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Abstract Background Healthcare associated infections (HAI) pose a major threat to healthcare systems resulting in an increased burden of disease. Surveillance plays a key role in rapidly identifying these infections and preventing further transmissions. Alas, in German hospitals, the majority of surveillance efforts have been heavily relying on labour intensive processes like manual chart review. In order to be able to identify further starting points for future digital tools and interventions to aid the surveillance of HAI we aimed to gain an understanding of the current state of digitalisation in the context of the general surveillance organisation in German clinics across all care-levels. The end user perspective of infection prevention and control (IPC) professionals was chosen to identify digital interventions that have the biggest impact on the daily surveillance work routines of IPC professionals. Perceived impediments in the advancement of surveillance digitalisation should be explored. Methods Following the development of an interview guideline, eight IPC professionals from seven German hospitals of different care levels were questioned in semi- structured interviews between December 2022 and January 2023. These included questions about general surveillance organisation, access to digital data sources, software to aid the surveillance process as well as current issues in the surveillance process and implementation of software systems. Subsequently, after full transcription, the interview sections were categorized in code categories (first deductive then inductive coding) and analysed qualitatively. Results Results were characterised by high heterogeneity in terms of general surveillance organisation and access to digital data sources. Software configuration of hospital and laboratory information systems (HIS/LIS) as well as patient data management systems (PDMS) varied not only between hospitals of different care levels but also between hospitals of the same care level. Outside research projects, neither fully automatic software nor solutions utilising artificial intelligence have currently been implemented in clinical routine in any of the hospitals. Conclusions Access to digital data sources and software is increasingly available to aid surveillance of HAI. Nevertheless, surveillance processes in hospitals analysed in this study still heavily rely on manual processes. In the analysed hospitals, there is an implementation and funding gap of (semi-) automatic surveillance solutions in clinical practice, especially in healthcare facilities of lower care levels.

Abstract Clonal transmission and horizontal gene transfer (HGT) contribute to the spread of vancomycin-resistant enterococci (VRE) in global healthcare. Our study investigated vesiduction, a HGT mechanism via membrane vesicles (MVs), for vanA and vanB genes that determine vancomycin resistance. We isolated MVs for VRE of different sequence types (STs) and analysed them by nanoparticle tracking analysis. Selected MV samples were subjected to DNA sequence analysis. In resistance transfer experiments, vancomycin-susceptible enterococci were exposed to MVs and bacterial supernatants of VRE. Compared to bacteria grown in lysogeny broth (MVs/LB), cultivation under vancomycin stress (MVs/VAN) resulted in increased particle concentrations of up to 139-fold (ST80). As a key finding, we could show that VRE isolates of ST80 and ST117 produced remarkably more vesicles at subinhibitory antibiotic concentrations (approx. 9.2 × 1011 particles/ml for ST80 and 2.4 × 1011 particles/ml for ST117) than enterococci of other STs (range between 1.8 × 1010 and 5.3 × 1010 particles/ml). In those MV samples, the respective resistance genes vanA and vanB were completely verifiable using sequence analysis. Nevertheless, no vancomycin resistance transfer via MVs to vancomycin-susceptible Enterococcus faecium was phenotypically detectable. However, our results outline the potential of future research on ST-specific MV properties, promising new insights into VRE mechanisms.

Abstract Background Bacterial infections are a major complication for patients undergoing allogeneic hematopoietic stem cell transplantation (HCT). Therefore, protective isolation is considered crucial to prevent nosocomial infections in this population. Here, the impact of intensified contact precautions on environmental contamination and the occurrence of bloodstream infections (BSI) in patients on a HCT unit were compared between two contact precaution measures. Methods A 2-year retrospective observational study was performed. In the first year, strict contact precaution measures were applied (i.e., protective isolation, the use of sterile personal protective equipment (PPE) by healthcare workers and visitors and sterilization of linen and objects that entered the patient’s room). After one year, contact precautions were reduced (i.e., no use of sterile PPE, no sterilization of linen and objects that entered the patient’s room). Environmental contamination in randomly selected patient rooms was monitored by sampling six standardized environmental sites in the respective patient treatment units. In a before-and-after study, the number of BSI episodes of those patients, who were accommodated in the monitored rooms was compared. Results In total, 181 treatment units were monitored. No significant difference in the contamination of anterooms and patient’s rooms between both groups was found. A total of 168 patients were followed for the occurrence of BSI during the entire study period (before: 84 patients, after: 84 patients). The total count of patients with BSI episodes showed a higher incidence in the period with reduced contact precautions (30/84 vs. 17/84, p = 0.039). The cause of this increasing number of BSI can be traced back to BSI episodes with common commensal bacteria (17/84 vs. 5/84, p = 0.011). Conclusions The implementation of maximal barrier measures did not reduce the bacterial contamination of the patients’ environment. The impact on the patients’ outcomes remain controversial. Further research is needed to investigate the impact of infection prevention measures on the clinical outcome of patients undergoing HCT.

