Mathematical pharmacodynamic modeling for antimicrobial assessment of ceftazidime/colistin versus gentamicin/meropenem combinations against carbapenem-resistant Pseudomonas aeruginosa biofilm.

BACKGROUND: Carbapenem-resistant Pseudomonas aeruginosa (CRPA) represents an escalating healthcare hazard with high mortality worldwide, especially in presence of biofilm. The current study aimed to evaluate the anti-biofilm potentials of ceftazidime, colistin, gentamicin, and meropenem alone and in combinations against biofilm-forming CRPA. METHODS: Biofilm killing and checkerboard assay were performed to detect the effectiveness of combined antibiotics against biofilms and planktonic cells, respectively. The bacterial bioburden retrieved from the established biofilms following treatment with combined antibiotics was utilized to construct a three-dimensional response surface plot. A sigmoidal maximum effect model was applied to determine the pharmacodynamic parameters (maximal effect, median effective concentration, and Hill factor) of each antibiotic to create a mathematical three-dimensional response surface plot. RESULTS: Data revealed statistically significant (p < 0.05) superior anti-biofilm potential in the case of colistin followed by a lower effect in the case of gentamicin and meropenem, while ceftazidime exhibited the least anti-biofilm activity. The fractional inhibitory concentration index (FICI ≤ 0.5) indicated synergism following treatment with the combined antibiotics. An elevated anti-biofilm activity was recorded in the case of gentamicin/meropenem compared to ceftazidime/colistin. Synergistic anti-biofilm potentials were also detected via the simulated pharmacodynamic modeling, with higher anti-biofilm activity in the case of the in vitro observation compared to the simulated anti-biofilm profile. CONCLUSIONS: The present study highlighted the synergistic potentials of the tested antibiotic combinations against P. aeruginosa biofilms and the importance of the mathematical pharmacodynamic modeling in investigating the efficacy of antibiotics in combination as an effective strategy for successful antibiotic therapy to tackle the extensively growing resistance to the currently available antibiotics.

Modulating the transcriptomic profile of multidrug-resistant Klebsiella pneumoniae biofilm formation by antibiotics in combination with zinc sulfate.

BACKGROUND: Klebsiella pneumoniae is a significant healthcare-associated pathogen. We investigated the antimicrobial interaction pattern between zinc sulfate and antibiotics against K. pneumoniae biofilm on the phenotypic and genotypic levels. METHODS: Determining the minimum biofilm inhibitory concentrations and the transcriptomic profile of K. pneumoniae biofilm formation genes post-treatment were carried out to evaluate the effect on the phenotypic and genotypic levels, respectively. RESULTS: Zinc enhanced the antibiofilm potentials of cephalosporins, aminoglycosides, and ertapenem, whereas it antagonizes the effectiveness of fluoroquinolones and meropenem on the phenotypic level. On the molecular level, zinc enhanced the anti-biofilm efficacies of cephalosporins (cefotaxime, ceftriaxone, ceftazidime, cefpirome, and cefepime) via down-regulating the expression of biofilm-related genes by 18-, 38-, 5-, 77- and 2-folds, respectively. Zinc in combination with aminoglycosides (kanamycin, gentamicin, and amikacin) reduced the expression of biofilm-related genes by 40-, 2602- and 20-folds, respectively, and by 2-folds in combination with ertapenem. However, a reduction in the down-regulatory potentials of fluoroquinolones was recorded following combination with zinc by 2-, 2-, 15- and 14-folds, respectively, and an up-regulation in the expression levels of the tested genes by 2-folds in the case of zinc/meropenem combination. CONCLUSIONS: Results revealed variable interaction patterns between different antibiotics in combination with zinc. Current findings also shed light on the antibiofilm potentials of zinc/antibiotics combinations especially when combining zinc with fluoroquinolones or meropenem to avoid their antagonistic effects.

Did a New Design of the Oxford Unicompartmental Knee Prosthesis Result in Improved Survival? A Study From the Norwegian Arthroplasty Register 2012-2021.

