Detecting Bacteria on Wounds with Hyperspectral Imaging in Fluorescence Mode

Chronic non-healing wounds represent an increasing problem. In order to enable physicians and nurses to make evidence based decisions on wound treatment, the professional societies call for supporting tools to be offered to physicians. Oxygen supply, bacteria colonization and other parameters influence the healing process. So far, these parameters cannot be monitored in an objective and routinely manner. Existing methods like the microbiological analysis of wound swabs, mean a great deal of effort and partly a long delay. In this paper 42 fluorescence images from 42 patients with diabetic foot ulcer, recorded with a hyperspectral imaging system (TIVITA®), converted for fluorescence imaging, were analysed. Beside the fluorescence images, information about the bacterial colonization is available from microbiological analysis of wound swabs. After preprocessing, principal component analysis, PCA, is used for data analysis with a 405 nm excitation wavelength, the emission wavelength range 510 - 745 nm is used for analysis. After dividing the data into a training and a test dataset it could be shown, that bacteria are detectable in the wound area. A quantification in bacterial colonization counts (BCC) was not in the focus of the research in this study stage

MRSA-Transmissions-Prävention mittels PCR-basierten Aufnahmescreening mit effektivierten Risikofaktoren und Beprobungsmethoden

Da unentdeckte MRSA-Träger ein erhöhtes Transmissionsrisiko bedeuten, ist eine frühzeitige und zuverlässige Erkennung entscheidend für die Prävention nosokomialer MRSA-Infektionen als auch für die Einleitung von schnellen und damit kostensparenden Hygienemaßnahmen. Hierbei übernimmt das Aufnahmescreening eine wichtige Funktion. Der Umfang und die Ausübung dieses Screenings obliegen dabei einer Risikobewertung durch die ausführende Einrichtung. Auf der dermatologischen Station des Universitätsklinikums Greifswald, mit einem hohen Anteil an akuten und chronischen Wunden, konnten hohe Prävalenz-, Inzidenz- und MRSA-Raten nachgewiesen werden. Dies hat im Mai/ Juni 2006 zu einem MRSA-Ausbruch geführt von dem 43% aller Patienten betroffen waren. Interventionsmaßnahmen, wie die Einführung eines generellen Aufnahmescreening im Zusammenspiel mit der Greifswalder 2-Filter-Strategie und den zugehörigen Infektionskontrollmaßnahmen zeigten sich sehr wirkungsvoll, sodass es zu keiner weiteren nosokomialen MRSA Transmissionen kam und die MRSA-Prävalenz gesenkt werden konnte. Die während der folgenden 4 ½ jährigen Interventionsperiode erhobenen Daten (z. B. MRSA-Prävalenz-, Inzidenz-, nosokomiale Inzidenz- und MRSA-Rate) wurden retrospektiv ausgewertet. Zur Sensitivitätssteigerung des Abstrichverfahrens wurde der lokalisationsspezifische Nachweis von MRSA-Positivität, der Zeitpunkt des ersten kulturellen Nachweises sowie der zeitliche Mehrwert einer PCR-basierten Testung untersucht und ausgewertet. Es konnte gezeigt werden, dass die höchste MRSA-Detektionsrate mit dem Abstreichen von Nasen, Wunden und Hautläsionen erreicht werden konnte (100,0%) und dass eine genaue PCR (hohe Sensitivität und Spezifizität) dazu beitragen kann, die Isolations- und Sanierungstage von Verdachtspatienten zu verringern. Aus wirtschaftlichen Gründen und mit Ausnahme von Patienten mit kurzer Krankenhausverweildauer ist eine PCR-Diagnostik auf dermatologischen Stationen als Bestandteil des Aufnahmescreenings für Patienten mit Wunden, anderen akuten und chronischen Hautläsionen und in Ausbruchssituationen zu empfehlen. Da ein generelles Screening aller Patienten unwirtschaftlich erscheint, wurde zur Analyse der Screening-Effizienz untersucht, welche Risikofaktoren (RF) sich als zielführend erweisen, um die Sensitivität eines selektiven Screenings gegenüber einem generellem Screening nicht substantiell zu beeinträchtigen. Hierzu wurden Patientendemographien, die Haupt- und Nebendiagnosen und das Vorhandensein von „klassischen“ RF (Robert Koch Institut) untersucht. In vorliegender Untersuchung wären insgesamt 35% der MR¬SA-positiven Patienten im Screening-Prozess, welcher nur „klassische“ RF nach den nationalen Empfehlungen verwendet, nicht erkannt worden. Daher wurden zur Ermittlung der Effektivität klassischer und potentiell neuer RF die MRSA-Ergebnisse sowohl mit den klassischen RF als auch mit sonstigen