Search

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.

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

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.

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.

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 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.

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.

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.

Issued primarily by COSPAR (the Committee On SPAce Research), international Planetary Protection Policies mandate that all spacecraft hardware in contact with extraterrestrial environments “of chemical evolution and/or origin of life interest and for which scientific opinion provides a significant chance of contamination which could compromise future investigations” (Kminek and Rummel, 2015) undergo biological burden control processes. These policies seek to limit the (forward) biological contamination of the target body by terrestrial microorganisms on the spacecraft, so that future missions to the target body will provide accurate and reliable scientific results. Also, these policies seek to prevent the (backward) biological contamination of the Earth by a sample returned from the target body. Bioburden reduction is an integral part of current space missions and its importance will magnify as bioburden requirements become more stringent in the future. Since life-detection and sample-return procedures require sterile handling in situ (to protect scientific results), subsystems and instruments which will be in contact with extraterrestrial matter must be sterilized to prevent a false positive. Since the first Viking mission, heat microbial reduction (HMR) has served as a well-understood common practice for reducing bioburden. More recently, NASA and ESA have approved a standard protocol for vapor hydrogen peroxide (VHP) microbial reduction to address some of the drawbacks of HMR by lowering operating costs and decreasing schedule impacts, as detailed in the certification processes conducted by NASA's Jet Propulsion Laboratory and Steris. Steris has also conducted many testing campaigns on behalf of JPL over the past 20 years. The main results of their campaigns are hence reported. However, even VHP has certain limitations that do not make it an all-encompassing microbial reduction/sterilization modality for spacecraft hardware. Therefore, this review also investigates the state-of-the-art sterilization and cleaning techniques used in other fields, such as in the medical, food, and drug industries, for application to flight hardware. Major techniques covered include cold atmospheric plasma, electron beam irradiation, and gamma irradiation. Some techniques have proven to be good candidates for adaptation for future NASA spacecraft missions. Techniques such as gamma irradiation (γ rad), can broaden the scope of NASA-approved protocols and expand the currently limited toolkit. Cleaning, the removal of bioburden, is also an important aspect of bioburden reduction; despite the best microbial reduction/sterilization technologies, dead microbes can interfere with and potentially invalidate the results of biosignature models of relevant celestial bodies. Therefore, cleaning techniques, such as carbon dioxide snow, can significantly contribute to the bioburden reduction process. With the development of standardized protocols for these additional microbial reduction/sterilization and cleaning modalities – in combination with the well-known techniques with NASA and ESA approved protocols – we anticipate that future space missions may be able to achieve a higher biological standard.

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.

Hospital associated infections (HAIs), infections acquired by patients during care in a hospital, remain a prevalent issue in the healthcare field. These infections often occur with the use of indwelling medical devices, such as endotracheal tubes (ETTs), that can result in ventilator-associated pneumonia (VAP). When examining the various routes of infection, VAP is associated with the highest incidence, rate of morbidity, and economic burden. Although ETTs are essential for the survival of patients requiring mechanical ventilation, their use comes with complications. The presence of an ETT in the airway impairs physiological host defense mechanisms for clearance of pathogens and provides a platform for oropharynx microorganism transport to the sterile tracheobronchial network. Antibiotics are administered to treat lower respiratory infections; however, they are not always effective and consequently can result in increased antibiotic resistance. Prophylactic approaches by altering the surface of ETTs to prevent the establishment and growth of bacteria have exhibited promising results. In addition, passive surface modifications that prevent bacterial establishment and growth, or active coatings that possess a bactericidal effect have also proven effective. In this review we aim to highlight the importance of preventing biofilm establishment on indwelling medical devices, focusing on ETTs. We will investigate successful antimicrobial modifications to ETTs and the future avenues that will ultimately decrease HAIs and improve patient care. STATEMENT OF SIGNIFICANCE: Infections that occur with indwelling medicals devices remain a constant concern in the medical field and can result in hospital-acquired infections. Specifically, ventilator associated pneumonia (VAP) occurs with the use of an endotracheal tube (ETT). Infections often require use of antibiotics and can result in patient mortality. Our review includes a summary of the recent collective work of antimicrobial ETT modifications and potential avenues for further investigations in an effort to reduce VAP associated with ETTs. Polymer modifications with antibacterial nature have been developed and tested; however, a focus on ETTs is lacking and clinical availability of new antimicrobial ETT devices is limited. Our collective work shows the successful and prospective applications to the surfaces of ETTs that can support researchers and physicians to create safer medical devices.

Background Weakly acidic hypochlorous acid (HOCl), a major inorganic bactericidal compound of innate immunity, is effective against a broad range of microorganisms. However, HOCl has never been described as a pharmaceutical drug for treatment of infected wounds. Here, we describe a study using HOCl solution, a reagent that has potential use in a clinical situation such as prevention and treatment of infection in chronic wounds. Methods HOCl solution (200 ppm, pH 6.5) was prepared by the in vitro addition of sodium hypochlorite to sterile water or saline at pH 6.5. The resulting solutions were used to evaluate in vitro cytotoxic and bacteriostatic properties against Pseudomonas aeruginosa. Furthermore, the bacteriostatic effect of the HOCl solutions was evaluated in vivo using P. aeruginosa-infected wounds on db/db diabetic mice. Results The HOCl solution exhibited concentration-dependent in vitro bacteriostatic activity against P. aeruginosa; HOCl in phosphate-buffered saline (PBS) also displayed in vitro cytotoxicity to human fibroblasts. Similarly, the cleansing of P. aeruginosa-infected wounds on db/db diabetic mice with HOCl solution yielded significantly decreased in vivo bacterial cell counts and there was no difference in granulation formation compared to cleansing with pure water. Conclusion Twelve days of once-daily cleansing of P. aeruginosa-infected wounds on db/db diabetic mice with HOCl solution resulted in significantly decreased P. aeruginosa bioburden, albeit with a minor delay in wound repair.

Background Infections have been linked to inadequately reprocessed flexible bronchoscopes, and recent investigations determined that pathogen transmission occurred even when bronchoscope cleaning and disinfection practices aligned with current guidelines. This multisite, prospective study evaluated the effectiveness of real-world bronchoscope reprocessing methods, using a systematic approach. Methods This study involved direct observation of reprocessing methods for flexible bronchoscopes, multifaceted evaluations performed after manual cleaning and after high-level disinfection, and assessments of storage conditions. Visual inspections of ports and channels were performed using lighted magnification and borescopes. Contamination was detected using microbial cultures and tests for protein, hemoglobin, and adenosine triphosphate (ATP). Researchers assessed reprocessing practices, and storage cabinet cleanliness was evaluated by visual inspection and ATP tests. Results Researchers examined 24 clinically used bronchoscopes. After manual cleaning, 100% of bronchoscopes had residual contamination. Microbial growth was found in 14 fully reprocessed bronchoscopes (58%), including mold, Stenotrophomonas maltophilia, and Escherichia coli/Shigella species. Visible irregularities were observed in 100% of bronchoscopes, including retained fluid; brown, red, or oily residue; scratches; damaged insertion tubes and distal ends; and filamentous debris in channels. Reprocessing practices were substandard at two of three sites. Conclusions Damaged and contaminated bronchoscopes were in use at all sites. Inadequate reprocessing practices may have contributed to bioburden found on bronchoscopes. However, even when guidelines were followed, high-level disinfection was not effective. A shift toward the use of sterilized bronchoscopes is recommended. In the meantime, quality management programs and updated reprocessing guidelines are needed.