Abstract Background Vancomycin-resistant enterococci (VRE) have emerged in the healthcare setting worldwide. Infections with these pathogens, i.e., bloodstream infections (BSI), are accompanied with an impaired patient outcome. Diverse factors comprising patient characteristics, therapeutic strategies, and infection control measures are positively or negatively associated with VRE BSI occurrence. However, whether sex-specific differences influence the frequency of VRE BSI is yet unknown. The aim of this systematic review was to comprehensively summarize and analyze sex prevalence in VRE BSI patients. Main text A systematic search for relevant articles was conducted in PubMed and Web of Science. After screening for eligibility, data extraction from included articles and risk of bias assessment were processed. The prevalence of male/female sex in VRE BSI patients and 95% CI were calculated for each study and summarized as pooled estimated effect. In total, nine articles met the inclusion criteria. Risk of bias assessment resulted in low (six studies) to moderate bias (three studies). The pooled prevalence of male patients suffering from VRE BSI was 59% resulting in a 1.4 male/female prevalence ratio. Conclusions Current literature suggests sex differences with male preference (59%) in the distribution of VRE BSI cases. Further primary studies should address the question of male-specific factors favoring the enhanced frequency of VRE BSI.

Abstract Background The availability of handheld, noninvasive sublingual video-microscopes allows for visualization of the microcirculation in critically ill patients. Recent studies demonstrate that reduced numbers of blood-perfused microvessels and increased penetration of erythrocytes into the endothelial glycocalyx are essential components of microvascular dysfunction. The aim of this study was to identify novel microvascular variables to determine the level of microvascular dysfunction in sepsis and its relationship with clinical variables. Methods This observational, prospective, cross-sectional study included 51 participants, of which 34 critically ill sepsis patients were recruited from intensive care units of a university hospital. Seventeen healthy volunteers served as controls. All participants underwent sublingual videomicroscopy by sidestream darkfield imaging. A new developed version of the Glycocheck™ software was used to quantify vascular density, perfused boundary region (PBR-an inverse variable of endothelial glycocalyx dimensions), red blood cell (RBC) velocity, RBC content, and blood flow in sublingual microvessels with diameters between 4 and 25 µm. Results A detailed analysis of adjacent diameter classes (1 µm each) of vessels between 4 and 25 µm revealed a severe reduction of vascular density in very small capillaries (5–7 µm), which correlated with markers of sepsis severity. Analysis of RBC velocity (VRBC) revealed a strong dependency between capillary and feed vessel VRBC in sepsis patients (R 2 = 0.63, p

Abstract Background Transplant recipients are at high risk for infections. However, donor-recipient transmission of multidrug-resistant organisms (MDROs) remains mostly unaddressed in the protocols of pre-transplant infection and colonization screening. Vancomycin-resistant enterococci (VRE) are MDROs that colonize the gastrointestinal tract and are associated with a significant burden of disease. Besides the high mortality of invasive VRE infections, chronic colonization leads to costly isolation measures in the hospital setting. Whereas most post-transplantation VRE infections are endogenous and thus preceded by colonization of the recipient, conclusive evidence of VRE transmission via allograft in the context of intestinal transplantation is lacking. Case presentation We describe a donor-derived VRE infection after intestinal transplantation including small bowel and right hemicolon. The recipient, a 54-year old male with history of mesenteric ischemia and small bowel perforation due to generalized atherosclerosis and chronic stenosis of the celiac trunk and the superior mesenteric artery, developed an intra-abdominal infection and bloodstream infection after transplantation. VRE isolates recovered from the patient as well as from the allograft prior to transplantation were analyzed via whole genome sequencing. Isolates showed to be genetically identical, thus confirming the transmission from donor to recipient. Conclusions This case underlines the relevance of donor-recipient VRE transmission and invasive infection in the context of intestinal transplantation, highlighting the need for preoperative MDRO screening that facilitates the prompt and effective treatment of possible infections as well as the timely establishment of contact precautions to prevent further spread.

Abstract Background Currently, hospitals have been forced to divert substantial resources to cope with the ongoing coronavirus disease 2019 (COVID-19) pandemic. It is unclear if this situation will affect long-standing infection prevention practices and impact on healthcare associated infections. Here, we report a nosocomial cluster of vancomycin-resistant enterococci (VRE) that occurred on a COVID-19 dedicated intensive care unit (ICU) despite intensified contact precautions during the current pandemic. Whole genome sequence-based typing (WGS) was used to investigate genetic relatedness of VRE isolates collected from COVID-19 and non-COVID-19 patients during the outbreak and to compare them to environmental VRE samples. Methods Five VRE isolated from patients (three clinical and two screening samples) as well as 11 VRE and six vancomycin susceptible Enterococcus faecium (E. faecium) samples from environmental sites underwent WGS during the outbreak investigation. Isolate relatedness was determined using core genome multilocus sequence typing (cgMLST). Results WGS revealed two genotypic distinct VRE clusters with genetically closely related patient and environmental isolates. The cluster was terminated by enhanced infection control bundle strategies. Conclusions Our results illustrate the importance of continued adherence to infection prevention and control measures during the COVID-19 pandemic to prevent VRE transmission and healthcare associated infections.

