Inactivation of Campylobacter jejuni by exposure to high-intensity 405-nm visible light

Although considerable research has been carried out on a range of environmental factors that impact on the survival of Campylobacter jejuni, there is limited information on the effects of violet/blue light on this pathogen. This investigation was carried out to determine the effects of high-intensity 405-nm light on C. jejuni and to compare this with the effects on two other important Gram-negative enteric pathogens, Salmonella enteritidis and Escherichia coli O157:H7. High-intensity 405-nm light generated from an array of 405-nm light-emitting diodes was used to inactivate the test bacteria. The results demonstrated that while all three tested species were susceptible to 405-nm light inactivation, C. jejuni was by far the most sensitive organism, requiring a total dose of 18J cm−2 of 405-nm light to achieve a 5-log10 reduction. This study has established that C. jejuni is particularly susceptible to violet/blue light at a wavelength of 405nm. This finding, coupled with the safety-in-use advantages of this visible (non-ultraviolet wavelength) light, suggests that high-intensity 405-nm light may have applications for control of C. jejuni contamination levels in situations where this type of illumination can be effectively applied

Effect of 405 nm high-intensity narrow-spectrum light on osteoblast function

A significant portion of medical devices fail due to acquired infection, with infection rates after arthroplasty surgery between 1-4%, and considerably higher after revision surgery. To reduce the associated costs of infection, a new preventative method is required. High intensity narrow spectrum (HINS) 405 nm light is a new technology shown to have bactericidal effects on a range of medically important bacteria[1]. The effect of HINS-light on osteoblasts and bacteria were investigated to determine the potential of this technology to contribute to infection prevention in operating theatres, during surgery and postoperative dressing changes

Synergistic efficacy of 405 nm light and chlorinated disinfectants for the enhanced decontamination of Clostridium difficile spores

The ability of Clostridium difficile to form highly resilient spores which can survive in the environment for prolonged periods causes major contamination problems. Antimicrobial 405 nm light is being developed for environmental decontamination within hospitals, however further information relating to its sporicidal efficacy is required. This study aims to establish the efficacy of 405 nm light for inactivation of C. difficile vegetative cells and spores, and to establish whether spore susceptibility can be enhanced by the combined use of 405 nm light with low concentration chlorinated disinfectants. Vegetative cells and spore suspensions were exposed to increasing doses of 405 nm light (at 70–225 mW/cm2) to establish sensitivity. A 99.9% reduction in vegetative cell population was demonstrated with a dose of 252 J/cm2, however spores demonstrated higher resilience, with a 10-fold increase in required dose. Exposures were repeated with spores suspended in the hospital disinfectants sodium hypochlorite, Actichlor and Tristel at non-lethal concentrations (0.1%, 0.001% and 0.0001%, respectively). Enhanced sporicidal activity was achieved when spores were exposed to 405 nm light in the presence of the disinfectants, with a 99.9% reduction achieved following exposure to 33% less light dose than required when exposed to 405 nm light alone. In conclusion, C. difficile vegetative cells and spores can be successfully inactivated using 405 nm light, the sporicidal efficacy can be significantly enhanced when exposed in the presence of low concentration chlorinated disinfectants. Further research may lead to the potential use of 405 nm light decontamination in combination with selected hospital disinfectants to enhance C. difficile cleaning and infection control procedures

Quantifying bacterial transfer from patients to staff during burns dressing and bed changes : implications for infection control

Routine nursing activities such as dressing/bed changes increase bacterial dispersal from burns patients, potentially contaminating healthcare workers (HCW) carrying out these tasks. HCW thus become vectors for transmission of nosocomial infection between patients. The suspected relationship between %total body surface area (%TBSA) of burn and levels of bacterial release has never been fully established. Bacterial contamination of HCW was assessed by contact plate samples (n = 20) from initially sterile gowns worn by the HCW during burns patient dressing/bed changes. Analysis of 24 gowns was undertaken and examined for relationships between %TBSA, time taken for activity, and contamination received by the HCW. Relationships between size of burn and levels of HCW contamination, and time taken for the dressing/bed change and levels of HCW contamination were best described by exponential models. Burn size correlated more strongly (R2 = 0.82, p < 0.001) than time taken (R2 = 0.52, p < 0.001), with levels of contamination received by the HCW. Contamination doubled with every 6–9% TBSA increase in burn size. Burn size was used to create a model to predict bacterial contamination received by a HCW carrying out bed/dressing changes. This may help with the creation of burn-specific guidelines on protective clothing worn by HCW caring for burns patients

