[Diagnostic performance of two antigen-tests compared to one PCR-Test to detect SARS-CoV-2 in an emergency department and emergency service]. / Diagnostische Leistungsfähigkeit von zwei Antigentests im Vergleich zu einem PCR-Test zum Nachweis von SARS-CoV-2 in einer Notaufnahme und im Rettungsdienst.

BACKGROUND: In the German hospital landscape and emergency care the COVID-19 pandemic was a stress test. Emergency medical health care in Germany is ensured by the supply chain between prehospital emergency rescue and clinical emergency care in the emergency rooms. In hospitals and emergency care settings a rapid, simple, accurate, and cost-effective test is needed to identify SARS-CoV­2. In the central emergency department it is important to strictly separate patients with suspected COVID-19 from non-infected emergency persons. METHODS: Given the background mentioned above, the performance of antigen tests in the ambulance service of the city Jena and the central emergency department of the university hospital Jena was analysed and in addition verified by using the RT-PCR gold standard. Several multiple testing procedures were performed by using antigen tests in the ambulance service and the central emergency department, and by using one or both of these antigen tests followed by the RT-PCR test. A total of 980 patients were included in the study over a two-month period (October/November 2022). RESULTS: The average age of all patients was 65 years. More than half of the actively treated patients came from the city of Jena. The sensitivity and specificity of the antigen tests were 66.7% and 99.2% in the clinical setting (the central emergency department) and 68.8% and 96.7% in the prehospital setting (in the ambulance service) compared to RT-PCR. In the prehospital setting the sensitivity of the antigen testing was slightly higher (2%) than the clinical antigen testing. Regarding the parallel testing, 6% of antigen tests had a false negative SARS-CoV­2 antigen test result in the ambulance service and 4.6% of antigen tests had a false negative SARS-CoV­2 antigen test result in the central emergency department. The false-negative antigen tests, and thus the potentially unrecognized individuals, were further reviewed by considering the Ct-value. CONCLUSION: The use of antigen testing in the ambulance service and the emergency department can lead to a quick classification of COVID and non-COVID areas of an emergency department. The measurement accuracy of antigen testing in the ambulance service and central emergency department is not equivalent to the RT-PCR. Nevertheless, antigen testing is a useful initial screening tool for early detection of SARS-CoV­2 in prehospital and clinical settings. Dual antigen testing may be useful for more accurate diagnosis of the SARS-CoV­2 pathogen.

Multidrug-resistant isolates from Ukrainian patients in a German health facility: a genomic surveillance study focusing on antimicrobial resistance and bacterial relatedness.

PURPOSE: Antimicrobial resistance is a pressing issue in Ukraine, with healthcare-associated infections caused by multidrug-resistant organisms being a major concern. A recent prospective multicenter study revealed a staggering rate of 48.4% antimicrobial resistance to carbapenems among Enterobacterales causing a healthcare-associated infection. We conducted a systematic survey to investigate the incidence rate and incidence density of carbapenemase-producing Gram-negative bacteria (CPGN) among refugees and war-wounded Ukrainians in connection with the German health system. METHODS: From the onset of the war until November 2022, seven Ukrainian patients were admitted to our hospital. Upon admission, screening samples and samples from the focus of suspected infection were taken from all seven patients. The incidence rate and the incidence density of CPGN were calculated as a result of the microbiological findings. We sequenced all CPGN using Illumina technology. RESULTS: The incidence rate of CPGN at our hospital was 0.06 for 2021 and 0.18 for 2022. All seven Ukrainian patients were infected or colonized with at least one CPGN, including K. pneumoniae (14/25), P. aeruginosa (6/25), A. baumannii (1/25), Providencia stutartii (1/25), C. freundii (1/25), and E. coli (2/25). Genomic surveillance revealed that (i) most frequently detected carbapenemases among all sequenced isolates were blaNDM (17/25) and blaOXA-48 (6/25), (ii) most commonly observed plasmid replicons among the K. pneumoniae isolates recovered from Ukrainian patients were Col(pHAD28) (12/14), IncHI1B(pNDM-MAR) (9/14), IncFIB(pNDM-Mar) (12/14), and (iii) clonal relation between the pathogens of the Ukrainian isolates, but not for the isolates from our hospital surveillance system. CONCLUSION: The rising prevalence of community-acquired colonization and infection with CPGN is having a direct effect on the infection prevention measures, such as higher number of isolations, reprocessing of patient rooms, additional microbiological testing and overall organization within hospitals.

