[Multiresistant Pathogens in Oncological and Cardiological Rehabilitation - Results of a Surveillance Study in Brandenburg]. / Multiresistente Erreger in der onkologischen und kardiologischen Rehabilitation ­ Ergebnisse einer Surveillancestudie in Brandenburg.

We investigated the prevalence of multidrug resistant pathogens in patients of oncologic and cardiologic rehabilitation units with 155 oncologic and 157 cardiologic patients undergoing microbiologic screening. It was found that 4.5% of oncologic as well as cardiologic patients were colonized with multidrug resistant pathogens. 2-MRGN and ESBL were the most encountered species (2.9%). 3-MRGN were found twice as frequent in oncologic patients (2.6 and 1.3%). Overall oncologic and cardiologic patients exhibit comparatively low prevalence rates for multidrug resistant pathogens.

Efficacy of 233 nm LED far UV-C-radiation against clinically relevant bacterial strains in the phase 2/ step 2 in vitro test on basis of EN 14561 and on an epidermis cell model.

INTRODUCTION: Healthcare-acquired infections and overuse of antibiotics are a common problem. Rising emergence of antibiotic and antiseptic resistances requires new methods of microbial decontamination or decolonization as the use of far-UV-C radiation. METHODS: The microbicidal efficacy of UV-C radiation (222 nm, 233 nm, 254 nm) was determined in a quantitative carrier test and on 3D-epidermis models against Staphylococcus (S.) aureus, S.epidermidis, S.haemolyticus, S.lugdunensis, Klebsiella pneumoniae, and Pseudomonas aeruginosa. To mimic realistic conditions, sodium chloride solution, mucin, albumin, artificial saliva, artificial wound exudate and artificial sweat were used. RESULTS: In sodium chloride solution, irradiation with a dose of 40 mJ/cm2 (233 nm) was sufficient to achieve 5 lg reduction independent of bacteria genus or species. In artificial sweat, albumin and artificial wound exudate, a reduction >3 lg was reached for most of the bacteria. Mucin and artificial saliva decreased the reduction to <2 lg. On 3D epidermis models, reduction was lower than in the carrier test. CONCLUSION: UV-C radiation at 233 nm was proven to be efficient in bacteria inactivation independent of genus or species thus being a promising candidate for clinical use in the presence of humans and on skin/mucosa.

Irradiation of human oral mucosa by 233 nm far UV-C LEDs for the safe inactivation of nosocomial pathogens.

The inactivation of multi resistant pathogens is an important clinical need. One approach is UV-C irradiation, which was previously not possible in vivo due to cytotoxicity. Recently, far UV-C irradiation at λ < 240 nm was successfully used on skin with negligible damage. A potential application site is the nasal vestibule, where MRSA accumulates and cannot be treated using antiseptics. We irradiated 3D mucosa models and excised human mucosa with 222 and 233 nm far UV-C in comparison to 254 nm and broadband UV-B. Eradication efficiency was evaluated by counting colony forming units; irritation potential was evaluated by hen's egg-chorioallantoic membrane assay and trans epithelial electrical resistance; cell viability was assessed by MTT. DNA damage and cell protective mechanisms were evaluated immunohistopathologically. On mucosa models, MRSA reduced by ≈ 5 log10 for 60 mJ/cm2 irradiation at 233 nm. A slightly increased cell viability was observed after 24 h. Lower doses showed lower irritation potential than the positive controls or commercial mouthwash, while 80 mJ/cm2 had strong irritation potential. DNA damage occurred only superficially and decreased after 24 h. On excised human mucosa, < 10% of keratinocytes were affected after 150 mJ/cm2 222 nm or 60 mJ/cm2 233 nm.

Application of 233 nm far-UVC LEDs for eradication of MRSA and MSSA and risk assessment on skin models.

