Panton-Valentine leukocidin-induced neutrophil extracellular traps lack antimicrobial activity and are readily induced in patients with recurrent PVL + -Staphylococcus aureus infections.

Staphylococcus aureus strains that produce the toxin Panton-Valentine leukocidin (PVL-SA) frequently cause recurrent skin and soft tissue infections. PVL binds to and kills human neutrophils, resulting in the formation of neutrophil extracellular traps (NETs), but the pathomechanism has not been extensively studied. Furthermore, it is unclear why some individuals colonized with PVL-SA experience recurring infections whereas others are asymptomatic. We thus aimed to (1) investigate how PVL exerts its pathogenicity on neutrophils and (2) identify factors that could help to explain the predisposition of patients with recurring infections. We provide genetic and pharmacological evidence that PVL-induced NET formation is independent of NADPH oxidase and reactive oxygen species production. Moreover, through NET proteome analysis we identified that the protein content of PVL-induced NETs is different from NETs induced by mitogen or the microbial toxin nigericin. The abundance of the proteins cathelicidin (CAMP), elastase (NE), and proteinase 3 (PRTN3) was lower on PVL-induced NETs, and as such they were unable to kill S. aureus. Furthermore, we found that neutrophils from affected patients express higher levels of CD45, one of the PVL receptors, and are more susceptible to be killed at a low PVL concentration than control neutrophils. Neutrophils from patients that experience recurring PVL-positive infections may thus be more sensitive to PVL-induced NET formation, which might impair their ability to combat the infection.

Monkeypox in-patients with severe anal pain.

Berlin is amongst the cities most affected by the current monkeypox outbreak. Here, we report clinical characteristics of the first patients with confirmed monkeypox admitted to our center. We analyzed anamnestic, clinical, and laboratory data. Within a period of 2 weeks, six patients were hospitalized in our unit. All were MSM and had practiced condomless receptive anal intercourse in the weeks preceding admission. The chief complaint in all patients but one was severe anal pain unprecedented in severity. Investigations revealed proctitis, as well as anal and rectal ulcers with detection of monkeypox virus. Our findings support the hypothesis that sexual transmission plays a role in the current outbreak.

Evaluation of a Meropenem and Piperacillin Monitoring Program in Intensive Care Unit Patients Calls for the Regular Assessment of Empirical Targets and Easy-to-Use Dosing Decision Tools.

The drug concentrations targeted in meropenem and piperacillin/tazobactam therapy also depend on the susceptibility of the pathogen. Yet, the pathogen is often unknown, and antibiotic therapy is guided by empirical targets. To reliably achieve the targeted concentrations, dosing needs to be adjusted for renal function. We aimed to evaluate a meropenem and piperacillin/tazobactam monitoring program in intensive care unit (ICU) patients by assessing (i) the adequacy of locally selected empirical targets, (ii) if dosing is adequately adjusted for renal function and individual target, and (iii) if dosing is adjusted in target attainment (TA) failure. In a prospective, observational clinical trial of drug concentrations, relevant patient characteristics and microbiological data (pathogen, minimum inhibitory concentration (MIC)) for patients receiving meropenem or piperacillin/tazobactam treatment were collected. If the MIC value was available, a target range of 1-5 × MIC was selected for minimum drug concentrations of both drugs. If the MIC value was not available, 8-40 mg/L and 16-80 mg/L were selected as empirical target ranges for meropenem and piperacillin, respectively. A total of 356 meropenem and 216 piperacillin samples were collected from 108 and 96 ICU patients, respectively. The vast majority of observed MIC values was lower than the empirical target (meropenem: 90.0%, piperacillin: 93.9%), suggesting empirical target value reductions. TA was found to be low (meropenem: 35.7%, piperacillin 50.5%) with the lowest TA for severely impaired renal function (meropenem: 13.9%, piperacillin: 29.2%), and observed drug concentrations did not significantly differ between patients with different targets, indicating dosing was not adequately adjusted for renal function or target. Dosing adjustments were rare for both drugs (meropenem: 6.13%, piperacillin: 4.78%) and for meropenem irrespective of TA, revealing that concentration monitoring alone was insufficient to guide dosing adjustment. Empirical targets should regularly be assessed and adjusted based on local susceptibility data. To improve TA, scientific knowledge should be translated into easy-to-use dosing strategies guiding antibiotic dosing.