Short-Wave Ultraviolet-Light-Based Disinfection of Surface Environment Using Light-Emitting Diodes: A New Approach to Prevent Health-Care-Associated Infections.

Ultraviolet (UV)-C irradiation is a promising method for microbial eradication on surfaces. Major developments have taken place in UV-C light-emitting diodes (LEDs) technology. In this study, we examined the suitability of UV-C LED-based surface disinfection in hospitals. We tested the efficacy of UV-C LED surface treatment on different microorganisms dried on a carrier surface or in a liquid solution. The influences of soiling, shading, surface material, radiation wavelength, microbial load and species on the disinfection performance were investigated. UV-C LED caused a reduction of >5 log10 levels of E. coli, S. aureus and C. albicans, whereas 3 log10 reduction was observed for G. stearothermophilus spores. The components of the medium led to a reduced UV-C LED efficiency compared to buffered solutions. We observed that the microbial load and the roughness of the carrier surface had a major influence on the UV-C LED disinfection efficiencies, whereas shading had no impact on inactivation. This study showed that UV-C is suitable for surface disinfection, but only under certain conditions. We showed that the main factors influencing microbial inactivation through UV-C light (e.g., intrinsic and extrinsic factors) had a similar impact when using a UV-C LED radiation source compared to a conventional UV-C lamp. However, the potential of LEDs is contributed by their adjustable wavelength and customizable geometry for the decontamination of medical devices and surfaces, and thereby their ability to overcome shading effects.

Influence of the Incubator as Direct Patient Environment on Bacterial Colonization of Neonates.

BACKGROUND: Preventing healthcare-associated infections (HAI) in neonatal intensive care units is a challenge of highest priority. For further insight into the incubator as direct patient environment and potential source for contamination, we present data correlating microbiological samples of very low birthweight infants in the form of colonization results of surveillance screenings with samples of their associated incubator in this study. METHODS: Samples were taken via rectal and throat swabs of neonates as well as Polywipe® sponges for the incubator. If the same bacterial species was found in corresponding neonate and incubator samples, whole genome sequencing via Illumina technology was performed. RESULTS: 52 microbiological species matches were found, and 30 matches were sequenced where we found 26 clonal pairs (12 E. faecalis, 10 S. aureus, 2 E. coli, 1 E. cloacae, and 1 E. faecium). CONCLUSION: The combinations of measurements of weekly screenings swabs, probing of surfaces with Polywipes®, and whole genome sequencing showed transmissions of microorganism and risk for potential non-physiological colonization of neonatal infants.

Do closed waste containers lead to less air contamination than opened? A clinical case study at Jena University Hospital, Germany.

Nosocomial infections are a growing challenge at hospitals. This clinical study aimed to investigate the influence of waste container construction ((open (O), closed (C), and hands-free opening (HF)) on microbial air contamination in a hospital setting. The results are intended to help develop guidelines for waste containers for the collection of non-infectious waste at hospitals and medical facilities. The clinical experiment was conducted at the University Hospital Jena, Germany. Air Impactor samples were performed and microbiologically evaluated for bacteria and fungi both quantitatively and qualitatively. The results were statistically determined using generalized estimating equations. Quantitatively, the lowest bacterial counts in ambient air were found around closed waste containers (114.74 CFU/m3) in comparison to HF (129.28 CFU/m3) and O (126.28 CFU/m3). For fungi, the surrounding air of C (2.08 CFU/m3) and HF (1.97 CFU/m3) waste containers showed a lower impact of fungal air contamination than for O (2.32 CFU/m3). Overall, it was shown that C are more preferable to HF and O waste containers from the point of view of microbial air contamination at hospitals.

Targeted Molecular Detection of Nosocomial Carbapenemase-Producing Gram-Negative Bacteria-On Near- and Distant-Patient Surfaces.

