Chui L.,Provincial Laboratory for Public Health |
Chui L.,University of Alberta |
Li V.,Provincial Laboratory for Public Health |
Fach P.,ANSES French Agency for Food |
And 8 more authors.
Journal of Clinical Microbiology | Year: 2015
Virulence markers in Shiga toxin-producing Escherichia coli (STEC) and their association with diseases remain largely unknown. This study determines the importance of 44 genetic markers for STEC (O157 and non-O157) from human clinical cases and their correlation to disease outcome. STEC isolated from a cattle surveillance program were also included. The virulence genes tested were present in almost all O157:H7 isolates but highly variable in non-O157 STEC isolates. Patient age was a significant determinant of clinical outcome.
Cembrowski G.S.,University of Alberta |
Tran D.V.,University of Alberta |
Clinical Chemistry and Laboratory Medicine | Year: 2010
Background: Most estimates of biologic variation (sb) are based on periodically acquiring and storing specimens, followed by analysis within a single analytic run. We demonstrate for many intensive care unit (ICU) tests, only patient results need be statistically analyzed to provide reliable estimates of sb. Methods: Over 11 months, approximately 28,000 blood gas measurements (including electrolyte panels and glucose) were performed on one of two Radiometer ABL800 FLEX analyzers (Radiometer, Copenhagen, Denmark) from 1676 ICU patients. We tabulated the measurements of paired intra-patient blood samples drawn within 24 h of each other. After removal of outliers, we calculated the standard deviations of duplicates (SDD) of the intra-patient pairs grouped in 2-h intervals: 0-2 h, 2-4 h, 4-6 h, ... 20-22 h and 22-24 h. The SDDs were then regressed against the time intervals of 2-14 h; extrapolation to zero time represents the sum of sb and short-term analytic variation (sa). Results: Substitution of experimentally derived analytic error permitted the calculation of coefficient of variation (biologic) (CVb) (100 sb/mean): pH, 0.3%; pCO2, 5.7%; pO2, 13%; Na+, 0.6%; K+, 4.8%; Cl-, 0.8%; HCO3 -, 3.2%; iCa++, 2.4%; and glucose, 10.3%. The CVb of the electrolytes very closely matches the lowest estimates obtained in the usual manner. Conclusions: Derivation of the ratio of biologic to analytic variation indicates that the ABL800 is extremely suitable for ICU testing. This analysis should be extended to other point of care instrument systems. © 2010 by Walter de Gruyter Berlin New York 2010.
Higgins T.,DynaLIFEDX |
Schnabl K.,DynaLIFEDX |
Savoy M.,DynaLIFEDX |
Rowe P.,DynaLIFEDX |
And 2 more authors.
Clinical Biochemistry | Year: 2012
Introduction: Hemoglobinopathies and thalassemias together form the most common genetic disease in the world. Double heterozygosity, in which there is a hemoglobin variant, in both the α- and non-α globin chains, is very unusual. A novel double heterozygosity of the α chain variant HbQ India with the non-α chain HbD Punjab is described. Methods and materials: The index case is a 39. year old female of Indian origin. HPLC analysis using the Bio Rad β thalassemia method and electrophoresis at both alkaline and acid pH were performed. Results: HPLC shows four major bands and electrophoresis at alkaline pH shows 3 bands and 2 bands at acid pH. Discussion: Both the HPLC and electrophoresis at alkaline and acid pH are consistent for the double heterozygous hemoglobin variants HbQ India and HbD Punjab. Conclusion: This is the first literature report of the double heterozygosity of HbQ India/HbD Punjab. © 2011 The Canadian Society of Clinical Chemists.
Ahmed-Bentley J.,University of Alberta |
Chandran A.U.,University of Alberta |
Joffe A.M.,University of Alberta |
French D.,DynaLIFEDX |
And 3 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2013
Overseas travel, as a risk factor for the acquisition of infections due to antimicrobial-resistant organisms, has recently been linked to carbapenemase-producing Gram-negative bacteria. Multiresistant Klebsiella pneumoniae, Escherichia coli, and Acinetobacter baumannii strains were isolated from a wound of a Canadian patient with a recent history of hospitalization in India. This resulted in the initiation of outbreak management that included surveillance cultures. Epidemiological and molecular investigations showed that NDM-1-producing K. pneumoniae ST16 and OXA-23-producing A. baumannii ST10 strains were transmitted to 5 other patients, resulting in the colonization of 4 patients and the death of 1 patient due to septic shock caused by the OXA-23-producing A. baumannii strain. The high rate of false positivity of the screening cultures resulted in additional workloads and increased costs for infection control and clinical laboratory work. We believe that this is the first report of an infection with carbapenemase-producing Gram-negative bacteria resulting in death attributed to a patient with recent foreign hospitalization. We recommend routine rectal and wound screening for colonization with multiresistant bacteria for patients who have recently been admitted to hospitals outside Canada. Copyright © 2013, American Society for Microbiology.
Estey M.P.,DynaLIFEDX |
Estey M.P.,University of Alberta |
Rodriguez-Capote K.,DynaLIFEDX |
Rodriguez-Capote K.,University of Alberta |
And 2 more authors.
Clinical Biochemistry | Year: 2015
Objectives: To investigate the underlying cause of unexpectedly low HbA1c results (3.3-3.5%) obtained by HPLC in three siblings undergoing routine screening for type 2 diabetes mellitus. Design and methods: HbA1c was measured using an alternate method based on a different analytical principle (the Siemens DCA 2000. + immunoassay). Hemoglobin fractionation was performed by HPLC on the BioRad Variant II, gel electrophoresis at acid and alkaline pH on the Sebia Hydrasys 2, and capillary electrophoresis on the Sebia Capillarys 2. Sequencing of the beta globin gene was also conducted. Results: HbA1c analysis by immunoassay gave significantly higher results, ranging from 5.2-5.5%. Hemoglobin fractionation by HPLC showed an abnormal peak comprising approximately 43% of total hemoglobin, suggesting the presence of a beta chain hemoglobin variant. Gel electrophoresis at alkaline pH revealed a very unusual pattern, with 3 abnormal bands migrating with Hb F, between Hb F and Hb S, and slightly cathodal to Hb S. A single band in the Hb A position was seen on gel electrophoresis at acid pH. Capillary electrophoresis revealed two abnormal peaks, comprising 42% and 5% of total hemoglobin. Sequencing of the beta globin gene showed heterozygosity for Hb Hirose (beta 37(C3) Trp>Ser), an extremely rare variant with a substitution at the α1β2 interface. Conclusions: We describe the chromatographic and electrophoretic properties of Hb Hirose, and demonstrate that this rare variant causes falsely low HbA1c results on the BioRad variant II Turbo 2.0. Recognition of this interference is crucial in order to prevent reporting erroneous results. © 2015 The Canadian Society of Clinical Chemists.