Multidrug resistance of the opportunistic pathogen Stenotrophomonas maltophilia is an increasing problem. Here, analyzing strains from 22 countries, the authors show that the S. maltophilia complex is divided into 23 monophyletic lineages and find evidence for intra-hospital transmission.

Achromobacter genus (including Achromobacter xylosoxidans, the most prevalent Achromobacter species in patients with cystic fibrosis) is poorly susceptible to most conventional antibiotics. Contribution of efflux by AxyABM, AxyXY-OprZ, and AxyEF-OprN and of target mutations were studied in clinical isolates of A. xylosoxidans and Achromobacter insuavis. Forty-one isolates longitudinally collected from 21 patients with CF were studied by whole-genome sequencing (WGS)-typing, determination of minimum inhibitory concentrations (MICs) of β-lactams, aminoglycosides, colistin, azithromycin, ciprofloxacin, chloramphenicol, and doxycycline, and expression (quantitative RT-PCR) and function (measure of the uptake of a fluorescent substrate) of efflux pumps. WGS-based typing resulted in 10 clusters comprising 2 or 3 isolates and 20 singletons. The efflux activity was high in strains with elevated MICs for amikacin or azithromycin. This work sheds a new light on the impact of efflux and target mutations in resistance of Achromobacter to several drugs.

Haematopoietic stem cell transplantation (HSCT) in paediatric patients with acute lymphoblastic leukaemia (ALL) is associated with a variety of infectious complications which result in significant morbidity and mortality. These patients are profoundly immunocompromised, and immune reconstitution after HSCT generally occurs in astrictly defined order. During the early phase after HSCT until engraftment, patients are at risk of infections due to presence of neutropenia and mucosal damage, with Gramme-positive and Gramme-negative bacteria and fungi being the predominant pathogens. After neutrophil recovery, the profound impairment of cell-mediated immunity and use of glucocorticosteroids for control of graft-vs.-host disease (GvHD) increases the risk of invasive mould infection and infection or reactivation of various viruses, such as cytomegalovirus, varicella zoster virus, Epstein-Barr virus and human adenovirus. In the late phase, characterised by impaired cellular and humoral immunity, particularly in conjunction with chronic GvHD, invasive infections with encapsulated bacterial infections are observed in addition to fungal and viral infections. HSCT also causes a loss of pretransplant naturally acquired and vaccine-acquired immunity; therefore, complete reimmunization is necessary to maintain long-term health in these patients. During the last two decades, major advances have been made in our understanding of and in the control of infectious complications associated with HSCT. In this article, we review current recommendations for the diagnosis, prophylaxis and treatment of infectious complications following HSCT for ALL in childhood.

Staphylococcus aureus bacteremia (SAB) is associated with a high mortality rate. The clinical outcome of SAB patients highly depends on early diagnosis, adequate antibiotic therapy and source control. In the context of the COVID-19 pandemic, the health care system faced additional organizational challenges and the question arose whether structured screening and triaging for COVID-19 and shifting resources influence the management of SAB. Patients (n = 115) with SAB were enrolled in a retrospective comparative study with historical controls (March 2019–February 2021). The quality of SAB therapy was assessed with a point score, which included correct choice of antibiotic, adequate dosage of antibiotic, sufficient duration of therapy, early start of therapy after receipt of findings, focus search and taking control blood cultures 3–4 days after starting adequate antibiotic therapy. The quality of treatment before and after the onset of the COVID-19 pandemic were compared. No significant differences in the total score points were found between the pre-COVID-19 and COVID-19 cohort. All quality indicators, except the correct duration of antibiotic therapy, showed no significant differences in both cohorts. Furthermore, there were no significant differences in the outcome between both cohorts. The treatment quality of SAB therapy was comparable before and during the COVID-19 pandemic.

Quantitative phase imaging (QPI) is a non-invasive, label-free technique used to detect aberrant cell morphologies caused by disease, thus providing a useful diagnostic approach. Here, we evaluated the potential of QPI to differentiate specific morphological changes in human primary T-cells exposed to various bacterial species and strains. Cells were challenged with sterile bacterial determinants, i.e., membrane vesicles or culture supernatants, derived from different Gram-positive and Gram-negative bacteria. Timelapse QPI by digital holographic microscopy (DHM) was applied to capture changes in T-cell morphology over time. After numerical reconstruction and image segmentation, we calculated single cell area, circularity and mean phase contrast. Upon bacterial challenge, T-cells underwent rapid morphological changes such as cell shrinkage, alterations of mean phase contrast and loss of cell integrity. Time course and intensity of this response varied between both different species and strains. The strongest effect was observed for treatment with S. aureus-derived culture supernatants that led to complete lysis of the cells. Furthermore, cell shrinkage and loss of circular shape was stronger in Gram-negative than in Gram-positive bacteria. Additionally, T-cell response to bacterial virulence factors was concentration-dependent, as decreases in cellular area and circularity were enhanced with increasing concentrations of bacterial determinants. Our findings clearly indicate that T-cell response to bacterial stress depends on the causative pathogen, and specific morphological alterations can be detected using DHM.

