Publications by authors named "Oliver Nolte"

Unlabelled: The European Committee on Antimicrobial Susceptibility Testing (EUCAST) recommends two steps for detecting beta-lactamases in Gram-negative bacteria. Screening for potential extended-spectrum beta-lactamase (ESBL), plasmid-mediated AmpC beta-lactamase, or carbapenemase production is confirmed. We aimed to validate generative pre-trained transformer (GPT)-4 and GPT-agent for pre-classification of disk diffusion to indicate potential beta-lactamases.

View Article and Find Full Text PDF

The objective of this study was to determine the prevalence, molecular epidemiology, and risk factors for gut colonization with extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E), carbapenemase-producing Enterobacterales (CPE), and vancomycin-resistant enterococci (VRE) in healthcare workers (HCWs). In September/October 2022, we performed a cross-sectional study among HCW from 14 institutions in Northeastern Switzerland. HCWs reported risk factors for antimicrobial resistance (covering the last 12-24 months) and provided rectal swabs.

View Article and Find Full Text PDF

Whole genome sequencing (WGS) has become a vital tool in clinical microbiology, playing an important role in outbreak investigations, molecular surveillance, and identification of bacterial species, resistance mechanisms and virulence factors. However, the complexity of WGS data presents challenges in interpretation and reporting, requiring tailored strategies to enhance efficiency and impact. This study explores the diverse needs of key stakeholders in healthcare, including clinical management, laboratory work, public surveillance and epidemiology, infection prevention and control, and academic research, regarding WGS-based reporting of clinically relevant bacterial species.

View Article and Find Full Text PDF

Manual microscopy of Gram stains from positive blood cultures (PBCs) is crucial for diagnosing bloodstream infections but remains labor intensive, time consuming, and subjective. This study aimed to evaluate a scan and analysis system that combines fully automated digital microscopy with deep convolutional neural networks (CNNs) to assist the interpretation of Gram stains from PBCs for routine laboratory use. The CNN was trained to classify images of Gram stains based on staining and morphology into seven different classes: background/false-positive, Gram-positive cocci in clusters (GPCCL), Gram-positive cocci in pairs (GPCP), Gram-positive cocci in chains (GPCC), rod-shaped bacilli (RSB), yeasts, and polymicrobial specimens.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the effects of reducing genomic sequencing on SARS-CoV-2 surveillance outcomes in Switzerland, analyzing over 143,000 sequences.
  • Results show that while some key outcomes like variant detection and cluster analysis could still be achieved with only 35% of the original sequencing effort, this reduction varies significantly by viral lineage.
  • The research highlights the need for genomic surveillance programs to balance cost and public health benefits, emphasizing that reduced sequencing may compromise accuracy in tracking emerging variants of concern.
View Article and Find Full Text PDF
Article Synopsis
  • A study analyzed 451 historic MRSA isolates from Switzerland, collected between 1965 and 1987, to uncover evolutionary patterns and resistance factors compared to modern MRSA samples and international genomes.
  • The researchers found 17 unique sequence types (STs), including five new STs, indicating a mix of both previously known and novel genetic variations.
  • The dominant type identified among early isolates was ST247-MRSA-I, showing early MRSA strains were primarily from clonal complex 8, while other complexes began appearing from 1980 onwards, highlighting changes in MRSA diversity over time.
View Article and Find Full Text PDF

Background: Increasing reports of multidrug resistance (MDR) in clinical have led to a necessity for new antimicrobials. Ceftazidime-avibactam (CZA) is indicated for use against MDR across a broad range of infection types and particularly those that are carbapenem resistant. This study sought to determine the molecular mechanisms of CZA and imipenem (IPM)-resistance in clinical isolates obtained from Swiss hospitals.

View Article and Find Full Text PDF

Importance: Elderly patients, especially men, are at risk of increased morbidity from coronavirus disease 2019 (COVID-19). Long-term data on troponin I levels in longitudinal observational studies of outpatients with mild to moderate COVID-19 are scarce.

Objective: This controlled cohort study aimed to evaluate the course of troponin I concentrations over a long period in convalescent COVID-19 outpatients with mild to moderate symptoms.

View Article and Find Full Text PDF

At our tertiary children's hospital, infections with newly detected methicillin-resistant Staphylococcus aureus (MRSA) among children attending primary (age 6-12 years) and secondary school (age 13-16 years) nearly doubled in 2018 compared to previous years. This observation initiated an epidemiological outbreak investigation including phenotypic (susceptibility testing) and genotypic (whole genome sequencing) characterization of the isolates. In addition, a cross-sectional study was conducted to determine source of the outbreak, colonization frequency and to identify risk factors for transmission using a questionnaire.

View Article and Find Full Text PDF

Objectives: Matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) is a widely used method for bacterial species identification. Incomplete databases and mass spectral quality (MSQ) still represent major challenges. Important proxies for MSQ are the number of detected marker masses, reproducibility, and measurement precision.