BACKGROUND: Unicompartmental knee arthroplasty (UKA) has generally shown higher revision rates than TKA, and this is particularly true for the femoral component. A twin-peg femoral component (Oxford Partial) has replaced the single-peg version (Oxford Phase III) of the widely used Oxford medial UKA, with the aim of improving femoral component fixation. The introduction of the Oxford Partial Knee also included a fully uncemented option. However, there has been relatively little evidence regarding the effect of these changes on implant survival and revision diagnoses from groups not associated with the implant design. QUESTIONS/PURPOSES: Using data from the Norwegian Arthroplasty Register, we asked: (1) Has the 5-year implant survival (free from revision for any cause) improved with the medial Oxford unicompartmental knee after the introduction of new designs? (2) Did the causes of revision change between the old and new designs? (3) Is there a difference in risk for specific revision causes between the uncemented and cemented versions of the new design? METHODS: We performed a registry-based observational study using data from the Norwegian Arthroplasty Register, a nationwide, mandatory and governmental registry with a high reporting rate. Between 2012 and 2021, 7549 Oxford UKAs were performed, and 105 were excluded due to combinations of the three designs, lateral compartment replacement, or hybrid fixation, leaving 908 cemented Oxford Phase III single-peg (used from 2012 to 2017), 4715 cemented Oxford Partial twin-peg (used from 2012 to 2021), and 1821 uncemented Oxford Partial twin-peg (used from 2014 to 2021), UKAs available for the analysis. The Kaplan-Meier method and Cox regression multivariate analysis were used to find the 5-year implant survival and the risk of revision (hazard ratio), when adjusting for age, gender, diagnosis, American Society of Anesthesiologists grade, and time period. The risk of revision for any cause and the risk of revision for specific causes were compared, first for the older with the two new designs, and second for the cemented with the uncemented version of the new design. Revision was defined as any operation exchanging or removing implant parts. RESULTS: The 5-year Kaplan-Meier overall implant survival (free from revision for any cause) for the medial Oxford Partial unicompartmental knee did not improve over the study period. The 5-year Kaplan-Meier survival was different (p = 0.03) between the groups: it was 92% (95% confidence interval [CI] 90% to 94%) for the cemented Oxford III, 94% (95% CI 93% to 95%) for the cemented Oxford Partial, and 94% (95% CI 92% to 95%) for the uncemented Oxford Partial. However, the overall risk of revision during the first 5 years was not different between the groups (Cox regression HR 0.8 [95% CI 0.6 to 1.0]; p = 0.09 and 1.0 [95% CI 0.7 to 1.4]; p = 0.89 for the cemented Oxford Partial and the uncemented Oxford Partial, respectively, compared with cemented Oxford III [HR 1]). The uncemented Oxford Partial had a higher risk of revision for infection (HR 3.6 [95% CI 1.2 to 10.5]; p = 0.02) compared with the cemented Oxford III. The uncemented Oxford Partial had a lower risk of revision for pain (HR 0.5 [95% CI 0.2 to 1.0]; p = 0.045) and instability (HR 0.3 [95% CI 0.1 to 0.9]; p = 0.03) compared with the cemented Oxford III. The cemented Oxford Partial had a lower risk of revision for aseptic femoral loosening (HR 0.3 [95% CI 0.1 to 1.0]; p = 0.04) compared with the cemented Oxford III. When comparing the uncemented and cemented versions of the new design, the uncemented Oxford Partial had a higher risk of revision for periprosthetic fracture (HR 15 [95% CI 4 to 54]; p = 0.001) and infection within the first year (HR 3.0 [95% CI 1.5 to 5.7]; p = 0.001) than the cemented Oxford Partial. CONCLUSION: Considering that we found no difference in overall risk of revision during the first 5 years but we found a higher risk of revision for infection, periprosthetic fracture, and higher per implant cost, we currently would recommend against the use of uncemented Oxford Partial over the cemented Oxford Partial or the cemented Oxford III. LEVEL OF EVIDENCE: Level III, therapeutic study.

The Chemical Profiling, Docking Study, and Antimicrobial and Antibiofilm Activities of the Endophytic fungi Aspergillus sp. AP5.

Growing data suggest that Aspergillus niger, an endophytic fungus, is a rich source of natural compounds with a wide range of biological properties. This study aimed to examine the antimicrobial and antibiofilm capabilities of the Phragmites australis-derived endophyte against a set of pathogenic bacteria and fungi. The endophytic fungus Aspergillus sp. AP5 was isolated from the leaves of P. australis. The chemical profile of the fungal crude extract was identified by spectroscopic analysis using LC-HRESIMS. The fungal-derived extract was evaluated for its antimicrobial activity towards a set of pathogenic bacterial and fungal strains including Staphylococcus aureus, Pseudomonas aeruginosa, Proteus vulgaris, Klebsiella sp., Candida albicans, and Aspergillus niger. Moreover, antibiofilm activity toward four resistant biofilm-forming bacteria was also evaluated. Additionally, a neural-networking pharmacophore-based visual screening predicted the most probable bioactive compounds in the obtained extract. The AP5-EtOAc extract was found to have potent antibacterial activities against S. aureus, E. coli, and Klebsiella sp., while it exhibited low antibacterial activity toward P. Vulgaris and P. aeruginosa and displayed anticandidal activity. The AP5-EtOAc extract had significant antibiofilm activity in S. aureus, followed by P. aeruginosa. The active metabolites' antifungal and/or antibacterial activities may be due to targeting the fungal CYP 51 and/or the bacterial Gyr-B.