Background and purpose — Facemasks play a role in preventing the respiratory spread of SARS-CoV-2, but their impact on the physician–patient relationship in the orthopedic outpatient clinic is unclear. We investigated whether the type of surgeons’ facemask impacts patients’ perception of the physician–patient relationship, influences their understanding of what the surgeon said, or affects their perceived empathy. Patients and methods — All patients with an appointment in the orthopedic outpatient clinic of a tertiary university hospital during the 2-week study period were included. During consultations, all surgeons wore a non-transparent (first study week) or transparent facemask (second study week). Results of 285 of 407 eligible patients were available for analysis. The doctor–patient relationship was evaluated using the standardized Patient Reactions Assessment (PRA) and a 10-point Likert-scale questionnaire ranging from 0 (strongly disagree) to 10 (strongly agree). Results — A non-transparent facemask led to more restrictions in the physician–patient communication and a worse understanding of what the surgeon said. Patients’ understanding improved with a transparent facemask with greatest improvements reported by patients aged 65 years and older (non-transparent: 6 [IQR 5–10] vs. transparent: 10 [IQR 9–10], p < 0.001) and by patients with a self-reported hearing impairment (non-transparent: 7 [IQR 3–7] vs. transparent: 9 [IQR 9–10], p < 0.001). The median PRA score was higher when surgeons wore a transparent facemask (p= 0.003). Interpretation — Surgeons’ non-transparent facemasks pose a new communication barrier that can negatively affect the physician–patient relationship. While emotional factors like affectivity and empathy seem to be less affected overall, the physician–patient communication and patients’ understanding of what the surgeon said seem to be negatively affected.

Stenotrophomonas maltophilia is an important nosocomial pathogen in immunocom-promised individuals and characterized by intrinsic resistance to broad-spectrum antibacterial agents. Limited data exists on its clinical relevance in immunocompromised pediatric patients, particularly those with hematological or oncological disorders. In a retrospective single center cohort study in pediatric patients receiving care at a large european pediatric hematology and oncology department, ten cases of invasive S.maltophilia infections (blood stream infections (BSI), 4; BSI and pneumonia, 3, or soft tissue infection, 2; and pneumonia, 1) were identified between 2010 and 2020. Seven patients had lymphoblastic leukemia and/or were post allogeneic hematopoietic cell transplantation. Invasive S.maltophilia infections occurred in a setting of indwelling central venous catheters, granulocytopenia, defective mucocutaneous barriers, treatment with broad-spectrum antibacterial agents, and admission to the intensive care unit. Whole genome sequencing based typing revealed no genetic relationship among four individual S.maltophilia isolates. The case fatality rate and mortality at 100 days post diagnosis were 40 and 50%, respectively, and three patients died from pulmonary hemorrhage. Invasive S.maltophilia infections are an emerging cause of infectious morbidity in patients receiving care at departments of pediatric hematology and oncology and carry a high case fatality rate.

ABSTRACT Vancomycin-resistant enterococci (VRE) are nosocomial pathogens with increasing prevalence worldwide. Extensive hygiene measures have been established to prevent infection transmission in hospitals. Here, we developed a predictive score system (the predictive vancomycin-resistant enterococci [PREVENT] score) to identify the clearance or persistence in patients with a history of VRE carrier status at readmission. Over a cumulative 3-year period, patients with a positive VRE carrier status were included. The study population was recruited in two successive time periods and separated into training data for predictive score development and validation data for evaluation of the predictive power. The risk factors for persistent VRE colonization were analyzed in a univariable analysis before development of a logistic regression model based on the potential risk factors. The score points were determined proportionally to the beta coefficients of the logistic regression model. The data from 448 (79%) patients were used as the training data, and those from 119 (21%) as the validation data. Multivariable analysis revealed the following variables as independent risk factors: age of ≥60 years, hemato-oncological disease, cumulative antibiotic treatment for >4 weeks, and a VRE infection. The resulting logistic regression model exhibited an acceptable area under the curve (AUC) of 0.81 (95% confidence interval [CI], 0.72 to 0.91). The predictive score system had a sensitivity of 82% (95% CI, 65 to 93%) and a specificity of 77% (95% CI, 66 to 85%). The developed predictive score system is a useful tool to assess the VRE carrier status of patients with a history of VRE colonization. On the basis of this risk assessment, more focused and cost-effective infection control measures can be implemented. IMPORTANCE Given the increasing relevance of VRE as nosocomial pathogens worldwide, infection prevention and control measures, including patient isolation and contact precautions, are indispensable to avoid their spread in the hospital setting. In this study, we developed and validated the PREVENT score, a tool for rapid risk assessment of VRE persistence in patients with a history of previous VRE colonization. The score is designed to be easily performed, employing clinical information available in a regular admission setting and immediately providing information to inform the decision of whether to adopt patient isolation and contact precautions during the hospital stay. After validation, the score was shown to accurately identify patients with persistent VRE colonization upon admission, representing a suitable option as (i) a complementary method yielding preliminary results significantly more quickly than culture-based VRE detection techniques and (ii) an alternative strategy for VRE detection in settings in which microbiological VRE screening is not routinely performed due to limited resources.