Background There have been reported outbreaks of carbapenem-resistant Enterobacteriaceae infections linked to endoscopes with elevator mechanisms. Adenosine triphosphate (ATP) testing has been used as a marker for bioburden and monitoring manual cleaning for flexible endoscopes with and without an elevator mechanism. The objective of this study was to determine whether routine ATP testing could identify areas of improvement in cleaning of endoscopes with an elevator mechanism. Methods ATP testing after manual cleaning of TJF-Q180V duodenoscopes and GF-UCT180 linear echoendoscopes (Olympus America Inc, Center Valley, PA) was implemented. Samples were tested from the distal end, the elevator mechanism, and water flushed through the lumen of the biopsy channel. Data were recorded and compared by time point, test point, and reprocessing technician. Results Overall failure rate was 6.99% (295 out of 4,219). The highest percentage of failed ATP tests (17.05%) was reported in the first quarter of routine testing, with an overall decrease in rates over time. The elevator mechanism and working channel lumen had higher failure rates than the distal end. Quality of manual cleaning between reprocessing technicians showed variation. Conclusion ATP testing is effective in identifying residual organic material and improving quality of manual cleaning of endoscopes with an elevator mechanism. Cleaning efficacy is influenced by reprocessing technicians and location tested on the endoscope. Close attention to the working channel and elevator mechanism during manual cleaning is warranted.

The HabitAbility: Brines, Irradiation and Temperature (HABIT) instrument will be part of the ExoMars 2022 mission (ESA/Roscosmos) and will be the first European In-situ Resource Utilization (ISRU) instrument capable of producing liquid water on Mars. HABIT is composed by two modules: Environmental Package (EnvPack) and Brine Observation Transition To Liquid Experiment (BOTTLE). EnvPack will help to study the current habitability conditions on Mars investigating the air and surface thermal ranges and Ultraviolet (UV) irradiance; and BOTTLE is a container with four independent vessels housing deliquescent salts, which are known to be present on Mars, where the liquid water will be produced after deliquescence. In order to prevent capillarity of deliquescent or hydrated salts, a mixture of deliquescent salts with Super Absorbent Polymer (SAP) based on polyacrylamide is utilized. This mixture has deliquescent and hydrogel properties and can be reused by applying a thermal cycle, complying thus with the purpose of the instrument. A High Efficiency Particulate Air (HEPA) grade filter made of polytetrafluroethylene (PTFE) porous membrane sandwiched between spunbounded non-woven fabric stands as a physical barrier allowing interaction between the gaseous molecules of the Martian atmosphere and the salt mixtures, and at the same time preventing the passage of any potential biological contamination from the cells to the outside or vice-versa. In addition to the physical barrier, a strict bioburden reduction and analysis procedure is applied to the hardware and the contained salt mixtures adhering to the European Cooperation for Space Standardization protocol of microbial examination of flight hardware (ECSS-Q-ST-70-55C). The deliquescent salts and the SAP products need to be properly treated independently to adhere to the planetary protection protocols. In this manuscript, we describe the bioburden reduction process utilized to sterilize the salt mixtures in BOTTLE and the assays adopted to validate the sterilization. We also describe the construction of a low-cost, portable ISO 7 cleanroom tent, exclusively designed for planetary protection tests. The sterilization process involves Dry Heat Microbial Reduction (DHMR) of the deliquescent salts and the SAP mixtures. The performance of SAP after DHMR is validated to ensure its working efficiency after sterilization. A slightly modified version of the standard swab assay is used in the validation process and a comparison is made between samples exposed to a thermal shock treatment and those without thermal shock, to determine the best assay to be applied for future space hardware utilizing such salt mixtures for planetary investigation and In-Situ Resource Utilization (ISRU). The demonstration of the compatibility of these products with the processes commonly required for space applications has implications for the future exploration of Mars., The authors of the paper would like to thank the Institute of Aerospace Medicine, DLR , Germany for their support to analyse the bioburden assay of the HABIT BOTTLE salt mixtures. The authors would also like to acknowledge Roberto Mantas-Nakhai for his contribution during the bioburden assay validation. HABIT is an instrument of the Luleå University of Technology (LTU), led by J. Martín-Torres (PI) and M-P. Zorzano (co-PI). The HABIT FM and EQM were fabricated by Omnisys, Sweden, under advice of LTU as part of the HABIT project development and funded by the Swedish National Space Agency ( SNSA ). M-P. Z's contribution has been partially supported by the Spanish State Research Agency ( AEI ) Project No. MDM-2017-0737 Unidad de Excelencia “María de Maeztu” - Centro de Astrobiología (INTA-CSIC). We acknowledge the Luleå University of Technology, the Wallenberg Foundation and the Kempe Foundation for support of the Mars research activities. We thank the ExoMars project team, European Space Agency (ESA), Roscosmos, Space Research Institute (IKI) and Omnisys Instruments AB for their hard work on the ExoMars 2022 mission. We acknowledge the Luleå University of Technology, the Wallenberg Foundation and the Kempe Foundation for support of the Mars research activities. The SpaceQ chamber has been developed together with Kurt J. Lesker Company and was funded by the Kempe Foundation.

Background A 2015 study matching use of disposable and reusable sharps containers (DSCs, RSCs) with Clostridium difficile infection (CDI) incidence found a decreased incidence with DSCs. We conducted microbiologic samplings and examined the literature and disease-transmission principles to evaluate the scientific feasibility of such an association. Methods (i) 197 RSCs were sampled for C. difficile at processing facilities; (ii) RSCs were challenged with high C. difficile densities to evaluate efficacy of automated decontamination; and (iii) 50 RSCs and 50 DSCs were sampled in CDI patient rooms in 7 hospitals. Results were coupled with epidemiologic studies, clinical requirements, and chain-of-infection principles, and tests of evidence of disease transmission were applied. Results C. difficile spores were found on 9 of 197 (4.6%) RSCs prior to processing. Processing completely removed C. difficile. In CDI patient rooms, 4 of 50 RSCs (8.0%) and 8 of 50 DSCs (16.0%) had sub-infective counts of C. difficile (P = .27). DSCs were in permanent wall cabinets; RSCs were removed and decontaminated frequently. Conclusion With C. difficile bioburden being sub-infective on both DSCs and RSCs, sharps containers being no-touch, and glove removal required after sharps disposal, we found 2 links in the chain of infection to be broken and 5 of 7 tests of evidence to be unmet. We conclude that sharps containers pose no risk of C. difficile transmission.

