AMP loaded in these model implants prevented adhesion of MRSA and the subsequent formation of MRSA biofilm on the surfaces of more than 80% of these implants, whereas biofilms did form on control implants made from the plain cement. The results of our experiments performed in the murine femoral canal indicate the potential for this murine osteomyelitis model to mimic actual operations in orthopedics.
- MeSH
- adenosinmonofosfát MeSH
- aminokyseliny MeSH
- antibakteriální látky farmakologie terapeutické užití MeSH
- antimikrobiální peptidy MeSH
- biofilmy MeSH
- kostní cementy MeSH
- methicilin rezistentní Staphylococcus aureus * MeSH
- modely nemocí na zvířatech MeSH
- myši MeSH
- ortopedické výkony * MeSH
- polymethylmethakrylát chemie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- antibakteriální látky terapeutické užití MeSH
- artroplastiky kloubů škodlivé účinky využití MeSH
- chirurgie operační MeSH
- infekce spojené s protézou prevence a kontrola MeSH
- kyčelní kloub * patofyziologie ultrasonografie MeSH
- lidé MeSH
- ortopedické výkony MeSH
- ortopedie MeSH
- primární prevence MeSH
- rizikové faktory MeSH
- směrnice pro lékařskou praxi jako téma MeSH
- tromboembolie prevence a kontrola MeSH
- vývojová kyčelní dysplazie diagnóza klasifikace prevence a kontrola MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
PURPOSE OF THE STUDY Periprosthetic joint infections in total knee arthroplasty (TKA) represent one of the most limiting factors of implantation. Frequency of this complication is up to 2.5% in primary implantation. Revision TKA with the use of DAIR (Debridement, Antibiotics and Implant Retention) procedure is a widely accepted method in treating infection, but the indication criteria have not been clearly defined as yet. The lack of uniformity prevails also with respect to the surgical technique and the importance of respective techniques for successful treatment. The purpose of this study was to evaluate the factors affecting the twoyear survival of TKA after treating the infection by DAIR. MATERIAL AND METHODS We conducted a monocentric retrospective analysis involving 52 cases of infected TKA managed with DAIR in the period between 2007 and 2016. The evaluation took into account such factors as the sex, age, history of revision surgery for aseptic or septic reasons, and pathogens. The patients were divided into groups based on the McPherson criteria. As to the procedure, we monitored the effect of administered antibiotics, time interval between the manifestation of symptoms of TKA infection and surgery, exchange of modular parts, and use of pulse lavage, continual lavage, local antibiotic carrier, or combination of these techniques. Treatment failure was defined as persistent infection and transition to chronic suppressive antibiotic therapy or need for revision surgery of the respective joint due to recurrent infection of TKA, or death directly associated with the treatment of infected TKA in the follow-up period of 2 years after DAIR. The R software (Team Development Core, 2017) was used to carry out the statistical analysis. The target variable was the failure at two years after surgery. The Generalized Linear Model (GLM) was used for the binary dependent variable - the socalled logistic model with a logit link function. RESULTS 32 of 52 patients (61.5%) were successfully treated, of whom 18 women (62.1%) and 14 men (60.9%). The effect of causative agent, administered antibiotics, polyethylene insert exchange, McPherson score or history of revision surgery of the respective joint for aseptic reasons was not confirmed. The history of revision surgery for infection of the affected joint had a strong negative impact on treatment success, 10 of 13 (76.9%) implants failed as against 10 of 39 (25.6%) implants with negative history of infection. The mean time from surgery to the manifestation of infection was 5.9 weeks (0.5-47.5). When surgery was performed within 2 weeks from the manifestation of infection, 1 of 15 (6.7%) cases failed. In case of a later surgery, 19 of 37 (51.4%) cases failed. As concerns the used surgical technique, 60% (9/15) failure was reported in case of the combination of pulse lavage and continual lavage, 36.4% (4/11) in case of the combination of pulse lavage and local antibiotic carrier, 25% (4/16) in case of separate continual lavage, and 66.7% (2/3) in case of continual lavage with local antibiotic carrier. DISCUSSION The importance of individual factors in revision surgery of periprosthetic joint infections of TKA remains unclear. The world literature indicates as a major negative effect the time factor, the positive history of infection of the affected implant, or other previous revision surgery for aseptic reasons. Ambiguous results are achieved in assessing the effect of the pathogen, administered antibiotics or presence of fistula, the statistical significance of which has not been confirmed in our study. Questionable is also the importance of individual surgical techniques. CONCLUSIONS DAIR is a suitable method in treating infections of stable TKA without the history of revision surgery for infection. The surgery should be performed within 2 weeks from the manifestation of symptoms. Key words: debridement, antibiotics, infection, implant retention, total knee arthroplasty.
