7 results on '"Elisa Kasbohm"'
Search Results
2. Detection of Mycobacterium avium ssp. paratuberculosis in Cultures From Fecal and Tissue Samples Using VOC Analysis and Machine Learning Tools
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Philipp Vitense, Elisa Kasbohm, Anne Klassen, Peter Gierschner, Phillip Trefz, Michael Weber, Wolfram Miekisch, Jochen K. Schubert, Petra Möbius, Petra Reinhold, Volkmar Liebscher, and Heike Köhler
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bacterial culture ,diagnostics ,machine learning ,Mycobacterium avium ssp. paratuberculosis ,paratuberculosis ,random forests ,Veterinary medicine ,SF600-1100 - Abstract
Analysis of volatile organic compounds (VOCs) is a novel approach to accelerate bacterial culture diagnostics of Mycobacterium avium subsp. paratuberculosis (MAP). In the present study, cultures of fecal and tissue samples from MAP-infected and non-suspect dairy cattle and goats were explored to elucidate the effects of sample matrix and of animal species on VOC emissions during bacterial cultivation and to identify early markers for bacterial growth. The samples were processed following standard laboratory procedures, culture tubes were incubated for different time periods. Headspace volume of the tubes was sampled by needle trap-micro-extraction, and analyzed by gas chromatography-mass spectrometry. Analysis of MAP-specific VOC emissions considered potential characteristic VOC patterns. To address variation of the patterns, a flexible and robust machine learning workflow was set up, based on random forest classifiers, and comprising three steps: variable selection, parameter optimization, and classification. Only a few substances originated either from a certain matrix or could be assigned to one animal species. These additional emissions were not considered informative by the variable selection procedure. Classification accuracy of MAP-positive and negative cultures of bovine feces was 0.98 and of caprine feces 0.88, respectively. Six compounds indicating MAP presence were selected in all four settings (cattle vs. goat, feces vs. tissue): 2-Methyl-1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol, heptanal, isoprene, and 2-heptanone. Classification accuracies for MAP growth-scores ranged from 0.82 for goat tissue to 0.89 for cattle feces. Misclassification occurred predominantly between related scores. Seventeen compounds indicating MAP growth were selected in all four settings, including the 6 compounds indicating MAP presence. The concentration levels of 2,3,5-trimethylfuran, 2-pentylfuran, 1-propanol, and 1-hexanol were indicative for MAP cultures before visible growth was apparent. Thus, very accurate classification of the VOC samples was achieved and the potential of VOC analysis to detect bacterial growth before colonies become visible was confirmed. These results indicate that diagnosis of paratuberculosis can be optimized by monitoring VOC emissions of bacterial cultures. Further validation studies are needed to increase the robustness of indicative VOC patterns for early MAP growth as a pre-requisite for the development of VOC-based diagnostic analysis systems.
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- 2021
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3. Detection of Low MAP Shedder Prevalence in Large Free-Stall Dairy Herds by Repeated Testing of Environmental Samples and Pooled Milk Samples
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Annika Wichert, Elisa Kasbohm, Esra Einax, Axel Wehrend, and Karsten Donat
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Mycobacterium avium subsp. paratuberculosis (MAP) ,environmental samples ,milk pools ,fecal culture ,real-time PCR ,ELISA ,Veterinary medicine ,SF600-1100 ,Zoology ,QL1-991 - Abstract
An easy-to-use and affordable surveillance system is crucial for paratuberculosis control. The use of environmental samples and milk pools has been proven to be effective for the detection of Mycobacterium avium subsp. paratuberculosis (MAP)-infected herds, but not for monitoring dairy herds certified as MAP non-suspect. We aimed to evaluate methods for the repeated testing of large dairy herds with a very low prevalence of MAP shedders, using different sets of environmental samples or pooled milk samples, collected monthly over a period of one year in 36 herds with known MAP shedder prevalence. Environmental samples were analyzed by bacterial culture and fecal PCR, and pools of 25 and 50 individual milk samples were analyzed by ELISA for MAP-specific antibodies. We estimated the cumulative sensitivity and specificity for up to twelve sampling events by adapting a Bayesian latent class model and taking into account the between- and within-test correlation. Our study revealed that at least seven repeated samplings of feces from the barn environment are necessary to achieve a sensitivity of 95% in herds with a within-herd shedder prevalence of at least 2%. The detection of herds with a prevalence of less than 2% is more challenging and, in addition to numerous repetitions, requires a combination of different samples.