Abstract Background Moraxella nonliquefaciens is a usually non-pathogenic biofilm-producing Gram-negative coccobacillus which may colonize the upper respiratory tract, rarely causing invasive disease. Although very rare, bloodstream infections caused by this organism have been described, showing often a fatal outcome. Here, we report the case of a pediatric cancer patient with bloodstream infection and sepsis due to M. nonliquefaciens showing full recovery after appropriate antibiotic treatment. Case presentation A three-year-old boy with stage IV neuroblastoma was admitted for high-dose chemotherapy with autologous stem cell rescue after standard neuroblastoma treatment. Despite receiving antimicrobial prophylaxis with trimethoprim/sulfamethoxazole, acyclovir and amphothericin B, the patient presented with fever of up to 39.5 °C and neutropenia. Besides a chemotherapy-related mucositis and an indwelling Broviac catheter (removed), no infection focus was identified on physical examination. Moraxella nonliquafaciens was identified in blood cultures. After antibiotic treatment and neutrophil recovery, the patient was fit for discharge. Conclusions The case described highlights the importance of an otherwise non-pathogenic microorganism, especially in immunosupressed cancer patients. It should be kept in mind that, although very infrequently, Moraxella nonliquefaciens may cause bloodstream infections that can be successfully treated with prompt focus identification and antibiotic therapy.

BackgroundStaphylococcus aureus is one of the most isolated pathogens from the airways of cystic fibrosis (CF) patients. There is a lack of information about the clonal nature of S. aureus cultured from CF patients and their impact on disease. We hypothesized that patients would differ in their clinical status depending on S. aureus clonal carriage profiles during persistence.MethodsDuring a 21-months prospective observational multicenter study (Junge et al., 2016), 3893 S. aureus isolates (nose, oropharynx, and sputa) were cultured from 183 CF patients (16 German centers, 1 Austrian center) and subjected to spa-sequence typing to assess clonality. Data were associated to lung function, age, gender, and antibiotic treatment by multivariate regression analysis.ResultsTwo hundred and sixty-five different spa-types were determined with eight prevalent spa-types (isolated from more than 10 patients): t084, t091, t008, t015, t002 t012, t364, and t056. We observed different carriage profiles of spa-types during the study period: patients being positive with a prevalent spa-type, only one, a dominant or related spa-type/s. Patients with more antibiotic cycles were more likely to be positive for only one spa-type (p = 0.005), while older patients were more likely to have related (p = 0.006), or dominant spa-types (p = 0.026). Two percent of isolates were identified as methicillin-resistant S. aureus (MRSA) and evidence of transmission of clones within centers was low.ConclusionThere was a significant association of antibiotic therapy and age on S. aureus carriage profiles in CF patients indicating that antibiotic therapy prevents acquisition of new clones, while during aging of patients with persisting S. aureus, dominant clones were selected and mutations in the spa-repeat region accumulated.

Since March 2020, the COVID-19 pandemic forced hospitals worldwide to intensify their infection control measures to prevent health care-associated transmission of SARS-CoV-2. The correct use of personal protective equipment, especially the application of masks, was quickly identified as priority to reduce transmission with this pathogen. Here, we report a nosocomial cluster of methicillin-resistant Staphylococcus aureus (MRSA) that occurred during the COVID-19 pandemic in a gynecology/obstetrics department, despite these intensified contact precautions. Five MRSA originating from clinical samples after surgical intervention led to an outbreak investigation. Firstly, this included environmental sampling of the operation theatre (OT) and, secondly, a point prevalence screening of patients and health care workers (HCW). All detected MRSA were subjected to whole genome sequencing (WGS) and isolate relatedness was determined using core genome multilocus sequence typing (cgMLST). WGS revealed one MRSA cluster with genetically closely related five patient and two HCW isolates differing in a single cgMLST allele at maximum. The outbreak was terminated after implementation of infection control bundle strategies. Although contact precaution measures, which are also part of MRSA prevention bundle strategies, were intensified during the COVID-19 pandemic, this MRSA outbreak could take place. This illustrates the importance of adherence to classical infection prevention strategies.

Hand hygiene is a cornerstone of infection prevention. However, few data are available for school children on their knowledge of infectious diseases and their prevention. The aim of the study was to develop and apply a standardized questionnaire for children when visiting primary schools to survey their knowledge about infectious diseases, pathogen transmission and prevention measures. Enrolling thirteen German primary schools, 493 questionnaires for grade three primary school children were included for further analyses, comprising 257 (52.1%) girls and 236 (47.9%) boys with an age range of 8–11 years. Out of 489 children, 91.2% participants indicated that they knew about human-to-human transmissible diseases. Of these, 445 children responded in detail, most frequently mentioning respiratory and gastrointestinal diseases, followed by childhood diseases. Addressing putative hygiene awareness-influencing factors, it was worrisome that more than 40.0% of the children avoided visiting the sanitary facilities at school. Most of the children (82.9%) noted that they did not like to use the sanitary facilities at school because of their uncleanliness and the poor hygienic behavior of their classmates. In conclusion, basic infection awareness exists already in primary school age children. Ideas about the origin and prevention of infections are retrievable, however, this knowledge is not always accurate and adequately contextualized. Since the condition of sanitary facilities has a strong influence on usage behavior, the child’s perspective should be given more consideration in the design and maintenance of sanitary facilities.