BACKGROUND: Here, we describe an integrative method to detect carbapenemase-producing Gram-negative bacteria (gn-Cp) on surfaces/fomites in the patient environment. We examined environmental samples from 28 patient rooms occupied with patients who were proven to be colonised with gn-Cp by rectal screening. METHODS: We took samples after 24 h, 72 h and one week. For sampling, we divided the patient environment into four parts and took samples from near- and extended patient areas. To obtain a representative bacterial swab from a larger surface, such as the patient cabinet, we used Polywipes. Bacterial DNA was isolated. Carbapenemase was detected with specific qPCR primers. RESULTS: With this culture- and molecular-based approach, we could control the effectiveness of cleaning and disinfection in everyday clinical practice. Therefore, we could track the spread of gn-Cp within the patient room. The number of positive detections fluctuated between 30.5% (mean value positive results after 72 h) and 35.2% (after 24 h and one week). CONCLUSION: The method used to detect multidrug-resistant bacteria in the environment of patients by using PolywipesTM is reliable and can therefore be used as an effective, new tool in hygiene and infection control.

[Hospital hygiene 2.0 : Cross-interface, molecular epidemiological early warning systems for prevention of multidrug-resistant pathogens]. / Krankenhaushygiene 2.0 : Schnittstellenübergreifende, molekularepidemiologische Frühwarnsysteme für die Prävention multiresistenter Erreger.

Infections caused by multidrug-resistant pathogens and their inpatient (nosocomial) and outpatient spread, pose increasing challenges to our healthcare system. Control strategies are derived from vertical (individual, pathogen-specific) and horizontal (general, pathogen-unspecific) preventive measures. The discussion of a competing "either or" has not proven to be effective in the past. In addition, the problem of multidrug-resistant pathogens cannot be solved solely in inpatient health care: the goals are a seamless communication and transparent cooperation between all actors in the healthcare system. Nowadays, modern molecular methods for pathogen typing are available, with the help of which transmission pathways can be clarified and hospital hygiene measures can be efficiently controlled. These procedures will be used increasingly more in the future to combat the problem of multidrug resistance across interfaces within regional network structures.

Use of MALDI-TOF mass spectrometry to detect nosocomial outbreaks of Serratia marcescens and Citrobacter freundii.

MALDI-TOF mass spectrometry (MS) may be used as a rapid typing method for nosocomial pathogens. Here, we evaluated MALDI-TOF MS for discrimination of hospital outbreak-related clusters of Serratia marcescens and carbapenemase-producing Citrobacter freundii. Thirty-three S. marcescens isolates collected from neonatal intensive care unit (NICU) patients, and 23 C. freundii isolates including VIM-positive isolates from a hospital colonization outbreak were measured by Vitek MS. Consensus spectra of each isolate were clustered using SARAMIS software. Genotyping was performed by whole-genome sequencing (WGS). First, a set of 21 S. marcescens isolates from 2014 with seven genotypes including three monoclonal clusters was used for the evaluation of MALDI-TOF typing. MS clustering was largely in agreement with genotyping results when the similarity cut-off for clonal identity was set on 90%. MALDI-TOF cluster analysis was then investigated for the surveillance of S. marcescens in the NICU in 2017 and demonstrated the introduction of new strains into the hospital and nosocomial transmissions. MS analysis of the C. freundii outbreak in 2016 revealed a monoclonal cluster of VIM-positive isolates and the separation of epidemiologically non-related VIM-positive and negative isolates. Two additional VIM-positive Citrobacter isolates from food samples were closely related to the large monoclonal cluster. WGS confirmed the MS results. MALDI-TOF MS may be used as a first-line typing tool for S. marcescens and C. freundii to detect transmission events in the hospital because isolates of an identical WGS type were grouped into the same MS cluster.

Microbiological monitoring of continuous positive airway pressure and resuscitation equipment in very-low birth weight infants.

BackgroundTo investigate the colonization of respiratory equipment and the rate of respiratory infections of very-low birth weight (VLBW) infants.MethodsThe prospective study includes 26 VLBW infants on continuous airway pressure (CPAP) from September until December 2012. Swabs from respiratory equipment and colonization/infections were evaluated.ResultsA total of 603 swabs was cultured with 298 isolates; 59% of cultures from CPAP equipment (n=337; 95% confidence interval (CI; 54;64)) and 19% from ambu bags (n=51; 95% CI (14;24)) were positive. Overall, 181/201 CPAP prongs and masks hosted 221 microorganisms. Colonization on days 3 and 7 were 93% and 87%, respectively, with an increase in pathogens and a decrease in skin flora (79% vs. 68%). Comparing the 58 paired swab results from days 3 and 7 showed an increase in Gram-negative bacteria (P=0.014). Eighteen infants had positive weekly screening results, with similar colonization of CPAP equipment, dominated by Enterobacteriacae. Pneumonia was diagnosed in two infants.ConclusionOf the CPAP equipment close to the patient, 90% was colonized with microorganisms increasing during 1 week of CPAP. The pathogens were dominated by gastrointestinal bacteria, and persisted over weeks. Frequent cleaning did not prevent pneumonia, although pneumonia rates were rare.