Background Covering the instrument table during surgery may decrease contamination. We hypothesized that (1) covering the instrument table in an operating room (OR) during static periods of nonuse and dynamic periods of active use would dramatically decrease the bacterial bioburden on the table, and (2) the use of sterile plastic table covers would be equivalent to sterile impervious paper covers in reducing the bioburden in a dynamic environment. Methods Bacterial contamination of the instrument table was evaluated by settle plates in static and dynamic ORs. Airborne particulate and bacterial contaminants were sampled throughout the room. Tested groups included instrument tables covered with sterile impervious paper covers, sterile plastic covers, or no covers. Results Covering the instrument table during static and dynamic operating room conditions resulted in a significantly decreased bacterial load on the instrument table. No differences were seen between paper and plastic covers. Conclusions A significant decrease in bacterial bioburden on the instrument table when the table was covered during static and dynamic periods was observed, suggesting the utility for covering the instrument table during periods of nonuse and during active surgeries.

Objective Antimicrobial wipes are increasingly used in health care settings. This study evaluates, in a clinical setting, the efficacy of sporicidal wipes versus a cloth soaked in a 1,000 ppm chlorine solution. Intervention A double-crossover study was performed on 2 different surgical and cardiovascular wards in a 1,000-bed teaching hospital over 29 weeks. The intervention period that consisted of surface decontamination with the preimpregnated wipe or cloth soaked in chlorine followed a 5-week baseline assessment of microbial bioburden on surfaces. Environmental samples from 11 surfaces were analyzed weekly for their microbial content. Results A total of 1,566 environmental samples and 1,591 ATP swabs were analyzed during the trial. Overall, there were significant differences in the recovery of total aerobic bacteria (P < .001), total anaerobic bacteria (P < .001), and ATP measurement (P < .001) between wards and between the different parts of the crossover study. Generally, the use of wipes produced the largest reduction in the total aerobic and anaerobic counts when compared with the baseline data or the use of 1,000 ppm chlorine. Collectively, the introduction of training plus daily wipe disinfection significantly reduced multidrug-resistant organisms recovered from surfaces. Reversion to using 1,000 ppm chlorine resulted in the number of sites positive for multidrug-resistant organisms rising again. Conclusions This double-crossover study is the first controlled field trial comparison of using preimpregnated wipes versus cotton cloth dipped into a bucket of hypochlorite to decrease surface microbial bioburden. The results demonstrate the superiority of the preimpregnated wipes in significantly decreasing microbial bioburden from high-touch surfaces.

Recently advances in miniaturization and automation have been utilized to rapidly decrease the time to result for microbiology testing in the clinic. These advances have been made due to the limitations of conventional culture-based microbiology methods, including agar plate and microbroth dilution, which have long turnaround times and require physicians to treat patients empirically with antibiotics before test results are available. Currently, there exist similar limitations in pharmaceutical sterility and bioburden testing, where the long turnaround times associated with standard microbiology testing drive costly inefficiencies in workflows. These include the time lag associated with sterility screening within drug production lines and the warehousing cost and time delays within supply chains during product testing. Herein, we demonstrate a proof-of-concept combination of a rapid microfluidic assay and an efficient cell filtration process that enables a path toward integrating rapid tests directly into pharmaceutical microbiological screening workflows. We demonstrate separation and detection of Escherichia coli directly captured and analyzed from a mammalian (i.e., CHO) cell culture with a 3.0 h incubation. The demonstration is performed using a membrane filtration module that is compatible with sampling from bioreactors, enabling in-line sampling and process monitoring.

Bioburden proliferation in filters from air conditioning systems of taxis represents a possible source of occupational exposure. The aim of this study was to determine the occurrence of fungi and bacteria in filters from the air conditioning system of taxis used for patient transportation and to assess the exposure of drivers to bioburden. Filters from the air conditioning systems of 19 taxis and 28 personal vehicles (used as controls) operating in three Portuguese cities including the capital Lisbon, were collected during the winter season. The occurrence and significance of bioburden detected in the different vehicles are reported and discussed in terms of colony-forming units (CFU) per 1 m2 of filter area and by the identification of the most frequently detected fungal isolates based on morphology. Azole-resistant mycobiota, fungal biomass, and molecular detection of Aspergillus species/strains were also determined. Bacterial growth was more prevalent in taxis (63.2%) than in personal vehicles (26.3%), whereas fungal growth was more prevalent in personal vehicles (53.6%) than in taxis (21.1–31.6%). Seven different azole-resistant species were identified in this study in 42.1% taxi filters. Levels of fungal biomass were above the detection limit in 63% taxi filters and in 75% personal vehicle filters. No toxigenic species were detected by molecular analysis in the assessed filters. The results obtained show that bioburden proliferation occurs widely in filters from the air conditioning systems of taxis, including the proliferation of azole-resistant fungal species, suggesting that filters should be replaced more frequently. The use of culture based-methods and molecular tools combined enabled an improved risk characterization in this setting.

Endoscopy-associated infection transmission is frequently linked to inadequate reprocessing. Residual organic material and moisture may foster biofilm development inside endoscopes. This study evaluated the effectiveness of endoscope drying and storage methods and assessed associations between retained moisture and contamination.Endoscope reprocessing, drying, and storage practices were assessed at 3 hospitals. Researchers performed visual examinations and tests to detect fluid and contamination on patient-ready endoscopes.Fluid was detected in 22 of 45 (49%) endoscopes. Prevalence of moisture varied significantly by site (5%; 83%; 85%; P .001). High adenosine triphosphate levels were found in 22% of endoscopes, and microbial growth was detected in 71% of endoscopes. Stenotrophomonas maltophilia, Citrobacter freundii, and Lecanicillium lecanii/Verticillium dahliae were found. Retained fluid was associated with significantly higher adenosine triphosphate levels (P .01). Reprocessing and drying practices conformed with guidelines at 1 site and were substandard at 2 sites. Damaged endoscopes were in use at all sites.Inadequate reprocessing and insufficient drying contributed to retained fluid and contamination found during this multisite study. More effective methods of endoscope reprocessing, drying, and maintenance are needed to prevent the retention of fluid, organic material, and bioburden that could cause patient illness or injury.

Background The early diagnosis of infection or sepsis in burns are important for patient care. Globally, a large number of burn centres advocate quantitative cultures of wound biopsies for patient management, since there is assumed to be a direct link between the bioburden of a burn wound and the risk of microbial invasion. Given the conflicting study findings in this area, a systematic review was warranted. Methods Bibliographic databases were searched with no language restrictions to August 2015. Study selection, data extraction and risk of bias assessment were performed in duplicate using pre-defined criteria. Substantial heterogeneity precluded quantitative synthesis, and findings were described narratively, sub-grouped by clinical question. Results Twenty six laboratory and/or clinical studies were included. Substantial heterogeneity hampered comparisons across studies and interpretation of findings. Limited evidence suggests that (i) more than one quantitative microbiology sample is required to obtain reliable estimates of bacterial load; (ii) biopsies are more sensitive than swabs in diagnosing or predicting sepsis; (iii) high bacterial loads may predict worse clinical outcomes, and (iv) both quantitative and semi-quantitative culture reports need to be interpreted with caution and in the context of other clinical risk factors. Conclusion The evidence base for the utility and reliability of quantitative microbiology for diagnosing or predicting clinical outcomes in burns patients is limited and often poorly reported. Consequently future research is warranted.

