Enterotoxigenic Escherichia coli (ETEC), the leading bacterial pathogen of travelers' diarrhea, is routinely detected by an established DNA hybridization protocol that is neither sensitive nor quantitative. Quantitative real-time polymerase chain reaction (qPCR) assays that detect the ETEC toxin genes eltA, sta1, and sta2 in clinical stool samples were developed and tested using donor stool inoculated with known quantities of ETEC bacteria. The sensitivity of the qPCR assays is 89%, compared with 22% for the DNA hybridization assay, and the limits of detection are 10,000-fold lower than the DNA hybridization assays performed in parallel. Ninety-three clinical stool samples, previously characterized by DNA hybridization, were tested using the new ETEC qPCR assays. Discordant toxin profiles were observed for 22 samples, notably, four samples originally typed as ETEC negative were ETEC positive. The qPCR assays are unique in their sensitivity and ability to quantify the three toxin genes in clinical stool samples.
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http://dx.doi.org/10.4269/ajtmh.13-0383 | DOI Listing |
Int J Microbiol
January 2025
Laboratory of Animal Hygiene, School of Veterinary Medicine, Kitasato University, Higashi 23-35-1, Towada Aomori 034-8628, Japan.
-a facultative intracellular pathogen of macrophages-causes bronchopneumonia in foals and patients who are immunocompromised. Virulent strains of possess a virulence-associated plasmid, which encodes a 15- to 17-kDa surface protein called virulence-associated protein A (VapA). VapA expression is regulated by temperature and pH.
View Article and Find Full Text PDFJ Oral Microbiol
January 2025
Department of Biosciences; Piracicaba School of Dentistry, University of Campinas, Piracicaba, Brazil.
Background: The aim of this article is to evaluate the effect of different portions of Platelet Rich Fibrin (PRF) membranes and liquid-PRF, prepared by two distinct protocols/centrifuges each, on the multispecies subgingival biofilm.
Materials And Methods: PRF membranes and liquid-PRF were prepared using two protocols: centrifuge 1 uses fixed acceleration while centrifuge 2, progressive acceleration. PRF samples were introduced into device concurrently with 33-species bacterial inoculum.
Anal Chem
January 2025
Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha, Hunan 410082, China.
DNA reaction equilibrium-based calculations have great potential in thermodynamic characterization, but their widespread applications are hindered by significant measurement deviation of equilibrium concentration. Here, we report the advantages of metastable DNA hybridization in reducing quantification deviation of equilibrium concentration and propose a universal and standardized strategy for measuring aptamer binding energy, termed metastable DNA reference calorimetry (MDRC). We built different MDRC-based algorithms tailored to different aptamer binding models, enabling the calculation of thermodynamic parameters for aptamers with one or more binding sites.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, 450001, China. Electronic address:
Background: DNA methylation catalyzed by various DNA methyltransferases (DNA MTases) is one of the important epigenetic regulations in both eukaryotes and prokaryotes. Therefore, the detection of DNA MTase activity is a vital target and direction in the study of methylation-related diseases.
Results: In this study, an ultrasensitive and robust strategy was developed for DNA MTase activity sensing based on bifunctional probe propelling multipath strand displacement amplification and CRISPR/Cas12a techniques.
Biochim Biophys Acta Mol Cell Res
January 2025
Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada; Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada. Electronic address:
Schizophrenia is a complex neuropsychiatric disorder featuring enhanced brain oxidative stress and deficient reelin protein. GFAP.HMOX1 mice that overexpress heme oxygenase-1 (HO-1) in astrocytes manifest a schizophrenia-like neurochemical, neuropathological and behavioral phenotype including brain oxidative stress and reelin downregulation.
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