dermatologisch relevanten Diagnosen korreliert. Es konnten, neben dem bereits bekannten klinischen RF Ulkus, noch zwei weitere neue RF ermittelt werden: Diabetes Typ II und atopische Dermatitis, die signifikant mit einer MRSA-Kolonisation verbunden waren. Durch Hinzufügen dieser beiden neuen Risikofaktoren würde sich die Detektionsrate um 18,3% erhöhen. Es ist zu behaupten, dass das Screening von Patienten mit Wunden nicht zu einer erhöhten Screening-Sensitivität führt, sofern atopische Dermatitis oder Diabetes mellitus Typ II oder ein anderer klassischer Risikofaktor nicht auch vorhanden ist. Dementsprechend lässt sich ein Aufnahmescreening empfehlen unter Berücksichtigung aller klassischen RF, allerdings ohne Wunde, aber mit Diabetes mellitus Typ II und atopischer Dermatitis. Allerdings sollte dies so lange nicht als verbindliche Empfehlung ausgesprochen werden bis weitere Studien mit größeren Untersuchungsgrößen durchgeführt wurden.Since undiscovered MRSA carriers represent an increased transmission risk, early and reliable detection is crucial for the prevention of nosocomial MRSA infections as well as for the initiation of rapid and thus cost-saving hygiene measures. Hereby, the admission screening takes on an important function. The scope and exercise of this screening depend on the risk assessment of the implementing institution. At the dermatological ward of the University Hospital Greifswald, with a high proportion of acute and chronic wounds, high MRSA-prevalence, MRSA-incidence and MRSA rates were detected. This resulted in a MRSA outbreak in May / June 2006 affecting 43% of all patients. Intervention measures, as the introduction of a general admission screening in combination with the “Greifswalder 2-Filter-Strategy” and the associated infection control measures, proved to be very effective, hence no further nosocomial MRSA transmissions occured and MRSA prevalence decreased. Data collected during the next 4½-year intervention period (e.g. MRSA prevalence, incidence, nosocomial incidence and MRSA rates) were retrospectively evaluated. To increase sensitivity of the swabbing procedure, the localization-specific detection of MRSA positivity, the time of the first cultural detection as well as the temporal added value of a PCR-based test were examined and evaluated. It could be shown that the highest MRSA detection rate could be achieved with swabbing noses, wounds and skin lesions (100%) and that accurate PCR (high sensitivity and specificity) may help to reduce the isolation and sanitation days of patients. For economic reasons and with the exception of patients with a short hospital stay, PCR diagnosis at dermatological wards is recommended as part of the admission screening for patients with wounds, other acute and chronic skin lesions and during outbreaks. Since general screening of all patients seems uneconomic, screening efficacy was analyzed to find out which risk factors (RF) are effective in order not to affect the sensitivity of selective compared to general screening. Patient demographics, main and secondary diagnoses and the presence of "classical" RF (Robert Koch Institute) were examined. In the present study, a total of 35% of MRSA-positive patients would not have been identified in the screening process using only "classic" RF according to the national recommendations. To determine the effectiveness of classical and potentially new RF, MRSA results were correlated with classical RF and other dermatologically relevant diagnoses. In addition to the already known clinical RF ulcer, two more new RF were identified: type II diabetes and atopic dermatitis, which were significantly associated with MRSA colonization. By adding these two new risk factors to admission screening, the detection rate would increase by 18.3%. It has to state that screening of patients with wounds does not lead to an increased screening sensitivity, as long atopic dermatitis or diabetes mellitus type II or another classical risk factor is present. Accordingly, admission screening can be recommended, taking into account all classical RF, without wounds, but with Type II diabetes mellitus and atopic dermatitis. However, this should not be pronounced as a binding recommendation until further studies with larger study sizes have been carried out

Treatment of recalcitrant actinic keratosis (AK) of the scalp by cold atmospheric plasma

