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Summary Background Bone allografts are harvested and transplanted under sterile conditions. However, the risk of bacterial contamination of grafts during these processes is a health concern. Bioburden testing and bacterial contamination detection are conducted to ensure allograft sterility. Aim The present study aimed to determine the incidence of bacterial contamination in bone allografts based on different classifications. Methods PROSPERO registration number was received for the study. Systematic searches were conducted in PubMed and EMBASE databases with relevant keywords from January 2000 to March 2021. After choosing related studies according to the PRISMA flow diagram, Stata software was used for data analysis. We considered I 2 ˃ 50% as heterogeneity between studies. Findings The overall incidence of bacterial contamination was 12.6% (95% CI 0.100, 0.152) among 19,805 bone allografts of 17 studies. The bacterial contamination rate among bone allografts was 10.8% before 2010 and 14.7% in 2010-March 2021. The contamination frequency in Asia, Europe, and Australia was 11.5%, 14.3%, and 5.2%, respectively. Bone contamination rates were higher in cadaver donors (19.9%), retrieval time sampling (13.5%), and swab samples (13.2%) compared to those in living donors (7.5%), implantation time sampling (6.9%), and bone fragments cultures (6.3%). Bacterial contamination was recovered 24.4%, 19.7%, 13.2%, and 21% from tibia, fibula, femoral, and other bones, respectively. Staphylococcus spp. was the predominant isolated bacteria from bones (63.2% of all isolated genera), followed by Propionibacterium spp. (10.6%). Conclusion The high contamination of bone allografts is a health concern, indicating the need for more health monitoring and improvement of standards.

SARS-CoV-2, declared a pandemic in March 2020, is the current global health challenge. The global bioburden of this virus is increasing at a rapid pace. Many antiviral drugs and vaccines have been registered for clinical trials because of their inhibitory activity observed in vitro. Currently, five types of vaccines have successfully passed Phase IV clinical trial and are being administered in populations worldwide. A plethora of experimental designs have been proposed worldwide in order to find a safe and efficacious treatment option. Therefore, it is necessary to provide baseline data and information to clinicians and researchers so that they can review the current status of therapeutics and efficacy of already developed vaccines. This review article summarizes all therapeutic options that may help to combat SARS-CoV-2.

Background and objective: The fitting of orthokeratology (ortho-k) and multifocal soft contact lenses (SCL) is becoming increasingly popular worldwide for reducing the rate of myopia progression. However, overnight wear use of lenses and microbial contamination of contact lenses and storage vials has been shown to increase the risk of corneal inflammatory and infiltrative events (CIEs). Therefore, we conducted a pilot study to compare the rate, level, and type of microbial contamination of contact lenses and storage vialswhen participants wear ortho-k and SCL in combination with a hydrogen-peroxide disinfecting system. Material and Methods: A prospective, single-centre, randomized, crossover study was conducted to evalu-ate the rate and level of contact lens and storage vials contamination during the use of ortho-k and SCL along with a hydrogen-peroxide disinfecting solution over two 10 day wearing periods. Ocular signs and symptoms were assessed during lens wear at baseline and after each wearing period. In addition, contact lens and storage vials were collected, and the type and amount of microbial contamination were evaluated using viable culture and standard identification methods.Results: Twenty-five adults were enrolled, and 21 completed the study. One (5%) ortho-k lens, five (24%) ortho-k storage vials, one (5%) SCL and one (5%) SCL storage vial were contaminated (P > 0.05), predominantly with Gram-positive bacteria. None of the participants had contamination with both ortho-k and SCL. No significant differences were found between the ocular signs, including conjunctival redness and roughness, or conjunctival or corneal staining (all P > 0.05), irrespective of using ortho-k or SCL. Conclusion: This study provides the first data that directly compares microbial contamination of ortho-K versus SCL in patients using a hydrogen-peroxide disinfection system. However, the overall microbial contamination rate of contact lens storage vials was much lower (30%) than the previously reported study with ortho-k lens wear. The results support conducting a larger clinical trial designed to understand differences in microbial contamination with different lens materials and modalities.

Background The COVID-19 pandemic highlighted the need for evidence-based approaches to decontamination and reuse of N95 filtering facepiece respirators (FFRs). We sought to determine whether vapourized hydrogen peroxide (VHP) reduced SARS-CoV-2 bioburden on FFRs without compromising filtration efficiency. We also investigated coronavirus HCoV-229E as a surrogate for decontamination validation testing. Methods N95 FFRs were laced with SARS-CoV-2 or HCoV-229E and treated with VHP in a hospital reprocessing facility. After sterilization, viral burden was determined using viral outgrowth in a titration assay, and filtration efficiency of FFRs was tested against ATSM F2299 and NIOSH TEB-STP-APR-0059. Results Viable SARS-CoV-2 virus was not detected after VHP treatment. One replicate of the HCoV-229E laced FFRs yielded virus after processing. Unexpired N95 FFRs retained full filtration efficiency after VHP processing. Expired FFRs failed to meet design-specified filtration efficiency and therefore are unsuitable for reprocessing. Discussion In-hospital VHP is an effective decontaminant for SARS-CoV-2 on FFRs. Further, filtration efficiency of unexpired respirators is not affected by this decontamination process. Conclusions VHP is effective in inactivating SARS-CoV-2 on FFRs without compromising filtration efficiency. HCoV-229E is a suitable surrogate for SARS-CoV-2 for disinfection studies.

BACKGROUND: The real-world impact of breathing zone air purification and coronavirus disease 2019 (COVID-19) mitigation measures on healthcare-associated infections is not well documented. Engineering solutions to treat airborne transmission of disease may yield results in controlled test chambers or single rooms, but have not been reported on hospital-wide applications, and the impact of COVID-19 mitigation measures on healthcare-associated infection rates is unknown. AIM: To determine the impact of hospital-wide bioaerosol treatment and COVID-19 mitigation measures on clinical outcomes. METHODS: The impact of the step-wise addition of air disinfection technology and COVID-19 mitigation measures to standard multi-modal infection control on particle counts, viral and bacterial bioburden, and healthcare-associated infection rates was investigated in a 124-bed hospital (>100,000 patient-days over 30 months). FINDINGS AND CONCLUSION: The addition of air disinfection technology and COVID-19 mitigation measures reduced airborne ultrafine particles, altered hospital bioburden, and reduced healthcare-associated infections from 11.9 to 6.6 (per 1000 patient-days) and from 6.6 to 1.0 (per 1000 patient-days), respectively (P

Bacterial infection remains a great challenge in wound healing, especially in chronic wounds. Multidrug-resistant organisms are increasing in acute and chronic wound infections, which compromise the chance of therapeutics. Resistance to conventional antibiotics has created an urge to study new approach/system that can effectively control wound infection and enhance healing. Wound cover/dressing must exhibit biocompatibility and effectiveness in reducing bioburden at the wound site. Collagen, a natural biopolymer, possesses advantages over synthetic and other natural materials due to its unique biological properties. It can act as an excellent wound dressing and controlled drug delivery system. Currently, antiseptic agents such as silver, iodine, and polyhexamethylene biguanide (PHMB)-incorporated scaffolds have become widely accepted in chronic wound healing. In this study, PHMB-incorporated collagen scaffold has been prepared and characterized using Fourier transform infrared spectroscopy (FTIR), circular dichroism (CD), and differential scanning calorimetry (DSC), which showed retention of collagen nativity and integration of PHMB. The scanning electron microscopy (SEM) analysis revealed the porous structures of scaffolds. The cytotoxicity analysis showed PHMB is nontoxic at the concentration of 0.01% (wt/wt). The agar diffusion test and bacterial adhesion study demonstrated the effectiveness of PHMB-incorporated collagen scaffold against both gram positive and negative strains. This study concludes that PHMB-incorporated collagen scaffold could have the potential for infected wound healing.