Development of an internet-delivered cognitive behavioral therapy program for use in combination with exercise therapy and education by patients at increased risk of chronic pain following total knee arthroplasty.

BACKGROUND: Approximately 20% of patients experience chronic pain after total knee arthroplasty (TKA). Due to the growing number of TKA procedures, this will affect an increasing number of people worldwide. Catastrophic thinking, dysfunctional illness perception, poor mental health, anxiety and depression characterize these non-improvers, and indicate that these patients may need individualized treatment using a treatment approach based on the bio-psycho-social health model. The present study developed an internet-delivered cognitive behavioral therapy (iCBT) program to be combined with exercise therapy and education for patients with knee osteoarthritis (OA) at increased risk of chronic pain after TKA. METHODS: The development process followed the first two phases of the UK Medical Research Council framework for complex interventions. In the development phase, the first prototype of the iCBT program was developed based on literature review, established iCBT programs and multidisciplinary workshops. The feasibility phase consisted of testing the program, interviewing users, condensing the program, and tailoring it to the patient group. A physiotherapist manual was developed and adapted to physiotherapists who will serve as mentors. RESULTS: The development process resulted in an iCBT program consisting of 10 modules with educational texts, videos and exercises related to relevant topics such as goalsetting, stress and pain, lifestyle, automatic thoughts, mindfulness, selective attention, worry and rumination. A physiotherapist manual was developed to guide the physiotherapists in supporting the patients through the program and to optimize adherence to the program. CONCLUSIONS: The iCBT program is tailored to patients at risk of chronic pain following TKA, and may be useful as a supplement to surgery and/or exercise therapy. A multicentre RCT will evaluate the iCBT program in combination with an exercise therapy and education program. This novel intervention may be a valuable contribution to the treatment of OA patients at risk of chronic pain after TKA. TRIAL REGISTRATION: The RCT is pre-registered at ClinicalTrials.gov: NCT03771430 11/12/2018.

The effectiveness of exercise therapy and education plus cognitive behavioral therapy, alone or in combination with total knee arthroplasty in patients with knee osteoarthritis - study protocol for the MultiKnee trial.

BACKGROUND: One in five patients report chronic pain following total knee arthroplasty (TKA) and are considered non-improvers. Psychological interventions such as cognitive behavioral therapy (CBT), combined with exercise therapy and education may contribute to reduced pain an improved function both for patients with OA or after TKA surgery, but the evidence for the effectiveness of such interventions is scarce. This randomized controlled trial with three arms will compare the clinical effectiveness of patient education and exercise therapy combined with internet-delivered CBT (iCBT), evaluated either as a non-surgical treatment choice or in combination with TKA, in comparison to usual treatment with TKA in patients with knee OA who are considered candidates for TKA surgery. METHODS: The study, conducted in three orthopaedic centers in Norway will include 282 patients between ages 18 and 80, eligible for TKA. Patients will be randomized to receive the exercise therapy + iCBT, either alone or in combination with TKA, or to a control group who will undergo conventional TKA and usual care physiotherapy following surgery. The exercise therapy will include 24 one hour sessions over 12 weeks led by a physiotherapist. The iCBT program will be delivered in ten modules. The physiotherapists will receive theoretical and practical training to advise and mentor the patients during the iCBT program. The primary outcome will be change from baseline to 12 months on the pain sub-scale from the Knee Injury and Osteoarthritis Outcome Score (KOOS). Secondary outcomes include the remaining 4 sub-scales from the KOOS (symptoms, function in daily living, function in sports and recreation, and knee-related quality of life), EQ-5D-5L, the Pain Catastrophizing Scale, the 30-s sit-to-stand test, 40-m walking test and ActiGraph activity measures. A cost-utility analysis will be performed using QALYs derived from the EQ-5D-5L and registry data. DISCUSSION: This is the first randomized controlled trial to investigate the effectiveness of exercise therapy and iCBT with or without TKA, to optimize outcomes for TKA patients. Findings from this trial will contribute to evidence-based personalized treatment recommendations for a large proportion of OA patients who currently lack an effective treatment option. TRIAL REGISTRATION: Clinicaltrials.gov : NCT03771430 . Registered: Dec 11, 2018.

Primary constrained and hinged total knee arthroplasty: 2- and 5-year revision risk compared with unconstrained total knee arthroplasty: a report on 401 cases from the Norwegian Arthroplasty Register 1994-2017.