Background and objectives: Actinic keratosis (AK) is a frequent cutaneous lesion usually developing on sun-exposed skin and may be evolving into invasive squamous cell carcinoma requiring expensive therapy. Size, site or number of lesions limits the efficacy and/or acceptability of surgical and chemical therapies. Up to now photodynamic therapy (PDT) is recommended as treatment of choice. Material and methods: A patient (75y, m) suffered from recalcitrant AK lesions on the scalp, forearms and face for more than 20y. Various treatments including PDT, ablative laser and cryotherapy or chemical treatments failed to eradicate these lesions especially on the scalp. We used a CE-certified cold atmospheric plasma (CAP) jet, the Maxium® electrosurgery unit with maxium® beamer (KLS Martin GmbH + Co. KG), to treat one scalp lesion in one session (60 s, 20 W, 6 L/min). Results: CAP was able to eradicate AK of the patient in one session and was well tolerated. Histologic examination showed complete cure of AK. Control histology and visits up to 26 months after treatment do not show relapse or other skin deterioration. Conclusion: CAP seems to be an effective, curative and economic (one single treatment) alternative to conventional treatment of recalcitrant AK with field cancerization with excellent tolerability

On the history of plasma treatment and comparison of microbiostatic efficacy of a historical high-frequency plasma device with two modern devices

Background: Cold atmospheric pressure plasma (CAP) with its many bioactive properties has defined a new medical field: the plasma medicine. However, in the related form of high-frequency therapy, CAP was even used briefly a century ago. The aim of this study was to review historic CAP treatments and to obtain data regarding the antimicrobial efficacy of a historical high-frequency plasma device.Methods: First, historic literature regarding the history of CAP treatment was evaluated, because in the modern literature no data were available. Second, the susceptibility of 5 different bacterial wound isolates, cultured on agar, to a historic plasma source (violet wand [VW]) and two modern devices (atmospheric pressure plasma jet [APPJ] and Dielectric Barrier Discharge [DBD]) was analyzed . The obtained inhibition areas (IA) were compared.Results: First, the most convenient popular historical electromedical treatments produced a so-called effluvia by using glass electrodes, related to today’s CAP. Second, all three tested plasma sources showed complete eradication of all tested microbial strains in the treated area. The “historical” cold VW plasma showed antimicrobial effects similar to those of modern APPJ and DBD regarding the diameter of the IA.Conclusion: Some retrograde evidence may be deducted from this, especially for treatment of infectious diseases with historical plasma devices. The underlying technology may serve as model for construction of modern sucessive devices

Detecting Bacteria on Wounds with Hyperspectral Imaging in Fluorescence Mode

Chronic non-healing wounds represent an increasing problem. In order to enable physicians and nurses to make evidence based decisions on wound treatment, the professional societies call for supporting tools to be offered to physicians. Oxygen supply, bacteria colonization and other parameters influence the healing process. So far, these parameters cannot be monitored in an objective and routinely manner. Existing methods like the microbiological analysis of wound swabs, mean a great deal of effort and partly a long delay. In this paper 42 fluorescence images from 42 patients with diabetic foot ulcer, recorded with a hyperspectral imaging system (TIVITA®), converted for fluorescence imaging, were analysed. Beside the fluorescence images, information about the bacterial colonization is available from microbiological analysis of wound swabs. After preprocessing, principal component analysis, PCA, is used for data analysis with a 405 nm excitation wavelength, the emission wavelength range 510 - 745 nm is used for analysis. After dividing the data into a training and a test dataset it could be shown, that bacteria are detectable in the wound area. A quantification in bacterial colonization counts (BCC) was not in the focus of the research in this study stage

Influence of preoperative skin sealing with cyanoacrylate on microbial contamination of surgical wounds following trauma surgery: a prospective, blinded, controlled observational study