Background Cutibacterium acnes is a common pathogen associated with surgical site infection after shoulder surgery; current standard of care products are largely ineffective at reducing C acnes bacterial burden before surgery. The purpose of this systematic meta-analysis was to assess the efficacy of peroxide-containing solutions (PCS) in decreasing the C acnes burden on the shoulder. Methods This was a systematic review of all level I and II studies investigating the effect of peroxidase-containing products for skin preparation. We extracted data regarding demographics, treatment details and timing, study methodology, and culture positivity. Forest plots were used to determine the pooled efficacy of peroxide solutions versus control. Results Seven studies with 412 patients were eligible for inclusion. Notable heterogeneity was observed in the manner and timing of peroxide application. Two studies applied PCS at the time of surgery; four studies applied PCS in the 24- to 72-hour period leading up to culture acquisition. Compared with the placebo, peroxide significantly diminished C acnes culture positivity (Hazard Ratio 0.174, P = 0.009). When considering using peroxide-containing products in the period leading up to surgery or at the time of surgery, in addition to standard preparation, the addition of peroxide significantly diminished C acnes culture positivity (HR 0.467, P = 0.004). Owing to study heterogeneity, we could not make notable comparisons based on the timing or duration of benzoyl peroxides application. Conclusions Despite heterogeneity in study design, pooled results of high-quality data suggest that the addition of PCS can markedly reduce C acnes bioburden. This review was not able to identify the ideal regimen for the utilization of PCS for reduction of C acnes burden. Level of evidence Level II.

Background The hospital environment has got more attention as evidence as source for bacterial transmission and subsequent hospital-acquired infection increased. Regular cleaning and disinfection have been proposed to lower the risk of infection, in particular for gram-positive bacteria. Auto-disinfecting surfaces would allow to decrease survival of pathogens, while limiting resource to achieve a safe environment in patient rooms. Methods A controlled trial to evaluate the antimicrobial effectiveness of a polyvinyl chloride foil containing an integrated silver-based agent (containing silver ions 2%) on high-touch surfaces in patient rooms. Results The overall log reduction of the mean values was 1.8 log10 CFU, the median 0.5 log10 CFU comparing bioburden of control vs antimicrobial foil (p Conclusions A foil containing an integrated silver-based agent applied to high-touch surfaces effectively results in lower recovery of important pathogens from such surfaces over a 6-month study period.

Standard manual cleaning and disinfection practices are often inadequate. Persistent contamination in the environment poses an infection risk that may be mitigated by no-touch disinfection systems. This study evaluates the efficacy of dry hydrogen peroxide (DHP) on microbial air and surface contamination as an adjunct to routine cleaning and disinfection in a large urban hospital.Surface samples were collected in five different hospital units, two pediatric and three adult, after manual cleaning on multiple days before and after DHP implementation. Air samples were also collected in each unit pre- and post-DHP use. Data outcomes were reported as colony forming units (CFU) with species identification.The overall mean surface microbial burden was reduced by 96.5 percent for all units post-DHP compared to baseline (P0.001), with the greatest reductions achieved on privacy curtains (99.5 %). Mean microbial air sample counts were also reduced post-DHP compared to pre-DHP.This study demonstrates that DHP was effective in reducing both air and surface microbial contamination in a variety of settings within a large, tertiary care hospital.

Sinopsis Antecedentes: Normalmente, las infecciones son tratadas con antimicrobianos (antibióticos, antisépticos, etc.). La resistencia antimicrobiana (AMR, por sus siglas en inglés) se ha convertido en una de las amenazas del siglo XXI más graves para la salud mundial. Las heridas pueden ser una fuente de infección al permitir la entrada libre de microorganismos dentro del cuerpo, incluyendo bacterias resistentes a antimicrobianos. El desarrollo de nuevos antimicrobianos (especialmente, antibióticos) no está siguiendo el ritmo de la evolución de microorganismos resistentes y de formas novedosas de abordar este problema con la urgencia que demanda. Una de estas iniciativas ha sido el desarrollo de programas de protección antimicrobiana (AMS, por sus siglas en inglés), que brindan capacitación a los trabajadores del área de la salud y controlan la prescripción, enfocándose en los antimicrobianos para reducir la probabilidad de que se produzca AMR. El uso de apósitos para herida que utilizan el aislamiento físico y el abordaje de retención, en vez de agentes antimicrobianos, para reducir la carga bacteriana ofrecen un abordaje novedoso para apoyar a los AMS. La fijación bacteriana por los apósitos y su retiro físico, en lugar de la muerte activa, minimiza su daño y, además, previene la liberación de endotoxinas dañinas. Objetivo: Resaltar los AMS para la promoción del uso correcto de antimicrobianos e investigar cómo los apósitos recubiertos con cloruro de dialquilcarbamilo (DACC) pueden ayudar a cubrir las metas de los AMS. Método: Se realizaron búsquedas en las bases de datos de revisiones sistemáticas, Medline, Cochrane y Google Scholar con el fin de identificar artículos publicados que describan los datos relacionados con los AMS, y el uso de una gran variedad de apósitos para heridas para la prevención y/o tratamiento de infecciones de la herida. La evidencia que respalda a los apósitos para heridas alternativos que pueden reducir la biocarga y prevenir y/o tratar la infección de heridas de forma tal que no maten ni dañen a los microorganismos (por ejemplo, fijándose activamente y retirando intactos a los microorganismos de las heridas) fue posteriormente revisada de forma oral. Conclusión: Algunos apósitos para heridas actúan a través de mecanismos que promueven la fijación y absorción física, aislamiento y retiro de microorganismos intactos de la base de la herida (por ejemplo, un apósito para heridas que utiliza la tecnología DACC para prevenir/reducir la infección). Esta es una herramienta valiosa que cumple con los requisitos del AMS (por ejemplo, reducción del uso de antimicrobianos en esquemas de tratamiento de heridas) al reducir la biocarga de la herida sin inducir/seleccionar bacterias resistentes.

Topical antimicrobials that reduce the bacterial bioburden within a chronically-infected wound may have helpful or harmful effects on the healing process. We used murine models of full-thickness skin wounds to determine the effects of the novel biofilm-dispersing wound gel (BDWG) and its gel base on the healing of uninfected wounds. The rate of wound closure over 19 days was comparable among the BDWG-treated (BT) wounds and the controls. Compared with the controls, histology of the BT wounds showed formation of a stable blood clot at day 1, more neovascularisation and reepithelialisation at day 3, and more organised healing at day 7. Fluorescence-activated cell sorting analysis showed a lower percentage of neutrophils in wounded tissues of the BT group at days 1 and 3, and significantly more M2 macrophages at day 3. Levels of proinflammatory cytokines and chemokines were increased over the uninjured baseline within the wounds of all treatment groups but the levels were significantly lower in the BT group at day 1, modulating the inflammatory response. Our results suggest that BDWG does not interfere with the wound healing process and may enhance it by lowering inflammation and allowing transition to the proliferative stage of wound healing by day 3.

OBJECTIVE To determine the effect of a mobile UV-C disinfection device on the environmental bacterial bioburden in veterinary facilities. SAMPLES 40 swab samples of surfaces from the operating theaters of 3 veterinary hospitals and 1 necropsy laboratory. PROCEDURES Various surfaces were swabbed, and collected material was eluted from the swabs in PBSS. Then, an aliquot of the sample fluid was processed with a bacteria-specific rapid metabolic assay to quantify bacterial bioburden. Each site was then treated with UV-C light with an automated disinfection device for approximately 45 minutes. The same surfaces were swabbed following UV-C treatment, and bioburden was quantified. The bioburden at additional time points, including after a second UV-C treatment, was determined for the small animal operating theater. RESULTS All surfaces at all sites had a persistent viable bacterial population following manual cleaning. Disinfection with UV-C achieved a mean bioburden reduction of 94% (SD, 5.2%; range, 91% to 95%) for all surfaces, compared with manual disinfection alone. Repeated UV-C treatment of the small animal operating theater reduced mean bioburden by 99% (SD, 0.8%), including no detectable bacteria on 4 of 10 surfaces. CONCLUSIONS AND CLINICAL RELEVANCE Disinfection with UV-C light may be a beneficial adjunct method for terminal disinfection of veterinary operating theaters to reduce environmental bioburden.

A mainstay of personal protective equipment during the coronavirus disease 2019 pandemic is the N95 filtering facepiece respirator. N95 respirators are commonly used to protect healthcare workers from respiratory pathogens, including the novel coronavirus severe acute respiratory syndrome coronavirus 2, and are increasingly employed by other frontline workers and the general public. Under routine circumstances, these masks are disposable, single-use items, but extended use and reuse practices have been broadly enacted to alleviate critical supply shortages during the coronavirus disease 2019 pandemic. Although extended-time single use presents a low risk of pathogen transfer, repeated donning and doffing of potentially contaminated masks presents increased risk of pathogen transfer. Therefore, efficient and safe decontamination methods for N95 masks are needed to reduce the risk of reuse and mitigate local supply shortages. Here, we review the available literature concerning use of germicidal ultraviolet-C (UV-C) light to decontaminate N95 masks. We propose a practical method for repeated point-of-use decontamination using commercially available UV-C cross-linker boxes from molecular biology laboratories to expose each side of the mask to 800-1200 mJ/cm2 of UV-C. We measure the dose that penetrated to the interior of the respirators and model the potential germicidal action on coronaviruses. Our experimental results, in combination with modeled data, suggest that such a UV-C treatment cycle should induce a >3-log-order reduction in viral bioburden on the surface of the respirators and a 2-log-order reduction throughout the interior. We find that a dose 50-fold greater does not impair filtration or fit of 3M 8210 N95 masks, indicating that decontamination can be performed repeatedly. As such, UV-C germicidal irradiation is a practical strategy for small-scale point-of-use decontamination of N95s.

Musculoskeletal allografts are used in reconstructive procedures, however, the risk of contamination with potential pathogens is possible, and safe transplantation requires multiple processing considerations. Hydrogen peroxide (H2O2) has commonly been used in bone washing because it can remove donor cells and eliminate antigens, pathogens, or cytotoxic agents from the matrix. The aim of this study was to evaluate the quantitative activity of H2O2 in a model of bone contamination with a high bacterial load to define the bioburden reduction. Twelve bone disc models were artificially contaminated with Staphylococcus aureus. The bones were treated with a washing process composed by antibiotics, 30% hydrogen peroxide, and 70% alcohol. Tryptic Soy Agar plates were directly inoculated with 100µL of each step of the washing process and colonies were counted in CFU/mL. Scanning electron microscopy was used for bone structural analysis before and after the washing process. After antibiotics, there was a drop of less than 1 log for cancellous bone and almost 1 log for cortical bone. However, after H2O2, there as a drop of 3 logs for cortical (p = 0.007), and 2 logs for cancellous bone (p = 0.063). The use of alcohol did not change the bioburden following H2O2 in cancellous and cortical bone. Despite the important drop of bacterial load, H2O2 was not enough to completely eradicate bacterial with this model of bioburden. H2O2 is useful in decontamination, but antibiotics have little activity, and alcohol is useless. The process is useful in decontamination up to 3 logs of bioburden.

This review focuses on techniques for reconstructing soft tissue injuries in host nationals that can be performed by non-plastic surgeons in a deployed environment. Advances in wound care technology and techniques have created opportunities to bring world-class care to injured host nationals. Negative pressure wound therapy with instillation can reduce bacterial bioburden, decrease the number of operative debridements, and decrease time to wound closure, saving scarce resources in a deployed setting. Perforator-based pedicle flaps can be utilized to cover large soft tissue defects with minimal donor site morbidity and excellent flap survival. Targeted muscle reinnervation can be performed at the time of an amputation to decrease chronic neuropathic pain. Techniques from simple to complex can be learned and successfully performed by the general, trauma, and orthopedic surgeons in austere locations in order to effectively leverage limited resources for the best outcomes for host nationals.

As part of an infection management protocol, antimicrobial dressings offer an appropriate, cost‐effective choice for the management of localised bioburden in chronic wounds. The choice of antimicrobial can impact significantly not only on the treatment outcomes and cost but also on the safety and well‐being of the patient. This retrospective study investigates these outcomes comparing health care records of 2572 patients with open chronic wounds, who were treated either with an Integrated Care Wound Bundle (ICB) including nanocrystalline silver (NCS) dressings (n = 330) or without NCS dressings and not on a ICB (n = 2242) in the community from March 2016 to March 2018. Wounds treated in the NCS dressing treatment bundle had a mean healing time of 10.46 weeks, vs 25.49 weeks for the non‐ICB treated wounds. In addition, the average interval time between dressing changes was in favour of the NCS dressing treatment bundle (3.98 vs 1.87 days), contributing to a substantial reduction in mean treatment labour costs ($1251 vs $6488). The use of a NCS dressing demonstrated improved efficacy and cost effectiveness of labour required for chronic wound management; highlighting the importance of choosing an effective antimicrobial dressing as part of an infection management protocol.

The aim of this study was to summarise the clinical evidence supporting almost 40 years of topical cadexomer iodine (CIOD) use in wound bed preparation by removing barriers to healing such as exudate, slough, bioburden, and infection and allowing chronic wound progression. A systematic review was conducted (Embase/PubMed, November 2020) to identify relevant comparative studies meeting inclusion criteria. Meta‐analyses were performed using a fixed‐effects (I 2

Antibiotic-resistance and bacterial bioburden are the threats to wound healing. Nanoparticles are a revolutionary advancement in nanomedicine owing to their antibacterial properties, to be used as a promising alternative to antibiotics. A wound dressing with antibacterial and anti-biofilm effects may be a plausible strategy in curbing wound exacerbation caused by bacterial infection. Silver nanoparticles (AgNPs) are known for their excellent antibacterial activity. In present study, biosynthesized AgNPs using spent mushroom substrate (SMS) as reducing agent while chitosan as stabilizing agent were successfully produced. The nanoparticles exhibited considerable antibacterial and anti-biofilm activities with higher sensitivity towards Gram-negative bacteria. These AgNPs were later incorporated into genipin-crosslinked gelatine hydrogels as a wound dressing. The hydrogels were characterized for their physical, rheological and swelling properties, besides in vitro release of AgNPs. The formulated hydrogels demonstrated an adequate release of the AgNPs with acceptable physical, rheological and swelling properties, suitable as a vehicle for wound drug delivery. The antibacterial and anti-biofilm of the hydrogels against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli were effective in inhibiting the growth of the selected bacteria with minimum inhibitory concentration (MIC) of 63 μg/mL. In summary, genipin-crosslinked gelatine hydrogels loaded with the AgNPs are a promising anti-microbial wound dressing, a potential strategy for combating biofilm of wound infections and accelerating healing.

As a consequence of the preference for homologous tissues, bone banks are the primary source of bone and tendon grafts. However, the bacterial, viral, and fungal contamination of these grafts remains a considerable challenge in bone banks and often results in high rates of graft discarding and infections in patients. This study intended to investigate bacterial contamination in 509 bone grafts harvested from 110 multiorgan donors. Specimen collection included bone and soft tissue retrieved from culture-swabbing as well as bone and capsule for histopathology. Microbiological, histopathological, and radiographic analyses were carried out. Secondary sterilization was also conducted using cobalt 60 at the dose of 2.5 × 104 Gy. There were 106 multi-organ donors. Of the 506 grafts, there were 54 Hemi pelvis, 191 femur, 142 tibia, and 119 fibulae. The surface swab contamination rate for all the grafts retrieved was 16.6%, and bone culture from all the grafts was 6.1%. When we looked at the incidence of contamination according to the location than the surface swab contamination rate for hemipelvis was 18 (33.3%), femur 30 (15.7%), tibia 21(14.7%) and fibula 15 (12.6%). The bone cultures were hemipelvis 12 (22.2%) femur 8 (4.1%), tibia 5 (3.5%) and fibula 6 (5.04%). These findings suggest that separate harvesting of the grafts in reverse order may help prevent contamination. The study also recommends discarding all grafts contaminated even with low pathogenicity organisms. However, bioburden needs to be further investigated to be detected and reduced.

The gold standard for microbial detection in prosthetic joint infections is the multiple culture of the peri-prosthetic tissue. The fluid cultures after sonication can improve the recovery of the microorganisms. The aim of this study was to evaluate the sonication technique with a plastic bag and the effect of refrigeration on microorganism detection with conventional culturing, MALDI-TOF MS and qPCR assay on an orthopedic screw model. We produced biofilms of Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans on orthopedic screws, which were stored under different conditions and temperatures before sonication. After sonication, the mass spectrometry by MALDI-TOF, qPCR and culture protocols was performed using the sonicated fluid, for detecting the microorganisms involved in the biofilm. The bacterial bioburden decreased by approximately one log after the refrigeration period, in the screws containing P. aeruginosa and S. aureus biofilms. All the microorganisms involved in the screw biofilms were detected with MALDI-TOF and qPCR. Significant reductions in CFU counts occurred only in groups stored in the plastic bag, indicating that changes in temperature and humidity may favor cell death. However, this variation is not important for this model as it did not affect the detection owing to the high counts obtained. Microbial identification by MALDI-TOF in sonicated fluid is feasible. With qPCR, there were no differences between the detection in the screws processed immediately or after refrigeration. It is necessary to consider whether or not the refrigeration period would affect microbial recovery in an explanted prosthesis.

Understanding the concepts of disinfection, sterilization, cleaning and asepsis is of prime importance to prevent transmission of infection to patients and to protect healthcare workers (HCWs). Proper disinfection of surfaces after cleaning, an important consideration at all times, has assumed special significance during the current pandemic. The global shortage of disposable equipment such as personal protective equipment (PPE), specifically N95 masks and surgical 3 ply masks, and other items makes the HCWs vulnerable to transmission of infection while caring for these patients. Therefore, resterilization of such items has assumed equal importance. Cleaning, the first step in the process of sterilization, is of vital importance to reduce bioburden. The type of disinfection required depends on the nature of the equipment and its intended use. For example, critical items need high-level decontamination. In this narrative review, we elaborate on the methods of decontamination and sterilization. Many chemicals can be used for both sterilization and disinfection, and the difference lies in the concentration of the chemical and exposure time. We have also summarized strategies which can be used for resterilization of single-use items, in view of the shortages caused by the current pandemic. How to cite this article Kothekar AT, Kulkarni AP. Basic Principles of Disinfection and Sterilization in Intensive Care and Anesthesia and Their Applications during COVID-19 Pandemic. Indian J Crit Care Med 2020;24(11):1114–1124.

Introduction: Quantitative Microbiology involves measurement of an absolute quantity of bacteria per unit of volume. The threshold to distinguish colonisation from infection is 105 CFU/g. Quantitative cultures are used in predicting the risk of post operative infection. Aim: To determine the role of quantitative bacteriology as a predictor of risk of infection in patients with open fractures. Materials and Methods: One hundred patients who had sustained open fractures of long bones were included in the study. During debridement before antiseptic wash, a piece of tissue (muscle/skin) was collected under aseptic precautions for quantitative culture. A quantitative count of ? 104cfu/gm was interpreted as significant microbial burden. These patients were followed up for 6 weeks for development of clinical signs of infection and two swabs were collected by Levine’s technique for semiquantitative culture. Results: The preoperative culture of the debrided tissue of 41% yielded a microbial load of ?104 cfu/gram among which 85.3% had 105 cfu/gram of microbial load. Polymicrobial growth was reported in 12.2% of patients. Postoperatively 39% developed signs of infection Seventy one percent of patients with 105 cfu/gram of microbial load in the preoperative period developed postoperative infection. All patients with polymicrobial growth in the preoperative debridement cultures with ?104 cfu/gm of microbial load, developed infection in the postoperative period. Conclusion: Quantitative Microbiology plays a precise role in predicting the risk of infection as it is valuable in estimating the bacterial bioburden. Polymicrobal etiology can lead to clinical infection if not managed effectively. Keywords: Quantitative, Infection, Bioburden, Fracture, Debridement.

Background Infected wound reconstruction risks persistent infection and potential flap loss. Taking advantage of negative pressure wound therapy with instillation's ability to decrease bioburden, we introduce a novel paradigm “flap plus sub-flap irrigation” for treatment of infected lower extremity wounds. Methods This is a retrospective review of all patients over a 2-year period who underwent wound reconstruction with flap plus sub-flap irrigation. After flap inset, irrigation tubing is placed under the flap and foam sponge placed superficial to the flap edges, with pressure set to −100 mmHg. Fifty milliliters of 0.5% sodium hypochlorite solution instills every 4 h with 15 min of soak time. Sub-flap irrigation is discontinued post-operative day #5. Results Eight patients with mean age of 47 years and mean follow up time of 21 months were identified. Seven patients (88%) had multidrug resistant infections, six (75%) had polymicrobial infections, and five had exposed hardware (63%). Wound etiology was most commonly motor vehicle collision (50%). Flaps included free ALT, (38%), radial forearm (25%), and latissimus dorsi (25%), as well as pedicled rectus femoris (13%). There were no flap losses or persistent infections. Two patients had delayed wound healing, one treated with skin grafting and the other with flap advancement. Conclusion This series demonstrates successful treatment of high-risk infected wounds with flap plus sub-flap irrigation. This strategy may mitigate risk of persistent infection and flap loss. Larger studies and comparative studies are required to elucidate indications and assess relative benefits of this treatment paradigm.

Background: The degree of tissue damage caused by related inflammatory and immunological sequelae poses a major therapeutic treatment problem in burn wounds. Chronic wounds frequently have a significant bioburden and pathogens that are resistant to antibiotics. This review article discusses present research on phototherapy, which is believed to be useful in managing wound bioburden and promoting healing. Objective: To evaluate the wound healing efficacy of polarized light therapy (BLT) against low-level laser therapy (Ga-As laser) in order to determine which is more efficient and successful at speeding burn healing. Subject and methods: The current study enrolled thirty patients having partial thickness thermal burn on the forearm (dermal burn). They were selected from Burn Unit at Legislation Association Hospital for Burns & Oncology. They were randomly assigned into two equal groups: Group (A) that included fifteen patients who received the BLT with mean age of 28.8 ± 2.51 years old and group (B) that enrolled fifteen patients who received LLLT with mean age of 29.6 ± 2.79 years old. Both groups also received traditional physical therapy and conservative treatment for the burn site three times weekly for four weeks. Results: Group A and B showed a significant reduction in colony count and wound surface area after treatment in comparison to that before treatment (p > 0.001). In group A, the colony count and wound surface area decreased by 38.63% and 55.1% respectively, but in group B, by 15.6% and 37.92% respectively. Conclusion: Both polarized light therapy and low-level laser therapy had a therapeutic efficiency on wound healing, but BLT is more efficient and more successful in the acceleration of the burned wounds healing.

In recent years there has been increasing advocacy for highly immunogenic gamma-irradiated vaccines, several of which are currently in clinical or pre-clinical trials. Importantly, various methods of mathematical modelling and sterility testing are employed to ensure sterility. However, these methods are designed for materials with a low bioburden, such as food and pharmaceuticals. Consequently, current methods may not be reliable or applicable to estimate the irradiation dose required to sterilize microbiological preparations for vaccine purposes, where bioburden is deliberately high. In this study we investigated the applicability of current methods to calculate the sterilizing doses for different microbes. We generated inactivation curves that demonstrate single-hit and multiple-hit kinetics under different irradiation temperatures for high-titre preparations of pathogens with different genomic structures. Our data demonstrate that inactivation of viruses such as Influenza A virus, Zika virus, Semliki Forest virus and Newcastle Disease virus show single-hit kinetics following exposure to gamma-irradiation. In contrast, rotavirus inactivation shows multiple-hit kinetics and the sterilizing dose could not be calculated using current mathematical methods. Similarly, Streptococcus pneumoniae demonstrates multiple-hit kinetics. These variations in killing curves reveal an important gap in current mathematical formulae to determine sterility assurance levels. Here we propose a simple method to calculate the irradiation dose required for a single log10 reduction in bioburden (D10) value and sterilizing doses, incorporating both single- and multiple-hit kinetics, and taking into account the possible existence of a resistance shoulder for some pathogens following exposure to gamma-irradiation.

This review of the literature concerning bacteria, antibiotics and tissue repair shows there are extensive data supporting microbial interference with wound healing once bacterial burden exceeds 104 CFU per unit of measure, The mechanism of bacterial interference lies largely in prolonging the inflammatory phase of tissue repair. Reducing the microbial bioburden allows tissue repair to continue. Systemic and topical antimicrobials appear critical to reducing the bioburden and facilitating repair. The current controversy over the use of antimicrobials in patients with chronically infected wounds, in particular, revolves around the definition of infection. The reliance on classic clinical signs of inflammation to support antimicrobial use in these patients is tenuous due to the lack of correlation of these signs with the microbial burden known to impair tissue repair.

Background: The WHO estimates that approximately 600 million people fall ill after consumption of contaminated food and over 420 000 die every year, resulting in loss of 33 million healthy life years. Hand hygiene is considered by the WHO to be the most effective preventive measure for infectious diseases including food borne diseases.Methods: A laboratory-based study involving convenient sampling of common brands alcohol-based hand sanitizers (ABHS) from retail community pharmacies and local supermarkets was conducted in Ilala District, Dar es salaam, Tanzania. The study was conducted, between December 2018 to January 2019. A modified protocol of The European Norm (EN) 1500 was used for in vivo testing of sampled ABHs. Efficacy was evaluated using standard strain of Escherichia coli. A total of 26 healthy volunteers were used for hand sanitization. The percentage of bioburden/microbial reduction was assessed at baseline and after treatment, and the log reduction factor calculated.Results: A total of 10 gel ABHS were purchased and assayed for antibacterial efficacy. Majority (70%) of ABHS were imported products and contained ethanol as the sole active ingredient. About 60% of them did not correctly indicate the label disclosure information on concentration of active ingredients. Only one product was efficacious against E. coli with log reduction of 3.75; while majority (70%) of the samples had poor bacterial efficacy with log reduction ranging from 0.140 -0.664.Conclusions: Most of ABHS gel products available in the Dar es Salaam market were not efficacious as per FDA and EN 1500 guidelines. Post market surveillance is recommended of the circulating ABH to safe guard consumers. Keywords: Hand sanitizers, efficacy, E. coli, EN 1500.

Background The degree to which daily intensive care unit (ICU) cleaning practices impacts bacterial burden is controversial. The study aimed to assess the utility of using adenosine triphosphate (ATP) bioluminescence assays for monitoring effectiveness of daily cleaning in ICU environments. Methods We sampled 364 total samples from 57 patient rooms and 18 common areas in 3 medical ICUs over 12 weeks, before and after routine daily cleaning. Endpoints were ATP levels (relative light units, RLU) and bacterial bioburden (colony forming units, CFU). Results High-touch surfaces in ICU patient rooms and common areas were contaminated before and after cleaning. Routine cleaning significantly reduced bacterial burden in patient rooms (0.14 log10 CFU reduction, P = .008; 0.21 log10 RLU reduction, P 20 CFUs, the proportion of sites with ATP readings >250 RLU was significantly higher than those with ATP readings ≤250 RLU (90.0% vs 10.0%, P Conclusion Routine cleaning significantly reduced bacterial burden on ICU environment surfaces. Although not an alternative to culture methods, ATP assays may be a useful technique to provide rapid feedback on surface cleanliness in ICU settings.

Presence of bacteria in wounds can delay healing. Addition of a regularly instilled topical solution over the wound during negative‐pressure wound therapy (NPWT) may reduce bioburden levels compared with standard NPWT alone. We performed a prospective, randomised, multi‐centre, post‐market trial to compare effects of NPWT with instillation and dwell of polyhexamethylene biguanide solution vs NPWT without instillation therapy in wounds requiring operative debridement. Results showed a significantly greater mean decrease in total bacterial counts from time of initial surgical debridement to first dressing change in NPWT plus instillation (n = 69) subjects compared with standard NPWT (n = 63) subjects (−0.18 vs 0.6 log10 CFU/g, respectively). There was no significant difference between the groups in the primary endpoint of required inpatient operating room debridements after initial debridement. Time to readiness for wound closure/coverage, proportion of wounds closed, and incidence of wound complications were similar. NPWT subjects had 3.1 times the risk of re‐hospitalisation compared with NPWT plus instillation subjects. This study provides a basis for exploring research options to understand the impact of NPWT with instillation on wound healing.

The current communication seeks to provide an updated narrative review on latest methods of reducing implant contaminations used during spine surgery. Recent literature review has shown that both preoperative reprocessing and intraoperative handling of implants seem to contaminate implants. In brief, during preoperative phase, the implants undergo repeated bulk cleaning with dirty instruments from the OR, leading to residue buildup at the interfaces and possibly on the surfaces too. This, due to its concealed nature, remains unnoticed by the SPD (sterile processing department) or other hospital staff. Nevertheless, these can be avoided by using individually prepackaged presterilized implants. In the intraoperative phase, the implants (in the sterile field) are directly touched by the scrub tech with soiled (assisting the surgeon dispose the tissues from the instruments in use) gloves for loading onto an insertion device. It is then kept exposed on the working table (either separately or next to the used instruments as the pedicles hole are being prepared). Latest investigation has shown that by the time it is implanted in the patient, it can harbor up to 10e7 bacterial colony-forming units. The same implants were devoid of such colony-forming units, when sheathed by an impermeable sterile sheath around the sterile implant.

Negative pressure wound therapy (NPWT) is gaining acceptance as a physical therapy for a wide variety of infected wounds. To gain insight into the response of bacteria to NPWT in vivo, the adaptive expression of biofilm regulators and adhesion factors of Staphylococcus aureus (S. aureus), the most frequently isolated pathogen in the clinic, during acute wound infection was investigated. A 3 cm full-thickness dermal wound was created on each side of a rabbit back and inoculated with green fluorescent protein-labeled S. aureus. NPWT was initiated at 6 h post inoculation, with the wound on the contralateral side as the untreated self-control. The wounds were subjected to a 28 day observation period. Histological analysis, laser scanning confocal microscopy and scanning electron microscopy revealed a transition of S. aureus to a free-living phenotype in tissues treated with NPWT, compared with microcolonies in untreated wounds. Viable bacteria counts showed a modest reduction in the bioburden of NPWT group on day 8 (P 4 days during both stages of colonization. Meanwhile, low expression levels of the effector molecule (RNAIII) of the accessory gene regulator type I (agr) system was detected in NPWT group, suggesting that the bacterial density in NPWT-treated wounds was under the threshold for agr activation, thus not leading to an active and invasive infection. The wounds treated by NPWT healed completely on day 28, compared with an average of an 8.11% defect area in the control group (P

SUMMARY Background Novel sink and U-trap designs have been developed to reduce contamination by users and diminish biofilm. Real-world experience with new sink designs and adjunctive measures such as ozone has been limited. Aims To assess a new sink design for splashback and to evaluate the ozonated water feature for reduction of microbial bioburden. Methods A portable sink unit was created that permitted the application of white absorbent paper to plexiglass shields beside and behind the sink. Participants, wearing painter coveralls and masks, spread 30 mL of tempera paint over their hands and washed for 20 s with neutral soap. Each participant repeated this five times sequentially, and cumulative results were recorded. Escherichia coli was exposed to ozonated water from the sink unit and to regular tap water and evaluated for microbial survival. Findings Compared with a conventional sink, the SmartFLO3 sink had less environmental contamination within the sink, surrounding area and splashback on to the participant. Despite modifications to enhance ozone generation, readings of reactive oxygen species did not exceed 0.3 ppm, and no significant bactericidal effect was demonstrated. Conclusions The SmartFLO3 sink reduces splashback and has the potential to reduce pathogen transmission from sinks. At the low levels of ozone generated in this study, no clear bacterial killing effect was observed compared with tap water alone.

