Flurin, Laure

Abstract Aims Effects of H2O2 producing electrochemical-bandages (e-bandages) on methicillin-resistant Staphylococcus aureus colonization and biofilm removal were assessed using a porcine explant biofilm model. Transport of H2O2 produced from the e-bandage into explant tissue and associated potential toxicity were evaluated. Methods and Results Viable prokaryotic cells from infected explants were quantified after 48 h treatment with e-bandages in three ex vivo S. aureus infection models: (1) reducing colonization, (2) removing young biofilms and (3) removing mature biofilms. H2O2 concentration-depth profiles in explants/biofilms were measured using microelectrodes. Reductions in eukaryotic cell viability of polarized and nonpolarized noninfected explants were compared. e-Bandages effectively reduced S. aureus colonization (p = 0.029) and reduced the viable prokaryotic cell concentrations of young biofilms (p = 0.029) with limited effects on mature biofilms (p > 0.1). H2O2 penetrated biofilms and explants and reduced eukaryotic cell viability by 32–44% compared to nonpolarized explants. Conclusions H2O2 producing e-bandages were most active when used to reduce colonization and remove young biofilms rather than to remove mature biofilms. Significance and Impact of Study The described e-bandages reduced S. aureus colonization and young S. aureus biofilms in a porcine explant wound model, supporting their further development as an antibiotic-free alternative for managing biofilm infections.

Initial microbiologic diagnosis of infective endocarditis (IE) relies on blood cultures and Bartonella and Coxiella burnetii serology. Small case series and one prospective study have preliminarily reported application of metagenomic sequencing on blood or plasma for IE diagnosis.

Abstract Background Next-generation sequencing (NGS) is increasingly used for periprosthetic joint infection (PJI) diagnosis, but its clinical utility is poorly defined. Shotgun metagenomic sequencing (sNGS) has been reported to identify PJI pathogens undetected by culture in sonicate fluid. However, sNGS is complex and costly. Here, 16S ribosomal RNA (rRNA) gene-based targeted metagenomic sequencing (tNGS) was compared to sNGS of sonicate fluid for microbial detection and identification in patients with total hip arthroplasty (THA) and total knee arthroplasty (TKA) failure. Methods A convenience sample of sonicate fluids derived from patients who had undergone THA or TKA removal, enriched with culture negative PJI cases, was tested. Samples had been previously tested by sNGS. For tNGS, samples were extracted, amplified by polymerase chain reaction targeting the V1 to V3 regions of the 16S rRNA gene, and sequenced on an Illumina MiSeq. Results A total of 395 sonicate fluids, including 208 from subjects with PJI, were studied. Compared with sonicate fluid culture, tNGS had higher positive percent agreement (72.1 vs 52.9%, P < .001), detecting potential pathogens in 48.0% of culture-negative PJIs. There was no difference between the positive percent agreement of tNGS (72.1%) and sNGS (73.1%, P = .83). Conclusions 16S rRNA gene-based tNGS is a potential diagnostic tool for PJI pathogen identification in sonicate fluid from failed THAs and TKAs in culture-negative cases, with similar performance characteristics to sNGS.

ABSTRACT. To date, no study has described the microbiological profile of surgical site infections (SSIs) after spine surgery in a tropical environment. The main objective of this study is to describe the microbiology and the risk factors of SSI after spinal surgery in a tropical climate. Our hypothesis is that the microbiology of SSIs in tropical areas is different to what is mainly described in temperate countries. As a consequence, the recommendation for antibiotic prophylaxis administered in the operative room, which mainly relays on the literature, might not be adequate in such countries. We included 323 consecutive patients who underwent a spinal intervention between 2017 and 2019, with a 2-year minimum follow-up. Objective ISO criteria were established in accordance with the criteria accepted by the Center of Disease Control in Atlanta. The identification of risk factors for SSI was carried out by uni- and multivariate analysis with a significance threshold of P < 0.05. The incidence of SSI was 7.7%. A total of 54.8% were in favor of a predominantly digestive origin of germs with an average of 1.68 bacteria found by ISO. Inadequate antibiotic prophylaxis was found in 54.8%. Age and body mass index were found to be independent risk factors for SSI. We report here an unusual microbiological profile of SSI with a predominance of gram-negative bacteria and a low proportion of Staphylococcus aureus and Staphylococcus epidermidis.

Abstract Background The yield of next-generation sequencing (NGS) added to a Sanger sequencing–based 16S ribosomal RNA (rRNA) gene polymerase chain reaction (PCR) assay was evaluated in clinical practice for diagnosis of bacterial infection. Methods PCR targeting the V1 to V3 regions of the 16S rRNA gene was performed, with amplified DNA submitted to Sanger sequencing and/or NGS (Illumina MiSeq) or reported as negative, depending on the cycle threshold value. A total of 2146 normally sterile tissues or body fluids were tested between August 2020 and March 2021. Clinical sensitivity was assessed in 579 patients from whom clinical data were available. Results Compared with Sanger sequencing alone (400 positive tests), positivity increased by 87% by adding NGS (347 added positive tests). Clinical sensitivity of the assay that incorporated NGS was 53%, which was higher than culture (42%, P &lt; .001), with an impact on clinical decision-making in 14% of infected cases. Clinical sensitivity in the subgroup that received antibiotics at sampling was 41% for culture and 63% for the sequencing assay (P &lt; .001). Conclusions Adding NGS to Sanger sequencing of the PCR-amplified 16S rRNA gene substantially improved test positivity. In the patient population studied, the assay was more sensitive than culture, especially in patients who had received antibiotic therapy.