Prevalence of Multidrug Resistant Bacteria in Refugees: A Prospective Case Control Study in an Obstetric Cohort.

Purpose To determine the prevalence of multidrug resistant (MDR) bacteria in a cohort of pregnant refugee women. Methods In a prospective case control study, surveillance cultures for MDR bacteria (methicillin-resistant Staphylococcus aureus [MRSA], vancomycin-resistant enterococci [VRE], MDR Gram-negative bacteria [MRGN]) were analysed between October 2015 and June 2016 from a cohort of 50 pregnant refugee women and 50 resident controls in the obstetric unit of a German tertiary referral hospital. Results Prevalence of MRSA was noticeably higher among refugee women compared to residents (6 vs. 0%). In addition, a trend towards a higher prevalence of VRE and MDR Gram-negative bacteria in refugees was shown (1.8 vs. 0%). Conclusions Due to the higher prevalence of MDR bacteria, surveillance cultures are justified in order to prevent nosocomial spread of MDR bacteria.

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.

Weekly screening supports terminating nosocomial transmissions of vancomycin-resistant enterococci on an oncologic ward - a retrospective analysis.

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.

Real-Time Genome Sequencing of Resistant Bacteria Provides Precision Infection Control in an Institutional Setting.

The increasing prevalence of multidrug-resistant (MDR) bacteria is a serious global challenge. Here, we studied prospectively whether bacterial whole-genome sequencing (WGS) for real-time MDR surveillance is technical feasible, returns actionable results, and is cost-beneficial. WGS was applied to all MDR isolates of four species (methicillin-resistant Staphylococcus aureus [MRSA], vancomycin-resistant Enterococcus faecium, MDR Escherichia coli, and MDR Pseudomonas aeruginosa) at the University Hospital Muenster, Muenster, Germany, a tertiary care hospital with 1,450 beds, during two 6-month intervals. Turnaround times (TAT) were measured, and total costs for sequencing per isolate were calculated. After cancelling prior policies of preemptive isolation of patients harboring certain Gram-negative MDR bacteria in risk areas, the second interval was conducted. During interval I, 645 bacterial isolates were sequenced. From culture, TATs ranged from 4.4 to 5.3 days, and costs were €202.49 per isolate. During interval II, 550 bacterial isolates were sequenced. Hospital-wide transmission rates of the two most common species (MRSA and MDR E. coli) were low during interval I (5.8% and 2.3%, respectively) and interval II (4.3% and 5.0%, respectively). Cancellation of isolation of patients infected with non-pan-resistant MDR E. coli in risk wards did not increase transmission. Comparing sequencing costs with avoided costs mostly due to fewer blocked beds during interval II, we saved in excess of €200,000. Real-time microbial WGS in our institution was feasible, produced precise actionable results, helped us to monitor transmission rates that remained low following a modification in isolation procedures, and ultimately saved costs.

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.

Analysis of bile colonization and intestinal flora may improve management in liver transplant recipients undergoing ERCP.

BACKGROUND: Immunosuppression, denervation of biliary tract, and presence of biliary strictures favor colonization of bile with microorganisms after liver transplantation. Little is known about spectrum and antibiotic susceptibility of this colonization. MATERIAL AND METHODS: Bile and feces were collected prospectively from 38 patients who underwent endoscopic retrograde cholangiopancreaticography after liver transplantation. Samples were analyzed for colonization and antibiotic susceptibility. RESULTS: From the 38 tested bile samples, 86.6% tested positive. Of those, 26 (78.8%) were polymicrobial. Of isolated bile samples, 52 (64.2%) were gram-positive, 22.2% were gram-negative, and 13.6% revealed Candida albicans. Most detectable gram-positive bacteria were Enterococcus faecium. Most detectable gram-negative bacteria were E. coli and Klebsiella pneumonia. Our analyses revealed high resistance rates of the isolates. Only 55.6% of isolates were sensitive to ciprofloxacin, 54% were sensitive to piperacillin/tazobactam, and 60.3% were sensitive to imipenem. High susceptibility rates were found for linezolid and vancomycin (72.9% and 72.6%, respectively). We found a high correlation between microorganisms found in bile and those isolated from stool. CONCLUSIONS: Bile of liver transplant recipients is frequently colonized with microorganisms. The starting point of this colonization is usually the intestine. Systematic analysis of bile colonization during endoscopic interventions on biliary tracts of liver transplant recipients might help to select effective prophylactic antibiotic regimes as well as to facilitate the choice of suitable antimicrobial therapy in case of septic complications.