Study design A prospective multicenter study. Objective The objective of this study was to assess bacterial contamination in current practices of pedicle screw handling and comparing it to a novel method of using an intraoperative, sterile implant guard for screws. Summary of background data Postoperative infections occur at the higher end of 2%-13%, as cited in the literature, and are underestimated due to various reasons in such publications. Despite concerns associated with vancomycin application immediately before closure, it is theoretically impossible to irrigate the screw-bone interface postimplantation. Consequently, any contamination of pedicle screw before implantation is permanent, and has the potential to cause deep-bone infection, or hardware loosening due to encapsulation of biofilm between the bone and the screw. Therefore, continued vigilance and effective preventive measures should be undertaken if available. Materials and methods Two groups of presterile individually-packaged pedicle screws, one incased in a sterile, protective guard (group 1: G) and the other without such a guard (group 2: NG), 31 samples in each group were distributed over 28 spinal fusion surgeries at 5 independent hospitals groups. Each were loaded onto the insertion device by the scrub tech and left on the sterile table. Twenty minutes later, the lead surgeon who had just finished preparing the surgical site, handles the pedicle screw, to check the fit with the insertion device. Then, instead of implantation, it was transferred to a sterile container using fresh sterile gloves for bacterial analysis. Results The standard unguarded pedicle screws presented bioburden in the range of 10 to 10 colonies forming units per screw, whereas the guarded pedicle screws showed no bioburden. Conclusion Standard, current, handling of pedicle screws leads to bacterial contamination, which can be avoided if the screws are sterilely prepackaged with an intraoperative guard (preinstalled).

Summary Background Pathogens involved in healthcare-associated infections can quickly spread in the environment, particularly to frequently touched surfaces, which can be reservoirs for pathogens. Aim The purpose of this study was to investigate naturally occurring bacterial contamination on touch surfaces in five French long-term care facilities and to compare bacterial populations recovered from copper and control surfaces. Methods More than 1300 surfaces were sampled. The collected bacteria were identified to obtain a global view of the cultivable bacterial populations colonizing touch surfaces. Haemolytic colonies and putative pathogens were also screened using specific agar plates and then identified with matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. In total, more than 3400 colonies were analysed. Findings Staphylococcus and Micrococcus were the two predominant genera present on touch surfaces, respectively occurring on 51.8% and 48.0% of control surfaces. In these facilities with relatively low bioburden, copper surfaces efficiently reduced the occurrence frequencies of three genera: Staphylococcus, Streptococcus and Roseomonas. Pathogenic species such as Staphylococcus aureus, Enterococcus faecalis and E. faecium were observed in very few samples. In addition, meticillin-resistant S. aureus was observed on five control surfaces and one copper surface. Conclusion Contamination of healthcare facilities touch surfaces can be the source for the spread of bacteria through the institution. This in situ study shows that the frequency of the contamination as well as the specific bacterial population bioburden is reduced on copper alloy surfaces.

Contamination of intravenous (IV) ports and stopcocks has been associated with postoperative infections. We tested the usability and efficacy of a novel passive shielding device to prevent such contamination even in the absence of hand hygiene or port disinfection. In a desktop setting with deliberately contaminated hands, qualitative port contamination was detected after 5/60 (8.3%; 95% confidence interval [CI], 2.8-18.4) control port injections versus 0/60 (0%; 95% CI, 0-6.0) shielded injections (P = .025). In clinical simulations with a quantitative bioburden assay (measured in relative light units [RLUs]), median (interquartile range [IQR]) postsimulation bioburden was 46 (32-53) vs 27 (21-42) RLU for the control versus intervention groups (P = .036), yielding a median shift of -13 RLU (95% CI, -2 to -26) in favor of the shielding. Usability of the device was acceptable to practitioners.

In pharmaceutical industry antimicrobial preservatives that restrict multiplication of microorganisms and decrease bioburden are usually added in composition of hydrophilic medicines that include components of natural origin to prevent possible risks of functional changes in drugs characteristics caused by microbial contamination. Therefore, microbiological purity (MBP) is a crucial criteria for medicines quality. The purpose of the work was to develop the MBP testing methodology for complex gel containing dense extract of hypericum herbs and calendula flowers using structural-mechanical and technological studies. Methodology for MBP testing of proposed gel was developed and justified considering criteria given in State Pharmacopoeia of Ukraine 2.0. Originality of MPT methodology consists in the gel’s antimicrobial action neutralization to decrease possible risks of false results occurrence (including microorganisms inhibited by antimicrobial action of the gel). The applicability of the methodology was determined comparing the number of test cultures CFUs in presence of gel under specified condition with number of CFUs in positive control. The methodology is suitable for microbiological purity testing of the sample, as well as for the Preservatives Efficacy Testing (PET). When applying the developed methodology, the antimicrobial action of the sample is completely eliminated. While developing the MPT methodology compliance with following acceptance criteria was confirmed for tested sample: Absence of Staphylococcus aureus (in 1 g); Absence of Pseudomonas aeruginosa (in 1 g); Total aerobic microbial count (TAMC) – 10² CFU per 1 g; Total combined yeasts and molds count (TYMC) – 10¹ CFU per 1 g. All the tested samples met the requirements of the 2.0. version of State Pharmacopoeia of Ukraine for non-sterile dosage forms for oromucosal and dermal use.

Orthopaedic implant use increases infection risk. Implant infection risk can be explained by the "race for the surface" concept, where there is competition between host-cell integration and bacterial colonisation. Although generally accepted, the temporal dynamics have not been elucidated in vivo. Using a bilateral intramedullary rat model, Staphylococcus aureus was injected into the tail vein either immediately after or 1, 3 and 7 d following implant placement. This allowed assessment of the temporal interplay between bacterial colonisation and host-cell adhesion by uncoupling implant placement and bacterial challenge. 2 weeks following inoculation, animals were anaesthetised, euthanised and implants and tissues harvested for bacterial enumeration. To assess host participation in implant protection, additional animals were not inoculated but euthanised at 1, 3 or 7 d and the host cells adhered to the implant were evaluated by flow cytometry and microscopy. As time between implant placement and bacterial challenge increased, infection rate and bioburden decreased. All implants had measurable bioburden when challenged at day 1, but only two implants had recoverable bacteria when inoculated 7 d after implant placement. This protection against infection corresponded to a shift in host cell population surrounding the implant. Initially, cells present were primarily non-differentiated stem cells, such as bone marrow mesenchymal stem cells, or immature haematopoietic cells. At day 7, there was a mature monocyte/macrophage population. The present study illustrated a direct relationship between host immune cell attachment and decrease in bacterial colonisation, providing guidance for antimicrobial release devices to protect orthopaedic implants against bacterial colonisation.