Sepsis is a leading cause of morbidity and mortality, annually affecting millions of people worldwide. Immediate treatment initiation is crucial to improve the outcome but despite great progress, early identification of septic patients remains a challenge. Recently, white blood cell morphology was proposed as a new biomarker for sepsis diagnosis. In this proof-of-concept study, we aimed to investigate the effect of different bacteria and their determinants on T-lymphocytes by digital holographic microscopy (DHM). We hypothesize that species- and strain-specific morphological changes occur, which may offer a new approach for early sepsis diagnosis and identification of the causative agent. Jurkat cells as a model system were exposed to different S. aureus or E. coli strains either using sterile determinants or living bacteria. Time-lapse DHM was applied to analyze cellular morphological changes. There were not only living bacteria but also membrane vesicles and sterile culture supernatant-induced changes of cell area, circularity, and mean phase contrast. Interestingly, different cellular responses occurred depending on both the species and strain of the causative bacteria. Our findings suggest that investigation of T-lymphocyte morphology might provide a promising tool for the early identification of bacterial infections and possibly discrimination between different causative agents. Distinguishing gram-positive from gram-negative infection would already offer a great benefit for the proper administration of antibiotics.

Abstract Background Vancomycin resistant enterococci (VRE) occur with enhanced frequency in hospitalised patients. This study elucidates the prevalence of VRE on admission among surgical intensive care unit (SICU) patients, whether these patients are at special risk for VRE acquisition and which risk factors support this process. Methods Patients admitted to SICUs of the University Hospital Münster were examined during August–October 2017. VRE screening was performed within 48 h after admission and directly prior to discharge of patients. In parallel risk factors were recorded to estimate their effect on VRE acquisition during SICU stay. Results In total, 374 patients (68% male) with a median age of 66 years were admitted to one of the SICUs during the investigation period. Of all, 336 patients (89.8%) were screened on admission and 268 (71.7%) on discharge. Nine patients were admitted with previously known VRE colonisation. Twelve (3.6%) further patients were VRE positive on admission. During ICU stay, eight (3.0%) additional patients turned out to be VRE colonised. Risk factors found to be significantly associated with VRE acquisition were median length of stay on the ICU (14 vs. 3 days; p = 0.01), long-term dialysis (12.5% vs. 2.0% of patients; p = 0.05), and antibiotic treatment with flucloxacillin (28.6% vs. 7.2% of patients; p = 0.01) or piperacillin/tazobactam (57.1% vs. 26.6% of patients; p = 0.01). Conclusions SICU patients are not at special risk for VRE acquisition. Previous stay on a SICU should therefore not be considered as specific risk factor for VRE colonisation.

Vancomycin-resistant enterococci (VRE) pose a public health challenge worldwide. While VRE bloodstream infections (VREBI) increase in Germany and Europe, population-based molecular data are scarce. We aimed to analyze the molecular epidemiology, demographic aspects, and geographical distribution of VREBI in the German Federal State of North-Rhine–Westphalia (NRW), located in the German–Dutch–Belgian border area, representing over 20% of Germany’s population. VREBI isolates were collected from hospitals across NRW between 2016 and 2019. Demographic data were gathered and anonymized upon sample collection. Multilocus sequence typing (MLST) and identification of glycopeptide resistance were carried out. Epidemiological analysis and geographical mapping were performed. Single VREBI isolates from 755 patients were analyzed. In total, 38.9% were female, and 80.0% were aged ≥ 60 years. The VREBI incidence per 100,000 inhabitants nearly tripled, from 0.52 (2016) to 1.48 (2019), particularly in male patients aged ≥ 50 years. The proportion of vanB reached 83% (n = 202/243) in 2018, overtaking vanA as the predominant glycopeptide resistance determinant, detected in close relation with ST117 isolates. The proportion of MLST sequence type (ST) 117 peaked in 2018, at 78.2% (n = 190/243). The major role of these emerging strains in invasive infections in central Europe requires novel strategies for their diagnosis, treatment, and prevention.

Vancomycin is frequently used for the treatment of C. difficile infections (CDI). There are concerns that this might increase the risk of selecting vancomycin resistant enterococci (VRE). Here, we evaluated whether there is an increased risk of VRE acquisition following vancomycin for CDI specific treatment. Patients with CDI, metronidazole, or oral vancomycin treatment and without preexisting VRE were monitored for VRE acquisition. VRE isolates from patients with acquired and preexisting colonization were collected and subjected to whole genome sequencing. In total, 281 patients (median age 56 years, 54% of the male sex) presented with toxin positive C. difficile. Of them, 170 patients met the inclusion criteria, comprising 37 patients treated with metronidazole and 133 treated with oral vancomycin. In total, 14 patients meeting the inclusion criteria acquired VRE (vancomycin: n = 11; metronidazole: n = 3). Statistical analysis revealed no significant differences between both VRE acquisition rates. Genetic comparison of detected VRE isolates resulted in eight clusters of closely related genotypes comprising acquired and preexisting strains. Our results suggest that vancomycin and metronidazole likewise increase the risk of VRE acquisition. Genetic comparison indicates that VRE acquisition is a result of both antibiotic selection and pathogen transmission.