Arteriovenous fistulas (AVFs) are vascular anomalies that may result in uncontrollable hemorrhage and non-healing wounds that are challenging to manage and require complex surgical reconstruction with thoughtful reconstructive strategies. In this case report, we present a patient with a threatened limb from a traumatic AVF and chronically infected hematoma. He required complex staged endovascular and open reconstruction followed by negative pressure wound therapy (NPWT) for optimal wound healing with excellent results. Polyvinyl alcohol particles were used as selective pre-operative embolic agents to achieve tissue ischemia prior to hematoma excision and reconstruction with pedicled nerve transfer to decrease neuroma formation. NPWT with instillation of Dakin's solution and dwell time was used to reduce the dead space while promoting the formation of granulation tissue and treating the infection by reducing the bioburden. After 1 week of NPWT, there was excellent granulation tissue with retraction of the wound allowing for split thickness skin grafting. The graft healed completely and allowed him to return to his baseline function and resume his dancing career at 1 year follow-up.

Early debridement and/or eschar removal is regarded as a significant step in the treatment of deep partial and full thickness burns. It aims to control wound bioburden and allows early wound closure by conservative treatment or skin grafting. Preservation of viable dermis accompanied by early wound closure, is regarded as a necessary step to reduce scar related complication, e.g. functional limitations and/or unaesthetic scar formation. Aside from the classical techniques of surgical excision as tangential excision for eschar removal, hydro-surgery, maggot therapy, laser, enzymatic debridement have been described as additional techniques in the burn surgeon's armamentarium. It is widely accepted that early eschar removal within 72h improves the outcome of burn wound treatment by reducing bacterial wound colonization, infection and length of hospital stay. In contrast, the right technique for eschar removal is still a matter of debate. There is increasing evidence that enzymatic debridement is a powerful tool to remove eschar in burn wounds, reducing blood loss, the need for autologous skin grafting and the number of wounds requiring surgical excision. In order to assess the role and clinical advantages of enzymatic debridement by a mixture of proteolytic enzymes enriched in Bromelain (Nexobrid®) beyond the scope of the literature and in view of users' experience, a European Consensus Meeting was scheduled. The aim was to provide statements for application, based on the mutual experience of applying enzymatic debridement in more than 500 adult and pediatric patients by the consensus panelists. Issues to be addressed were: indications, pain management and anesthesia, timing of application, technique of application, after-intervention care, skin grafting after enzymatic debridement, blood loss, training strategies and learning curve and areas of future research needs. Sixty-eight (68) consensus statements were provided for the use of enzymatic debridement. The degree of consensus was remarkably high, with a unanimous consensus in 88.2% of statements, and lowest degree of consensus of 70% in only 3 statements. This consensus document may serve as preliminary guideline for the use of enzymatic debridement with user-oriented recommendations until further evidence and systematic guidelines are available.

Background Context Infections remain a leading complication associated with spinal arthrodesis, regardless of the use of prophylactic antibiotics and improved surgical techniques, with incidence of infection as high as 8.2%. Infection prolongs antibiotic usage, increases hospital time, and inevitably inflates overall treatment costs. Local antibiotics, such as vancomycin, have been used in combination with fusion materials over the past decade to decrease infection risk. An ideal graft material would serve a dual role: encouraging vertebral fusion while reducing the incidence of infection. Purpose The objective of this study was to thoroughly evaluate the use of a vancomycin-loaded demineralized bone matrix (vDBM) for fusion capability while reducing the incidence of surgical site infection. Study Design Antimicrobial efficacy and spinal fusion were evaluated using a preclinical rabbit model of posterolateral fusion. Materials and Methods Vancomycin-loaded demineralized bone matrix was prepared and evaluated for in vitro release kinetics and bacterial inhibition. In vivo antibacterial efficacy and fusion capability were performed using a model of posterolateral fusion in a rabbit. First, 10 New Zealand white rabbits underwent a bilateral posterolateral fusion procedure, were inoculated with Staphylococcus aureus , and were treated with either demineralized bone matrix (DBM) or vDBM . Fourteen days after the procedure, the animals were anesthetized and euthanized, and the transverse process was harvested and enumerated for bacterial quantification. Concurrently, 21 New Zealand white rabbits underwent the same procedure and were euthanized 8 weeks after surgery and were evaluated for fusion by manual palpation and radiographic scoring. In addition, two groups of six animals received the DBM or vDBM material as described, but the graft was combined with equal volumes of milled harvest iliac crest bone graft (ICBG). Eight weeks after surgery, these animals were euthanized and also evaluated for fusion by manual palpation and radiographic scoring. Results Vancomycin continued to be released from the vDBM over the course of 6 days while maintaining sufficient eluate concentrations to maintain a zone of inhibition similar or larger than a vancomycin control. In vivo, vDBM significantly reduced the amount of bacteria within the fusion site compared with DBM, with a 4-log decrease in bacterial bioburden. The use of vDBM, however,showed a decrease in the fusion rate compared with DBM when used in a sterile wound. In a S. aureus -contaminated wound, both the DBM and the vDBM showed decreased fusion rates.Considering DBM materials were most commonly used as autograft extenders, additional animals received either DBM plus ICBG in a sterile wound or vDBM plus ICBG in a contaminated wound. Both groups had similar fusion rates and similar fusion volumes after 8 weeks in vivo. Conclusions Whereas vDBM reduced the overall bioburden within a contaminated surgical site of posterolateral fusion, the addition of the vancomycin to the DBM reduced the fusion capability of the DBM graft. The addition of ICBG to vDBM restored the fusion capability of the graft while reducing the overall infection.

Contaminated hospital surfaces contribute significantly to the transmission of health care-associated infections. Although disinfectants reduce bioburden by up to 99%, bacterial growth can rebound within hours to precleaning levels. We tested the effectiveness of an innovative, long-acting water-stable organosilane (WSO) to achieve sustained decreases in bioburden on hard surfaces.A 5-month prospective, randomized, double-blind controlled study was performed. Eighteen intensive care unit rooms were randomly divided into placebo or treatment groups. Hard surfaces in all rooms were cleaned using the same protocol, except the placebo surfaces were cleaned with an inert saline solution and the treatment surfaces were treated with the WSO. Binomial regression with repeated measures were used to assess mean reductions in total bioburden as measured by colony forming units.The placebo resulted in average reductions in total colony forming units of 35% to 40% (relative risk reduction [RRR], 0.65; P .01) and the WSO group averaged reductions of colony forming units by 66% to 99% (RRR, 0.55; P .001). Total Staphylococcus aureus increased among the placebo rooms 30% (RRR, 0.69; P .001), whereas in treatment rooms there was a reduction of 50%-60% (RRR, 0.57; P .01). Although both sets of rooms saw reductions in bioburden or colony forming units, application of the WSO resulted in larger reductions. There was also greater variability in reductions in the placebo arm.This is the first randomized, double-blind controlled study of an innovative WSO on high-touch hard surfaces at risk for high bioburdens. Sustained reductions of bioburden with the monthly application of this unique WSO may be associated with significant reductions in the risk of health care-associated infections.