The consumption of herbal medicine and herbal medicinal products has been on the rise lately. This has led to an increase in research on herbal medicine and its different formulations to gain more knowledge in their constituents, therapeutic effects, its mechanism, and their undesired or toxic effects. The purpose of this study was to evaluate toxicity profile, phytochemical constituents, microbial quality and immunomodulatory properties of Goko cleanser®, Beta cleanser® and Weifa body defense mixtures®. Acute oral toxicity, phytochemical screening and the microbial quality was evaluated. The immunomodulatory activities of the herbal mixtures were studied using the Carbon Clearance Test, Cyclophosphamide Induced Neutropenia, Delayed-type Hypersensitivity Test and Humoral Antibody Assay with the Sheep Erythrocytes as antigen. The result indicated that the herbal mixtures showed no toxic effect on the test animals. The phytochemical analysis showed an adequate presence of immunomodulatory phytochemicals. The result also revealed that Beta cleanser® was contaminated with S. aureus and E. coli. The three test herbal mixtures, at doses tested, increased the phagocytic index by stimulating the reticuloendothelial cells and increasing their phagocytosis ability. The test herbal mixtures also showed significant protection against cyclophosphamide-induced neutropenia by increasing the depleted levels of leucocytes. The herbal mixtures aided the mobilization of macrophages and memory T cells as seen in the result of the Delayed-Type Hypersensitivity Test. The result of the humoral antibody test showed that the herbal mixtures exhibited a dose-dependent stimulatory effect on B cell maturation and differentiation into antibody-secreting plasma cells. Key words: Immunomodulatory, Phytochemistry, Microbial Quality, Toxicity profile, Herbal Formulation.

Deep infections following primary joint replacement cause great suffering to patients and have high treatment costs.1 In the general population, and especially in those that have recent contact with healthcare facilities, the bacteria Staphylococcus aureus often colonise the skin and the upper airways without causing disease. However, indolent in the skin, the same bacteria may cause devastating infection associated with implant devices and not least in orthopaedic surgery. There is extensive literature on specific measures aimed at reducing patients’ own bioburden with S. aureus before surgery summarised in the National Institute of Health and Care guidelines.2 3 Universal strategy is more cost-effective than a ‘screen and treat’ strategy.2 Use of triclosan-coated sutures is recommended by several major public health organisations.2 4 5 In contrast, we found one single publication describing the effect of prolonged decolonisation on the incidence of prosthetic joint infection (PJI) after surgery.6 However, there has been more attention towards postoperative factors on PJI.7 In an overall ‘zero harm’ healthcare improvement project at Drammen Hospital (DH) and Kongsberg Hospital (KH), part of the Vestre Viken Hospital Trust, we aimed to eliminate the incidence of PJI caused by S. aureus . Compliance with the decolonising protocol is a major issue for success. Hence, in this quality improvement project, we developed a highly standardised protocol for all patients admitted for acute (hip only) and planned surgeries (hip, knee, shoulder). The combined intervention included use of triclosan-coated sutures and patient decolonisation on the incidence of …

Background Specialist cleanroom garments are a potential vector for transmission of microorganisms within these facilities. In order to maintain the low bioburden of such clothing it has been perceived best practice for operators to dress wearing sterile cleanroom gloves. However, the efficacy of such glove use upon the resultant bacterial contamination of the surface of cleanroom garments has not previously been evaluated. Aim To compare surface bacterial contamination of cleanroom garments following their donning by operators dressing with or without gloves. Methods Following prior handwashing and systematic donning of cleanroom clothing by operators dressing wearing either no gloves, non-sterile nitrile gloves or sterile cleanroom latex gloves, a direct agar contact method was immediately undertaken to test garment surfaces at 7 specific sites. Following incubation bacterial levels were suitably quantified. Findings Comparing levels of growth displayed on plates used to test the surface of cleanroom garments worn by operators dressing with no gloves, non–sterile gloves or sterile cleanroom gloves, no significant difference was observed between the percentage of contact plates displaying growth and the levels of growth observed on plates, from any of the sites tested. Conclusion Omission of gloves in line with a systematic handwashing procedure prior to the cleanroom garment donning process, may result in modest economic and environmental gain coupled with a slightly less burdensome procedure. However, this is reliant on rigorous adherence to handwashing protocol and assessment of associated risk factors.

Filtering respiratory protection devices (FRPD) are mandatory for workers to wear in the Portuguese waste-sorting industry. Previous results regarding microbial contamination found on FRPD interior layer raised the question of whether microbial contamination from the exhalation valve would also have cytotoxicity effects. Since the FRPD exhalation valves are very close to workers’ nose and mouth, they represent a source of exposure to bioburden by inhalation. This study aimed to evaluate the cytotoxicity of the microbial contamination present in the FRPD exhalation valves. For this purpose, the cytotoxicity effects were determined through the MTT assay in two different cell lines (human A549 epithelial lung cells, and swine kidney cells) and compared with previous results obtained with FRPD interior layers. The contamination present in the FRPD exhalation valves presented some cytotoxicity on epithelial lung cells, suggesting the inhalation route as a potential route of exposure through the use of FRPD in the waste-sorting industry. Half-maximal (50%) inhibitory concentration (IC50) values were lower for FRPD interior layer than exhalation valves in lung cells, with overall cytotoxicity lower in exhalation valves when compared to interior layer (z = −4.455, p = 0.000). Higher bacterial counts in TSA were correlated with lower IC50 values, thus, higher cytotoxicity effect in lung cells. No statistically significant differences were detected among different workplaces.

SIGNIFICANCE Water exposure during contact lens wear can transfer pathogenic microorganisms to the eye, causing ocular complications. This study determined that water exposure is prevalent among lens wearers and is independently associated with higher case contamination. Contact lens compliance education to minimize water exposure should be reenforced by contact lens organizations and practitioners. PURPOSE Given the increasing association between water exposure and contact lens disease, this study aimed to explore the effect of water exposure and storage case contamination in soft contact lens users. METHODS A total of 165 daily soft lens wearers completed a self-administered questionnaire on contact lens hygiene. Lens cases were collected, and microbial analysis was conducted using an adenosine triphosphate assay (for overall microbial bioburden) and limulus amebocyte lysate assay (for endotoxin levels). The lens hygiene (excellent, >35; moderate, 28 to 35; poor, 1, poor) scores measured the compliance and water exposure during lens wear, respectively. Multiple regression determined the association between water behaviors and case contamination. RESULTS The average (standard deviation) age of participants was 28 (13.5) years (18 to 78 years), and 65% were female. The average overall microbial bioburden of storage cases was 3.10 (0.98) log colony-forming unit/mL (1.09 to 5.94 log colony-forming unit/mL). Forty-five percent of participants reported showering, 49.7% reported swimming while wearing lenses (65.4% of whom swam without goggles), 27.8% used wet hands to handle lenses, and 17.5% used tap water to rinse storage cases. Showering with lenses significantly increased the risk of higher storage case bioburden (P = .001), whereas using wet hands (P = .01) doubled the risk of higher case endotoxin levels (odds ratio, 2.41; confidence interval 1.19 to 4.86). CONCLUSIONS Water contact behavior while wearing lenses is prevalent among soft lens wearers and is associated with higher case contamination. Practitioners may improve contact lens education to reduce water exposure and case contamination to reduce the risk of lens-related adverse events.

Objective: To clarify the role of microbiological swabs in surgical decision-making, we investigated the effect of negative-pressure wound therapy (NPWT) and serial surgical debridement on bacterial bioburden in hard-to-heal wounds and ultimately correlated them with the success of surgical closure. Method: All patients were treated with surgical debridement, jet lavage and NPWT before their wounds were finally closed. The treatment effect was assessed by correlating microbiological swabs obtained immediately after intervention with those obtained after removal of the dressings during the following surgical procedures. The result of the last microbiological swab taken before definitive surgical closure was correlated with the requirement for revision surgery. Results: We included the results of 704 microbiological swabs from 97 patients in 110 wound localisations in this monocentric, retrospective study. NPWT did not improve bacterial bioburden in 77% of cases and the duration of NPWT did not affect the result. Furthermore, no significant effect of NPWT could be found for either anaerobic (p=0.96) or aerobic bacteria (p=0.43). In contrast, surgical debridement increased bacterial load in approximately 60% of cases. If sterile wound swabs could be obtained at all, it was during the first four surgical debridements in 60% of patients; after that only 10% became sterile. Conclusions: Sterile microbiological wound swabs before surgical closure were associated with lower rates of revision surgery, while low or medium bacterial loads did not increase revision rates.