Abstract Background Stenotrophomonas maltophilia ubiquitously occurs in the hospital environment. This opportunistic pathogen can cause severe infections in immunocompromised hosts such as hematopoietic stem cell transplantation (HSCT) recipients. Between February and July 2016, a cluster of four patients on the HSCT unit suffered from S. maltophilia bloodstream infections (BSI). Methods For epidemiological investigation we retrospectively identified the colonization status of patients admitted to the ward during this time period and performed environmental monitoring of shower heads, shower outlets, washbasins and toilets in patient rooms. We tested antibiotic susceptibility of detected S. maltophilia isolates. Environmental and blood culture samples were subjected to whole genome sequence (WGS)-based typing. Results Of four patients with S. maltophlilia BSI, three were found to be colonized previously. In addition, retrospective investigations revealed two patients being colonized in anal swab samples but not infected. Environmental monitoring revealed one shower outlet contaminated with S. maltophilia. Antibiotic susceptibility testing of seven S. maltophlia strains resulted in two trimethoprim/sulfamethoxazole resistant and five susceptible isolates, however, not excluding an outbreak scenario. WGS-based typing did not result in any close genotypic relationship among the patients’ isolates. In contrast, one environmental isolate from a shower outlet was closely related to a single patient’s isolate. Conclusion WGS-based typing successfully refuted an outbreak of S. maltophilia on a HSCT ward but uncoverd that sanitary installations can be an actual source of S. maltophilia transmissions.

Abstract Background To investigate the impact of weekly screening within the bundle of infection control measures to terminate vancomycin-resistant enterococci (VRE) transmissions on an oncologic ward. Methods A cluster of 12 VRE colonisation and five infections was detected on an oncologic ward between January and April 2015. Subsequently, the VRE point prevalence was detected and, as part of a the bundle of infection control strategies to terminate the VRE cluster, we isolated affected patients, performed hand hygiene training among staff on ward, increased observations by infection control specialists, intensified surface disinfection, used personal protective equipment and initiated an admission screening in May 2015. After a further nosocomial VRE infection in August 2015, a weekly screening strategy of all oncology patients on the respective ward was established while admission screening was continued. Whole genome sequencing (WGS)-based typing was applied to determine the clonal relationship of isolated strains. Results Initially, 12 of 29 patients were VRE colonised; of these 10 were hospital-acquired. During May to August, on average 7 of 40 patients were detected to be VRE colonised per week during the admission screening, showing no significant decline compared to the initial situation. WGS-based typing revealed five different clusters of which three were due to vanB- and two vanA-positive enterococci. After an additional weekly screening was established, the number of colonised patients significantly declined to 1/53 and no further nosocomial cases were detected. Conclusions Weekly screening helped to differentiate between nosocomial and community-acquired VRE cases resulting in earlier infection control strategies on epidemic situations for a successful termination of nosocomial VRE transmissions.

Infections caused by multidrug-resistant organisms (MDROs) are associated with prolonged hospitalization and higher risk of mortality. Patients arriving in the hospital via the emergency department (ED) are screened for the presence of MDROs in compliance with the screening protocols in order to apply the correct isolation measures. In the Dutch–German border region, local hospitals apply their own screening protocols which are based upon national screening protocols. The contents of the national and local MDRO screening protocols were compared on vancomycin-resistant enterococci (VRE), methicillin-resistant Staphylococcus aureus (MRSA), and carbapenemase-producing and carbapenem-resistant Enterobacteriaceae (CPE/CRE). The practicality of the screening protocols was evaluated by performing an audit. As a result, the content of the MDRO screening protocols differed regarding risk factors for MDRO carriage, swab site, personal protective equipment, and isolation measures. The observations and questionnaires showed that the practicality was sufficient; however, the responsibility was not designated clearly and education regarding the screening protocols was deemed inappropriate. The differences between the MDRO screening protocols complicate patient care in the Dutch–German border region. Arrangements have to be made about the responsibility of the MDRO screening, and improvements are necessary concerning education regarding the MDRO screening protocols.

During the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, healthcare systems worldwide have to prevent nosocomial SARS-CoV-2 transmission while maintaining duty of care. In our study, we characterize the transmission dynamic of SARS-CoV-2 in inpatients and healthcare workers (HCWs) at the University Hospital Münster (UHM) in northwest Germany. We identified 27 cases of healthcare-associated SARS-CoV-2 infections (4 inpatients and 23 HCWs) who had contact with patients and/or HCWs without the use of adequate PPE. The contacts of these index cases were followed up for SARS-CoV-2 infection after unprotected exposure and a quantitative measure of probability of becoming infected, the attack rate, was calculated. In addition, transmission was evaluated in the context of infection control measures established during the pandemic and we compared the epidemiological data of all index cases, including symptoms and Ct values of virology test results. The overall attack rate in the hospital setting was 1.3% (inpatients 0.9%, HCWs 1.6%). However, during an outbreak, the attack rate was 25.5% (inpatients 20.0%, HCWs 29.6%). For both scenarios, HCWs had a higher attack rate illustrating their role in healthcare-associated SARS-CoV-2 transmission. Taken together, our experiences demonstrate how infection control measures can minimize the transmission of SARS-CoV-2 in the healthcare setting.

