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We evaluated the analytical performance of three commercial molecular assays for rapid detection of Clostridioides difficile toxin B in stool samples. The results were compared with results from the BD MAX™ Cdiff assay. We analyzed forty negative and thirty-two positive stool samples with three rapid assays: Roche cobas® Liat® Cdiff, SD Biosensor STANDARD™ M10 C. difficile and Cepheid Xpert® C. difficile BT. The assays demonstrated a sensitivity of 96.9 %, 96.9 % and 100.0 % and a specificity of 100 %, 97.5 % and 97.5 %, respectively. There is limited data available on the analytical performance of the newly introduced STANDARD™ M10 C. difficile assay. In this study, all three rapid assays demonstrated similarly high analytical performance and can be used for detection of toxigenic C. difficile., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Background: Independent evaluations that deploy clinical patient samples are important in assessing the performance of commercial tests used for serological screening of viral hepatitis and HIV in clinical laboratories., Objectives: We compared the analytical performance of Abbott Architect i2000SR, Abbott Alinity i, DiaSorin Liaison XL, and Siemens Atellica for the following analytes: anti-HAV IgG/anti-HAV total, anti-HAV IgM, HBsAg, anti-HBc IgM, Anti-HBc, HBeAg, anti-HBe, anti-HBs, anti-HCV, and HIV Ag/Ab. In addition, anti-HBc IgM, HBeAg, and anti-HBe were evaluated for Abbott Architect, Abbott Alinity and DiaSorin Liaison., Study Design: Pseudonymized clinical serum specimens (N = 98-200 for each analyte) were selected for the analysis according to their reactivity on the Abbott Architect. The results were compared against Abbott Architect and against consensus., Results: A generally high agreement was observed between the tests. Abbott Alinity had the lowest anti-HAV IgG/total specificity (75.9% against Abbott Architect and 83.0% against consensus). The comparatively low sensitivity of Siemens Atellica (78.2%), Abbott Alinity (87.5%) and DiaSorin Liaison (89.3%) for anti-HAV IgM against Abbott Architect may reflect a higher false-positive rate of Abbott Architect. Particular variation was observed in the sensitivity values of anti-HBc, HBsAg and HIV Ag/Ab between the test methods. DiaSorin Liaison anti-HBs gave consistently higher values as compared to the other tests., Conclusions: The serodiagnostic methods for HIV and viral hepatitis of Abbott Architect, Abbott Alinity, DiaSorin Liaison, and Siemens Atellica performed well in comparison with each other. The observed differences between the tests will provide useful information for clinical laboratories in planning their workflows for screening and confirmation., (Copyright © 2022. Published by Elsevier B.V.)

We investigated the N-utilizing bacterial community in anoxic brackish groundwater of the low and intermediate level nuclear waste repository cave in Olkiluoto, Finland, at 100 m depth using (15)N-based stable isotope probing (SIP) and enrichment with (14∕15)N-ammonium or (14∕15)N-nitrate complemented with methane. Twenty-eight days of incubation at 12°C increased the concentration of bacterial 16S rRNA and nitrate reductase (narG) gene copies in the substrate amended microcosms simultaneously with a radical drop in the overall bacterial diversity and OTU richness. Hydrogenophaga/Malikia were enriched in all substrate amended microcosms and Methylobacter in the ammonium and ammonium+methane supplemented microcosms. Sulfuricurvum was especially abundant in the nitrate+methane treatment and the unamended incubation control. Membrane-bound nitrate reductase genes (narG) from Polarimonas sp. were detected in the original groundwater, while Burkholderia, Methylibium, and Pseudomonas narG genes were enriched due to substrate supplements. Identified amoA genes belonged to Nitrosomonas sp. (15)N-SIP revealed that Burkholderiales and Rhizobiales clades belonging to the minority groups in the original groundwater used (15)N from ammonium and nitrate as N source indicating an important ecological function of these bacteria, despite their low number, in the groundwater N cycle in Olkiluoto bedrock system.