Background: Blood pressure (BP) readings taken in clinics are often higher than BP readings taken in a research setting. Recent guidelines and clinical trials have highlighted the necessity of using automated office blood pressure (AOBP) devices and standardizing measurement procedures. The goal of the present study was to compare AOBP vs manual BP measurement in both research and clinical environments in which operators and devices were the same and measurement procedures were standardized and optimal.
View Article and Find Full Text PDFGenomic antimicrobial resistance (AMR) prediction tools have the potential to support foodborne illness outbreak investigations through their application in the analysis of bacterial genomes from causative strains. The AMR marker profile of a strain of interest, initially identified in outbreak-associated clinical samples, may serve as the basis for customization of selective enrichment media, facilitating its recovery from samples in a food safety investigation. Different possibilities for AMR analyses include the use of comprehensive AMR gene databases such as the Comprehensive Antibiotic Resistance Database, which can be mined with in-house bioinformatics alignment tools (e.
View Article and Find Full Text PDFThe determination of Shiga toxin (ST) subtypes can be an important element in the risk characterization of foodborne ST-producing Escherichia coli (STEC) isolates for making risk management decisions. ST subtyping methods include PCR techniques based on electrophoretic or pyrosequencing analysis of amplicons and in silico techniques based on whole genome sequence analysis using algorithms that can be readily incorporated into bioinformatics analysis pipelines for characterization of isolates by their genetic composition. The choice of technique will depend on the performance characteristics of the method and an individual laboratory's access to specialized equipment or personnel.
View Article and Find Full Text PDFWe describe the translation of a cloth-based hybridization array system (CHAS), a colorimetric DNA detection method that is used by food inspection laboratories for colony screening of pathogenic agents, onto a microfluidic chip format. We also introduce an articulated centrifugal platform with a novel fluid manipulation concept based on changes in the orientation of the chip with respect to the centrifugal force field to time the passage of multiple components required for the process. The platform features two movable and motorized carriers that can be reoriented on demand between 0 and 360° during stage rotation.
View Article and Find Full Text PDFControl strains of bacterial pathogens such as Escherichia coli O157:H7 are commonly processed in parallel with test samples in food microbiology laboratories as a quality control measure to assure the satisfactory performance of materials used in the analytical procedure. Before positive findings can be reported for risk management purposes, analysts must have a means of verifying that pathogenic bacteria (e.g.
View Article and Find Full Text PDFNon-O157 enterohemorrhagic Escherichia coli in priority serogroups O26, O45, O103, O111, O121, and O145 are increasingly recognized as important human pathogens. In the present study, a panel of monoclonal antibodies (MAbs) to the lipopolysaccharide O antigens of E. coli in serogroups O26, O45, O103, O111, O121, and O145 was produced.
View Article and Find Full Text PDFA simple immunoenzymatic enterohemorrhagic Escherichia coli (EHEC) colony check (ECC) assay was developed for the presumptive identification of priority EHEC colonies isolated on plating media from enrichment broth cultures of foods. With this approach, lipopolysaccharide extracted from a colony is spotted on the grid of a polymyxin-coated polyester cloth strip, and bound E. coli serogroup O26, O45, O103, O111, O121, O145, and O157 antigens are subsequently detected by sequential reactions with a pool of commercially available peroxidase-conjugated goat antibodies and tetramethylbenzidine substrate solution.
View Article and Find Full Text PDFThe growth characteristics of 96 shiga toxin-producing Escherichia coli (STEC) strains representing 36 different O-types (including priority O types O26, O45, O103, O111, O121, O145 and O157) on commercial and in-house agar media were studied. The ability of the strains to grow on agar media with varying selective supplement formulations was evaluated using MacConkey Agar (MAC); Rainbow® Agar O157 (RBA); Rainbow® Agar O157 with manufacturer-recommended selective supplements (RBA-NT); Rainbow® Agar O157 with USDA-recommended selective supplements (RBA-USDA); CHROMagar STEC™ (CH STEC); Tryptone Bile agar containing cefixime and tellurite (TBA-CT); Tryptone Bile agar containing cefixime, tellurite, eosin and methylene blue (TBA-EM); and VTEC agar. All of the strains were able to grow on MAC, RBA and VTEC agar, whereas a number of strains (including some non-O157 priority O types) were unable to grow on the highly selective media CH STEC, RBA-NT, RBA-USDA, TBA-EM and TBA-CT.
