Isolates of enterohemorrhagic Escherichia coli (EHEC) of serotype O104:H21 implicated in a 1994 outbreak of hemorrhagic colitis in Montana were analyzed for the presence of trait EHEC virulence markers. By using a multiplex PCR that specifically amplifies several genes, the O104:H21 strains were found to carry only the Shiga toxin 2 gene (stx2) and to express Stx2. They did not have the eaeA gene for gamma-intimin, which is typically found in O157:H7, or the alpha- or beta-intimin derivatives, which are common in other EHEC and enteropathogenic E. coli serotypes. Results of the multiplex PCR also indicated that the ehxA gene for enterohemolysin was absent from O104:H21. This, however, was not consistent with the results of a phenotypic assay that showed them to be hemolytic or a PCR analysis with another set of ehxA-specific primers, which indicated the presence of ehxA. To resolve this discrepancy, the ehxA region in O104:H21 and O157:H7 strains, to which the multiplex PCR primers anneal, was cloned and sequenced. Comparison of the sequences showed that the upstream primer binding site in the ehxA gene of O104:H21 was not identical to that of O157:H7. Specifically, there were several base mutations, including an A-to-G substitution at the 3' end of the primer binding site. These base mutations are presumably not unique to O104:H21, since other enterohemolytic serotypes were also not detected with the ehxA primers used in the multiplex PCR. Comparison of the ehxA sequences of O104:H21 strains with those of other Stx-producing E. coli strains showed that they more closely resembled those of O8:H19 strains, which have cluster II ehxA genes, than those of O157:H7 strains, which have cluster I ehxA sequences. By modifying the upstream ehxA primer, the multiplex PCR was able to detect ehxA genes in both O157:H7 and O104:H21 strains.
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http://dx.doi.org/10.1128/JCM.39.1.24-28.2001 | DOI Listing |
Ann Hematol
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Service de Thérapie Cellulaire et d'Hématologie Clinique, CHU Estaing, Clermont-Ferrand, France.
The advent of BTK inhibitors has been transformative in the management of patients with chronic lymphocytic leukemia or other B-cell lymphoproliferative disorders. However, emergence of BTK or PLCG2 mutations lead to resistance to these compounds and are now a growing concern in clinical practice. Assessing BTK mutations is now becoming a priority to guide the therapeutic decision at further relapse.
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Division of Infectious Diseases, Naval Medical Center San Diego, 34800 Bob Wilson Drive, San Diego, CA, 92134, USA; Department of Medicine, Uniformed Services University, 4301 Jones Bridge Road, Bethesda, MD 20814, USA.
Entamoeba histolytica infections range from asymptomatic intestinal amebiasis to more severe syndromes like invasive colitis or hepatic abscess. While diagnostic tests available for assessing these infections have evolved, the optimal use of newer diagnostics like enteric multiplex Polymerase Chain Reaction (PCR) panels has not been fully established. Here we describe the case of a 34-year-old male with an amebic liver abscess (ALA) that was diagnosed via multiplex Gastrointestinal (GI) PCR panel on formed stool and subsequently confirmed by testing liver abscess fluid (off-label) on the same multiplex GI PCR panel leading to rapid diagnosis and targeted treatment modification with excellent outcome.
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January 2025
Department of Oncology, Vejle Hospital, University Hospital of Southern Denmark, Beriderbakken 4, 7100, Vejle, Denmark; Danish Colorectal Cancer Center South, Vejle Hospital, Beriderbakken 4, 7100, Vejle, Denmark; Department of Regional Health Research, University of Southern Denmark, Campusvej 55, 5230, Odense M, Denmark.
Background: Decision regarding local treatment of colorectal liver metastases (CRLM) is a multidisciplinary assessment, and liver intervention should be performed when the metastases are deemed resectable. There is no standard biomarker to aid neither this decision nor the postoperative treatment decisions. The present prospective, observational study aimed to investigate the potential clinical utility of a combined tumor-specific and organ-specific methylated circulating DNA assay in the perioperative setting of CRLM.
View Article and Find Full Text PDFInt J Neonatal Screen
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Cellular, Molecular and Genomics Biomedicine Group, La Fe Health Research Institute, 46026 Valencia, Spain.
Spinal muscular atrophy (SMA) is a degenerative neuromuscular condition resulting from a homozygous deletion of the survival motor neuron 1 () gene in 95% of patients. A timely diagnosis via newborn screening (NBS) and initiating treatment before the onset of symptoms are critical for improving health outcomes in affected individuals. We carried out a screening test by quantitative PCR (qPCR) to amplify the exon seven of using dried blood spot (DBS) samples.
View Article and Find Full Text PDFFront Microbiol
January 2025
Roman L. Hruska, US Meat Animal Research Center, Meat Safety and Quality Research Unit, USDA ARS, Clay Center, NE, United States.
Introduction: Non-typhoidal (NTS) are leading bacterial agents of foodborne illnesses and a global concern for human health. While there are over 2,600 different serovars of NTS, epidemiological data suggests that certain serovars are better at causing disease than others, resulting in the majority of reported human illnesses in the United States. To improve food safety, there is a need to rapidly detect these more pathogenic serovars to facilitate their removal from the food supply.
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