Initial Experience With SARS-CoV-2-Neutralizing Monoclonal Antibodies in Kidney or Combined Kidney-Pancreas Transplant Recipients.

Background: Antiviral drugs have shown little impact in patient infected with acute respiratory coronavirus 2 (SARS-CoV-2). Especially for immunocompromised persons positive for SARS-CoV-2, novel treatments are warranted. Recently, the U.S. FDA has granted an emergency use authorization (EUA) to two monoclonal antibodies (mAb) targeting the viral spike protein: bamlanivimab and casivirimab and imdevimab. As per the EUA, all SARS-CoV-2 positive organ transplant recipients can receive mAb treatment. Patients and methods: We queried our center's transplant registry to identify SARS-CoV-2 infected recipients treated with single doses of either Bamlanivimab or casivirimab/imdevimab up to May 31, 2021. We analyzed clinical outcomes, renal function and virus-specific antibodies. The co-primary endpoints were hospitalization due to COVID-19 and SARS-CoV-2 RT-PCR negativity. Results: Thirteen patients at a median interval of 55 (IQR, 26-110) months from transplant were treated: 8 with bamlanivimab and 5 with casivirimab/imdevimab. In all, 4/13 (31%) patients were hospitalized at some time, while 11/13 (85%) achieved PCR negativity. 2/4 hospitalized patients received mAb as rescue treatment. Overall mortality was 23%, with one death attributable to transplant-associated lymphoma. All six patients infected with the B 1.1.7 variant were alive at last contact. Conclusion: mAb treatment appears effective when administered early to SARS-CoV-2-infected transplant recipients.

Preparing for patients with high-consequence infectious diseases: Example of a high-level isolation unit.

INTRODUCTION: Patients with high-consequence infectious diseases (HCID) are rare in Western Europe. However, high-level isolation units (HLIU) must always be prepared for patient admission. Case fatality rates of HCID can be reduced by providing optimal intensive care management. We here describe a single centre's preparation, its embedding in the national context and the challenges we faced during the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pandemic. METHODS: Ten team leaders organize monthly whole day trainings for a team of doctors and nurses from the HLIU focusing on intensive care medicine. Impact and relevance of training are assessed by a questionnaire and a perception survey, respectively. Furthermore, yearly exercises with several partner institutions are performed to cover different real-life scenarios. Exercises are evaluated by internal and external observers. Both training sessions and exercises are accompanied by intense feedback. RESULTS: From May 2017 monthly training sessions were held with a two-month and a seven-month break due to the first and second wave of the SARS-CoV-2 pandemic, respectively. Agreement with the statements of the questionnaire was higher after training compared to before training indicating a positive effect of training sessions on competence. Participants rated joint trainings for nurses and doctors at regular intervals as important. Numerous issues with potential for improvement were identified during post processing of exercises. Action plans for their improvement were drafted and as of now mostly implemented. The network of the permanent working group of competence and treatment centres for HCID (Ständiger Arbeitskreis der Kompetenz- und Behandlungszentren für Krankheiten durch hochpathogene Erreger (STAKOB)) at the Robert Koch-Institute (RKI) was strengthened throughout the SARS-CoV-2 pandemic. DISCUSSION: Adequate preparation for the admission of patients with HCID is challenging. We show that joint regular trainings of doctors and nurses are appreciated and that training sessions may improve perceived skills. We also show that real-life scenario exercises may reveal additional deficits, which cannot be easily disclosed in training sessions. Although the SARS-CoV-2 pandemic interfered with our activities the enhanced cooperation among German HLIU during the pandemic ensured constant readiness for the admission of HCID patients to our or to collaborating HLIU. This is a single centre's experience, which may not be generalized to other centres. However, we believe that our work may address aspects that should be considered when preparing a unit for the admission of patients with HCID. These may then be adapted to the local situations.

Development of a Model-Informed Dosing Tool to Optimise Initial Antibiotic Dosing-A Translational Example for Intensive Care Units.

The prevalence and mortality rates of severe infections are high in intensive care units (ICUs). At the same time, the high pharmacokinetic variability observed in ICU patients increases the risk of inadequate antibiotic drug exposure. Therefore, dosing tailored to specific patient characteristics has a high potential to improve outcomes in this vulnerable patient population. This study aimed to develop a tabular dosing decision tool for initial therapy of meropenem integrating hospital-specific, thus far unexploited pathogen susceptibility information. An appropriate meropenem pharmacokinetic model was selected from the literature and evaluated using clinical data. Probability of target attainment (PTA) analysis was conducted for clinically interesting dosing regimens. To inform dosing prior to pathogen identification, the local pathogen-independent mean fraction of response (LPIFR) was calculated based on the observed minimum inhibitory concentrations distribution in the hospital. A simple, tabular, model-informed dosing decision tool was developed for initial meropenem therapy. Dosing recommendations achieving PTA > 90% or LPIFR > 90% for patients with different creatinine clearances were integrated. Based on the experiences during the development process, a generalised workflow for the development of tabular dosing decision tools was derived. The proposed workflow can support the development of model-informed dosing tools for initial therapy of various drugs and hospital-specific conditions.

Which parameters support disposition decision in suspected COVID-19 cases in the emergency department (ED): a German clinical cohort study.

OBJECTIVES: One major goal of the emergency department (ED) is to decide, whether patients need to be hospitalised or can be sent home safely. We aim at providing criteria for these decisions without knowing the SARS-CoV-2 test result in suspected cases. SETTING: Tertiary emergency medicine. PARTICIPANTS: All patients were treated at the ED of the Charité during the pandemic peak and underwent SARS-CoV-2 testing. Patients with positive test results were characterised in detail and underwent a 14-day-follow-up. PRIMARY AND SECONDARY OUTCOME MEASURES: Logistic regression and classification and regression tree (CART) analyses were performed to identify predictors (primary endpoint), which confirm safe discharge. The clinical endpoint was all-cause mortality or need for mechanical ventilation during index stay or after readmission. RESULTS: The primary test population of suspected COVID-19 consisted of n=1255 cases, 45.2% were women (n=567). Of these, n=110 tested positive for SARS-CoV-2 (8.8%). The median age of SARS-CoV-2-positive cases was 45 years (IQR: 33-66 years), whereas the median age of the group tested negative for SARS-CoV-2 was 42 years (IQR: 30-60 years) (p=0.096). 43.6% were directly admitted to hospital care.CART analysis identified the variables oxygen saturation (<95%), dyspnoea and history of cardiovascular (CV) disease to distinguish between high and low-risk groups. If all three variables were negative, most patients were discharged from ED, and the incidence of the clinical endpoint was 0%. The validation cohort confirmed the safety of discharge using these variables and revealed an incidence of the clinical endpoint from 14.3% in patients with CV disease, 9.4% in patients with dyspnoea and 18.2% in patients with O2 satuaration below 95%. CONCLUSIONS: Based on easily available variables like dyspnoea, oxygen saturation, history of CV disease, approximately 25% of patients subsequently confirmed with COVID-19 can be identified for safe discharge. TRIAL REGISTRATION NUMBER: DRKS00023117.

Rothia aeria and Rothia dentocariosa as biofilm builders in infective endocarditis.

BACKGROUND: Rothia sp. are Gram-positive bacteria in the class of Actinobacteria that are part of the physiological oral flora. In rare cases, Rothia aeria and Rothia dentocariosa can cause infective endocarditis (IE). The biofilm potential of Rothia in endocarditis is unknown. METHODS: Specimen from two cases of Rothia endocarditis were obtained during cardiac surgery. One of the patients suffered mitral valve IE from Rothia aeria. In the other case, IE of a prosthetic pulmonary valve was caused by Rothia dentocariosa. Fluorescence in situ hybridization (FISH) was used for visualization of microorganisms within heart valve tissues in combination with PCR and sequencing (FISHseq). RESULTS: The two heart valve specimens featured mature biofilms of bacteria that were identified by FISHseq as Rothia aeria and Rothia dentocariosa, respectively. FISH showed in situ biofilms of both microorganisms that feature distinct phenotypes for the first time ex vivo. Both of our reported cases were treated successfully by heart valve surgery and antibiotic therapy using beta-lactam antibiotics. CONCLUSION: The biofilm potential of Rothia sp. must be taken into account. The awareness of Rothia aeria and Rothia dentocariosa as rare but relevant pathogens for infective endocarditis must be raised. Use of biofilm-effective antibiotics in Rothia IE should be discussed.

[Rare infections of the lungs not endemic in Germany]. / Seltene, in Deutschland nicht endemische Infektionen der Lunge.

This article describes viral, bacterial, fungal and parasitic infections, which are not endemic and little known in Germany. Avian influenza, Middle East respiratory syndrome (MERS) and the plague can all lead to severe pulmonary complications with a high mortality. In addition, there is a risk of nosocomial spread and therefore patients must always be isolated. Melioidosis, blastomycosis, paracoccidioidomycosis, and histoplasmosis are primarily often misclassified as community-acquired pneumonia due to typical causative organisms. A detailed anamnesis focussing on exposure in endemic areas is key to the diagnosis. Paragonimiasis is often manifested a few weeks after consumption of raw seafood and pronounced eosinophilia is typical. Relevant aspects of the epidemiology, clinical course, treatment and, if applicable, prevention are presented as cases of these diseases can occur at any time in Germany.

[New developments in outpatient parenteral antibiotic therapy (OPAT)]. / Neue Entwicklungen in der ambulanten parenteralen Antibiotikatherapie (APAT).

Long term intravenous antibiotic therapy is required for the treatment of selected infections. Outpatient parenteral antibiotic therapy (OPAT) allows patients who require intravenous treatment to be treated outside of the hospital with equal efficacy and safety as in-hospital; prolonged intravenous antibiotic therapy is required for the treatment of selected infections. OPAT is particularly beneficial for patients. Staying at home and resuming everyday life lead to significantly higher patient satisfaction and quality of life. Furthermore, the risk of nosocomial infections can be reduced, especially through multi-resistant pathogens. Outpatient prescriptions shorten the inpatient length of stay and costs can be saved. Additionally the reception capacities of hospitals will be increased.

[Antibiotic Stewardship in Community-Acquired Pneumonia]. / Antibiotic Stewardship bei ambulant erworbener Pneumonie.

Antibiotic stewardship (ABS) denotes structured and continuous measures to improve the quality of prescribing anti-infectives. The aim is to achieve optimal treatment results and to minimize undesirable effects, especially the emergence of antibiotic resistance. This review summarizes the most important ABS principles based on recently published studies with implications for the management of community-acquired pneumonia. Local guidelines, education and training and "prospective audit and feedback" are established strategies to improve the management of patients with community-acquired pneumonia. However, the implementation of ABS programs requires trained personnel and may be impeded by limited structural and time resources. Hence, electronic health records and computer-based interventions are useful support for ABS programs and offer potential to facilitate ABS in inpatient and outpatient care. PCR-based rapid diagnostic tests, PCT-guided algorithms and penicillin allergy testing are suitable procedures to supplement ABS programs.

Severe infections of Panton-Valentine leukocidin positive Staphylococcus aureus in children.

Infections caused by Panton-Valentine leukocidin-positive Staphylococcus aureus (PVL-SA) mostly present as recurrent skin abscesses and furunculosis. However, life-threatening infections (eg, necrotizing pneumonia, necrotizing fasciitis, and osteomyelitis) caused by PVL-SA have also been reported.We assessed the clinical phenotype, frequency, clinical implications (surgery, length of treatment in hospitals/intensive care units, and antibiotic treatments), and potential preventability of severe PVL-SA infections in children.Total, 75 children treated for PVL-SA infections in our in- and outpatient units from 2012 to 2017 were included in this retrospective study.Ten out of 75 children contracted severe infections (PVL-methicillin resistant S aureus n = 4) including necrotizing pneumonia (n = 4), necrotizing fasciitis (n = 2), pyomyositis (n = 2; including 1 patient who also had pneumonia), mastoiditis with cerebellitis (n = 1), preorbital cellulitis (n = 1), and recurrent deep furunculosis in an immunosuppressed patient (n = 1). Specific complications of PVL-SA infections were venous thrombosis (n = 2), sepsis (n = 5), respiratory failure (n = 5), and acute respiratory distress syndrome (n = 3). The median duration of hospital stay was 14 days (range 5-52 days). In 6 out of 10 patients a history suggestive for PVL-SA colonization in the patient or close family members before hospital admission was identified.PVL-SA causes severe to life-threatening infections requiring lengthy treatments in hospital in a substantial percentage of symptomatic PVL-SA colonized children. More than 50% of severe infections might be prevented by prompt testing for PVL-SA in individuals with a history of abscesses or furunculosis, followed by decolonization measures.