A newly developed UVC LED source with an emission wavelength of 233 nm was proved on bactericidal efficacy and skin tolerability. The bactericidal efficacy was qualitatively analysed using blood agar test. Subsequently, quantitative analyses were performed on germ carrier tests using the MRSA strain DSM11822, the MSSA strain DSM799, S. epidermidis DSM1798 with various soil loads. Additionally, the compatibility of the germicidal radiation doses on excised human skin and reconstructed human epidermis was proved. Cell viability, DNA damage and production of radicals were assessed in comparison to typical UVC radiation from discharge lamps (222 nm, 254 nm) and UVB (280-380 nm) radiation for clinical assessment. At a dose of 40 mJ/cm2, the 233 nm light source reduced the viable microorganisms by a log10 reduction (LR) of 5 log10 levels if no soil load was present. Mucin and protein containing soil loads diminished the effect to an LR of 1.5-3.3. A salt solution representing artificial sweat (pH 8.4) had only minor effects on the reduction. The viability of the skin models was not reduced and the DNA damage was far below the damage evoked by 0.1 UVB minimal erythema dose, which can be regarded as safe. Furthermore, the induced damage vanished after 24 h. Irradiation on four consecutive days also did not evoke DNA damage. The radical formation was far lower than 20 min outdoor visible light would cause, which is classified as low radical load and can be compensated by the antioxidant defence system.

Skin tolerant inactivation of multiresistant pathogens using far-UVC LEDs.

Multiresistant pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) cause serious postoperative infections. A skin tolerant far-UVC (< 240 nm) irradiation system for their inactivation is presented here. It uses UVC LEDs in combination with a spectral filter and provides a peak wavelength of 233 nm, with a full width at half maximum of 12 nm, and an irradiance of 44 µW/cm2. MRSA bacteria in different concentrations on blood agar plates were inactivated with irradiation doses in the range of 15-40 mJ/cm2. Porcine skin irradiated with a dose of 40 mJ/cm2 at 233 nm showed only 3.7% CPD and 2.3% 6-4PP DNA damage. Corresponding irradiation at 254 nm caused 15-30 times higher damage. Thus, the skin damage caused by the disinfectant doses is so small that it can be expected to be compensated by the skin's natural repair mechanisms. LED-based far-UVC lamps could therefore soon be used in everyday clinical practice to eradicate multiresistant pathogens directly on humans.

[Hyperspectral imaging demonstrates microcirculatory effects of postoperative exercise therapy in Dupuytren's disease]. / Hyperspektralimaging demonstriert mikrozirkulatorische Effekte postoperativer Ergotherapie bei Patienten mit Morbus Dupuytren.

BACKGROUND: Dupuytren's disease (DD) is a common connective tissue disorder of the hand. To prevent recurrence of contractures, patients usually receive early postoperative ergotherapy (ET). However, it is yet unknown how this measure impacts on local blood flow and hence on the occurrence or prevention of postoperative complications. Hyperspectral imaging (HSI) allows for a quantitative evaluation of tissue perfusion by measuring oxygen saturation and tissue water content. OBJECTIVE: The aim of this work was to evaluate the microcirculatory effects of early ET after partial fasciectomy in DD using HSI for optimised treatment and prevention. PATIENTS AND METHODS: In five patients, the oxygen saturation and tissue water content of the hand were measured before and 20 min after exercise therapy on the first two postoperative days using HSI. RESULTS: HSI demonstrated improved tissue perfusion in terms of quantity and quality following ET in all patients. After ET, all patients showed a relative increase in oxygen saturation of up to 20 % and a reduction in tissue water of up to 17 %. CONCLUSION: HIS allows for a fast and non-invasive evaluation of increased oxygen supply and decreased tissue water content in the surgical site after partial fasciectomy in DD following postoperative exercise therapy. This may improve wound healing and decrease the rate of recurrence in DD.

Hyperspectral imaging as a possible tool for visualization of changes in hemoglobin oxygenation in patients with deficient hemodynamics - proof of concept.

There is a lack of imaging tools for the evaluation of spatial alterations in microcirculation including blood oxygen saturation and hemoglobin distribution but recent innovative developments in hyperspectral technology may offer a solution. We examined different hemodynamic disorders in patients suffering from scleroderma, Dupuytren surgery, chronic foot ulcera and skin infections. Superficial and deeper blood oxygen saturation, hemoglobin distribution and water content were determined using hyperspectral imaging (HSI). In the patient with scleroderma, distinct cutaneous low perfused regions correlated with macroscopic skin aspects and seem to be potential therapy control marker. With HSI accurate clinical evaluation of a macroscopic conspicuous wound after Dupuytren surgery was possible and influenced further surveillance decisions. HSI clearly revealed the spatial geometry and also the clinically related perfusion parameters of abscess formation and chronic ulcer wounds. The hemodynamically relevant parameters like blood oxygen saturation (1 mm to approx. 6 mm subcutaneous), total hemoglobin distribution and tissue water content can be easily determined and visualized with HSI in near real time. Hence, this technique seems to be suitable for routine diagnostics of acute and chronic wounds as well as for the examination of systemic hemodynamic disturbances. Special indications may be transplant surveillance and monitoring of therapeutical interventions.

