Ralstonia pickettii bloodstream infections with potential genomic link to internationally distributed contaminated saline solution, Germany, October 2023.

Ralstonia pickettii is a Gram-negative rod which may cause invasive infections when they contaminate liquid medical products. After R. pickettii was detected in blood cultures and a stem cell product from three patients in a tertiary care hospital in Germany, whole genome sequencing of these three isolates and two water isolates from the environment was performed. Core genome multilocus sequence typing analysis showed that the three patient isolates were closely related and there was a large distance to the environmental isolates. In a genomic comparison, the patients' isolates were distantly related to an R. pickettii strain from a cluster in Australia suspected to be caused by contaminated saline produced in India, while all liquid medical products with a link to all patients were produced in Europe or the United States. Our data point towards an ongoing risk by an unknown common source that could be traced back to medical products contaminated with R. pickettii and potentially distributed worldwide. Investigating invasive R. pickettii infections, identifying and testing medical products administered to the patients and timely whole genome sequencing may help identify the exact source of this potentially global outbreak.

Development and Evaluation of a Core Genome Multilocus Sequencing Typing (cgMLST) Scheme for Serratia marcescens Molecular Surveillance and Outbreak Investigations.

Serratia marcescens can cause a range of severe infections and contributes to nosocomial outbreaks. Although whole-genome sequencing (WGS)-based typing is the standard method for molecular surveillance and outbreak investigation, there is no standardized analytic scheme for S. marcescens core genome multilocus sequence typing (cgMLST). Here, the development and evaluation of a S. marcescens cgMLST scheme is reported with the goal of enabling a standardized methodology and typing nomenclature. Four hundred ninety-one high-quality S. marcescens WGS data sets were extracted from public databases and-using the genomic sequence of NCBI reference strain S. marcescens Db11 (NZ_HG326223.1) as a starting point-all Db11 genes present in ≥97% data sets used to create a cgMLST scheme. The novel scheme was evaluated using WGS data from 24 outbreak investigations (n = 175 isolates) distributed over three continents. Analysis of Db11 genes within the 491 data sets identified 2,692 target genes present in ≥97% of genomes (mean, 99.1%; median, 99.9%). These genes formed the novel cgMLST scheme, covering 47.8% of nucleotides in the Db11 genome. Analyzing 175 isolates from 24 outbreaks using the novel scheme gave comparable results to previous typing efforts for both general groupings and allelic distances within clusters. In summary, a novel cgMLST scheme for S. marcescens was developed and evaluated. The scheme and its associated nomenclature will improve standardization of typing efforts for molecular surveillance and outbreak investigation, allowing better understanding of S. marcescens genomic epidemiology and facilitating interlaboratory comparisons.

Prospective surveillance of colonization and disease by methicillin-resistant Staphylococcus aureus (MRSA) at a European pediatric cancer center.

PURPOSE: Children and adolescents undergoing treatment for cancer or allogeneic hematopoietic cell transplantation are at increased risk for methicillin-resistant Staphylococcus aureus (MRSA). We therefore examined the occurrence and outcome of MRSA colonization and infection in patients of a large European pediatric cancer center. METHODS: In a prospective observational cohort study conducted between 2007 and 2018, nasopharyngeal swabs for culture of MRSA were obtained from all admitted patients. The primary endpoint of the study was the colonization rate over time. Secondary endpoints included genetic relatedness of isolates, time burden of isolation measures, and results of decolonization efforts. RESULTS: During the study period, MRSA screening identified 34 colonized patients (median age: 10 years; range: 0-21) without trends over time. MRSA colonization was associated with the presence of classical risk factors. There was no molecular evidence of patient-to-patient transmission. A standard MRSA eradication regimen led to a lasting eradication of the organism in 26 of 34 patients. MRSA infection occurred in two patients with no associated fatalities. CONCLUSION: Prospective monitoring revealed low rates of MRSA colonization and infection at our center. These low rates and the absence of patient-to-patient transmission support the effectiveness of the management bundle of MRSA identification, isolation, and decolonization.

Frequency of Diarrhea, Stool Specimen Collection and Testing, and Detection of Clostridioides Difficile Infection Among Hospitalized Adults in the Muenster/Coesfeld Area, Germany.

Clostridioides difficile infection (CDI) often manifests as diarrhea, particularly in adults of older age or with underlying comorbidities. However, only severe cases are notifiable in Germany. Moreover, failure to collect a stool specimen from inpatients with diarrhea or incomplete testing may lead to underdiagnosis and underreporting of CDI. We assessed the frequency of diarrhea, stool specimen collection, and CDI testing to estimate CDI underdiagnosis and underreporting among hospitalized adults. In a ten-day point-prevalence study (2019-2021) of nine hospitals in a defined area (Muenster/Coesfeld, North Rhine-Westphalia, Germany), all diarrhea cases (≥ 3 loose stools in 24 h) among adult inpatients were captured via medical record screening and nurse interviews. Patient characteristics, symptom onset, putative origin, antibiotic consumption, and diagnostic stool sampling were collected in a case report form (CRF). Diagnostic results were retrieved from the respective hospital laboratories. Among 6998 patients screened, 476 (7%) diarrhea patients were identified, yielding a hospital-based incidence of 201 cases per 10,000 patient-days. Of the diarrheal patients, 186 (39%) had a stool sample collected, of which 160 (86%) were tested for CDI, meaning that the overall CDI testing rate among diarrhea patients was 34%. Toxigenic C. difficile was detected in 18 (11%) of the tested samples. The frequency of stool specimen collection and CDI testing among hospitalized diarrhea patients was suboptimal. Thus, CDI incidence in Germany is likely underestimated. To assess the complete burden of CDI in German hospitals, further investigations are needed.

A prospective multicentre screening study on multidrug-resistant organisms in intensive care units in the Dutch-German cross-border region, 2017 to 2018: the importance of healthcare structures.

BackgroundAntimicrobial resistance poses a risk for healthcare, both in the community and hospitals. The spread of multidrug-resistant organisms (MDROs) occurs mostly on a local and regional level, following movement of patients, but also occurs across national borders.AimThe aim of this observational study was to determine the prevalence of MDROs in a European cross-border region to understand differences and improve infection prevention based on real-time routine data and workflows.MethodsBetween September 2017 and June 2018, 23 hospitals in the Dutch (NL)-German (DE) cross-border region (BR) participated in the study. During 8 consecutive weeks, patients were screened upon admission to intensive care units (ICUs) for nasal carriage of meticillin-resistant Staphylococcus aureus (MRSA) and rectal carriage of vancomycin-resistant Enterococcus faecium/E. faecalis (VRE), third-generation cephalosporin-resistant Enterobacteriaceae (3GCRE) and carbapenem-resistant Enterobacteriaceae (CRE). All samples were processed in the associated laboratories.ResultsA total of 3,365 patients were screened (median age: 68 years (IQR: 57-77); male/female ratio: 59.7/40.3; NL-BR: n = 1,202; DE-BR: n = 2,163). Median screening compliance was 60.4% (NL-BR: 56.9%; DE-BR: 62.9%). MDRO prevalence was higher in DE-BR than in NL-BR, namely 1.7% vs 0.6% for MRSA (p = 0.006), 2.7% vs 0.1% for VRE (p < 0.001) and 6.6% vs 3.6% for 3GCRE (p < 0.001), whereas CRE prevalence was comparable (0.2% in DE-BR vs 0.0% in NL-BR ICUs).ConclusionsThis first prospective multicentre screening study in a European cross-border region shows high heterogenicity in MDRO carriage prevalence in NL-BR and DE-BR ICUs. This indicates that the prevalence is probably influenced by the different healthcare structures.

Surgeons' non-transparent facemasks challenge the physician-patient relationship in the orthopedic outpatient clinic of a tertiary university hospital during the COVID-19 pandemic: a prospective cohort study of 285 patients.

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.

First Reported Nosocomial Outbreak of Severe Acute Respiratory Syndrome Coronavirus 2 in a Pediatric Dialysis Unit.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a life-threatening respiratory condition caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and was initially detected in China in December 2019. Currently, in Germany >140 000 cases of COVID-19 are confirmed. Here we report a nosocomial outbreak of SARS-CoV-2 infections in the pediatric dialysis unit of the University Hospital Münster (UHM). METHODS: Single-step real-time reverse-transcription polymerase chain reaction (rRT-PCR) from nasopharyngeal swabs was used to diagnose the index patient and identify infected contacts. Epidemiological links were analyzed by patient interviews and medical record reviews. In addition, each contact was assessed for exposure to the index case and monitored for clinical symptoms. Cycle threshold (Ct) values of all positive test results were compared between symptomatic and asymptomatic cases. RESULTS: Forty-eight cases were involved in this nosocomial outbreak. Nine contact cases developed laboratory-confirmed COVID-19 infections. Two SARS-CoV-2-positive cases remained clinically asymptomatic. Eleven cases reported flulike symptoms without positive results. Ct values were significantly lower in cases presenting typical COVID-19 symptoms, suggesting high viral shedding (P = .007). CONCLUSIONS: Person-to-person transmission was at the heart of a hospital outbreak of SARS-CoV-2 between healthcare workers (HCWs) and patients in the pediatric dialysis unit at UHM. Semiquantitative rRT-PCR results suggest that individuals with high viral load pose a risk to spread SARS-CoV-2 in the hospital setting. Our epidemiological observation highlights the need to develop strategies to trace and monitor SARS-CoV-2-infected HCWs to prevent COVID-19 outbreaks in the hospital setting.

Identification of novel sublingual parameters to analyze and diagnose microvascular dysfunction in sepsis: the NOSTRADAMUS study.

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 (R2 = 0.63, p < 0.0001) but not in healthy controls (R2 = 0.04, p = 0.43), indicating impaired capillary (de-)recruitment in sepsis. This finding enabled the calculation of capillary recruitment and dynamic capillary blood volume (CBVdynamic). Moreover, adjustment of PBR to feed vessel VRBC further improved discrimination between sepsis patients and controls by about 50%. By combining these dynamic microvascular and glycocalyx variables, we developed the microvascular health score (MVHSdynamic™), which decreased from 7.4 [4.6-8.7] in controls to 1.8 [1.4-2.7] in sepsis patients (p < 0.0001) and correlated with sepsis severity. CONCLUSION: We introduce new important diameter-specific quantification and differentiated analysis of RBC kinetics, a key to understand microvascular dysfunction in sepsis. MVHSdynamic, which has a broad bandwidth to detect microvascular (dys-) function, might serve as a valuable tool to detect microvascular impairment in critically ill patients.

Gram Staining: a Comparison of Two Automated Systems and Manual Staining.

Various Gram staining automated systems are available to accelerate and standardize the staining process, but a systematic comparison of different systems is largely lacking. The objective of this study was to evaluate two devices in comparison to manual Gram staining. Clinical samples (n = 500; University Hospital Münster, Germany; May to June 2020) were simultaneously Gram stained manually and with two automated Gram stainers (Previ Color Gram, bioMérieux, and ColorAX2, Axonlab). The quality was assessed based on four criteria: (i) homogeneous staining of bacteria/fungi, (ii) uniform staining of the background, (iii) absence of staining artifacts, and (iv) congruency between culture and microscopy. Each criterion was rated with 0 (absence) or 1 (presence) point to calculate a quality score (0 to 4 points). The costs for each staining procedure were calculated based on consumables and hands-on time (applying the average wage of a laboratory technician in the public service for Germany and the United States). The mean (± standard deviation [SD]) quality scores were comparable for manual staining (3.06 ± 0.91) and Previ Color Gram (3.04 ± 0.90; P = 0.6), while significantly lower scores were achieved by ColorAX2 (2.57 ± 1.09; P < 0.0001). The total cost per Gram stain was €1.13/$1.34 for Previ Color Gram, €0.80/$0.83 for manual, and €0.60/$0.71 for ColorAX2, respectively. The quality and costs per slide vary significantly between instruments of different manufacturers.

The 2011 German Enterohemorrhagic Escherichia Coli O104:H4 Outbreak-The Danger Is Still Out There.

Enterohemorrhagic Escherichia coli (EHEC) are Shiga toxin (Stx) producing bacteria causing a disease characterized by bloody (or non-bloody) diarrhea, which might progress to hemolytic uremic syndrome (HUS). EHEC O104:H4 caused the largest ever recorded EHEC outbreak in Germany in 2011, which in addition showed the so far highest incidence rate of EHEC-related HUS worldwide. The aggressive outbreak strain carries an unusual combination of virulence traits characteristic to both EHEC-a chromosomally integrated Stx-encoding bacteriophage, and enteroaggregative Escherichia coli-pAA plasmid-encoded aggregative adherence fimbriae mediating its tight adhesion to epithelia cells. There are currently still open questions regarding the 2011 EHEC outbreak, e.g., with respect to the exact molecular mechanisms resulting in the hypervirulence of the strain, the natural reservoir of EHEC O104:H4, and suitable therapeutic strategies. Nevertheless, our knowledge on these issues has substantially expanded since 2011. Here, we present an overview of the epidemiological, clinical, microbiological, and molecular biological data available on the 2011 German EHEC O104:H4 outbreak.

