Michael Oberle

Bio: Michael Oberle is an academic researcher. The author has contributed to research in topics: Spore. The author has an hindex of 2, co-authored 2 publications receiving 20 citations.

Non-Seasonal Variation of Airborne Aspergillus Spore Concentration in a Hospital Building.

Abstract: Nosocomial fungal infections are gaining increased attention from infectiologists. An adequate investigation into the levels of airborne Aspergillus and other fungal spores in hospital settings, under normal conditions, is largely unknown. We monitored airborne spore contamination in a Swiss hospital building in order to establish a seasonally-dependent base-line level. Air was sampled using an impaction technique, twice weekly, at six different locations over one year. Specimens were seeded in duplicate on Sabouraud agar plates. Grown colonies were identified to genus levels. The airborne Aspergillus spore concentration was constantly low throughout the whole year, at a median level of 2 spores/m3 (inter-quartile range = IQR 1–4), and displayed no seasonal dependency. The median concentration of other fungal spores was higher and showed a distinct seasonal variability with the ambient temperature change during the different seasons: 82 spores/m3 (IQR 26–126) in summer and 9 spores/m3 (IQR 6–15) in winter. The spore concentration varied considerably between the six sampling sites in the building (10 to 26 spores/m3). This variability may explain the variability of study results in the literature.

Diagnostic performance of a SARS-CoV-2 IgG/IgM lateral flow immunochromatography assay in symptomatic patients presenting to the emergency department.

Abstract: Chemistry and Immunology Laboratory, Institute of Laboratory Medicine, Kantonsspital Aarau AG, Tellstrasse 25, 5001 Aarau, Switzerland, Phone: +41 62 838 53 15, E-mail: luca.bernasconi@ ksa.ch. https://orcid.org/0000-0001-6647-6448 Michael Oberle, Cornelia Ottiger, Hans Fankhauser and Angelika Hammerer-Lercher: Institute of Laboratory Medicine, Kantonsspital Aarau AG, Aarau, Switzerland Valentin Gisler: Institute of Laboratory Medicine, Kantonsspital Aarau AG, Aarau, Switzerland; and Department for Infectious Diseases and Hospital Hygiene, Kantonsspital Aarau AG, Aarau, Switzerland Philipp Schuetz: University Department of Medicine, Kantonsspital Aarau and Faculty of Medicine, University of Basel, Aarau, Switzerland Christoph A. Fux: Department for Infectious Diseases and Hospital Hygiene, Kantonsspital Aarau AG, Aarau, Switzerland Letter to the Editor

High Diversity of Fungi in Air Particulate Matter

Abstract: Fungal spores can account for large proportions of air particulate matter, and they may potentially influence the hydrological cycle and climate as nuclei for water droplets and ice crystals in clouds, fog, and precipitation. Moreover, some fungi are major pathogens and allergens. The diversity of airborne fungi is, however, not well-known. By DNA analysis we found pronounced differences in the relative abundance and seasonal cycles of various groups of fungi in coarse and fine particulate matter, with more plant pathogens in the coarse fraction and more human pathogens and allergens in the respirable fine particle fraction (<3 μm). Moreover, the ratio of Basidiomycota to Ascomycota was found to be much higher than previously assumed, which might also apply to the biosphere.

Seasonal variation of the dominant allergenic fungal aerosols – One year study from southern Indian region

Abstract: Quantitative estimations of fungal aerosols are important to understand their role in causing respiratory diseases to humans especially in the developing and highly populated countries. In this study we sampled and quantified the three most dominantly found allergenic airborne fungi, Aspergillus fumigatus, Cladosporium cladosporioides, and Alternaria alternata from ambient PM10 samples using the quantitative PCR (qPCR) technique in a southern tropical Indian region, for one full year. Highest concentrations of A. fumigatus and C. cladosporioides were observed during monsoon whereas A. alternata displayed an elevated concentration in winter. The meteorological parameters such as temperature, relative humidity, wind speed, and precipitation exhibited a substantial influence on the atmospheric concentrations of allergenic fungal aerosols. The morphological features of various allergenic fungal spores present in the PM10 were investigated and the spores were found to possess distinct structural features. In a maiden attempt over this region we correlate the ambient fungal concentrations with the epidemiological allergy occurrence to obtain firsthand and preliminary information about the causative fungal allergen to the inhabitants exposed to bioaerosols. Our findings may serve as an important reference to atmospheric scientists, aero-biologists, doctors, and general public.

Characteristics, predictors and outcomes among 99 patients hospitalised with COVID-19 in a tertiary care centre in Switzerland: an observational analysis.

Abstract: Aims of the study To describe admission characteristics, risk factors and outcomes of patients with coronavirus disease 2019 (COVID-19) hospitalised in a tertiary care hospital in Switzerland during the early phase of the pandemic. Methods This retrospective cohort study included adult patients with a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection confirmed by polymerase chain reaction (PCR) testing and hospitalised at the cantonal hospital Aarau (Switzerland) between 26 February 2020 and 30 April 2020. Our primary endpoint was severe COVID-19 progression defined as a composite of transfer to the intensive care unit (ICU) and in-hospital mortality. Results A total of 99 patients (median age 67 years [interquartile range 56n76], 37% females) were included and 35% developed severe COVID-19 progression (24% needed ICU treatment, 19% died). Patients had a high burden of comorbidities with a median Charlson comorbidity index of 3 points and a high prevalence of hypertension (57%), chronic kidney disease (28%) and obesity (27%). Baseline characteristics with the highest prognostic value for the primary endpoint by means of area under the receiver operating characteristic curve were male gender (0.63) and initial laboratory values including shock markers (lactate on ambient air 0.67; lactate with O2 supply 0.70), markers of inflammation (C-reactive protein 0.72, procalcitonin 0.80) and markers of compromised oxygenation (pO2 0.75 on ambient air), whereas age and comorbidities provided little prognostic information. Conclusion This analysis provides insights into the first consecutively hospitalised patients with confirmed COVID-19 at a Swiss tertiary care hospital during the initial period of the pandemic. Markers of disease progression such as inflammatory markers, markers for shock and impaired respiratory function provided the most prognostic information regarding severe COVID-19 progression in our sample.

The effect of temperature on airborne filamentous fungi in the indoor and outdoor space of a hospital.

Abstract: Fungi are one of the bioaerosols in indoor air of hospitals. They have adverse effects on staff and patients. The aim of this study was to investigate the effects of three incubation temperature on the density and composition of airborne fungi in an indoor and outdoor space of hospital. Sabouraud dextrose agar was used for culture the fungi. For improvement of aseptic properties, chloramphenicol was added to this medium. The density of airborne fungi was less than 282 CFU/m3. The highest density was detected in emergency room and the lowest of them was in neonatal intensive care unit (NICU) and operation room (OR). Results showed that fungi levels at 25 °C were higher than 37 and 15 °C (p = 0.006). In addition, ten different genera of fungi were identified in all departments. The predominant fungi were Fusarium spp., Penicillium spp., Paecilomyces spp., and Aspergillus niger. Moreover, the density and trend of distribution of Fusaruim spp. in the indoor space was directivity to outdoor space by ventilation system. The present study has provided that incubation temperature had effect on airborne fungi remarkably. We are suggested that more studies would be conducted on incubation temperature and other ambient factors on airborne fungi.