Ambulance vehicles are an essential part of emergency clinical services. Bioburden control in ambulances, through cleaning and disinfection, is crucial to minimize hospital-acquired infections, cross contamination and exposure of patients and ambulances‘ crew. In Portugal, firefighter crews are responsible, besides fire extinction, for first aid and urgent pre-hospital treatment. This study assessed the bioburden in Portuguese firefighters’ ambulances with a multi-approach protocol using active and passive sampling methods. Fungal resistance profile and mycotoxins detection in ambulances' ambient, and S. aureus (SA) prevalence and resistance profile in ambulances' ambient and colonization in workers were also investigated. Toxigenic fungi with clinical relevance, namely Aspergillus section Fumigati, were found on ambulance's air in the hazardous dimension range. Interestingly, surface contamination was higher after cleaning in several sampling sites. Prevalence of S. aureus was 3% in environmental samples, of which 2% were methicillin-sensitive (MSSA) and 1% methicillin-resistant (MRSA). About 2.07 fungal species were able to grow in at least one azole, ranging from one (44% samples) to five (6% samples) species in each azole. Mycotoxins were detected in mops and electrostatic dust cloths. Colonization by S. aureus in the firefighter crew was observed with a high associated prevalence, namely 48%, with a 24% prevalence of MSSA (8/33) and 21% of MRSA (7/33). Additional studies are needed to determine the potential risk of infection transmission between different vehicle fleets and under varying conditions of use. This will strengthen the paramedic sector's mission to save lives without putting their own health and safety at risk.

Background There are no guidelines or quality benchmarks specific to ureteroscope reprocessing, and patient injuries and infections have been linked to ureteroscopes. This prospective study evaluated ureteroscope reprocessing effectiveness. Methods Reprocessing practices at 2 institutions were assessed. Microbial cultures, biochemical tests, and visual inspections were conducted on sterilized ureteroscopes. Results Researchers examined 16 ureteroscopes after manual cleaning and sterilization using hydrogen peroxide gas. Every ureteroscope had visible irregularities, such as discoloration, residual fluid, foamy white residue, scratches, or debris in channels. Tests detected contamination on 100% of ureteroscopes (microbial growth 13%, adenosine triphosphate 44%, hemoglobin 63%, and protein 100%). Contamination levels exceeded benchmarks for clean gastrointestinal endoscopes for hemoglobin (6%), adenosine triphosphate (6%), and protein (100%). A new, unused ureteroscope had hemoglobin and high protein levels after initial reprocessing, although no contamination was found before reprocessing. Conclusions Flexible ureteroscope reprocessing methods were insufficient and may have introduced contamination. The clinical implications of residual contamination and viable microbes found on sterilized ureteroscopes are unknown. Additional research is needed to evaluate the prevalence of suboptimal ureteroscope reprocessing, identify sources of contamination, and determine clinical implications of urinary tract exposure to reprocessing chemicals, organic residue, and bioburden. These findings reinforce the need for frequent audits of reprocessing practices and the routine use of cleaning verification tests and visual inspection as recommended in reprocessing guidelines.

Background: Negative pressure wound therapy is a ubiquitous wound management resource. The influence of NPWT on the bacterial bioburden of the subjacent wound remains unclear. We sought to examine the evidence. Datasources: MEDLINE, Embase, PubMed, the Cochrane Database of Systematic Reviews and the Cochrane Controlled Trials Register were searched for articles quantitatively evaluating bacterial load under NPWT. Results: Twenty-four studies met the inclusion criteria including 4 randomised controlled trials, 8 clinical series and 12 experimental studies. Twenty studies evaluated conventional NPWT while 4 evaluated Infiltration-based NPWT. While 8 studies using conventional NPWT failed to demonstrate an observable effect on bacterial load, 7 studies reported that NPWT was inherently bacteriostatic and 5 others reported species selectivity with suppression of non-fermentive Gram-negative bacilli (NFGNB), including pseudomonas spp. Simultaneously, there was some evidence of enhanced proliferation of Gram-positive cocci where the niche was cleared of NFGNB. Two of the 4 studies using infiltration-based NPWT also reported selectively impaired proliferation of pseudomonas spp. Conclusion: The assumption that NPWT suppresses bacterial proliferation is oversimplified. There is evidence that NPWT exhibits species selectivity, suppressing the proliferation of NFGNB. However, this may depopulate the niche for exploitation by Gram-positive cocci. This, in turn, has implications for the use of NPWT where highly virulent strains of Gram-positive cocci have been isolated, as well as the duration of NPWT therapy and frequency of dressing changes.

Background Periprosthetic joint infection (PJI) after total joint arthroplasty (TJA) is a serious complication with multiple etiologies. Prior spine literature has shown that later cases in the day were more likely to develop surgical site infection. However, the effect of case order on PJI after TJA is unknown. This study aims to determine the influence of case order, prior infected case, and terminal cleaning on the risk for a subsequent PJI. Methods A retrospective, single-institution study was conducted on 31,499 TJAs performed from 2000 to 2014. Case order was determined by case start times per date within the same operating room. PJI was defined by the Musculoskeletal Infection Society criteria. Logistic regression was used to determine risk factors for a subsequent PJI. Results Noninfected cases followed an infected case in 92 of 31,499 cases (0.29%) and were more likely to develop PJI (adjusted odds ratio [OR], 2.43; P = .029). However, terminal cleaning after infected cases did not affect the risk for PJI in cases the following morning (OR, 1.42; P = .066). Case order had an OR of 0.98 ( P = .655), implying that later cases did not have a higher likelihood of infection. Conclusion Although surgical case order is not an independent risk factor for subsequent PJI, TJA cases following an infected case in the same room on the same day have a higher infection risk. Despite improved sterile technique and clean air operating rooms, the risk of contaminating a TJA with pathogens from a prior infected case appears to be high. Terminal cleaning appears to be effective in reducing the bioburden in the operating room.

Objectives This study sought to develop a validated, reproducible sterilization protocol, which could be used in the reprocessing of cardiac implantable electronic devices (CIEDs). Background Access to cardiac CIED therapy in high-income and in low- and middle-income countries varies greatly. CIED reuse may reduce this disparity. Methods A cleaning and sterilization protocol was developed that includes washing CIEDs in an enzymatic detergent, screw cap and set screw replacement, brushing, inspection, and sterilization in ethylene oxide. Validation testing was performed to assure compliance with accepted standards. Results With cleaning, the total mean bioburden for each of 3 batches of 10 randomly chosen devices was reduced from 754 to 10.1 colony-forming units. After sterilization with ethylene oxide, with 3 half-cycle and 3 full-cycle processes, none of the 90 biological indicator testers exhibited growth after 7 days. Through cleaning and sterilization, protein and hemoglobin concentrations were reduced from 99.2 to 1.42 μg/cm 2 and from 21.4 to 1.03 μg/cm 2 , respectively. Mean total organic carbon residual was 1.44 parts per million (range 0.36 to 2.9 parts per million). Endotoxin concentration was not detectable at the threshold of Conclusions CIEDs can be cleaned and sterilized according to a standardized protocol achieving a 12-log reduction of inoculated product, resulting in sterility assurance level of 10 –6 .