[Blood culture diagnostic--challenge or routine standard of care?]. / Sepsis und Multiorganversagen - Blutkulturdiagnostik: Herausforderung oder Routine?

Blood cultures are an essential diagnostic tool to investigate suspected cases of sepsis. However, several studies indicate that (compared with other countries) blood culture diagnostics is only rarely performed in German healthcare facilities. Reasons for this are unknown, but could include clinicians' perception that the turn-around time of results is delayed or that contamination rates are high. Therefore, this article aims to summarize important aspects involved in assuring quality of blood culture diagnostics as well as innovative approaches.

The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in Germany.

BACKGROUND: For decades, methicillin-resistant Staphylococcus aureus (MRSA) has been a major cause of infection in hospitals and nursing homes (health care-associated MRSA, HA-MRSA). Beginning in the late 1990s, many countries have also experienced a rising incidence of MRSA infection outside of the health care setting (community-associated MRSA, CA-MRSA). Moreover, animal reservoirs are increasingly considered to represent an important source of human MRSA acquisition. In this review article the authors describe the current epidemiological situation of MRSA in Germany. METHODS: This review is based on pertinent articles published up to 2010 that were retrieved by a selective PubMed search, as well as on publications issued by national reference institutions up to 2010. RESULTS: There are about 132 000 cases of MRSA in German hospitals each year. MRSA is found in about 18% to 20% of all inpatient-derived culture specimens that are positive for S. aureus. CA-MRSA is not yet endemic in Germany; important risk factors for its acquisition include travel to high-prevalence areas and household contact with persons that harbor a CA-MRSA infection. Agricultural livestock is the main animal reservoir for MRSA, which is often zoonotically transmitted from animals to human beings by direct contact. However, both CA-MRSA and MRSA from animal reservoirs can be imported into hospitals and cause nosocomial infections. CONCLUSION: Hospitals and nursing homes were once the main reservoirs of MRSA, but new ones have now emerged outside of the healthcare setting. Efforts to prevent MRSA and limit its spread must rise to this new challenge.

Risk variants in the S100B gene predict elevated S100B serum concentrations in healthy individuals.

Several lines of evidence suggest an important role of the S100B protein and its coding gene in different neuropathological and psychiatric disorders like dementia, bipolar affective disorders and schizophrenia. To clarify whether a direct link exists between gene and gene product, that is, whether S100B variants directly modulate S100B serum concentration, 196 healthy individuals were assessed for S100B serum concentrations and genotyped for five potentially functional S100B SNPs. Functional variants of the serotonergic genes 5-HT1A and 5-HTT possibly modulating S100B serum levels were also studied. Further, publicly available human postmortem gene expression data were re-analyzed to elucidate the impact of S100B, 5-HT1A and 5-HTT SNPs on frontal cortex S100B mRNA expression. Several S100B SNPs, particularly rs9722, and the S100B haplotype T-G-G-A (including rs2186358-rs11542311-rs2300403-rs9722) were associated with elevated S100B serum concentrations (Bonferroni corrected P < 0.05). Of these, rs11542311 was also associated with S100B mRNA expression directly (Bonferroni corrected P = 0.05) and within haplotype G-A-T-C (rs11542311-rs2839356-rs9984765-rs881827; P = 0.004), again with the G-allele increasing S100B expression. Our results suggest an important role of S100B SNPs on S100B serum concentrations and S100B mRNA expression. It hereby links recent evidence for both, the impact of S100B gene variation on various neurological or psychiatric disorders like dementia, bipolar affective disorders and schizophrenia and the strong relation between S100B serum levels and these disorders.