Moraxella nonliquefaciens bloodstream infection and sepsis in a pediatric cancer patient: case report and literature review.

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.

Staphylococcus aureus in the airways of cystic fibrosis patients - A retrospective long-term study.

BACKGROUND: Cystic fibrosis (CF) is an autosomal recessive disease associated with chronic airway infections by Staphylococcus aureus as one of the earliest and most prevalent pathogens. We conducted a retrospective study to determine the S. aureus infection status of CF patients treated since 1994 at two certified CF-centres in Münster, Germany, to get insights into the dynamics of S. aureus airway infection and the clinical impact on lung function on a long-term perspective. MATERIALS AND METHODS: We used data from our microbiological database collected between 1994 and 2016 for patients treated at two centres in Münster, Germany, respectively, to determine the infection status for S. aureus. Furthermore, the resistance to selected antibiotics was determined for all patients' isolates and for 15 patients on a longitudinal basis. In addition, the prevalence of adaptive phenotypes such as small colony variants (SCVs) and mucoid S. aureus was assessed. RESULTS: For this study, 2867 patient years with respiratory specimens (mean of 9.3 years for every patient, range 1-22 years) were evaluated for 283 CF patients (median age of 7 years at the beginning of the observation period, range 0-57 years, 51% male). 18% of patients were rarely infected by S. aureus (≤24% of observation years), 20% of patients intermittently (25-49%) and 61% persistently (≥50% of observation period). Susceptibility testing for 12969 S. aureus isolates resulted in resistance to methicillin in 9%, trimethoprim/sulfamethoxazole in 10%, levofloxacin in 14%, gentamicin in 20%, erythromycin and/or clindamycin in 30% and penicillin in 80% of all isolates. S. aureus isolates of 15 patients revealed dynamics of resistance with increase, decrease and loss of resistant isolates to the analysed antibiotics during the study period. SCVs were isolated at least once from 42% (n = 118) of patients and mucoid isolates from 2% (n = 7) of patients. In the last study year, 89 patients were infected by S. aureus only, 44 patients by S. aureus and Pseudomonas aeruginosa and 18 by P. aeruginosa only. Patients infected by S. aureus only were younger and had better lung function compared to the other two groups. CONCLUSIONS: We determined a high percentage of patients with persistent S. aureus infection. During persistence, mostly fluctuation of resistance against various antibiotics was observed in the isolates indicating acquisition and loss of resistance genes by S. aureus. The prevalence of adaptive phenotypes during long-term persistence was high for SCVs (42% of patients), but low for mucoid isolates (2% of patients), which might be underestimated for mucoid phenotypes due to the retrospective study design and the difficulty to detect mucoid isolates in primary cultures. While patients with S. aureus only had better lung function and were younger, no difference was found between the group of P. aeruginosa and S. aureus co-infection and P. aeruginosa only with previous S. aureus infection.

Control of Multidrug-Resistant Pseudomonas aeruginosa in Allogeneic Hematopoietic Stem Cell Transplant Recipients by a Novel Bundle Including Remodeling of Sanitary and Water Supply Systems.