Mesenchymal stromal/stem cells (MSCs) have demonstrated pro-healing properties including an anti-inflammatory cytokine profile and the promotion of angiogenesis via expression of growth factors in pre-clinical models. MSCs encapsulated in poly(ethylene glycol) diacrylate (PEGdA) and thiolated gelatin poly(ethylene glycol) (Gel-PEG-Cys) crosslinked hydrogels have led to controlled cellular presentation at wound sites with favorable wound healing outcomes. However, the therapeutic potential of MSC-loaded hydrogels may be limited by non-specific protein adsorption on the delivery matrix that could facilitate the initial adhesion of microorganisms and subsequent virulent biofilm formation. Antimicrobials loaded concurrently in the hydrogels with MSCs could reduce microbial bioburden and promote healing, but the antimicrobial effect on the MSC wound healing capacity and the antibacterial efficacy of the hydrogels is unknown. We demonstrate that minocycline specifically induces a favorable change in MSC migration capacity, proliferation, gene expression, extracellular matrix (ECM) attachment, and adhesion molecule and growth factor release with subsequent increased angiogenesis. We then demonstrate that hydrogels loaded with MSCs, minocycline, vancomycin, and linezolid can significantly decrease bacterial bioburden. Our study suggests that minocycline can serve as a dual mechanism for the regenerative capacity of MSCs and the reduction of bioburden in triple antimicrobial-loaded hydrogels.Wound healing is a complex biological process that can be hindered by bacterial infection, excessive inflammation, and inadequate microvasculature. In this study, we develop a new formulation of poly(ethylene glycol) diacrylate and thiolated gelatin poly(ethylene glycol) crosslinked hydrogels loaded with minocycline, vancomycin, linezolid, and mesenchymal stromal/stem cells that induces a favorable wound healing phenotype in mesenchymal stromal/stem cells and prevents bacterial bioburden on the hydrogel. This combinatorial approach to biomaterial development has the potential to impact wound healing for contaminated full thickness cutaneous wounds.

Environmental disinfection has become the new frontier in the ongoing battle to reduce the risk of health care-associated infections. Evidence demonstrating the persistent contamination of environmental surfaces despite traditional cleaning and disinfection methods has led to the widespread acceptance that there is both a need for reassessing traditional cleaning protocols and for using secondary disinfection technologies. Ultraviolet-C (UV-C) disinfection is one type of no-touch technology shown to be a successful adjunct to manual cleaning in reducing environmental bioburden. The dilemma for the infection preventionist, however, is how to choose the system best suited for their facility among the many UV-C surface disinfection delivery systems available and how to build a case for acquisition to present to the hospital administration/C-suite. This article proposes an approach to these dilemmas based in part on the experience of 2 health care networks.

Purpose To assess corneal epithelial microstructure via confocal microscopy and determine if cellular changes are associated with lens care solutions during daily wear of silicone hydrogel contact lenses. Methods Corneal in vivo confocal microscopy with the Nidek ConfoScan4 was performed at baseline and after 5 months of lotrafilcon A daily contact lens wear. Enrolled participants were randomized to use either a polyhexamethylene biguanide (PHMB) preserved multipurpose care solution (MPS) or a peroxide based solution system. Lens and storage case bioburden were assessed with aerobic culture methods. Univariate and multivariable analyses were done to evaluate the association between solution use, or solution-related clinical covariates, and morphologic differences (hyper-reflectivity) in the superficial epithelial cells and epithelial basal cell density. Results Data on 139 participants were available for analysis of superficial epithelial cells while data on 92 participants were available for epithelial basal cell density. Five months after randomization to the solution groups, 33% of participants had visible hyper-reflective cells. More participants using MPS had ≥1 hyper-reflective cells compared to peroxide users at 5 months (44% vs. 22%; p=0.006). Similarly at 5 months, more participants with solution-induced corneal staining (SICS) had ≥1 hyper-reflective cells compared to non-SICS participants (57% vs. 29%; p=0.010). The adjusted odds ratios (ORs) for risk of presenting with hyper-reflective cells in MPS users or SICS participants was 2.7 (95% CI; 1.27–5.65) and 3.4 (95% CI; 1.29–8.97), respectively. Basal cell density decreased by over 350 cells/mm 2 over time (about 6%) in participants who had substantial bioburden on their lenses or in their storage case. Conclusion The confocal microscope can detect epithelial cellular changes in vivo during contact lens wear. Hyper-reflective superficial epithelial cells are associated with a PHMB preserved solution and decreases in basal epithelial cell density may be associated with bacterial bioburden.

Summary Background Critical care patients are at increased risk of infection. Near-patient surfaces act as reservoirs of microbial soil, which may contain pathogens. Aim To correlate soil levels with hand-touch frequency of near-patient sites in an intensive care unit (ICU). Methods Five sites around each bed in a 10-bed ICU were screened for total microbial soil (cfu/cm 2 ) and Staphylococcus aureus every month for 10 months. Selected sites were infusion pump and cardiac monitor, left and right bedrails, and bed table. Ten 1 h covert audits of hand-touch frequency of these sites were performed in order to provide an average hand-touch count, which was modelled against soil levels obtained from microbiological screening. Findings Seven of 10 staphylococci were found in conjunction with gross contamination of a specific site ( P =0.005) and the same proportion from three most frequently touched sites (bedrails and bed table). There was a linear association between four sites demonstrating gross microbial contamination (>12 cfu/cm 2 ) and mean number of hand-touch counts ( P =0.08). The bed table was handled most but was not the most contaminated site. We suspected that customary placement of alcohol gel containers on bed tables may have reduced microbiological yield. Removing the gel container from one table confirmed its inhibitory effect on microbial contamination after rescreening (19% vs 50% >12 cfu/cm 2 : P =0.007). Conclusion Surface bioburden at near-patient sites in ICU is associated with hand-contact frequencies by staff and visitors. This supports the need for targeted hygienic cleaning in a high-risk healthcare environment.

Touchless ultraviolet disinfection (UVD) devices effectively reduce the bioburden of epidemiologically relevant pathogens, including Clostridium difficile. During a 25-month implementation period, UVD devices were deployed facilitywide for the terminal disinfection of rooms that housed a patient who tested positive for C difficile. The deployment was performed with structured education, audit and feedback, and resulted in a multidisciplinary practice change that maximized the UVD capture rate from 20% to 100%.