Bactericidal effect of corona discharges in atmospheric air

The present paper explores the possibilities of using impulsive and steady-state corona discharges for bio-decontamination operations. A high tension tubular corona electrode was stressed with positive or negative dc voltage with magnitude up to 26 kV, and a grounded mesh was used as an opposite electrode. Different operational regimes of this corona generator were investigated for the production of ozone in air flow and the inactivation of microorganisms. The test microorganisms used in this work were Escherichia coli and Staphylococcus aureus, populations of which were seeded onto agar plates. These bacterial plates were located behind the grounded mesh electrode to assess bactericidal efficacy. The results show that corona discharges have a strong bactericidal effect, for example positive flashing corona discharges were able to reduce populations of the test microorganism by 94% within a 30-60 sec time interval. Negative steady-state corona discharges also produce noticeable bactericidal effect, reducing population of E. coli and S. aureus by more than 97% within 120 sec energisation interval. The bactericidal efficiency of different corona discharge modes and its correlation with ozone levels produced by these discharges is discussed. The results obtained in this work will help in the design and development of compact plasma systems for environmental application

405 nm light exposure of osteoblasts and inactivation of bacterial isolates from arthroplasty patients : potential for new disinfection applications?

Infection rates after arthroplasty surgery are between 1-4 %, rising significantly after revision procedures. To reduce the associated costs of treating these infections, and the patients' post-operative discomfort and trauma, a new preventative method is required. High intensity narrow spectrum (HINS) 405 nm light has bactericidal effects on a wide range of medically important bacteria, and it reduced bacterial bioburden when used as an environmental disinfection method in a Medical Burns Unit. To prove its safety for use for environmental disinfection in orthopaedic theatres during surgery, cultured osteoblasts were exposed to HINS-light of intensities up to 15 mW/cm2 for 1 h (54 J/cm2). Intensities of up to 5 mW/cm2 for 1 h had no effect on cell morphology, activity of alkaline phosphatase, synthesis of collagen or osteocalcin expression, demonstrating that under these conditions this dose is the maximum safe exposure for osteoblasts; after exposure to 15 mW/cm2 all parameters of osteoblast function were significantly decreased. Viability (measured by protein content and Crystal Violet staining) of the osteoblasts was not influenced by exposure to 5 mW/cm2 for at least 2 h. At 5 mW/cm2 HINS-light is an effective bactericide. It killed 98.1 % of Staphylococcus aureus and 83.2 % Staphylococcus epidermis populations seeded on agar surfaces, and is active against both laboratory strains and clinical isolates from infected hip and knee arthroplasties. HINS-light could have potential for development as a method of disinfection to reduce transmission of bacteria during arthroplasty, with wider applications in diverse surgical procedures involving implantation of a medical device. With kind permission of full reproduction from eCM journal (www.ecmjournal.org). Founded by scientists for the benefit of Science rather than profit

Use of simulated patients to develop communication skills in nursing education: An integrative review

Background Registered nurses are expected to communicate effectively with patients. To improve on this skill education programmes in both hospital and tertiary settings are increasingly turning to simulation modalities when training undergraduate and registered nurses. The roles simulated patients (SPs) assume can vary according to training purposes and approach. Aims The first aim is to analyse how SPs are used in nursing education to develop communication skills. The second aim is to evaluate the evidence that is available to support the efficacy of using SPs for training nurses in communication skills and finally to review the SP recruitment and training procedure. Design An Integrative review. Data Sources A search was conducted on CINAHL, Psych-info, PubMed, Google Scholar, Scopus, Ovid, Medline, and ProQuest databases. Keywords and inclusion/exclusion criteria were determined and applied to the search strategy. Review Methods The integrative review included Nineteen studies from 2006-2016. Critical Appraisal Skills Program (CASP) method of evaluation was utilised. Emergent themes were extracted with similar and divergent perspectives. Results Analysis identified seven clinical contexts for communication skills training (CST) and two SP roles from the eighteen studies. SPs were either directly involved in the teaching of communication (active role) or used in the evaluation of the effectiveness of a communication skills program (passive role). A majority of studies utilised faculty-designed measurement instruments. Conclusion The evidence presented in the 19 articles indicates that the use of SPs to teach nurse-patient communication skills targets more challenging clinical interactions. Engaging SPs in both CST program facilitation and course evaluation provides nurse educators with a strong foundation to develop further pedagogical and research capacity. Expanding the utilisation of SPs to augment nurses’ communication skills and ability to engage with patients in a broader range of clinical contexts with increased methodological rigor is recommended. © 2016 Elsevier Lt

Inactivation of C. difficile by 405 nm HINS-light

This poster discusses using 405nm HINS-light to make Clostridium difficile cells and spores inactive

Simulated patients enhance discharge processes for patients with type 2 diabetes

As hospital lengths of stay are reduced and patients are organised to return home with the expectation of managing more complex issues, preparing patients and their families for discharge becomes more challenging. Patients with chronic health conditions, such as type 2 diabetes typically have poorer health outcomes post discharge and higher readmission rates (Peter et al. 2015). Preparing nurses to perform safe, complex patient discharge will likely lead to improved patient confidence in self-management, and potentially better outcomes