Background: The aim of this study was to develop and validate a multiplex real-time PCR assay for simultaneous identification and toxigenic type characterization of Clostridium difficile.
Methods: The multiplex real-time PCR assay targeted and simultaneously detected triose phosphate isomerase (tpi) and binary toxin (cdtA) genes, and toxin A (tcdA) and B (tcdB) genes in the first and sec tubes, respectively. The results of multiplex real-time PCR were compared to those of the BD GeneOhm Cdiff assay, targeting the tcdB gene alone. The toxigenic culture was used as the reference, where toxin genes were detected by multiplex real-time PCR.
Results: A total of 351 stool samples from consecutive patients were included in the study. Fifty-five stool samples (15.6%) were determined to be positive for the presence of C. difficile by using multiplex real-time PCR. Of these, 48 (87.2%) were toxigenic (46 tcdA and tcdB-positive, two positive for only tcdB) and 11 (22.9%) were cdtA-positive. The sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of the multiplex real-time PCR compared with the toxigenic culture were 95.6%, 98.6%, 91.6%, and 99.3%, respectively. The analytical sensitivity of the multiplex real-time PCR assay was determined to be 10(3) colony forming unit (CFU)/g spiked stool sample and 0.0625 pg genomic DNA from culture. Analytical specificity determined by using 15 enteric and non-clostridial reference strains was 100%.
Conclusions: The multiplex real-time PCR assay accurately detected C. difficile isolates from diarrheal stool samples and characterized its toxin genes in a single PCR run.
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http://dx.doi.org/10.3343/alm.2015.35.3.306 | DOI Listing |
BMC Microbiol
January 2025
Cellular Interactions of Bacterial Pathogens, Centre for Biological Threats and Special Pathogens, Highly Pathogenic Microorganisms (ZBS 2), Robert Koch Institute, Seestraße 10, 13353, Berlin, Germany.
Background: The zoonotic and highly infectious pathogen Francisella tularensis is the etiological agent of tularemia. Tularemia in humans is mainly caused by F. tularensis subspecies tularensis and holarctica, but Francisella species like F.
View Article and Find Full Text PDFJ Mass Spectrom
February 2025
Center for Bioinformatics and Computational Biology, University of Delaware, Newark, Delaware, USA.
The development of a real-time system for characterizing individual biomolecule-containing aerosol particles presents a transformative opportunity to monitor respiratory conditions, including infections and lung diseases. Existing molecular assay technologies, although effective, rely on costly reagents, are relatively slow, and face challenges in multiplexing, limiting their use for real-time applications. To overcome these challenges, we developed digitalMALDI, a laser-based mass spectrometry system designed for single-particle characterization.
View Article and Find Full Text PDFDiagn Microbiol Infect Dis
January 2025
Department of Clinical Laboratory, DongGuan Song Shan Lake Tungwah Hospital, Dongguan, Guangdong 523820, China. Electronic address:
Hypervirulent Klebsiella pneumoniae (hvKP) pose significant challenges to clinical anti-infective treatment and has emerged as a major threat to global public health. In this study, we employed the loop-mediated isothermal amplification (LAMP) assays with OTG (orange to green) visual dye and multiplex quantitative real-time PCR (qRT-PCR) assay to rapidly detect hvKP. We determined the detection limits of the LAMP methods for K.
View Article and Find Full Text PDFInfect Prev Pract
March 2025
San Juan Bautista School of Medicine, Caguas, Puerto Rico.
Background: Mobile phones used by healthcare workers (HCWs) in hospitals are significant reservoirs of drug-resistant bacteria responsible for hospital-acquired infections (HAIs).
Aim: The objective of this study was to assess the level of contamination with such bacteria in outpatient clinics.
Methods: Swabs from 83 HCWs' mobile phones were processed using standard biochemical and enzymatic procedures to identify pathogenic bacteria.
A novel, to the best of our knowledge, approach for the modal decomposition of a fiber laser beam is demonstrated using a spatial mode multiplexer. Since the modal decomposition is carried out optically, this approach is able to obtain the modal content at speeds up to the GHz level. In order to demonstrate such performance, we have applied this approach to the modal analysis of a -switched pulse generated in a multimode fiber with alternating intra-pulse mode content.
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