Every year, thousands of soldiers and civilians succumb to burn wound trauma with highly unfavorable outcomes. We previously established a modified Walker-Mason rat scald model exhibiting a P. aeruginosa infection. Here we characterize deep partial- (DPT) and full-thickness (FT) burn wounds inoculated with Staphylococcus aureus. Male Sprague-Dawley rats (350–450 g) inflicted with 10% total body surface area burn inoculated with S. aureus (103–5 CFU/wound) were monitored over an 11-day period. S. aureus rapidly dominated the wound bed, with bacterial loads reaching at least 1 × 109 CFU/g tissue in all wounds. Within 3 days, S. aureus biofilm formation occurred based on genetic transcripts and Giemsa staining of the tissue. S. aureus infection resulted in a slightly faster recruitment of neutrophils in FT wounds, which was related to necrotic neutrophils. The extent of the inflammatory response in S. aureus infected burn wounds correlated with elevated G-CSF, GM-CSF, GRO/KC and/or TNF-α levels, but a majority of pro- and anti-inflammatory cytokines (IL-1β, IL-6, IFN-γ, IL-10, and IL-13) were found to be suppressed, compared to burn-only controls. S. aureus infection resulted in dynamic changes in DAMPs, including elevated HMGB-1 and reduced levels of circulating hyaluronan within FT wounds. S. aureus also reduced complement C3 at all time points in DPT and FT wounds. These changes in DAMPs are believed to be correlated with burn severity and S. aureus specific bioburden. Collectively, this model showcases the evasiveness of S. aureus through dampening the immune response to flourish in the burn wound.

Objective:To investigate the frequency of environmental contamination in hospital areas outside patient rooms and in outpatient healthcare facilities.Design:Culture survey.Setting:This study was conducted across 4 hospitals, 4 outpatient clinics, and 1 surgery center.Methods:We conducted 3 point-prevalence culture surveys for methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Clostridioides difficile, Candida spp, and gram-negative bacilli including Enterobacteriaceae, Pseudomonas aeruginosa, Acinetobacter baumanii, and Stenotrophomonas maltophilia in each facility. In hospitals, high-touch surfaces were sampled from radiology, physical therapy, and mobile equipment and in emergency departments, waiting rooms, clinics, and endoscopy facilities. In outpatient facilities, surfaces were sampled in exam rooms including patient and provider areas, patient bathrooms, and waiting rooms and from portable equipment. Fluorescent markers were placed on high-touch surfaces and removal was assessed 1 day later.Results:In the hospitals, 110 (9.4%) of 1,195 sites were positive for 1 or more bacterial pathogens (range, 5.3%–13.7% for the 4 hospitals) and 70 (5.9%) were positive for Candida spp (range, 3.7%–5.9%). In outpatient facilities, 31 of 485 (6.4%) sites were positive for 1 or more bacterial pathogens (range, 2% to 14.4% for the 5 outpatient facilities) and 50 (10.3%) were positive for Candida spp (range, 3.9%–23.3%). Fluorescent markers had been removed from 33% of sites in hospitals (range, 28.4%–39.7%) and 46.3% of sites in outpatient clinics (range, 7.4%–82.8%).Conclusions:Surfaces in hospitals outside patient rooms and in outpatient facilities are frequently contaminated with healthcare-associated pathogens. Improvements in cleaning and disinfection practices are needed to reduce contamination.

Introduction: Wound healing is characterised by haemostatic, inflammatory, proliferative and remodelling phases. In the presence of comorbidities such as diabetes, healing can stall and chronic wounds may result. Infection is detrimental to these wounds and associated with poor outcomes. Wounds are contaminated with microbes and debris, and factors such as host resistance, bacterial virulence, species synergy and bioburden determine whether a wound will deteriorate to critically colonised/infected states. Biofilms are sessile microbial communities, exhibiting high-level antibiotic tolerance and resistance to host defences. Biofilm in critically colonised wounds can contribute to delayed healing. Little is known about clinical presentation and diagnosis of wound biofilms. Objective: To identify from the literature clinical signs, symptoms and biomarkers that may indicate biofilm in chronic wounds. Methods: This review will be guided by the Preferred Reporting Items for Systematic Reviews extension for Scoping Reviews (PRISMA-ScR), and the Joanna Briggs Institute Manual for Evidence Synthesis. Studies of any design in any language recruiting adult patients with venous, diabetic, pressure or mixed arterial-venous ulcers and reporting data on clinical signs/symptoms of biofilm are eligible. Searches of Medline, Embase, CINAHL, Cochrane Central, Scopus, Web of Science, Google scholar and BASE will be conducted from inception to present. Reference scanning and contact with content experts will be employed. Title/abstract screening and full text selection will be executed by two reviewers independently. Discrepancies will be resolved by discussion between reviewers or through third party intervention. Data will be extracted by a single reviewer and verified by a second. Clinical signs and symptoms data will be presented in terms of study design, setting and participant demographic data. Discussion: Understanding biofilm impact on chronic wounds is inconsistent and based largely on in vitro research. This work will consolidate clinical signs, symptoms and biomarkers of biofilm in chronic wounds reported in the literature.

The validation of a radiation sterilization dose involves an initial sterilization dose determination as well as maintenance of that sterilization dose. The procedures for maintenance of the sterilization dose typically include the periodic use of two types of tests: bioburden and dose audits. The details for the procedures are outlined in the ISO radiation sterilization standards. These documents also provide guidelines for recommended actions in response to the results of the two tests. The results for the dose audit are based on the number of positive tests of sterility (TOS) for products that have been irradiated at a verification or experimental dose. When the dose audit yields TOS positives, it is often thought that they indicate a sterilization failure and nonsterile product. The belief that any TOS positive is a failure is an incorrect assumption because of the statistical basis used for the determination of the sterilization dose. This article will outline the truth of what dose audit TOS positives mean in terms of the sterility assurance of product, as well as the consequences of TOS positives.

Introduction: During a pandemic, when the supply of N95 filtering facepiece respirators (FFRs) is limited, health care workers may reuse N95 FFRs. Room temperature storage of N95 FFRs—waiting before reuse—could be a simple low-cost method to reduce severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) bioburden in such a situation. The U.S. Centers for Disease Control and Prevention specify this as a strategy for reducing self-contamination risk during a time of N95 FFR shortage. Objective: To review the literature on persistence of SARS-CoV-2 on surfaces to assess room temperature waiting times for bioburden reduction on N95 FFRs. Methods: The literature was searched for studies evaluating room temperature persistence of SARS-CoV-2. A 3-log decay time was extracted from published data for quantitative comparison between different studies. Studies using surgical masks and non-peer-reviewed studies that include N95 FFRs were used to draw conclusions. Key Findings: Experimental and analytical choices vary between studies and impact the estimated 3-log decay time. There is not a clear understanding of which material properties are significant. There are no peer-reviewed studies of virus persistence on an N95 FFR. Discussion and Conclusions: SARS-COV-2 inactivation occurs spontaneously at room temperature. The precise timing depends on factors including humidity, temperature, and surface material. In reviewed studies, a 7-day waiting period encompasses the 3-log reduction in infectious titer of SARS-COV-2 on specific N95 FFRs and surgical masks. Owing to variations between studies and among N95 FFR materials and room temperature conditions, it is impossible to extrapolate from these limited data to assign a precise 3-log decay time for all used N95 FFRs.

Highlights • We used quantitative microbial risk assessment to relate surface disinfection efficacy to COVID-19 infection risk. • Little log10 reductions may be needed for low viral bioburden conditions. • >2 log10 may be needed to achieve risks, We used a quantitative microbial risk assessment approach to relate log10 disinfection reductions of SARS-CoV-2 bioburden to COVID-19 infection risks. Under low viral bioburden, minimal log10 reductions may be needed to reduce infection risks for a single hand-to-fomite touch to levels lower than 1:1,000,000, as a risk comparison point. For higher viral bioburden conditions, log10 reductions of more than 2 may be needed to achieve median infection risks of less than 1:1,000,000.