View Article and Find Full Text PDFA method has been developed for the detection in beef trim of priority Shiga toxin-producing E. coli (STEC) strains, defined as E. coli possessing the virulence factors stx1 and/or stx2 and intimin (eae), with O serogroups O26, O45, O103, O111, O121, O145, or O157.
View Article and Find Full Text PDFA cloth-based hybridization array system (CHAS) was developed for the identification of foodborne colony isolates of seven priority enterohemorrhagic Escherichia coli (EHEC-7) serogroups targeted by U. S. food inspection programs.
View Article and Find Full Text PDFIntroduction: The objectives of this project were two-fold, to: (1) implement rapid, simple, and inexpensive test methods enabling the detection of the foodborne pathogens Escherichia coli O157:H7 and Salmonella in foods and related samples, for the purpose of establishing basic on-site food microbiology testing capability at the Nunavik Research Centre (NRC) in Kuujjuaq, with the provision of hands-on training in the operation of methods; and (2) use this new capability to conduct a survey of the eastern Canadian Arctic in order to ascertain the prevalence of E. coli O157:H7 and Salmonella in traditional meats derived from arctic food animals.
Methods: To verify the effectiveness of training provided to NRC staff, proficiency test samples consisting of ground beef inoculated with salmonellae and E.
At Cape Vera (Devon Island, Nunavut, Canada), a seabird colony of northern fulmars (Fulmarus glacialis) congregates and releases nutrients through the deposition of guano to the coastal terrestrial environment, thus creating nutrient-fertilized habitats important to insects, birds, and mammals. Here we determined whether mercury was similarly enriched in various terrestrial food web components in this High Arctic coastal ecosystem due to seabird inputs. Stable isotopes (delta(15)N, delta(13)C) were used to identify trophic linkages and possible routes of contaminant transfer in the food web.
View Article and Find Full Text PDFNalidixic acid-resistant (NalR) mutants of Salmonella enterica serovar Berta and Escherichia coli O157:H7 were derived from wild-type laboratory cultures to serve as distinguishable control strains for routine use in food microbiology testing programs. The prevalence of the NalR phenotype among different bacteria was verified using panels of related and unrelated strains with the ability to grow vigorously on plating media containing nalidixic acid, being restricted to the NalR mutants. The NalR phenotype was stable in both mutant strains over several generations in the absence of selective pressure and enabled their differentiation from wild-type bacteria on the basis of their ability to grow on plating media containing nalidixic acid.
View Article and Find Full Text PDFA simple macroarray system based on the use of polyester cloth as the solid phase for DNA hybridization has been developed for the identification and characterization of bacteria on the basis of the presence of various virulence and toxin genes. In this approach, a multiplex polymerase chain reaction (PCR) incorporating digoxigenin-dUTP is used to simultaneously amplify different marker genes, with subsequent rapid detection of the amplicons by hybridization with an array of probes immobilized on polyester cloth and immunoenzymatic assay of the bound label. As an example of the applicability of this cloth-based hybridization array system (CHAS) in the characterization of foodborne pathogens, a method has been developed enabling the detection of antibiotic resistance and other marker genes associated with the multidrug-resistant food pathogen Salmonella enterica subsp.
View Article and Find Full Text PDFDifferent methods for labelling polymerase chain reaction (PCR) products with non-radioactive labels for their detection by hybridization with immobilized DNA probes were compared. The use of digoxigenin (DIG) as a label provided greater sensitivity than biotin in a PCR system targeting the invA gene from Salmonella typhimurium. Incorporation of digoxigenin into amplicons in the form of 5'-DIG-labelled oligonucleotide primers resulted in better assay signals and was more economical than DIG-labelled dUTP.
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