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- 2022
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4. R Packages for Data Quality Assessments and Data Monitoring: A Software Scoping Review with Recommendations for Future Developments
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Joany Mariño, Elisa Kasbohm, Stephan Struckmann, Lorenz A. Kapsner, and Carsten O. Schmidt
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data quality ,data quality monitoring ,data reporting ,exploratory data analysis ,initial data analysis ,R project for statistical computing ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Data quality assessments (DQA) are necessary to ensure valid research results. Despite the growing availability of tools of relevance for DQA in the R language, a systematic comparison of their functionalities is missing. Therefore, we review R packages related to data quality (DQ) and assess their scope against a DQ framework for observational health studies. Based on a systematic search, we screened more than 140 R packages related to DQA in the Comprehensive R Archive Network. From these, we selected packages which target at least three of the four DQ dimensions (integrity, completeness, consistency, accuracy) in a reference framework. We evaluated the resulting 27 packages for general features (e.g., usability, metadata handling, output types, descriptive statistics) and the possible assessment’s breadth. To facilitate comparisons, we applied all packages to a publicly available dataset from a cohort study. We found that the packages’ scope varies considerably regarding functionalities and usability. Only three packages follow a DQ concept, and some offer an extensive rule-based issue analysis. However, the reference framework does not include a few implemented functionalities, and it should be broadened accordingly. Improved use of metadata to empower DQA and user-friendliness enhancement, such as GUIs and reports that grade the severity of DQ issues, stand out as the main directions for future developments.
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- 2022
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5. Genome-wide analyses identify a role for SLC17A4 and AADAT in thyroid hormone regulation
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Alexander Teumer, Layal Chaker, Stefan Groeneweg, Yong Li, Celia Di Munno, Caterina Barbieri, Ulla T. Schultheiss, Michela Traglia, Tarunveer S. Ahluwalia, Masato Akiyama, Emil Vincent R. Appel, Dan E. Arking, Alice Arnold, Arne Astrup, Marian Beekman, John P. Beilby, Sofie Bekaert, Eric Boerwinkle, Suzanne J. Brown, Marc De Buyzere, Purdey J. Campbell, Graziano Ceresini, Charlotte Cerqueira, Francesco Cucca, Ian J. Deary, Joris Deelen, Kai-Uwe Eckardt, Arif B. Ekici, Johan G. Eriksson, Luigi Ferrrucci, Tom Fiers, Edoardo Fiorillo, Ian Ford, Caroline S. Fox, Christian Fuchsberger, Tessel E. Galesloot, Christian Gieger, Martin Gögele, Alessandro De Grandi, Niels Grarup, Karin Halina Greiser, Kadri Haljas, Torben Hansen, Sarah E. Harris, Diana van Heemst, Martin den Heijer, Andrew A. Hicks, Wouter den Hollander, Georg Homuth, Jennie Hui, M. Arfan Ikram, Till Ittermann, Richard A. Jensen, Jiaojiao Jing, J. Wouter Jukema, Eero Kajantie, Yoichiro Kamatani, Elisa Kasbohm, Jean-Marc Kaufman, Lambertus A. Kiemeney, Margreet Kloppenburg, Florian Kronenberg, Michiaki Kubo, Jari Lahti, Bruno Lapauw, Shuo Li, David C. M. Liewald, Lifelines Cohort Study, Ee Mun Lim, Allan Linneberg, Michela Marina, Deborah Mascalzoni, Koichi Matsuda, Daniel Medenwald, Christa Meisinger, Ingrid Meulenbelt, Tim De Meyer, Henriette E. Meyer zu Schwabedissen, Rafael Mikolajczyk, Matthijs Moed, Romana T. Netea-Maier, Ilja M. Nolte, Yukinori Okada, Mauro Pala, Cristian Pattaro, Oluf Pedersen, Astrid Petersmann, Eleonora Porcu, Iris Postmus, Peter P. Pramstaller, Bruce M. Psaty, Yolande F. M. Ramos, Rajesh Rawal, Paul Redmond, J. Brent Richards, Ernst R. Rietzschel, Fernando Rivadeneira, Greet Roef, Jerome I. Rotter, Cinzia F. Sala, David Schlessinger, Elizabeth Selvin, P. Eline Slagboom, Nicole Soranzo, Thorkild I. A. Sørensen, Timothy D. Spector, John M. Starr, David J. Stott, Youri Taes, Daniel Taliun, Toshiko Tanaka, Betina Thuesen, Daniel Tiller, Daniela Toniolo, Andre G. Uitterlinden, W. Edward Visser, John P. Walsh, Scott G. Wilson, Bruce H. R. Wolffenbuttel, Qiong Yang, Hou-Feng Zheng, Anne Cappola, Robin P. Peeters, Silvia Naitza, Henry Völzke, Serena Sanna, Anna Köttgen, Theo J. Visser, and Marco Medici
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Science - Abstract
Thyroid dysfunction is a common public health problem and associated with cardiovascular co-morbidities. Here, the authors carry out genome-wide meta-analysis for thyroid hormone (TH) levels, hyper- and hypothyroidism and identify SLC17A4 as a TH transporter and AADAT as a TH metabolizing enzyme.