Abstract Background Central-line associated bloodstream infection (CLABSI) contributes to mortality and cost. While aseptic dressings and antibiotic-impregnated catheters can prevent extraluminal infections, intraluminal infections remain a source of CLABSIs with limited prevention options. Methods In this proof-of-concept study, an electrochemical intravascular catheter (e-catheter) prototype capable of electrochemically generating hypochlorous acid intraluminally on the surface of platinum electrodes polarized at a constant potential of 1.5 VAg/AgCl was developed. After 24h of pre-polarization at 1.5 VAg/AgCl, their activity was tested by inoculating four clinical isolates derived from catheter-related infections, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecium and Escherichia coli. Figure 1. In vitro catheter and e-catheter models. Results E-catheters generated a mean HOCl concentration of 15.86±4.03 μM and had a mean pH of 6.14±0.79. e-catheters prevented infections with all four species, with an average reduction of 8.41±0.61 log10 CFU/mL at 48h compared to controls. Figure 3. Measurement of pH and HOCl at 48 hours in polarized e-catheters. Each dot represents a replicate; bars represent means. Figure 4. Prevention of infection after 48 hours of polarization (24 hours of infections) using e-catheters (polarized and non-polarized) compared to blank catheters. * indicates statistically significant reduction of cell counts in polarized e-catheter compared to blank catheter (p &lt;0.05). Conclusion Polarized e-catheters which generate low amounts of HOCl continuously should be further developed to prevent intraluminal infection. Disclosures Haluk Beyenal, Ph.D, patent (Other Financial or Material Support, HB holds a patent: Beyenal H CD, Fransson BA, Sultana ST. . 2018. Electrochemical reduction or prevention of infections. U.S. patent 20180207301A1, international patent WO/2017/011635.) Robin Patel, MD, 1928 Diagnostics (Consultant)BioFire Diagnostics (Grant/Research Support)ContraFect Corporation (Grant/Research Support)Curetis (Consultant)Hylomorph AG (Grant/Research Support)IDSA (Other Financial or Material Support, Editor's Stipend)Infectious Diseases Board Review Course (Other Financial or Material Support, Honoraria)Mammoth Biosciences (Consultant)NBME (Other Financial or Material Support, Honoraria)Netflix (Consultant)Next Gen Diagnostics (Consultant)PathoQuest (Consultant)PhAST (Consultant)Qvella (Consultant)Samsung (Other Financial or Material Support, Patent Royalties)Selux Diagnostics (Consultant)Shionogi & Co., Ltd. (Grant/Research Support)Specific Technologies (Consultant)TenNor Therapeutics Limited (Grant/Research Support)Torus Biosystems (Consultant)Up-to-Date (Other Financial or Material Support, Honoraria) Robin Patel, MD, BioFire (Individual(s) Involved: Self): Grant/Research Support; Contrafect (Individual(s) Involved: Self): Grant/Research Support; IDSA (Individual(s) Involved: Self): Editor's stipend; NBME, Up-to-Date and the Infectious Diseases Board Review Course (Individual(s) Involved: Self): Honoraria; Netflix (Individual(s) Involved: Self): Consultant; TenNor Therapeutics Limited (Individual(s) Involved: Self): Grant/Research Support; to Curetis, Specific Technologies, Next Gen Diagnostics, PathoQuest, Selux Diagnostics, 1928 Diagnostics, PhAST, Torus Biosystems, Mammoth Biosciences and Qvella (Individual(s) Involved: Self): Consultant

Catheter-related infections constitute an economic and mortality burden in health care. Several options are available to reduce the risk of infection, but only a few focus on preventing intraluminal infection, which occurs in long-term catheters, most often used for dialysis, prolonged treatment, or chemotherapy.

Abstract Background CERTAIN (Checklist for Early Recognition and Treatment of Acute Illness and iNjury) has been shown to improve critical care process and patient outcomes in international ICUs with variable resources. Methods CERTAIN education program derived from this approach is designed, promoted, and implemented following the Logic model. Through the roadmap of the Logic model, we presented a dynamic, longitudinal implementation framework that had sufficient rigor yet offers flexibility to reach the need of the existing and emerging diversified medical education projects. Results Using the Logic model, the delivery of the CERTAIN education program is optimized to deliver relevant education content in various environments. During the COVID-19 outbreak, the implementational framework demonstrated that it could serve as an excellent template for effective response to global pandemics. Conclusions The Logical model is useful as a facilitation tool for planning and evaluating innovative education delivery and dissemination. The CERTAIN program provided an example for other continuous professional education projects.

AbstractChronic wound infections caused by biofilm‐forming microorganisms represent a major burden to healthcare systems. Treatment of chronic wound infections using conventional antibiotics is often ineffective due to the presence of bacteria with acquired antibiotic resistance and biofilm‐associated antibiotic tolerance. We previously developed an electrochemical scaffold that generates hydrogen peroxide (H2O2) at low concentrations in the vicinity of biofilms. The goal of this study was to transition our electrochemical scaffold into an H2O2‐generating electrochemical bandage (e‐bandage) that can be used in vivo. The developed e‐bandage uses a xanthan gum‐based hydrogel to maintain electrolytic conductivity between e‐bandage electrodes and biofilms. The e‐bandage is controlled using a lightweight, battery‐powered wearable potentiostat suitable for use in animal experiments. We show that e‐bandage treatment reduced colony‐forming units of Acinetobacter buamannii biofilms (treatment vs. control) in 12 h (7.32 ± 1.70 vs. 9.73 ± 0.09 log10[CFU/cm2]) and 24 h (4.10 ± 12.64 vs. 9.78 ± 0.08 log10[CFU/cm2]) treatments, with 48 h treatment reducing viable cells below the limit of detection of quantitative and broth cultures. The developed H2O2‐generating e‐bandage was effective against in vitro A. baumannii biofilms and should be further evaluated and developed as a potential alternative to topical antibiotic treatment of wound infections.