Hyperspectral imaging: innovative diagnostics to visualize hemodynamic effects of cold plasma in wound therapy.

An important clinical potential of cold atmospheric plasma (CAP) lies in tumor and wound treatment, whereby the last-mentioned is well-referenced already. However, the underlying mechanisms of improved wound healing have not been sufficiently clarified yet, in particular the influence of CAP on microcirculation. Hyperspectral imaging (HSI) enables the visualization of microcirculation of large tissue areas, thus this technique seems to be a candidate to examine CAP effects on perfusion and oxygen saturation in wounds. During clinical wound management, one chronic wound caused by peripheral arterial occlusive disease and one acute wound after surgical removal of cervical lymph nodes were examined using HSI before and after CAP treatment. HSI was able to demonstrate CAP effects on microcirculation showing a relevant increase of superficial and deeper cutaneous oxygen saturation together with elevated hemoglobin concentration in treated and also surrounding wound area. For the first time, it was shown that CAP improves the superficial and deeper oxygenation and hemoglobin perfusion in and around the treated area of acute and chronic wounds. This effect may contribute to healing support by CAP in wounds. HSI seems suitable for evaluating and monitoring CAP effects in clinical settings.

Hyperspectral imaging as a novel diagnostic tool in microcirculation of wounds.

Monitoring of perfusion is a cornerstone in surgery, phlebology and basic science to proof wound healing by interventions. In chronic wound management it is of utmost importance to realize and parametrize wound bed perfusion to verify actual, and plan further treatment by noninvasive diagnostics. Up to now monitoring is based on visual inspection of wounds as conventionally practiced over more than decades. The main problems of visual inspection are the lack of standardization and comparability because of interindividual variations. Therefore technical performance with contact free probes based on standardized perfusion measuring is strongly needed. Hyperspectral imaging (HSI) was investigated to overcome manual and visual wound inspection in monitoring of wound healing. HSI works noninvasive, and imaging of relevant perfusion parameters is possible without the need of contrast enhancing drugs. METHODS: HSI technology uses imaging spectroscopic analysis in visual and near infrared spectrum to get information on imaged tissue in less than 10 s. Tissue is radiated by broad spectrum light and the following parameters are calculated from remitted spectra: the grade of oxygenation and the volume proportion of hemoglobin (in superficial and also deeper (8 mm) tissues. The calculated data comprise the "Tissue hemoglobin oxygen saturation" (StO2) as percental oxygenation index to assess superficial perfusion (VIS-spectrum), the "Near infrared perfusion" (NIR) to assess deeper perfusion (near infrared spectrum) and the "Tissue hemoglobin index" (THI) to measure the percental volume of hemoglobin of surface perfusion (VIS-spectrum). The measurements of these parameters are calculated as false color-coded perfusion results on screen.We investigated different kind of wounds (combustion, infection, ulcer wounds, wounds in immune disorders, trauma wounds) determining superficial and deeper oxygen saturation, hemoglobin distribution and water content using hyperspectral imaging with TIVITA™ Tissue system. RESULTS: Hyperspectral Imaging allowed easy real time determination and visualization of hemodynamically relevant parameters- superficial and deeper oxygen saturation, total hemoglobin and tissue water content. In the patient with scleroderma, acral lesions with decreased perfusion correlated well with necrotic skin aspects.HSI clearly revealed macroscopic conspicuous suture wounds after Dupuytren surgery, infected soft tissue wounds with strong inflammatory hyperemia, edema in burn injuries, spatial geometry of abscess formation and chronic ulcer wounds. All measurements influenced further surveillance decisions. Hyperspectral imaging seems suitable for routine diagnostics and monitoring of skin and soft tissue lesions like acute and chronic wounds. It allows surveillance of postoperative suture wounds and burn wounds. Special indications may be transplant surveillance and monitoring of therapeutical interventions.