Worldwide shortages of personal protective equipment during COVID-19 pandemic has forced the implementation of methods for decontaminating face piece respirators such as N95 respirators. The use of UV irradiation to reduce bioburden of used respirators attracts attention, making proper testing protocols of uttermost importance. Currently artificial saliva is used but its comparison to human saliva from the UV disinfection perspective is lacking. Here we characterize UV spectra of human and artificial saliva, both fresh and after settling, to test for possible interference for UV-based disinfection. ASTM 2720 artificial saliva recipe (with either porcine or bovine mucin) showed many discrepancies from average (N = 18) human saliva, with different mucins demonstrating very different UV absorbance spectra, resulting in very different UV transmittance at different wavelength. Reducing porcine mucin concentration from 3 to 1.7 g/L brought UVA254 in the artificial saliva to that of average human saliva (although not for other wavelengths), allowing 254 nm disinfection experiments. Phosphate saline and modified artificial saliva were spiked with 8.6 log CFU/ml B. subtilis spores (ATCC 6633) and irradiated at dose of up to 100 mJ/cm2, resulting in 5.9 log inactivation for a saline suspension, and 2.8 and 1.1 log inactivation for ASTM-no mucin and ASTM-1.7 g/L porcine mucin 2 μL dried droplets, respectively. UVC irradiation of spores dried in human saliva resulted in 2.3 and 1.5 log inactivation, depending on the size of the droplets (2 vs 10 μL, respectively) dried on a glass surface. Our results suggest that in the presence of the current standard dried artificial saliva it is unlikely that UVC can achieve 6 log inactivation of B. subtilis spores using a realistic UV dose (e.g. less than 2 J/cm2) and the ATSM saliva recipe should be revised for UV decontamination studies.

Fungal keratitis (FK) accounts for approximately half of the microbial keratitis encountered in low middle income countries (LMICs) and predominantly affect the working rural-poor. FK causes significant morbidity with the majority of patients left with moderate or worse visual impairment and approximately 25 % requiring expensive and often unsuccessful surgical interventions. The severity of FK and the resultant corneal damage or resolution can be attributed to i) the virulence and bioburden of the fungal pathogen, ii) the host defense mechanism and immune response and iii) sub-optimal diagnostics and anti-fungal treatment strategies. This review provides a comprehensive overview of the multifaceted components that drive FK progression and resolution, highlighting where knowledge gaps exist and areas that warrant further research.

Copper has long been known to have antimicrobial activity and is used in drinking water treatment and transportation. It has been recognized by the American Environmental Protection Agency as the first metallic antimicrobial agent in 2008. With ongoing waterborne hospital-acquired infections and antibiotic resistance, research on copper as an antimicrobial agent is again very attractive. Many studies have shown that the use of copper surface and copper particles could significantly reduce the environmental bioburden. This review highlights in its first part all the conditions described in the literature to enhance copper antimicrobial activity. Secondly, the different antimicrobial applications of copper in water treatment, hospital care units and public applications are presented. Finally, the future research needs on copper as an antimicrobial agent are discussed.

Background Ultraviolet (UV) spectrum light for decontamination of patient care areas is an effective way to reduce transmission of infectious pathogens. Our purpose was to investigate the efficacy of an automated UV-C device to eliminate bioburden on hospital computer keyboards. Methods The study took place at an academic hospital in Chicago, Illinois. Baseline cultures were obtained from keyboards in intensive care units. Automated UV-C lamps were installed over keyboards and mice of those computers. The lamps were tested at varying cycle lengths to determine shortest effective cycles. Delay after use and prior to cycle initiation was varied to minimize cycle interruptions. Finally, 218 postinstallation samples were analyzed. Results Of 203 baseline samples, 193 (95.1%) were positive for bacteria, with a median of 120 colony forming units (CFU) per keyboard. There were numerous bacteria linked to health care–associated infections (HAIs), including Staphylococcus , Streptococcus , Enterococcus , Pseudomonas , Pasteurella , Klebsiella , Acinetobacter , and Enterobacter . Of the 193 keyboards, 25 (12.3%) had gram-negative species. Of 218 postinstallation samples, 205 (94%) were sterile. Of the 13 that showed bacterial growth, 6 produced a single CFU. Comparison of pre- and post-UV decontamination median CFU values (120 and 0, respectively) revealed a >99% reduction in bacteria. Conclusions The UV lamp effectively decontaminates keyboards with minimal interruption and low UV exposure. Further studies are required to determine reduction of HAI transmission with use of these devices.

Over the last decade, carbapenemase-producing organisms (CPOs) have spread worldwide, becoming a major public health concern. This article reports the authors' experience in dealing with a burns patient infected with CPOs, and the decontamination methods employed to render a burns shock room safe for re-use. The shock room was cleaned after being vacated, but environmental sampling cultured multiple CPOs. A second decontamination was undertaken comprising a detergent, steam and hypochlorite clean followed by hydrogen peroxide misting, and no CPOs were cultured after subsequent environmental sampling. A burns patient harbouring CPOs contaminates the surroundings heavily, so standard cleaning is insufficient to reduce the environmental bioburden.

The National Aeronautics and Space Administration (NASA) imposes bioburden limitations on all spacecraft destined for solar system bodies that might harbor evidence of extant or extinct life. The subset of microorganisms trapped within solid materials during manufacture and assembly is referred to as encapsulated bioburden. In the absence of spacecraft-specific data, NASA relies on specification values to estimate total spacecraft encapsulated bioburden, typically 30 endospores/cm 3 or 300 viable cells/cm 3 in non-electronic materials. Specification values for endospores have been established conservatively, and represent no less than an order of magnitude greater abundance than that derived from empirical assessments of actual spacecraft materials. The goal of this study was to generate data germane to determining whether revised bulk encapsulated material values (lower than those estimated by historical specifications) tailored specifically to the materials designated in modern-day spacecraft design could be used, on a case-by-case basis, to comply with planetary protection requirements. Organic materials having distinctly different chemical properties and configurations were selected. This required more than one experimental and analytical approach. Filtration was employed for liquid electrolytes, lubricants were suspended in an aqueous solution and solids (wire and epoxy sealant) were cryogenically milled. The final data characteristic for all bioburden estimates was microbial colony formation in rich agar growth medium. To assess survival potential, three non-spore-forming bacterial cell lines were systematically encapsulated in an epoxy matrix, liberated via cryogenic grinding, and cultured. Results suggest that bulk solid materials harbor significantly fewer encapsulated microorganisms than are estimated by specification values. Lithium-ion battery electrolyte reagents housed fewer than 1 CFU/cm 3 . Results also demonstrated that non-spore-forming microorganisms are capable of surviving encapsulation within, and liberation from, epoxy solids. It must be noted, however, that all purposely spiked experimental solids, resulted in very low recovery (1 × 10 −3 –1 × 10 −5 CFU/cm 3 ) of viable organisms.

Summary Background The use of disinfectant pre-soaked wipes (DPW) to decontaminate high-touch environmental surfaces (HTES) by wiping is becoming increasingly widespread in the healthcare environment. However, DPW are rarely tested using conditions simulating their field use, and the label claims of environmental surface disinfectants seldom include wiping action. Aim To evaluate the new E2967-15 standard test specific to wipes, particularly their ability to decontaminate surfaces and to transfer acquired contamination to clean surfaces. Methods ASTM Standard E2967-15 was used by three independent laboratories to test the efficacy of five types of commercially available wipe products. All data generated were pulled together, and reproducibility and repeatability of the standard were measured. Findings All the commercial DPW tested achieved a >4log 10 (>99.99%) reduction in colony-forming units (CFU) of Staphylococcus aureus and Acinetobacter baumanii with 10s of wiping, but only one DPW containing 0.5% accelerated H 2 O 2 prevented the transfer of bacteria to another surface. Conclusion This newly introduced standard method represents a significant advance in assessing DPW for microbial decontamination of HTES, and should greatly assist research and development, and in making more relevant and reliable claims on marketed DPW.