With high numbers of refugees arriving in Europe uncertainty exists as to whether multidrug-resistant organisms are imported into the healthcare system. In our study, we identified 383 refugee-inpatients admitted to the University Hospital Münster, Germany between September 2015 and September 2016. For this patient cohort screening for Methicillin-resistant Staphylococcus aureus (MRSA), multidrug-resistant Gram-negative bacteria (MDR-GNB) and Vancomycin-resistant enterococci (VRE) was recommended in our institution. Until May 2016 pre-emptive isolation was applied to all refugee-inpatients until the exclusion of these multidrug-resistant organisms. MRSA were found in 34 refugee-patients (9.8%), MDR-GNB in 25 refugee-patients (12.9%) and VRE in none of the refugee patients. We did not find any strains carrying carbapenemases. Whole genome sequencing (WGS) data demonstrated that the respective isolates were genetically heterogeneous and revealed no transmission of refugee-patient isolates to other patients. We therefore omitted pre-emptive isolation as an infection control measure for this group of patients. Furthermore, molecular typing did not show evidence for nosocomial transmission from refugee-patients to other patients. Standard hygiene measures successfully prevented the transmission of refugee-patient isolates to other patients and as a result introduction into the healthcare system. This underlines that any multidrug-resistant organisms present within this cohort are not of any extraordinary concern for health systems.

Vancomycin-resistant enterococci (VRE) are relevant nosocomial pathogens with an increasing incidence in the last decades. Their transmission is optimal in the hospital setting, as it offers two potential, large reservoirs that are closely related: susceptible patients and their environment. Here we investigate the role of the hospital environment in the nosocomial transmission of VRE by establishing concrete links between contaminated surfaces and colonized/infected patients in outbreak and non-outbreak settings. Environmental and patient VRE isolates were collected between 2013 and 2019 and analyzed by whole-genome sequencing (WGS), subsequent multilocus sequence typing (MLST), and core genome (cg) MLST. Pairs of isolates differing in vanA (72.7%), vanB (24%), or both (3.3%). Of the 53 environmental isolates, 51 were found to form five clusters with genetically related patient isolates (n = 97 isolates). WGS confirms the role of the environment in the transmission dynamics of VRE in both the outbreak and non-outbreak settings, highlighting the importance of prevention and control of VRE spread.

Vancomycin-resistant enterococci (VRE) are important nosocomial pathogens that require effective infection control measures, representing a challenge for healthcare systems. This study aimed at identifying risk factors associated with prolonged VRE carriage and determining the rate of clearance that allows the discontinuation of contact precautions. During a 2-year study, screening was performed in patients with a history of VRE or at risk of becoming colonized. After bacterial identification and antibiotic susceptibility testing, glycopeptide resistance was confirmed by PCR. Isolates were compared via whole genome sequence-based typing. Risk factors were recorded, and follow-up screening was performed upon readmission, defining patients as long-term carriers if still colonized ≥10 weeks after first detection. Of 1059 patients positive for VRE, carriage status was assessed upon readmission in 463 patients. VRE was cleared in 56.4% of the cases. Risk factors associated with long-term persistence were hospital stays (frequency, length), hemato-oncological disease, systemic treatment with steroids, and use of antibiotics. No specific genotypic clustering was observed in patients with VRE clearance or persistence. VRE clearance is possibly underestimated. The identification of risk factors favoring long-term carriage may contribute to a targeted implementation of infection control measures upon readmission of patients with history of VRE.

Preventing the spread of multidrug-resistant Gram-negative bacteria (MDRGNB) is a public health priority. However, the definition of MDRGNB applied for planning infection prevention measures such as barrier precautions differs depending on national guidelines. This is particularly relevant in the Dutch–German border region, where patients are transferred between healthcare facilities located in the two different countries, because clinicians and infection control personnel must understand antibiograms indicating MDRGNB from both sides of the border and using both national guidelines. This retrospective study aimed to compare antibiograms of Gram-negative bacteria and classify them using the Dutch and German national standards for MDRGNB definition. A total of 31,787 antibiograms from six Dutch and four German hospitals were classified. Overall, 73.7% were no MDRGNB according to both guidelines. According to the Dutch and German guideline, 7772/31,787 (24.5%) and 4586/31,787 (12.9%) were MDRGNB, respectively (p < 0.0001). Major divergent classifications were observed for extended-spectrum β-lactamase (ESBL) -producing Enterobacteriaceae, non-carbapenemase-producing carbapenem-resistant Enterobacteriaceae, Pseudomonas aeruginosa and Stenotrophomonas maltophilia. The observed differences show that medical staff must carefully check previous diagnostic findings when patients are transferred across the Dutch–German border, as it cannot be assumed that MDRGNB requiring special hygiene precautions are marked in the transferred antibiograms in accordance with both national guidelines.