Background and purpose - The number of primary, highly constrained knee arthroplasty implants has increased with a theoretically increased risk of early failure. Therefore we analyzed the risk of all revision following total knee arthroplasty (TKA) in patients receiving a hinged or condylar constrained knee (CCK) compared with a conventional unconstrained TKA. Patients and methods - The analyses included 401 primary highly constrained or hinged implants from 1994 to 2017. Kaplan-Meier survival curves were used to evaluate time to first revision with a maximum follow-up of 20 years. Cox regression was used to calculate hazard ratio (HR) comparing condylar constrained knee (CCK), hinged, and unconstrained TKA. Results - Kaplan-Meier estimated prosthesis survival after 2 years was 94.8% (95% CI 91.4-98.2) and 93.5% after 5 years for the primary CCK and 91.0% (CI 86.6-95.4) after 2 years and 85.5% after 5 years for the primary hinged TKA. Adjusted for sex, age groups, diagnosis, time period, previous surgery, and surgery time HR was 1.4 (CI 0.8-2.3) for the CCK and 2.4 (CI 1.6-3.7) for the hinged implants. The most common cause of revision in hinged implants was infection: 14 of 22 revisions. When excluding infection as revision cause, there were no differences in survival between the implant types. Estimated survival excluding infection revisions at 5 years was 96% for unconstrained, CCK, and hinged primary TKA implants. Interpretation - Primary rotating hinge total knee arthroplasty had a higher risk of revision compared with conventional TKA after 2 and 5 years' follow-up. Infection was the most common cause of revision. When excluding infection revisions from the survival analysis, hinged and CCK implants had similar performance to unconstrained TKA.

Have the Causes of Revision for Total and Unicompartmental Knee Arthroplasties Changed During the Past Two Decades?

BACKGROUND: Revisions after knee arthroplasty are expected to increase, and the epidemiology of failure mechanisms is changing as new implants, technology, and surgical techniques evolve. QUESTIONS/PURPOSES: (1) Was there improvement in survival for TKA and unicompartmental knee arthroplasty (UKA) when comparing two consecutive 11-year periods with similar followups in a national registry? (2) Were there changes in the causes of revision during the two times? (3) Could the changes in revision causes be attributed to patient or implant characteristics? METHODS: A total of 60,623 TKAs (2426 revisions) and 7648 UKAs (725 revisions) were selected from the Norwegian Arthroplasty Register and analyzed based on year of primary surgery: 1994 to 2004 (Period 1) and 2005 to 2015 (Period 2). TKAs had median followup of 3.5 years in Period 1 and 4.2 years in Period 2. Median followup for UKAs was 2.7 years in Period 1 and 4.6 years in Period 2. Of the patients included in the registry, 99.6% were accounted for at the time of analysis, whereas 0.4% had moved abroad. We used Kaplan-Meier analyses and log-rank test to investigate changes in survival. Relative risk of revision in Period 2 relative to Period 1 was calculated for each registered revision cause in a Cox regression model adjusted for age, sex, diagnosis, fixation, and patella resurfacing. RESULTS: For TKAs, the 10-year Kaplan-Meier survival free from revision improved from Period 1 to Period 2 from 91% (95% CI, 90%-92%) to 94% (95% CI, 94%-95%; p < 0.001). Revisions resulting from aseptic loosening of the femoral component, polyethylene wear/breakage, patellar dislocation, and unexplained pain decreased, whereas revisions resulting from early infection increased. Patients in Period 2 were younger and more often men compared with patients in Period 1. A higher risk of revision was found for male sex (relative risk [RR], 1.1; 95% CI, 1.0-1.2; p = 0.048) and age younger than 65 years (RR, 1.7; 95% CI, 1.6-1.9; p < 0.001). With UKAs, the 10-year survival free from revision was 80% (95% CI, 76%-84%) in Period 1 and 81% (95% CI, 79%-83%; p = 0.261) in Period 2. Revisions resulting from tibial aseptic loosening, polyethylene wear/breakage, and periprosthetic fractures decreased, but there were more revisions resulting from progression of osteoarthritis. In Period 2, there were more men and the average age was younger than for patients in Period 1. For UKAs, age younger than 65 years had a higher risk of revision (RR, 1.7; 95% CI, 1.5-2.0; p < 0.001), whereas sex did not affect the risk of revision. CONCLUSIONS: We found an improvement in survival free from revision for TKA in the last period, but no similar improvement for UKA, and the survivorship for UKAs remains rather dramatically lower than that observed for TKAs. The decision to perform a UKA should be made with the explicit awareness that its survivorship is substantially inferior to that of TKA; any perceived advantages of UKA should be balanced against this issue of its decreased durability. LEVEL OF EVIDENCE: Level III, therapeutic study.