- MeSH
- antibakteriální látky terapeutické užití MeSH
- debridement MeSH
- infekce spojené s protézou * chirurgie MeSH
- lidé MeSH
- míra přežití MeSH
- reoperace MeSH
- retrospektivní studie MeSH
- totální endoprotéza kolene * škodlivé účinky MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Vancomycin is often used in orthopedic surgery as a local prophylaxis of bacterial infection. The aim of this work was to compare the release of vancomycin and its biologically inactive crystalline degradation products (CDP-1) during in vitro experiments from different types of local antibiotic delivery systems (bone grafts and bone cements). The concentrations of vancomycin and its crystalline degradation products were determined by high-performance liquid chromatography. Each experiment was performed in a phosphate buffer solution over 21 days. Morselized bone grafts, synthetic bone cements Palacos and Copal, and synthetic bone grafts were tested as local carriers of vancomycin. The highest concentration approximately 670 mg/L of vancomycin was released from synthetic bone grafts Actifuse. Even after 21 days, the concentration of vancomycin was still above the minimum inhibitory concentration (MIC). The maximum concentration of vancomycin released in two experiments with human bone grafts exceeded 600 mg/L during the first day and was still above MIC level 21 days later when the experiment was concluded. By comparing the synthetic bone cements Palacos and Copal, Copal had the average maximum concentration of only 32.4 mg/L and Palacos 35.7 mg/L. The concentration of vancomycin fell below the MIC for vancomycin-resistant Staphylococcus aureus (VRSA) on the seventh day with Palacos and the ninth day with Copal. This study showed the insufficient concentration of released vancomycin from synthetic bone cements at the end of the experiment. For improvement of local prophylaxis, it would be beneficial to increase the amount of vancomycin in bone cements.
- MeSH
- antibakteriální látky analýza metabolismus MeSH
- kostní cementy analýza MeSH
- lidé MeSH
- methicilin rezistentní Staphylococcus aureus účinky léků MeSH
- mikrobiální testy citlivosti MeSH
- transplantace kostí MeSH
- vankomycin analýza metabolismus MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The α-defensins (AD) present in synovial fluid have been regarded as constituting the most accurate periprosthetic joint infection (PJI) biomarker. The methods most commonly used for estimating AD as a biomarker are the qualitative Synovasure® PJI tests, based on the technique of lateral flow, and quantitative enzyme-linked immunosorbent assay (ELISA). Here, we propose a novel test based on detecting α-defensins in synovial fluid by high-performance liquid chromatography (HPLC). Synovial fluid was collected from 157 patients diagnosed with PJI, infectious arthritis (IA), arthrosis, reactive arthritis, and rheumatoid arthritis. AD concentrations in the fluid were determined by HPLC, and these same samples were used for additional diagnostic analyses. The results were statistically processed to calculate cutoff concentrations for PJI and IA. HPLC testing showed a sensitivity of 94% and a specificity of 92% for diagnosis of PJI, and a sensitivity of 97% and a specificity of 87% for diagnosis of IA. Using HPLC, we detected in synovial fluid a combination of three α-defensins: human neutrophil peptides HNP1, HNP2, and HNP3. All measured AD concentration values shown in this work refer to the sum of these three individual concentrations. Our study shows that the HPLC method meets the conditions for measuring precise concentrations of the sum of AD and can be recommended as part of a diagnostic array for PJI and IA diagnostics. By this method, we have verified that higher levels of AD in synovial fluid can also be seen in rheumatoid illnesses, crystal arthropathies, and reactive arthritis.
- Publikační typ
- časopisecké články MeSH