View Article and Find Full Text PDF

Aqueous-organic redox flow batteries (RFBs) have gained considerable interest in recent years, given their potential for an economically viable energy storage at large scale. This, however, strongly depends on both the robustness of the underlying electrolyte chemistry against molecular decomposition reactions as well as the device's operation. With regard to this, the presented study focuses on the use of in situ IR spectroscopy in combination with a multivariate curve resolution approach to gain insight into both the molecular structures of the active materials present within the electrolyte as well as crucial electrolyte state parameters, represented by the electrolyte's state of charge (SOC) and state of health (SOH).

View Article and Find Full Text PDF

Among 400 species from respiratory samples in Switzerland, was the most frequent species. Non- spp were more prevalent among solid organ transplant recipients and after azole exposure. Azole resistance was detected in 4 isolates, 3 of them with the "environmental" mutation TR/L98H in the gene.

View Article and Find Full Text PDF

Background: Despite the adoption of strict infection prevention and control measures, many hospitals have reported outbreaks of multidrug-resistant organisms (MDRO) during the Coronavirus 2019 (COVID-19) pandemic. Following an outbreak of carbapenem-resistant Acinetobacter baumannii (CRAB) in our institution, we sought to systematically analyse characteristics of MDRO outbreaks in times of COVID-19, focussing on contributing factors and specific challenges in controlling these outbreaks.

Methods: We describe results of our own CRAB outbreak investigation and performed a systematic literature review for MDRO (including Candida auris) outbreaks which occurred during the COVID-19 pandemic (between December 2019 and March 2021).

View Article and Find Full Text PDF

Flow batteries (FBs) currently are one of the most promising large-scale energy storage technologies for energy grids with a large share of renewable electricity generation. Among the main technological challenges for the economic operation of a large-scale battery technology is its calendar lifetime, which ideally has to cover a few decades without significant loss of performance. This requirement can only be met if the key parameters representing the performance losses of the system are continuously monitored and optimized during the operation.

View Article and Find Full Text PDF

This first pilot trial on external quality assessment (EQA) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) whole-genome sequencing, initiated by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Genomic and Molecular Diagnostics (ESGMD) and the Swiss Society for Microbiology (SSM), aims to build a framework between laboratories in order to improve pathogen surveillance sequencing. Ten samples with various viral loads were sent out to 15 clinical laboratories that had free choice of sequencing methods and bioinformatic analyses. The key aspects on which the individual centers were compared were the identification of (i) single nucleotide polymorphisms (SNPs) and indels, (ii) Pango lineages, and (iii) clusters between samples.

View Article and Find Full Text PDF

Objectives: We aimed to assess the burden of extended-spectrum β-lactamase (ESBL)-producing Enterobacterales in Swiss long-term care facilities (LTCFs) to describe the molecular epidemiology, describe the intrainstitutional and regional clusters of resistant pathogens, and identify independent institution- and resident-level factors associated with colonization.

Design: Cross-sectional study.

Setting And Participants: From August to October 2019, we performed a point prevalence study among residents from 16 LTCFs in Western and Eastern Switzerland (8 per region).

View Article and Find Full Text PDF

In cystic fibrosis, dynamic and complex communities of microbial pathogens and commensals can colonize the lung. Cultured isolates from lung sputum reveal high inter- and intraindividual variability in pathogen strains, sequence variants, and phenotypes; disease progression likely depends on the precise combination of infecting lineages. Routine clinical protocols, however, provide a limited overview of the colonizer populations.

View Article and Find Full Text PDF

This study compares the findings of different detection methods for microorganisms in patients with ureteral stents undergoing secondary ureterorenoscopy including the use of a novel validated examination pipeline for biofilms on ureteral stents. Of the included 94 patients, 21.3% showed bacteriuria in preoperative urine cultures.

View Article and Find Full Text PDF

Background: Current knowledge of the urinary tract microbiome is limited to urine analysis and analysis of biofilms formed on Foley catheters. Bacterial biofilms on ureteral stents have rarely been investigated, and no cultivation-independent data are available on the microbiome of the encrustations on the stents.

Results: The typical encrustations of organic and inorganic urine-derived material, including microbial biofilms formed during 3-6 weeks on ureteral stents in patients treated for kidney and ureteral stones, and without reported urinary tract infection at the time of stent insertion, were analysed.

View Article and Find Full Text PDF

Purpose: To evaluate the influence of biofilms on morbidity associated with short-term ureteral stenting using contemporary methods of biofilm examination and validated assessment of symptoms.

Methods: Patients undergoing temporary ureteral stenting for secondary ureterorenoscopy due to urinary calculi were prospectively included. The German Ureteral Stent Symptoms Questionnaire (USSQ) was used to assess stent-associated morbidity.

View Article and Find Full Text PDF