Patient and surgical factors affecting procedure duration and revision risk due to deep infection in primary total knee arthroplasty.

BACKGROUND: The aim of this study was to assess which patient and procedure factors affected both the risk of infection as well as procedure duration. Additionally, to assess if procedure duration affected the revision risk due to deep infection in total knee arthroplasty (TKA) patients and in a subgroup of low-risk patients. METHODS: 28,262 primary TKA with 311 revisions due to deep infection were included from the Norwegian Arthroplasty Register (NAR) and analysed from primary surgery from 2005 until 31st December 2015 with a 1 and 4 year follow up. The risk of revision due to deep infection was calculated in a multivariable Cox regression model including patient and procedure related risk factors, assessing Hazard Ratio (HR) with 95% confidence interval (CI). RESULTS: Multivariate analysis showed statistically significant associations with revision due to deep infection and increased procedure duration for male patients, ASA3+ (American Society of Anesthesiologists) and perioperative complications. Procedure duration ≥110 min (75 percentile) had a higher risk of deep infection compared to duration <75 min (25 percentile), in the unadjusted analysis (HR = 1.8, 95% CI 1.3-2.5, p = 0.001) and in the adjusted analysis (HR = 1.5, 95% CI 1.0-2.1, p = 0.03). For low-risk patients, procedure duration did not increase the risk of infection. CONCLUSION: Male patients, ASA 3+ patients and perioperative complications were risk factors both for longer procedure duration and for deep infection revisions. Patients with a high degree of comorbidity, defined as ASA3+, are at risk of infection with longer procedure durations. The occurrence of perioperative complications potentially leading to a more complex and lengthy procedure was associated with a higher risk of infection. Long procedure duration in itself seems to have minor impact on infection since we found no association in the low-risk patient.

Hospital volume and the risk of revision in Oxford unicompartmental knee arthroplasty in the Nordic countries -an observational study of 14,496 cases.

BACKGROUND: High procedure volume and dedication to unicompartmental knee arthroplasty (UKA) has been suggested to improve revision rates. This study aimed to quantify the annual hospital volume effect on revision risk in Oxfordu nicompartmental knee arthroplasty in the Nordic countries. METHODS: 14,496 cases of cemented medial Oxford III UKA were identified in 126 hospitals in the four countries included in the Nordic Arthroplasty Register Association (NARA) database from 2000 to 2012. Hospitals were divided by quartiles into 4 annual procedure volume groups (≤11, 12-23, 24-43 and ≥44). The outcome was revision risk after 2 and 10 years calculated using Kaplan Meier method. Multivariate Cox regression analysis was used to assess the Hazard Ratio (HR) of any revision due to specific reasons with 95% confidence intervals (CI). RESULTS: The implant survival was 80% at 10 years in the volume group ≤11 procedures per year compared to 83% in other volume groups. The HR adjusted for age category, sex, year of surgery and nation was 0.87 (95% CI: 0.76-0.99, p = 0.036) for the group 12-23 procedures per year, 0.78 (95% CI: 0.68-0.91, p = 0.002) for the group 24-43 procedures per year and 0.82 (95% CI: 0.70-0.94, p = 0.006) for the group ≥44 procedures per year compared to the low volume group. Log-rank test was p = 0.003. The risk of revision for unexplained pain was 40-50% higher in the low compared with other volume groups. CONCLUSION: Low volume hospitals performing ≤11 Oxford III UKAs per year were associated with an increased risk of revision compared to higher volume hospitals, and unexplained pain as revision cause was more common in low volume hospitals.

The risk of revision in total knee arthroplasty is not affected by previous high tibial osteotomy.

BACKGROUND AND PURPOSE: Previous studies have found different outcomes after revision of knee arthroplasties performed after high tibial osteotomy (HTO). We evaluated the risk of revision of total knee arthroplasty with or without previous HTO in a large registry material. PATIENTS AND METHODS: 31,077 primary TKAs were compared with 1,399 TKAs after HTO, using Kaplan-Meier 10-year survival percentages and adjusted Cox regression analysis. RESULTS: The adjusted survival analyses showed similar survival in the 2 groups. The Kaplan-Meier 10-year survival was 93.8% in the primary TKA group and 92.6% in the TKA-post-HTO group. Adjusted RR was 0.97 (95% CI: 0.77-1.21; p = 0.8). INTERPRETATION: In this registry-based study, previous high tibial osteotomy did not appear to compromise the results regarding risk of revision after total knee arthroplasty compared to primary knee arthroplasty.

Higher revision risk for unicompartmental knee arthroplasty in low-volume hospitals.

BACKGROUND AND PURPOSE: Some studies have found high complication rates and others have found low complication rates after unicompartmental knee arthroplasty (UKA). We evaluated whether hospital procedure volume influences the risk of revision using data from the Norwegian Arthroplasty Register (NAR). MATERIALS AND METHODS: 5,791 UKAs have been registered in the Norwegian Arthroplasty Register. We analyzed the 4,460 cemented medial Oxford III implants that were used from 1999 to 2012; this is the most commonly used UKA implant in Norway. Cox regression (adjusted for age, sex, and diagnosis) was used to estimate risk ratios (RRs) for revision. 4 different volume groups were compared: 1-10, 11-20, 21-40, and > 40 UKA procedures annually per hospital. We also analyzed the reasons for revision. RESULTS AND INTERPRETATION: We found a lower risk of revision in hospitals performing more than 40 procedures a year than in those with less than 10 UKAs a year, with an unadjusted RR of 0.53 (95% CI: 0.35-0.81) and adjusted RR of 0.59 (95% CI: 0.39-0.90). Low-volume hospitals appeared to have a higher risk of revision due to dislocation, instability, malalignment, and fracture than high-volume hospitals.

Chitosan-Aspirin Combination Inhibits Quorum-Sensing Synthases (lasI and rhlI) in Pseudomonas aeruginosa.

BACKGROUND: Quorum sensing (QS) controls the virulence of P. aeruginosa. This study aims to determine the anti-QS activity of aspirin alone and in combination with chitosan to reach maximum inhibition. We tested ten virulent Pseudomonas aeruginosa (P. aeruginosa) isolates and screened for N-acyl homoserine lactone (AHL) production using Agrobacterium tumefaciens as a biosensor. P. aeruginosa isolates were treated with sub-minimum inhibitory concentrations (MICs) of aspirin and chitosan-aspirin. We used broth microdilution and checkerboard titration methods to determine the MICs and the synergistic effect of these two compounds, respectively. Real-time polymerase chain reaction (PCR) was used to estimate the anti-QS activity of the aspirin-chitosan combination on the expression of lasI and rhlI genes. RESULTS: Aspirin decreased the motility and production of AHLs, pyocyanin, and biofilm. Chitosan potentiated the inhibitory effect of aspirin. The chitosan-aspirin combination inhibited lasI and rhlI gene expression in PAO1 (ATCC 15692) by 7.12- and 0.92-fold, respectively. In clinical isolates, the expression of lasI and rhlI was decreased by 1.76 × 102- and 1.63 × 104-fold, respectively. Molecular docking analysis revealed that aspirin could fit into the active sites of the QS synthases lasI and rhlI with a high binding affinity, causing conformational changes that resulted in their inhibition. CONCLUSIONS: The chitosan-aspirin combination provides new insights into treating virulent and resistant P. aeruginosa.

Detectable quorum signaling molecule via PANI-metal oxides nanocomposites sensors.

The detection of N-hexanoyl-l-homoserine lactone (C6-HSL), a crucial signal in Gram-negative bacterial communication, is essential for addressing microbiologically influenced corrosion (MIC) induced by sulfate-reducing bacteria (SRB) in oil and gas industries. Metal oxides (MOx) intercalated into conducting polymers (CPs) offer a promising sensing approach due to their effective detection of biological molecules such as C6-HSL. In this study, we synthesized and characterized two MOx/polyaniline-dodecyl benzene sulfonic acid (PANI-DBSA) nanocomposites, namely ZnO/PANI-DBSA and Fe2O3/PANI-DBSA. These nanocomposites were applied with 1% by-weight carbon paste over a carbon working electrode (WE) for qualitative and quantitative detection of C6-HSL through electrochemical analysis. The electrochemical impedance spectroscopy (EIS) confirmed the composites' capability to monitor C6-HSL produced by SRB-biofilm, with detection limits of 624 ppm for ZnO/PANI-DBSA and 441 ppm for Fe2O3/PANI-DBSA. Furthermore, calorimetric measurements validated the presence of SRB-biofilm, supporting the EIS analysis. The utilization of these MOx/CP nanocomposites offers a practical approach for detecting C6-HSL and monitoring SRB-biofilm formation, aiding in MIC management in oil and gas wells. The ZnO/PANI-DBSA-based sensor exhibited higher sensitivity towards C6-HSL compared to Fe2O3/PANI-DBSA, indicating its potential for enhanced detection capabilities in this context. Stability tests revealed ZnO/PANI-DBSA's superior stability over Fe2O3/PANI-DBSA, with both sensors retaining approximately 85-90% of their initial current after 1 month, demonstrating remarkable reproducibility and durability.

Exercise therapy, education, and cognitive behavioral therapy alone, or in combination with total knee arthroplasty, in patients with knee osteoarthritis: a randomized feasibility study.

BACKGROUND: One in five patients experience chronic pain 1 year after total knee arthroplasty (TKA), highlighting the need for enhanced treatment strategies to improve outcomes. This feasibility trial aimed to optimize the content and delivery of a complex intervention tailored to osteoarthritis (OA) patients at risk of poor outcome after TKA and assess the feasibility of initiating a full-scale multicenter randomized controlled trial (RCT). METHODS: Patients scheduled for TKA were included between August 2019 and June 2020 and block-randomized into one of three groups: (a) 12-week exercise therapy and education (ExE) and 10-module internet-delivered cognitive behavioral therapy (iCBT), (b) TKA followed by ExE and iCBT and (c) TKA and standard postoperative care. Outcomes were (i) recruitment and retention rate, (ii) compliance to the intervention and follow-up, (iii) crossover, and (iv) adverse events, reported by descriptive statistics. RESULTS: Fifteen patients were included in the study. Only 1 out of 146 patients screened for eligibility was included during the first 4 months. During the next 3 months, 117 patients were not included since they lived too far from the hospital. To increase the recruitment rate, we made three amendments to the inclusion criteria; (1) at-risk screening of poor TKA outcome was removed as an eligibility criterion, (2) patients across the country could be included in the study and (3) physiotherapists without specific certification were included, receiving thorough information and support. No patients withdrew from the study or crossed over to surgery during the first year. Nine out of 10 patients completed the ExE program and six out of 10 completed the iCBT program. Fourteen out of 15 patients completed the 1-year follow-up. One minor adverse event was registered. CONCLUSIONS: Except for recruitment and compliance to iCBT, feasibility was demonstrated. The initial recruitment process was challenging, and necessary changes were made to increase the recruitment rate. The findings informed how a definitive RCT should be undertaken to test the effectiveness of the complex intervention. TRIAL REGISTRATION: The MultiKnee RCT, including the feasibility study, is pre-registered at ClinicalTrials.gov: NCT03771430 11/12/2018.

Endophytic Aspergillus hiratsukae mediated biosynthesis of silver nanoparticles and their antimicrobial and photocatalytic activities.

In the current study, endophytic Aspergillus hiratsukae was used for the biosynthesis of silver nanoparticles (Ag-NPs) for the first time. The characterizations were performed using X ray diffraction (XRD), Transmission electron microscopy (TEM), Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), Dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FT-IR), and UV-Vis spectroscopy. The obtained results demonstrated the successful formation of crystalline, spherical Ag-NPs with particle diameters ranging from 16 to 31 nm. The FT-IR studied and displayed the various functional groups involved, which played a role in capping and reducing agents for Ag-NPs production. The SEM-EDX revealed that the main constituent of the AS-formed sample was primarily Ag, with a weight percentage of 64.2%. The mycosynthesized Ag-NPs were assessed for antimicrobial as well as photocatalytic activities. The antimicrobial results indicated that the synthesized Ag-NPs possess notable antibacterial efficacy against Staphylococcus aureus, Bacillus subtilis, and Escherichia coli, with minimum inhibitory concentrations (MICs) of Ag-NPs ranging from 62.5 to 250 µg/mL. Moreover, the biosynthesized Ag-NPs demonstrated weak antifungal activity against Aspergillus brasiliensis and Candida albicans, with MICs of 500 and 1,000 µg/mL, respectively. In addition, the mycosynthesized Ag-NPs exhibited photocatalytic activity toward acid black 2 (nigrosine) dye under both light and dark stimulation. Notably, After 300 min exposure to light, the nigrosine dye was degraded by 93%. In contrast, 51% degradation was observed after 300 min in darkness. In conclusion, Ag-NPs were successfully biosynthesized using endophytic A. hiratsukae and also exhibited antimicrobial and photocatalytic activities that can be used in environmental applications.

Enhancing physical characteristics and antibacterial efficacy of chitosan through investigation of microwave-assisted chemically formulated chitosan-coated ZnO and chitosan/ZnO physical composite.

This study investigates the creation and analysis of chitosan-zinc oxide (CS-ZnO) nanocomposites, exploring their effectiveness in inhibiting bacteria. Two synthesis approaches, physical and chemical, were utilized. The CS-ZnO nanocomposites demonstrated strong antibacterial properties, especially against Staphylococcus aureus, a Gram-positive bacterium. Chemically synthesized nanocomposites (CZ10 and CZ100) exhibited larger inhibition zones (16.4 mm and 18.7 mm) compared to physically prepared CS-Z5 and CS-Z20 (12.2 mm and 13.8 mm) against Staphylococcus aureus. Moreover, CZ nanocomposites displayed enhanced thermal stability, with decomposition temperatures of 281°C and 290°C, surpassing CS-Z5 and CS-Z20 (260°C and 258°C). The residual mass percentages at 800°C were significantly higher for CZ10 and CZ100 (58% and 61%) than for CS-Z5 and CS-Z20 (36% and 34%). UV-Visible spectroscopy revealed reduced band gaps in the CS-ZnO nanocomposites, indicating improved light absorption. Transmission electron microscopy (TEM) confirmed uniform dispersion of ZnO nanoparticles within the chitosan matrix. In conclusion, this research underscores the impressive antimicrobial potential of CS-ZnO nanocomposites, especially against Gram-positive bacteria, and highlights their enhanced thermal stability. These findings hold promise for diverse applications in industries such as medicine, pharmaceuticals, and materials science, contributing to the development of sustainable materials with robust antimicrobial properties.

Evaluation of the Cariogenic and Anti-Cariogenic Potential of Human Colostrum and Colostrum-Derived Probiotics: Impact on S. mutans Growth, Biofilm Formation, and L. rhamnosus Growth.

Human colostrum (HC) is essential for oral health as it is rich in probiotics that could affect the growth of the cariogenic S. mutans and its biofilm formation; hindering dental caries in advance. In this study, HC was collected from 36 healthy mothers 1-3 days postpartum. The effect of HC on oral health was carried out by assessing the impact of HC and its derived probiotics' cell-free supernatants (CFS) on the growth of S. mutans (using modified well diffusion) and its biofilm formation (using microtiter plate assay). Moreover, the effect of whole HC on L. rhamnosus, a probiotic oral bacterium, was examined. Probiotics were isolated and identified phenotypically by API 50 CH carbohydrate fermentation and genotypically by 16S rRNA amplification. The in vitro study revealed that HC has cariogenic activity and is associated with biofilm formation. Biofilm strength was inversely proportional to HC dilution (p-value < 0.0001). Nevertheless, HC and colostrum-derived probiotics improve oral health by inhibiting the growth of caries-inducing S. mutans with lower inhibition to L. rhamnosus probiotics. The CFS of isolated probiotics reduced the biofilm formation via the cariogenic S. mutans. These results are not only promising for caries eradication, but they also highlight the importance of breastfeeding infants from their first hours to shape healthy oral microbiota, protecting them from various diseases including dental caries.

Green Biosynthesis of Selenium Nanoparticles Using Orange Peel Waste: Characterization, Antibacterial and Antibiofilm Activities against Multidrug-Resistant Bacteria.

There is an increase of pathogenic multidrug-resistant bacteria globally due to the misuse of antibiotics. Recently, more scientists used metal nanoparticles to counteract antibacterial resistance. In this study, orange peel waste (OPW) was used for selenium nanoparticles' (Se-NPs) biosynthesis through the green and ecofriendly method, and their applications as antibacterial and antibiofilm agents. Green biosynthesized Se-NPs were characterized using FTIR, XRD, SEM, EDAX, and TEM. Characterization results revealed that biosynthesized Se-NPs were highly crystalline, spherical, and polydisperse, and had sizes in the range of 16-95 nm. The biosynthesized Se-NPs were evaluated as antibacterial and antibiofilm activities against multidrug-resistant bacteria. Results illustrated that Se-NPs exhibited potential antibacterial activity against Gram-positive bacteria (S. aureus ATCC 29213 and biofilm-producing clinical isolates of S. aureus) and Gram-negative bacteria (Pseudomonas aeruginosa PAO1, MDR, biofilm, and quorum-sensing and producing clinical isolates of MDR P. aeruginosa, MDR E. coli, and K. pneumonia). Moreover, results illustrated that S. aureus ATCC 29213 was the most sensitive bacteria to Se-NPs at 1000 µg/mL, where the inhibition zone was 35 mm and MIC was 25 µg/mL. Furthermore, Se-NPs at 0.25 and 0.5 MIC decreased the biofilm significantly. The largest inhibition of biofilm was noticed in MDR K. pneumonia, which was 62% and 92% at 0.25 and 0.5 MIC, respectively. In conclusion, Se-NPs were successfully biosynthesized using OPW through the green method and had promising antibacterial and antibiofilm activity against multidrug-resistant bacteria, which can be used later in fighting resistant bacteria.