Antibiofilm Activities of Biogenic Silver Nanoparticles Against Candida albicans

Biofilms are microbial colonies that are encased in an organic polymeric matrix and are resistant to antimicrobial treatments. Biofilms can adhere to both biotic and abiotic surfaces, allowing them to colonize medical equipment such as urinary and intravenous catheters, mechanical heart valves, endotracheal tubes, and prosthetic joints. Candida albicans biofilm is the major etiological cause of the pathogenesis of candidiasis in which its unobstructed growth occurs in the oral cavity; trachea, and catheters that progress to systemic infections in the worst scenarios. There is an urgent need to discover novel biofilm preventive and curative agents. In the present investigation, an effort is made to observe the role of cyanobacteria-derived AgNPs as a new antibiofilm agent with special reference to candidiasis. AgNPs synthesized through the green route using Anabaena variabilis cell extract were characterized by UV–visible spectroscopy. The nanoparticles were spherical in shape with 11–15 nm size and were monodispersed. The minimum inhibitory concentration (MIC) of AgNPs was obtained at 12.5 μg/mL against C. albicans. AgNPs 25 μg/mL showed 79% fungal cell membrane permeability and 22.2% ROS production. AgNPs (25 μg/mL) also facilitated 62.5% of biofilm inhibition and degradation. Therefore, AgNPs could be considered as a promising antifungal agent to control biofilm produced by C. albicans.

Gram stain microscopy in septic arthritis

Septic arthritis is a serious condition that can lead to rapid destruction of joint if it is not rapidly diagnosed and treated appropriately. The reported annual incidence is 10 in 100 000 although this increases to 70 in 100 000 in those with risk factors for developing septic arthritis mainly rheumatoid arthritis and immune-compromised patients. The aim of this study is to examine the sensitivity and specificity, and thus the clinical usefulness, of gram stain results. This was a single centre, retrospective case series. All joint aspirates over a three year period from May 2015 to April 2018 were reviewed. The gram stain and final culture results noted. 830 samples were included from both native and replaced joints. Native joints accounted for a total of 701 cases (84%) of the aspirates, whilst those obtained from prosthetic joints 129 (16%). In 74 (9%) cases there was a discrepancy between the gram stain and culture results. The sensitivity of the gram stain in this case series is 22% and the specificity of the test is 99.6%. The clinician should have a low threshold for overlooking a negative gram stain result and place greater emphases on the clinical findings in conjunction with biochemical markers.

Micromonas micros Infection of a Prosthetic Hip Joint: A Case Report and Review of the Literature

Micromonas micros is an oral anaerobic Gram-positive coccus and is a commensal of the mouth, and it is rarely isolated in prosthetic joint infections (PJIs) and even less frequently related to a preceding dental procedure with eventual hematogenous seeding of the prosthetic joint. Here, we present a case of a 56-year-old male with a prosthetic hip joint who developed Micromonas micros prosthetic hip joint infection with symptoms starting a few days after a dental procedure and not having received periprocedural antibiotic prophylaxis. He recovered well with surgical intervention and antimicrobial therapy. We conducted a literature review of prosthetic hip joint infections caused by Micromonas micros as well as briefly discuss current guidelines on antibiotic prophylaxis in patients with prosthetic joints undergoing dental procedures and some knowledge gaps.

Carbon nanofibers assist in the manufacture of prosthetic joints, promote tissue, organ, nerve regeneration and development, and improve anticancer therapy impact and chemosensitization for a range of tumor types

Carbon nanofibers (CNFs) have initiated a new era of outstanding biological applications for future generations. CNFs can be used as efficient and unique biocompatible reinforcing materials, biosensors, perfect platforms for supporting nanoparticles and immobilizing biomolecules, and wound dressing support due to their surface functionality, ensuring biocompatibility and coupling with metallic nanoparticles or organics. Using CNFs helps to build artificial joints, promoting tissue, organ, and nerve regeneration and development. In addition, multiple published studies have revealed CNF's ability to boost the impact and chemosensitization of anticancer therapies for a range of tumor types while lowering undesirable drug effects. Also, the toxicity of CNFs as effective biomaterials was explored, as well as the limits. CNF research focuses on biomedical applications, such as tissue engineering and biosensors. The bulk of these biological applications utilise CNTs, graphene, and fullerene, although CNFs are still rarely cited in these domains. As a result, increased emphasis and effort should be placed on examining the potential benefits of adopting CNFs. Lastly, the dearth of proven evidence on CNF toxicity should push scientists to complete the dataset necessary for CNF risk assessment. For example, short- and long-term chronic animal bioassays and standard tests can be utilized to replicate real-world conditions for occupational, local, and systemic administration of CNFs.

Should all hip and knee prosthetic joints be aspirated prior to revision surgery?

Aims It is essential to exclude a periprosthetic joint infection (PJI) prior to revision surgery. It is recommended to routinely aspirate the joint before surgery. However, this may not be necessary in a subgroup of patients. The aim of our study was to investigate if specific clinical and implant characteristics could be identified to rule out a PJI prior to revision surgery. Methods We retrospectively evaluated clinical and implant characteristics of patients who underwent a hip or knee revision surgery between October 2015 and October 2018. Patients were diagnosed with a PJI according to the MSIS diagnostic criteria. Results A total of 156 patients were analyzed, including 107 implants that were revised because of prosthetic loosening and 49 because of mechanical failure (i.e. instability, malalignment or malpositioning). No PJI was diagnosed in the group with mechanical failure. In the prosthetic loosening group, 20 of 107 were diagnosed with a PJI (19%). Although there was a significantly lower chance of having a PJI with an implant age of > 5 years combined with a CRP < 5 mg/L, an infection was still present in 3 out of 39 cases (8%). Conclusion Implants with solely mechanical failure without signs of loosening and low inflammatory parameters probably do not require a synovial fluid aspiration. These results need to be confirmed in a larger cohort of patients. In case of prosthetic loosening, all joints need to be aspirated before surgery as no specific characteristic could be identified to rule out an infection.

Direct continuous electromyographic control of a powered prosthetic ankle for improved postural control after guided physical training: A case study

Despite the promise of powered lower limb prostheses, existing controllers do not assist many daily activities that require continuous control of prosthetic joints according to human states and environments. The objective of this case study was to investigate the feasibility of direct, continuous electromyographic (dEMG) control of a powered ankle prosthesis, combined with physical therapist-guided training, for improved standing postural control in an individual with transtibial amputation. Specifically, EMG signals of the residual antagonistic muscles (i.e. lateral gastrocnemius and tibialis anterior) were used to proportionally drive pneumatical artificial muscles to move a prosthetic ankle. Clinical-based activities were used in the training and evaluation protocol of the control paradigm. We quantified the EMG signals in the bilateral shank muscles as well as measures of postural control and stability. Compared to the participant’s daily passive prosthesis, the dEMG-controlled ankle, combined with the training, yielded improved clinical balance scores and reduced compensation from intact joints. Cross-correlation coefficient of bilateral center of pressure excursions, a metric for quantifying standing postural control, increased to .83(±.07) when using dEMG ankle control (passive device: .39(±.29)). We observed synchronized activation of homologous muscles, rapid improvement in performance on the first day of the training for load transfer tasks, and further improvement in performance across training days (p = .006). This case study showed the feasibility of this dEMG control paradigm of a powered prosthetic ankle to assist postural control. This study lays the foundation for future study to extend these results through the inclusion of more participants and activities.

Differences between infected and noninfected synovial fluid

Aims The diagnosis of joint infections is an inexact science using combinations of blood inflammatory markers and microscopy, culture, and sensitivity of synovial fluid (SF). There is potential for small molecule metabolites in infected SF to act as infection markers that could improve accuracy and speed of detection. The objective of this study was to use nuclear magnetic resonance (NMR) spectroscopy to identify small molecule differences between infected and noninfected human SF. Methods In all, 16 SF samples (eight infected native and prosthetic joints plus eight noninfected joints requiring arthroplasty for end-stage osteoarthritis) were collected from patients. NMR spectroscopy was used to analyze the metabolites present in each sample. Principal component analysis and univariate statistical analysis were undertaken to investigate metabolic differences between the two groups. Results A total of 16 metabolites were found in significantly different concentrations between the groups. Three were in higher relative concentrations (lipids, cholesterol, and N-acetylated molecules) and 13 in lower relative concentrations in the infected group (citrate, glycine, glycosaminoglycans, creatinine, histidine, lysine, formate, glucose, proline, valine, dimethylsulfone, mannose, and glutamine). Conclusion Metabolites found in significantly greater concentrations in the infected cohort are markers of inflammation and infection. They play a role in lipid metabolism and the inflammatory response. Those found in significantly reduced concentrations were involved in carbohydrate metabolism, nucleoside metabolism, the glutamate metabolic pathway, increased oxidative stress in the diseased state, and reduced articular cartilage breakdown. This is the first study to demonstrate differences in the metabolic profile of infected and noninfected human SF, using a noninfected matched cohort, and may represent putative biomarkers that form the basis of new diagnostic tests for infected SF. Cite this article: Bone Joint Res 2021;10(1):85–95.

An Evaluation of Antimicrobial Prophylaxis for Dental Procedures at a Veterans Healthcare System; A Role for Senior Care Pharmacists?

OBJECTIVE: The primary objective of this study was to determine the prevalence of appropriate use of antibiotics before a dental procedure.<br/> DESIGN: Retrospective cohort study.<br/> SETTING: Veterans Healthcare Systems.<br/> PARTICIPANTS: Veterans who filled outpatient prescriptions for antimicrobial dental prophylaxis at the Veterans Administration Western New York Healthcare System from December 1, 2017, through October 1, 2019.<br/> INTERVENTIONS: None.<br/> MAIN OUTCOME MEASURES: Use of antibiotic dental prophylaxis was deemed appropriate if in accordance with guideline recommendations. Descriptive statistics were used to summarize data.<br/> RESULTS: A total of 130 veterans receiving antibiotics for dental prophylaxis were included in this evaluation. Of those who were included, only 16.9% received appropriate antibiotic dental prophylaxis. Patients with a prosthetic joint were significantly more likely to be inappropriately prescribed antibiotics for dental prophylaxis. Approximately 87% of patients who were inappropriately prescribed antibiotic prophylaxis had prosthetic joints (P < .0001).<br/> CONCLUSION: Most antibiotics for dental prophylaxis are prescribed inappropriately. The large amount of inappropriately used antibiotics in this study highlights the need for dental stewardship in our veteran population. Antibiotics for dental prophylaxis therefore represent an important stewardship target in the outpatient setting. This may be an ideal opportunity for senior care pharmacists to intervene upon.