Background: Infections by multidrug-resistant Pseudomonas aeruginosa (MDRPa) are an important cause of morbidity and mortality in patients after allogeneic hematopoietic stem cell transplantation (HSCT). Humid environments can serve as a reservoir and source of infection by this pathogen. To minimize the risk of infection from these reservoirs, we performed extensive remodeling of sanitation and water installations as the focus of our hygiene bundle. Methods: During the reconstruction of our transplantation unit (April 2011-April 2014) we implemented several technical modifications to reduce environmental contamination by and subsequent spreading of MDRPa, including a newly designed shower drain, disinfecting siphons underneath the sinks, and rimless toilets. During a 3-year study period (2012-2014), we tracked the number of patients affected by MDRPa (colonized and/or infected) and the outcome of infected patients, and monitored the environmental occurrence of this pathogen. We further performed whole-genome sequencing of nosocomial MDRPa strains to evaluate genotypic relationships between isolates. Results: Whereas 31 (9.2%; 18 colonized, 13 infected) patients were affected in 2012 and 2013, the number decreased to 3 in 2014 (17%; 3 colonized, 0 infected). Lethality by MDRPa similarly decreased from 3.6% to 0%. Environmental detection of MDRPa decreased in toilets from 18.9% in 2012-2013 to 6.1% in the following year and from 8.1% to 3.0%, respectively, in shower outlets. Whole-genome sequencing showed close relationships between environmental and patient-derived isolates. Conclusions: Hospital construction measures aimed at controlling environmental contamination by and spread of MDRPa are effective at minimizing the risk of highly lethal MDRPa infections.

Management of destructive Candida albicans spondylodiscitis of the cervical spine: a systematic analysis of literature illustrated by an unusual case.

PURPOSE: Candida induced spondylodiscitis of the cervical spine in immunocompetent patients is an extremely rare infectious complication. Since clinical symptoms might be nonspecific, therapeutic latency can lead to permanent spinal cord damage, sepsis and fatal complications. Surgical debridement is strongly recommended but there is no standard antimycotic regime for postsurgical treatment. This paper summarizes available data and demonstrates another successfully treated case. METHODS: The systematic analysis was performed according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. PubMed and Web of Science were scanned to identify English language articles. Additionally, the authors describe the case of a 60-year-old male patient who presented with a Candida albicans induced cervical spondylodiscitis after an edematous pancreatitis and C. albicans sepsis. Anterior cervical corpectomy and fusion of C4-C6, additional anterior plating, as well as posterior stabilization C3-Th1 was followed by a 6-month antimycotic therapy. There was neither funding nor conflict of interests. RESULTS: A systematic literature analysis was conducted and 4599 articles on spondylodiscitis were scanned. Only four cases were found reporting about a C. albicans spondylodiscitis in a non-immunocompromised patient. So far, our patient was followed up for 2 years. Until now, he shows free of symptoms and infection parameters. Standard testing for immunodeficiency showed no positive results. CONCLUSION: Candida albicans spondylodiscitis of the cervical spine presents a potentially life-threatening disease. To our knowledge, this is the fifth case in literature that describes the treatment of C. albicans spondylodiscitis in an immunocompetent patient. Surgical debridement has to be considered, following antimycotic regime recommendations vary in pharmaceutical agents and treatment duration.

Whole-Genome Sequencing Elucidates Epidemiology of Nosocomial Clusters of Acinetobacter baumannii.

We characterized two epidemiologically similar Acinetobacter baumannii clusters from two separate intensive care units (ICU) using core genome multilocus sequence typing. Clonal spread was confirmed in ICU-1 (12 of 14 isolates shared genotypes); in ICU-2, all genotypes (13 isolates) were diverse, thus excluding transmissions and enabling adequate infection control measures.

A qualitative, multi-centre approach to the current state of digitalisation and automation of surveillance in infection prevention and control in German hospitals.

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.

Role of membrane vesicles in the transmission of vancomycin resistance in Enterococcus faecium.

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.

Sink Drains in a Neonatal Intensive Care Unit: A Retrospective Risk Assessment and Evaluation.

Water systems in health care facilities can form reservoirs for Gram-negative bacteria. While planning a new neonatal intensive care unit (NICU), we performed a retrospective evaluation of potential risks from water-diverting systems on the existing NICU of our tertiary care University Hospital. During 2017 to 2023, we recorded nine nosocomial cluster events with bacterial pathogens in our NICU. Of these, three clusters of Gram-negative bacteria were potentially related to sink drains: A Klebsiella oxytoca, a Pseudomonas aeruginosa, and an Enterobacter hormaechei cluster were uncovered by clinical routine screening of patients and breastmilk samples. They were confirmed using whole-genome sequencing and a subsequent core genome multilocus sequence typing (cgMLST) algorithm. Our observations highlight that the implementation of sink drains in a NICU may have negative effects on patients' safety. Construction planning should concentrate on the avoidance of washbasins in patient rooms when redesigning sensitive areas such as NICUs.

Application of Digital Holographic Microscopy to Analyze Changes in T-Cell Morphology in Response to Bacterial Challenge.

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.