Objective: Intraoperative bacterial contamination is a risk factor for surgical site infections (SSIs). This prospective, randomized, blinded, controlled trial (Reg. No. BB08/12) investigated the effect of a cyanoacrylate-based skin sealant (InteguSeal) on intraoperative wound contamination during trauma surgery. Methods: A total of 128 patients undergoing trauma surgery were assigned randomly to an intervention (n = 62) or a control group (n = 66). Surgical sites were investigated at three locations: maximum incision depth (base), wound margin prior to wound closure (margin), and the surgical sutures (suture). Colony-forming units (CFU) were counted after 48 h of incubation. Results: Overall, significantly lower CFU counts were obtained for samples from the intervention group at all three sample sites compared to the control group. The difference, however, was only significant for the suture site (p = 0.040). Conclusions: Preoperative sealing reduced microbial contamination on sutures during surgery, while the overall wound contamination remained unchanged. Hence, prevention of the clinically more relevant deep SSIs may not be expected. However, this study was not designed to detect differences in the rate of SSI. The role of the reduction in suture contamination with regard to the prevention of SSI remains to be evaluated

Wada test results contribute to the prediction of change in verbal learning and verbal memory function after temporal lobe epilepsy surgery

In recent years, the clinical usefulness of the Wada test (WT) has been debated among researchers in the field. Therefore, we aimed to assess its contribution to the prediction of change in verbal learning and verbal memory function after epilepsy surgery. Data from 56 patients with temporal lobe epilepsy who underwent WT and subsequent surgery were analyzed retrospectively. Additionally, a standard neuropsychological assessment evaluating attentional, learning and memory, visuospatial, language, and executive function was performed both before and 12 months after surgery. Hierarchical linear regression analyses were used to determine the incremental value of WT results over socio-demographic, clinical, and neuropsychological characteristics in predicting postsurgical change in patients’ verbal learning and verbal memory function. The incorporation of WT results significantly improved the prediction models of postsurgical change in verbal learning (∆R2 = 0.233, p = .032) and verbal memory function (∆R2 = 0.386, p = .005). Presurgical performance and WT scores accounted for 41.8% of the variance in postsurgical change in verbal learning function, and 51.1% of the variance in postsurgical change in verbal memory function. Our findings confirm that WT results are of significant incremental value for the prediction of postsurgical change in verbal learning and verbal memory function. Thus, the WT contributes to determining the risks of epilepsy surgery and, therefore, remains an important part of the presurgical work-up of selected patients with clear clinical indications

Seizure Semiology in Antibody-Associated Autoimmune Encephalitis

Kaaden T, Madlener M, Angstwurm K, et al. Seizure Semiology in Antibody-Associated Autoimmune Encephalitis. Neurology(R) neuroimmunology & neuroinflammation. 2022;9(6): e200034 .BACKGROUND AND OBJECTIVES: To assess seizure characteristics in antibody (ab)-associated autoimmune encephalitis (ab + AE) with the 3 most prevalent abs against N-methyl-d-aspartate receptor (NMDAR), leucine-rich glioma-inactivated protein 1 (LGI1), and glutamic acid decarboxylase (GAD).; METHODS: Multicenter nationwide prospective cohort study of the German Network for Research in Autoimmune Encephalitis.; RESULTS: Three hundred twenty patients with ab + AE were eligible for analysis: 190 NMDAR+, 89 LGI1+, and 41 GAD+. Seizures were present in 113 (60%) NMDAR+, 69 (78%) LGI1+, and 26 (65%) GAD+ patients and as leading symptoms for diagnosis in 53 (28%) NMDAR+, 47 (53%) LGI+, and 20 (49%) GAD+ patients. Bilateral tonic-clonic seizures occurred with almost equal frequency in NMDAR+ (38/51, 75%) and GAD+ (14/20, 70%) patients, while being less common in LGI1+ patients (27/59, 46%). Focal seizures occurred less frequently in NMDAR+ (67/113; 59%) than in LGI1+ (54/69, 78%) or in GAD+ patients (23/26; 88%). An aura with deja-vu phenomenon was nearly specific in GAD+ patients (16/20, 80%). Faciobrachial dystonic seizures (FBDS) were uniquely observed in LGI1+ patients (17/59, 29%). Status epilepticus was reported in one-third of NMDAR+ patients, but only rarely in the 2 other groups. The occurrence of seizures was associated with higher disease severity only in NMDAR+ patients.; DISCUSSION: Seizures are a frequent and diagnostically relevant symptom of ab + AE. Whereas NMDAR+ patients had few localizing semiological features, semiology in LGI1+ and GAD+ patients pointed toward a predominant temporal seizure onset. FBDS are pathognomonic for LGI1 + AE. Status epilepticus seems to be more frequent in NMDAR + AE. Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology