Point-of-Care Method T2Bacteria®Panel Enables a More Sensitive and Rapid Diagnosis of Bacterial Blood Stream Infections and a Shorter Time until Targeted Therapy than Blood Culture.

BACKGROUND: Rapid diagnosis and identification of pathogens are pivotal for appropriate therapy of blood stream infections. The T2Bacteria®Panel, a culture-independent assay for the detection of Escherichia coli, Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa in blood, was evaluated under real-world conditions as a point-of-care method including patients admitted to the internal medicine ward due to suspected blood stream infection. METHODS: Patients were assigned to two groups (standard of care-SOC vs. T2). In the SOC group 2 × 2 blood culture samples were collected, in the T2 group the T2Bacteria®Panel was performed additionally for pathogen identification. RESULTS: A total of 94 patients were included. Pathogens were detected in 19 of 50 patients (38%) in the T2 group compared to 16 of 44 patients (36.4%) in the SOC group. The median time until pathogen detection was significantly shorter in the T2 group (4.5 h vs. 60 h, p < 0.001), as well as the time until targeted therapy (antibiotic with the narrowest spectrum and maximal effectiveness) (6.4 h vs. 42.2 h, p = 0.043). CONCLUSIONS: The implementation of the T2Bacteria®Panel for patients with sepsis leads to an earlier targeted antimicrobial therapy resulting in earlier sufficient treatment and decreased excessive usage of broad-spectrum antimicrobials.

Surgical site infection after trochanteric and subtrochanteric fractures: a single centre retrospective analysis.

Surgical site infection (SSI) following osteosynthesis of trochanteric or subtrochanteric fractures is a rare but serious complication with incidence rate ranging from 1 to 3%. SSIs are associated with higher mortality and increased length of hospital stay resulting in higher healthcare costs and loss of life quality. In this retrospective analysis all patients with SSI following osteosynthesis of trochanteric or subtrochanteric fractures at the Department of Trauma Surgery were identified. We included all surgical procedures performed from 1992 to 2018, using data from electronic health records and SSI-Trauma-Registry. The aim was to describe epidemiological data, as well as to identify parameters correlating with the occurrence of SSI and mortality. Of 2753 patients, 53 (1.9%) developed SSI. Longer operative time was demonstrated among patients with SSI (P = 0.008). Mortality during the first postoperative year was significantly higher in the SSI group (32.1% vs. 19.1%; P = 0.018), with detection of methicillin-sensitive (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA; HR 4.13, CI 95% 1.24-13.80; P = 0.021) or Enterococcus spp. (HR 5.58, CI 95% 1.67-18.65; P = 0.005) being independent risk factors. Male sex (HR 2.25, 95% CI 1.86-2.73; P < 0.001) and higher mean age (HR 1.05, 95% CI 1.04-1.06; P < 0.001) were found to be predictors for 1-year mortality in non-infected patients. SSI rate was low with 1.9% and longer duration of surgery was associated with infection. Patients with SSI had a higher 1-year mortality, with detection of MSSA, MRSA and enterococci significantly increasing the risk of dying. Male sex and higher age were risk factors for one-year mortality in patients without SSI.

Revisiting the personal protective equipment components of transmission-based precautions for the prevention of COVID-19 and other respiratory virus infections in healthcare.

The COVID-19 pandemic highlighted some potential limitations of transmission-based precautions. The distinction between transmission through large droplets vs aerosols, which have been fundamental concepts guiding infection control measures, has been questioned, leading to considerable variation in expert recommendations on transmission-based precautions for COVID-19. Furthermore, the application of elements of contact precautions, such as the use of gloves and gowns, is based on low-quality and inconclusive evidence and may have unintended consequences, such as increased incidence of healthcare-associated infections and spread of multidrug-resistant organisms. These observations indicate a need for high-quality studies to address the knowledge gaps and a need to revisit the theoretical background regarding various modes of transmission and the definitions of terms related to transmission. Further, we should examine the implications these definitions have on the following components of transmission-based precautions: (i) respiratory protection, (ii) use of gloves and gowns for the prevention of respiratory virus infections, (iii) aerosol-generating procedures and (iv) universal masking in healthcare settings as a control measure especially during seasonal epidemics. Such a review would ensure that transmission-based precautions are consistent and rationally based on available evidence, which would facilitate decision-making, guidance development and training, as well as their application in practice.

COVID-19 patient and personal safety - lessons learnt for pandemic preparedness and the way to the next normal.

BACKGROUND: The COVID-19 pandemic has profoundly challenged societies and healthcare systems in particular. To prevent the spread of SARS-CoV-2, infection prevention and control (IPC) strategies had to be developed on the local, national and international level. The aim of this study is to provide details of the COVID-19 experience at the Vienna General Hospital (VGH) in the context of the national and international COVID-19 response for learning and improvement. METHODS: This is a retrospective report, outlining the evolution of IPC measures and challenges encountered at the health facility (VGH), the national (Austria) and global level between February 2020 and October 2022. RESULTS: The IPC strategy at the VGH has been continuously adapted to changes in the epidemiological setting, new legal directives and Austrian by-laws. The current strategy, nationally and internationally, focuses on endemicity rather than maximum transmission risk reduction. For the VGH, this has recently resulted in an increase in COVID-19 clusters. To protect our particularly vulnerable patients, many COVID-19 precautions have been maintained. Barriers to adequate IPC implementation at the VGH and other hospitals include a lack of sufficient isolation options and non-adherence with universal face mask regulations. Globally, misinformation on COVID-19 hampered an effective response. CONCLUSIONS: This retrospective analysis of the COVID-19 response at the VGH and international reports underline the need for pandemic preparedness, readiness and response by improving future hospital design and infrastructure, conducting regular trainings for protective attire and increasing health literacy as now recently published in a concise document by WHO.

EPI-Net One Health reporting guideline for antimicrobial consumption and resistance surveillance data: a Delphi approach.

Strategic and standardised approaches to analysis and reporting of surveillance data are essential to inform antimicrobial resistance (AMR) mitigation measures, including antibiotic policies. Targeted guidance on linking full-scale AMR and antimicrobial consumption (AMC)/antimicrobial residues (AR) surveillance data from the human, animal, and environmental sectors is currently needed. This paper describes the initiative whereby a multidisciplinary panel of experts (56 from 20 countries-52 high income, 4 upper middle or lower income), representing all three sectors, elaborated proposals for structuring and reporting full-scale AMR and AMC/AR surveillance data across the three sectors. An evidence-supported, modified Delphi approach was adopted to reach consensus among the experts for dissemination frequency, language, and overall structure of reporting; core elements and metrics for AMC/AR data; core elements and metrics for AMR data. The recommendations can support multisectoral national and regional plans on antimicrobials policy to reduce resistance rates applying a One Health approach.

ESCMID/EUCIC clinical practice guidelines on perioperative antibiotic prophylaxis in patients colonized by multidrug-resistant Gram-negative bacteria before surgery.

SCOPE: The aim of the guidelines is to provide recommendations on perioperative antibiotic prophylaxis (PAP) in adult inpatients who are carriers of multidrug-resistant Gram-negative bacteria (MDR-GNB) before surgery. METHODS: These evidence-based guidelines were developed after a systematic review of published studies on PAP targeting the following MDR-GNB: extended-spectrum cephalosporin-resistant Enterobacterales, carbapenem-resistant Enterobacterales (CRE), aminoglycoside-resistant Enterobacterales, fluoroquinolone-resistant Enterobacterales, cotrimoxazole-resistant Stenotrophomonas maltophilia, carbapenem-resistant Acinetobacter baumannii (CRAB), extremely drug-resistant Pseudomonas aeruginosa, colistin-resistant Gram-negative bacteria, and pan-drug-resistant Gram-negative bacteria. The critical outcomes were the occurrence of surgical site infections (SSIs) caused by any bacteria and/or by the colonizing MDR-GNB, and SSI-attributable mortality. Important outcomes included the occurrence of any type of postsurgical infectious complication, all-cause mortality, and adverse events of PAP, including development of resistance to targeted (culture-based) PAP after surgery and incidence of Clostridioides difficile infections. The last search of all databases was performed until April 30, 2022. The level of evidence and strength of each recommendation were defined according to the Grading of Recommendations Assessment, Development and Evaluation approach. Consensus of a multidisciplinary expert panel was reached for the final list of recommendations. Antimicrobial stewardship considerations were included in the recommendation development. RECOMMENDATIONS: The guideline panel reviewed the evidence, per bacteria, of the risk of SSIs in patients colonized with MDR-GNB before surgery and critically appraised the existing studies. Significant knowledge gaps were identified, and most questions were addressed by observational studies. Moderate to high risk of bias was identified in the retrieved studies, and the majority of the recommendations were supported by low level of evidence. The panel conditionally recommends rectal screening and targeted PAP for fluoroquinolone-resistant Enterobacterales before transrectal ultrasound-guided prostate biopsy and for extended-spectrum cephalosporin-resistant Enterobacterales in patients undergoing colorectal surgery and solid organ transplantation. Screening for CRE and CRAB is suggested before transplant surgery after assessment of the local epidemiology. Careful consideration of the laboratory workload and involvement of antimicrobial stewardship teams before implementing the screening procedures or performing changes in PAP are warranted. High-quality prospective studies to assess the impact of PAP among CRE and CRAB carriers performing high-risk surgeries are advocated. Future well-designed clinical trials should assess the effectiveness of targeted PAP, including the monitoring of MDR-GNB colonization through postoperative cultures using European Committee on Antimicrobial Susceptibility Testing clinical breakpoints.

Infection prevention and control policies in hospitals and prevalence of highly resistant microorganisms: an international comparative study.

BACKGROUND: There are differences in infection prevention and control (IPC) policies to prevent transmission of highly resistant microorganisms (HRMO). The aim of this study is to give an overview of the IPC policy of six European hospitals and their HRMO prevalence, to compare the IPC policies of these hospitals with international guidelines, and to investigate the hospitals' adherence to their own IPC policy. METHODS: The participating hospitals were located in Salzburg (Austria), Vienna (Austria), Kayseri (Turkey), Piraeus (Greece), Rome (Italy) and Rotterdam (The Netherlands). Data were collected via an online survey. Questions were aimed at prevalence rates in the years 2014, 2015, 2016 of carbapenemase-producing Klebsiella pneumoniae (CPK), carbapenemase-producing Pseudomonas aeruginosa (CPPA), vancomycin-resistant Enterococcus faecium (VRE) and hospitals' IPC policies of 2017. Implemented IPC measures (i.e. with a self-reported adherence of > 90%) were counted (26 points maximal). RESULTS: The self-reported prevalence of CPK per year was low in the Austrian and Dutch hospitals and high in the Turkish and Greek hospitals. CPPA was highly prevalent in the Turkish hospital only, while the prevalence of VRE in four hospitals, except the Austrian hospitals which reported lower prevalence numbers, was more evenly distributed. The Dutch hospital had implemented the most IPC measures (n = 21), the Turkish and Greek hospitals the least (n = 14 and 7, respectively). CONCLUSION: Hospitals with the highest self-reported prevalence of CPK and CPPA reported the least implemented IPC measures. Also, hospitals with a higher prevalence often reported a lower adherence to own IPC policy.

Provision of safe patient care during the COVID-19 pandemic despite shared patient rooms in a tertiary hospital.

BACKGROUND: The COVID-19 pandemic has resulted in the disruption of healthcare systems. Vienna General Hospital (VGH), a tertiary hospital located in Austria, ran at almost full capacity despite high levels of community SARS-CoV-2 transmission and limited isolation room capacity. To ensure safe patient care, a bundle of infection prevention and control (IPC) measures including universal pre-admission screening and serial SARS-CoV-2 testing during hospitalization was implemented. We evaluated whether testing as part of our IPC approach was effective in preventing hospital outbreaks during different stages of the pandemic. METHODS: In this retrospective single center study, we analyzed the SARS-CoV-2 PCR test results of cases admitted to VGH between a low (15/05/2020-01/08/2020) and a high incidence period (15/09/2020-18/05/2021). Outcomes were the diagnostic yield of (a) admission screening, (b) the yield of serial testing during hospitalization and (c) the occurrence of healthcare-associated COVID-19 (HA-COVID-19) and SARS-CoV-2 related hospital outbreaks. RESULTS: The admission test positivity rate was 0.2% during the low and 2.3% during the high incidence phase. Regarding test conversions, 0.04% (low incidence phase) and 0.5% (high incidence phase) of initially negative cases converted to a positive test result within 7 days after admission The HA-COVID-19 incidence rate per 100,000 patient days was 1.0 (low incidence phase) and 10.7 (high incidence phase). One COVID-19 outbreak affecting eight patients in total could be potentially ascribed to the non-compliance with our IPC protocol. CONCLUSION: Testing in conjunction with other IPC measures enabled the safe provision of patient care at a hospital with predominantly shared patient rooms despite high case numbers in the community.

Routine Surveillance of Healthcare-Associated Infections Misses a Significant Proportion of Invasive Aspergillosis in Patients with Severe COVID-19.

Rates of invasive aspergillosis (IA) among COVID-19 ICU patients seem to reach over 30% in certain settings. At Vienna General Hospital (VGH), all rooms in COVID-19 ICUs were put under negative pressure as a protective measure, thus increasing the risk of exposure to environmental pathogens for patients. Even though all ICU patients are surveilled for healthcare-associated infections (HAI), there were concerns that the routine protocol might not be sufficient for IA detection. We reviewed the electronic patient charts of all patients with COVID-19 admitted to ICUs between 1 March 2020 and 31 July 2021 for fungal co- or superinfections, comparing four diagnostic algorithms based on different recommendations for the diagnosis of IA (according to EORTC/MSG, BM-AspICU, IAPA and CAPA) to our routine surveillance protocol. We found that out of 252 patients who were admitted to the ICU during the study period, 25 (9.9%) fulfilled the criteria of probable or possible IA of at least one algorithm. The IAPA definitions detected 25 and the CAPA definition 23 probable and 2 possible cases, out of which only 16 were classified as hospital-acquired IA by routine surveillance. In conclusion, adjustment of the routine protocol using a classification system especially designed for respiratory viral illness seems useful for the surveillance of IA in a highly vulnerable patient cohort.

ESCMID guidelines on testing for SARS-CoV-2 in asymptomatic individuals to prevent transmission in the health care setting.

SCOPE: This guideline addresses the indications for direct testing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in asymptomatic individuals in health care facilities, with the aim to prevent SARS-CoV-2 transmissions in these settings. The benefit of testing asymptomatic individuals to create a safe environment for patients and health care workers must be weighed against potential unintended consequences, including delaying necessary treatments owing to false positive results and lower quality of care owing to strict isolation measures. METHODS: A total of nine PICOs (population, intervention, comparison, outcome) on the topic of testing asymptomatic individuals was selected by the panel members. Subsequently, a literature search for existing guidelines and systematic reviews was performed on PubMed, Epistemonikos, and RecMap using relevant filters available in each database. Data on article/recommendation type, setting, target population, intervention, and quality of the evidence were extracted. Credibility of the systematic reviews was evaluated using the AMSTAR tool, and level of agreement with available recommendation was evaluated with the AGREE II score. Because the evidence available from systematic reviews was deemed insufficiently updated to formulate relevant recommendations, an additional search targeting relevant guidance documents from major public health institutions and original studies was performed. Provisional recommendations were discussed via web conferences until agreement was reached, and final recommendations were formulated according to the GRADE approach. RECOMMENDATIONS: Recommendations were formulated regarding systematic testing in asymptomatic individuals upon admission to a health care setting, during hospital stay, before elective procedures, and before scheduled nonsurgical procedures. Moreover, recommendations regarding testing of asymptomatic visitors, personal caregivers, and health care workers in health care facilities were presented. Recommendations also were given on contact tracing in asymptomatic patients or health care workers and the possibility of a negative screening test to shorten the quarantine period. Furthermore, if applicable, recommendations were specified to transmission rate and vaccination coverage.

The effectiveness of surface disinfectants and a micellic H2O2 based water disinfectant on Candida auris.

BACKGROUND: As infection control faces new challenges from emerging, multidrug resistant strains of the yeast Candida auris, this study was conducted in order to examine the efficacy of hospital surface disinfectants and a new water disinfectant against C. auris biofilm forms. METHODS: We tested four reference strains of C. auris (NCPF8971, NCPF8977, NCPF8984, DSM21092) and one C. albicans strain (ATCC10231) against disinfectants based on ethanol (ETH), quaternary ammonium (QAC), a combination of glutaraldehyde, quaternary ammonium and surfactant (ALD) and potassium peroxymonosulfate (PP) as well as 3.4% H2O2 and 4.25% H2O2 alone. In addition, a micellic-based formulation containing 17% v/v hydrogene peroxide disinfectant (mH2O2) was tested. The efficacy of the disinfectants was measured in a 96-well plate using tetrazolium salt reduction (XTT) and the log10 reduction assay. RESULTS: ETH and QAC displayed in clinically recommended concentrations more than 5log10 reduction and more than 80% XTT activity reduction for all of the Candida biofilms and planktonic cells. Only biofilms of C. auris NCPF8984 were additionally sensitive to all remaining disinfectants. All tested C. auris biofilms were sensitive to PP disinfectant and showed more than 5log10 reduction. However, the XTT assay showed a reduction of less than 80% for the PP disinfectant, indicating the presence of active but non-culturable cells. The 25% mH2O2 (corresponding to 4.25% H2O2) killed Candida biofilms after 1 minute.

Governance aspects of large-scale implementation of automated surveillance of healthcare-associated infections.

OBJECTIVES: Surveillance of healthcare-associated infections (HAI) is increasingly automated by applying algorithms to routine-care data stored in electronic health records. Hitherto, initiatives have mainly been confined to single healthcare facilities and research settings, leading to heterogeneity in design. The PRAISE network - Providing a Roadmap for Automated Infection Surveillance in Europe - designed a roadmap to provide guidance on how to move automated surveillance (AS) from the research setting to large-scale implementation. Supplementary to this roadmap, we here discuss the governance aspects of automated HAI surveillance within networks, aiming to support both the coordinating centres and participating healthcare facilities as they set up governance structures and to enhance involvement of legal specialists. METHODS: This article is based on PRAISE network discussions during two workshops. A taskforce was installed that further elaborated governance aspects for AS networks by reviewing documents and websites, consulting experts and organizing teleconferences. Finally, the article has been reviewed by an independent panel of international experts. RESULTS: Strict governance is indispensable in surveillance networks, especially when manual decisions are replaced by algorithms and electronically stored routine-care data are reused for the purpose of surveillance. For endorsement of AS networks, governance aspects specifically related to AS networks need to be addressed. Key considerations include enabling participation and inclusion, trust in the collection, use and quality of data (including data protection), accountability and transparency. CONCLUSIONS: This article on governance aspects can be used by coordinating centres and healthcare facilities participating in an AS network as a starting point to set up governance structures. Involvement of main stakeholders and legal specialists early in the development of an AS network is important for endorsement, inclusivity and compliance with the laws and regulations that apply.

PRAISE: providing a roadmap for automated infection surveillance in Europe.

INTRODUCTION: Healthcare-associated infections (HAI) are among the most common adverse events of medical care. Surveillance of HAI is a key component of successful infection prevention programmes. Conventional surveillance - manual chart review - is resource intensive and limited by concerns regarding interrater reliability. This has led to the development and use of automated surveillance (AS). Many AS systems are the product of in-house development efforts and heterogeneous in their design and methods. With this roadmap, the PRAISE network aims to provide guidance on how to move AS from the research setting to large-scale implementation, and how to ensure the delivery of surveillance data that are uniform and useful for improvement of quality of care. METHODS: The PRAISE network brings together 30 experts from ten European countries. This roadmap is based on the outcome of two workshops, teleconference meetings and review by an independent panel of international experts. RESULTS: This roadmap focuses on the surveillance of HAI within networks of healthcare facilities for the purpose of comparison, prevention and quality improvement initiatives. The roadmap does the following: discusses the selection of surveillance targets, different organizational and methodologic approaches and their advantages, disadvantages and risks; defines key performance requirements of AS systems and suggestions for their design; provides guidance on successful implementation and maintenance; and discusses areas of future research and training requirements for the infection prevention and related disciplines. The roadmap is supported by accompanying documents regarding the governance and information technology aspects of implementing AS. CONCLUSIONS: Large-scale implementation of AS requires guidance and coordination within and across surveillance networks. Transitions to large-scale AS entail redevelopment of surveillance methods and their interpretation, intensive dialogue with stakeholders and the investment of considerable resources. This roadmap can be used to guide future steps towards implementation, including designing solutions for AS and practical guidance checklists.

Ultraviolet disinfection robots to improve hospital cleaning: Real promise or just a gimmick?

The global COVID-19 pandemic due to the novel coronavirus SARS-CoV-2 has challenged the availability of traditional surface disinfectants. It has also stimulated the production of ultraviolet-disinfection robots by companies and institutions. These robots are increasingly advocated as a simple solution for the immediate disinfection of rooms and spaces of all surfaces in one process and as such they seem attractive to hospital management, also because of automation and apparent cost savings by reducing cleaning staff. Yet, there true potential in the hospital setting needs to be carefully evaluated. Presently, disinfection robots do not replace routine (manual) cleaning but may complement it. Further design adjustments of hospitals and devices are needed to overcome the issue of shadowing and free the movement of robots in the hospital environment. They might in the future provide validated, reproducible and documented disinfection processes. Further technical developments and clinical trials in a variety of hospitals are warranted to overcome the current limitations and to find ways to integrate this novel technology in to the hospitals of to-day and the future.

Filamentous Fungal Infections in a Tertiary Care Setting: Epidemiology and Clinical Outcome.

Information on the distribution of filamentous fungal pathogens, which cause potential life-threatening invasive infections mostly in immunocompromised persons, is of great importance. The aim of this study was to evaluate the epidemiology and clinical outcome in patients with infections due to filamentous fungi at the University Hospital of Vienna, Austria. We conducted a retrospective observational study and consecutively included patients of any age with filamentous fungal infections between 2009 and 2017. The classification for probable and proven invasive filamentous fungal infections was based on the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group (EORTC) criteria or the expert opinion of an experienced clinical mycologist. We included 129 patients (median age: 52 years; 47.3% female) with episodes of 101 proven and probable invasive and 35 localized filamentous fungal infections (16 sinus, 14 eye, one ear, and four deep cutaneous). Aspergillus fumigatus alone accounted for 50.3% of the fungi, which was followed by the Mucorales group (13.7%) and Fusarium spp. (8.5%). Diagnosis was mainly based on culture findings. The lung was the most frequent site of infection. The 30-day and 90-day overall mortality of invasive fungal infections was 30.2% and 42.7%, respectively. We observed a high all-cause mortality among patients with invasive filamentous fungal infections. Prospective data collection in a nationwide registry would be necessary to provide important information on surveillance to clinicians and other decision-makers.

White Paper: Bridging the gap between human and animal surveillance data, antibiotic policy and stewardship in the hospital sector-practical guidance from the JPIAMR ARCH and COMBACTE-MAGNET EPI-Net networks.

BACKGROUND: Antimicrobial surveillance and antimicrobial stewardship (AMS) are essential pillars in the fight against antimicrobial resistance (AMR), but practical guidance on how surveillance data should be linked to AMS activities is lacking. This issue is particularly complex in the hospital setting due to structural heterogeneity of hospital facilities and services. The JPIAMR ARCH and COMBACTE-MAGNET EPI-Net networks have joined efforts to formulate a set of target actions for linking surveillance data with AMS activities. METHODS: A scoping review of the literature was carried out addressing research questions on three areas: (i) AMS leadership and accountability; (ii) antimicrobial usage and AMS; (iii) AMR and AMS. Consensus on the target actions was reached through a RAND-modified Delphi process involving over 40 experts in different fields from 18 countries. RESULTS: Evidence was retrieved from 51 documents. Initially 38 targets were proposed, differentiated as essential or desirable according to clinical relevance, feasibility and applicability to settings and resources. In the first consultation round, preliminary agreement was reached for 32 targets. Following a second consultation, 27 targets were approved, 11 were deleted and 4 were suggested for rephrasing, leading to a final approved list of 34 target actions in the form of a practical checklist. CONCLUSIONS: This White Paper provides a pragmatic and flexible tool to guide the development of calibrated hospital-surveillance-based AMS interventions. The strength of this tool is that it is a comprehensive perspective that takes into account the hospital patient case-mix and the related epidemiology, which ultimately drives antimicrobial usage, and the feasibility in low-resource settings.

A novel micellar formulation based on natural plant extracts enhances the efficacy of hydrogen peroxide against biofilms of Staphylococcus spp. and Pseudomonas aeruginosa.

The antibacterial efficacy of hydrogen peroxide encapsulated in micelles (mH2O2) against biofilms was compared with that of hydrogen peroxide alone and of three commercially available aqueous biocides. The activity of mH2O2 on 24-h biofilms of reference strains of Staphylococcus spp. and Pseudomonas aeruginosa was tested in a static microtiter plate model. The biofilms were incubated with mH2O2 (17% v/v H2O2, 2% lactic acid, 0.3% phytoextract, H2O) and its individual ingredients and compared with three aqueous biocides at different concentrations and times of exposure. After 5-min exposure, 10% mH2O2 (corresponding to 1.7% v/v H2O2) achieved > 8 log10 reductions against all the test strains, while 1.7% H2O2 achieved a maximum of 1.5 log10 reduction. After 5-min exposure, none of the commercially available biocides tested showed themselves to be capable of completely eliminating the test strains embedded in biofilms. Hydrogen peroxide encapsulated in micelles demonstrated enhanced activity against planktonic cells and biofilms of Staphylococcus spp. and P. aeruginosa.

Disinfection of contaminated metal implants with an Er:YAG laser.

Infections related to orthopedic procedures are considered particularly severe when implantation materials are used, because effective treatments for biofilm removal are lacking. In this study, the relatively new approach for infection control by using an erbium:yttrium-aluminum-garnet (Er:YAG) laser was tested. This laser vaporizes all water containing cells in a very effective, precise, and predictable manner and results in only minimal thermal damage. For preliminary testing, 42 steel plates and 42 pins were seeded with mixed cultures. First, the minimally necessary laser energy for biofilm removal was determined. Subsequently, the effectiveness of biofilm removal with the Er:YAG laser and the cleansing of the metal implants with octenidine-soaked gauze was compared. Then, we compared the effectiveness of biofilm removal on 207 steel pins from 41 patients directly after explantation. Sonication and scanning electron microscopy were used for analysis. Laser fluences exceeding 2.8 J/cm2 caused a complete extinction of all living cells by a single-laser impulse. Cleansing with octenidine-soaked gauze and irradiation with the Er:YAG laser are both thoroughly effective when applied to seeded pins. In contrast, when explanted pins with fully developed biofilms were analyzed, we found a significant advantage of the laser procedure. The Er:YAG laser offers a secure, complete, and nontoxic eradication of all kinds of pathogens from metal implants without damaging the implant and without the possible development of resistance. The precise noncontact removal of adjacent tissue is a decisive advantage over conventional disinfectants. Therefore, laser irradiation could become a valuable method in every debridement, antibiotics, and implant retention procedure.