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- 2018
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6. Detection of Paratuberculosis in Dairy Herds by Analyzing the Scent of Feces, Alveolar Gas, and Stable Air
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Michael Weber, Peter Gierschner, Anne Klassen, Elisa Kasbohm, Jochen K. Schubert, Wolfram Miekisch, Petra Reinhold, and Heike Köhler
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classification models ,dairy cows ,exhaled breath ,fecal headspace ,Mycobacterium avium ssp. paratuberculosis (MAP) ,paratuberculosis ,Organic chemistry ,QD241-441 - Abstract
Paratuberculosis is an important disease of ruminants caused by Mycobacterium avium ssp. paratuberculosis (MAP). Early detection is crucial for successful infection control, but available diagnostic tests are still dissatisfying. Methods allowing a rapid, economic, and reliable identification of animals or herds affected by MAP are urgently required. This explorative study evaluated the potential of volatile organic compounds (VOCs) to discriminate between cattle with and without MAP infections. Headspaces above fecal samples and alveolar fractions of exhaled breath of 77 cows from eight farms with defined MAP status were analyzed in addition to stable air samples. VOCs were identified by GC–MS and quantified against reference substances. To discriminate MAP-positive from MAP-negative samples, VOC feature selection and random forest classification were performed. Classification models, generated for each biological specimen, were evaluated using repeated cross-validation. The robustness of the results was tested by predicting samples of two different sampling days. For MAP classification, the different biological matrices emitted diagnostically relevant VOCs of a unique but partly overlapping pattern (fecal headspace: 19, alveolar gas: 11, stable air: 4–5). Chemically, relevant compounds belonged to hydrocarbons, ketones, alcohols, furans, and aldehydes. Comparing the different biological specimens, VOC analysis in fecal headspace proved to be most reproducible, discriminatory, and highly predictive.
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- 2021
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7. Potential Biological and Climatic Factors That Influence the Incidence and Persistence of Highly Pathogenic H5N1 Avian Influenza Virus in Egypt
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Ahmed H. Salaheldin, Elisa Kasbohm, Heba El-Naggar, Reiner Ulrich, David Scheibner, Marcel Gischke, Mohamed K. Hassan, Abdel-Satar A. Arafa, Wafaa M. Hassan, Hatem S. Abd El-Hamid, Hafez M. Hafez, Jutta Veits, Thomas C. Mettenleiter, and Elsayed M. Abdelwhab
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H5N1 ,highly pathogenic avian influenza virus ,poultry ,meteorological factors ,epidemiology ,ducks ,Microbiology ,QR1-502 - Abstract
Highly pathogenic H5N1 avian influenza virus (A/H5N1) of clade 2.2.1 is endemic in poultry in Egypt where the highest number of human infections worldwide was reported. During the last 12 years the Egyptian A/H5N1 evolved into several genotypes. In 2007-2014 vaccinated poultry suffered from antigenic drift variants of clade 2.2.1.1 and in 2014/2015 an unprecedented upsurge of A/H5N1 clade 2.2.1.2 occurred in poultry and humans. Factors contributing to the endemicity or re-emergence of A/H5N1 in poultry in Egypt remain unclear. Here, three potential factors were studied: climatic factors (temperature, relative humidity, and wind speed), biological fitness in vitro, and pathogenicity in domestic Pekin and Muscovy ducks. Statistical analyses using negative binomial regression models indicated that ambient temperature in winter months influenced the spread of A/H5N1 in different geographic areas analyzed in this study. In vitro, at 4 and 56°C 2.2.1.1 and recent 2.2.1.2 viruses were more stable than other viruses used in this study. Further, Pekin ducks were more resistant than Muscovy ducks and the viruses were excreted for up to 2 weeks post-infection assuming a strong role as a reservoir. Taken together, ambient temperature in winter months potentially contributes to increasing outbreaks in some regions in Egypt. Heat stability of clade 2.2.1.1 and recent 2.2.1.2 viruses probably favors their persistence at elevated temperatures. Importantly, asymptomatically infected Pekin ducks may play an important role in the spread of avian and human-like A/H5N1 in Egypt. Therefore, control measures including targeted surveillance and culling of silently infected Pekin ducks should be considered.
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- 2018
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