Background It is generally agreed that contaminated hospital surfaces play a role in the transmission of hospital-acquired infections (HAIs). The ability of an antimicrobial agent, engineered at Emory University, to reduce bacterial bioburden on hospital surfaces was examined. A quantitative microbial risk assessment was also conducted to quantify the potential reduction of human health risks associated with application of this antimicrobial product. Methods A 1-arm, prospective observational study was conducted. High-frequency contact surfaces within 18 hospital patient rooms were sampled in between patient use. Negative binomial regression with repeated measures was used to examine log CFU/100 cm 2 reductions in total, gram-negative, and Staphylococcus aureus microorganisms. Standard risk assessment methods were used. Results Multivariate regression demonstrated significant reductions in gram-negative ( P S aureus ( P = .009) bacteria with increasing patient turnover. No reduction was observed in total bacteria ( P = .93). Infection risks were reduced by 4 and 3 logs for gram-positive and gram-negative bacteria, respectively. These risk reductions, along with HAI survey studies, suggest that application of this antimicrobial product could prevent as many as 5%-10% of HAIs. Conclusions This study was the first evaluation of a distinctive antimicrobial agent for hospital surface treatment. The findings provide support for the utility of an antimicrobial product in potentially reducing HAI transmission from contaminated environment surfaces.

Background Anesthesia workstations (AWs) are a reservoir for pathogenic organisms potentially associated with surgical site infections. This study examined the effectiveness of the Tru-D SmartUVC device (Tru-D LLC, Nashville, TN) on bioburden reduction (BR) on AWs. Methods Strips of tissue inoculated with a known concentration of either Staphylococcus aureus , Enterococcus faecalis , or Acinetobacter sp were placed on 22 high-touch surfaces of an AW. Half of the AW surfaces received direct ultraviolet (UV) light exposure and half received indirect exposure. Two inoculated strips, in sterile tubes outside of the room, represented the control. Trials were conducted on AWs in an operating room and a small room. Strips were placed in a saline solution, vortexed, and plated on blood agar to assess BR by the number of colony forming units. Results All experimental trials, compared with controls, exhibited a BR >99%. There was a significantly greater reduction of E faecalis colony forming units in the operating room AW under direct exposure ( P = .019) compared with indirect exposure. There was no significant difference in reduction when comparing AWs between rooms. Conclusion Regardless of room size and exposure type, automated UV-C treatment greatly influences BR on AW high-touch surfaces. Hospitals instituting an automated UV-C system as an infection prevention adjunct should consider utilizing it in operating rooms for BR as part of a horizontal infection prevention surgical site infection-reduction strategy.

In Portugal, mechanical protection gloves (MPG) are of mandatory use and during their use sweat is released and, consequently, the humidity of the material increases leading to conditions favorable to the growth of microorganisms. However, no studies have been conducted in MPG to assess the bioburden. This study intended to determine the bioburden present in MPG and their biological effects, and to discuss the possibility to use MPG as a passive method to assess occupational exposure to microbial contamination. Fungal burden was characterized through molecular tools for fungal toxigenic species, and antifungal resistance and mycotoxins profiles were determined. Cell viability was determined in swine kidney (SK) monolayer and hepatocellular carcinoma (Hep G2) cell lines. All MPG samples presented Gram-negative bacteria. The fungal contamination ranged from 0 CFU.m−2 in both MEA and DG18, to 5.09 × 106 and 2.75 × 106 and the most commonly fungi found was Aspergillus spp. (50.46%). Azole resistant Aspergillus sections were found in azole supplemented media. Aspergillus sections (Circumdati, Flavi, Fumigati and Versicolores) were detected by molecular tools in 66 out of 67 samples. The most reported mycotoxin was mycophenolic acid (89.6%). HepG2 cells appear to be more sensitive to MPG contamination, with high cytotoxicity (IC50 MPG can be used in passive sampling to assess occupational exposure to bioburden in waste sorting industries and contribute for risk characterization. Some contaminants of MPG had cytotoxic potential and affected the biology of hepatic cells more than renal cells.

BACKGROUND CONTEXT Though techniques for sterilizing surgical tools and supplies have steadily improved, current standards for operating room (OR) disinfection have become antiquated – providing continued convenience for pathogenic organisms and surgical site infections. Pulsed-xenon ultraviolet (PX-UV) disinfection is an opportunity for standardized, touch-free disinfection that may serve as a supplement to manual terminal cleaning. The combination of manual and PX-UV disinfection may provide the greatest reduction in OR bioburden, as measured by colony-forming units (CFUs), and frequency of site contamination. Here, the bioburden and site contamination of ORs following manual cleaning and PX-UV disinfection are explored. PURPOSE Determine impact of manual vs manual and PX-UV disinfection on CFUs in spine operating suites. STUDY DESIGN/SETTING N/A PATIENT SAMPLE N/A OUTCOME MEASURES N/A METHODS Fifteen ORs were sampled at three different time points – before terminal manual cleaning, after terminal manual cleaning, and after PX-UV. For each OR, at each time point, five high-touch surfaces were cultured using a Tryptone Soy Agar touch plate. A total of 225 samples were acquired. Samples were incubated for 24 hours and the number of colony-forming units reported. Distinct colonies were identified. Descriptive statistics and Rank Sum Testing with a Bonferroni correction were used to analyze results. RESULTS There was a 26.8% reduction of CFUs after manual cleaning (p>0.8014) and an 81.0% reduction of CFUs after PX-UV (p = 0.0086). Overall, the combination of manual and PX-UV disinfection resulted in an 86.10% reduction in CFUs (p = 0.004). The frequency of sites with CFUs prior to cleaning was 26.7%. There was no change in frequency of sites with CFUs after manual cleaning. Following PX-UV cleaning, the frequency of sites with CFUs reduced to 8.0%, which is a 70.0% reduction in sites with CFUs. Interestingly, the frequency of sites with an increase in CFUs after manual cleaning was 20.0%. There was no occurrence of an increase in CFUs after PX-UV disinfection. CONCLUSIONS The combination of PX-UV with manual cleaning yields the greatest reduction in OR bioburden as measured by CFUs. Manual cleaning alone resulted in a low reduction of CFUs and no change in the frequency of site contamination. Though some individual sites demonstrated elimination of CFUs following manual cleaning, there were a number of sites that had an increase in CFUs. This may represent cross contamination due to the inconsistent nature of manual terminal cleaning. The use of PX-UV disinfection resulted in a significant reduction in CFUs when compared to both the pre- and postmanual cleaning time points. PX-UV disinfection also yielded a reduction in the frequency of site contamination. This reduction in both bioburden and contaminated sites may contribute to a decreased risk of surgical site infection. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.