Last data update: May 13, 2024. (Total: 46773 publications since 2009)
Records 1-7 (of 7 Records) |
Query Trace: Tyrrell F[original query] |
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International circumpolar surveillance: update on the interlaboratory quality control program for Streptococcus pneumoniae, 2009 to 2020
Golden AR , Griffith A , Simons BC , Reasonover A , Slotved HC , Lefebvre B , Kristinsson KG , Hurteau D , Tyrrell GJ , Bruce MG , Martin I . Microbiol Spectr 2024 e0424523 The International Circumpolar Surveillance (ICS) program is a population-based surveillance network for invasive bacterial diseases throughout Arctic countries and territories. The ICS quality control program for Streptococcus pneumoniae serotyping and antimicrobial susceptibility testing has been ongoing since 1999. Current participating laboratories include the Provincial Laboratory for Public Health in Edmonton, Alberta; Laboratoire de santé publique du Québec in Sainte-Anne-de-Bellevue, Québec; the Centers for Disease Control's Arctic Investigations Program in Anchorage, Alaska; the Neisseria and Streptococcus Reference Laboratory at Statens Serum Institut in Copenhagen, Denmark; the Department of Clinical Microbiology, Landspitali in Reykjavik, Iceland; and Public Health Agency of Canada's National Microbiology Laboratory in Winnipeg, Manitoba. From 2009 to 2020, 140 isolates of S. pneumoniae were distributed among the six laboratories as part of the quality control program. Overall serotype concordance was 96.9%, with 99.3% concordance to pool level. All participating laboratories had individual concordance rates >92% for serotype and >97% for pool. Overall concordance by modal minimum inhibitory concentration (MIC) for testing done by broth microdilution or Etest was 99.1%, and >98% for all antimicrobials tested. Categorical concordance was >98% by both CLSI and EUCAST criteria. For two laboratories performing disc diffusion, rates of concordance by modal MIC were >97% for most antimicrobials, except chloramphenicol (>93%) and trimethoprim/sulfamethoxazole (>88%). Data collected from 12 years of the ICS quality control program for S. pneumoniae demonstrate excellent (≥95%) overall concordance for serotype and antimicrobial susceptibility testing results across six laboratories. IMPORTANCE: Arctic populations experience several social and physical challenges that lead to the increased spread and incidence of invasive diseases. The International Circumpolar Surveillance (ICS) program was developed to monitor five invasive bacterial diseases in Arctic countries and territories. Each ICS organism has a corresponding interlaboratory quality control (QC) program for laboratory-based typing, to ensure the technical precision and accuracy of reference testing services for these regions, and identify and correct potential problems. Here, we describe the results of the ICS Streptococcus pneumoniae QC program, from 2009 to 2020. Excellent overall concordance was achieved for serotype and antimicrobial susceptibility testing results across six laboratories. Ongoing participation in these QC programs ensures the continuation of quality surveillance systems within Arctic populations that experience health disparities. |
Etymologia: Coronavirus
Henry R . Emerg Infect Dis 2020 26 (5) 1027 The first coronavirus, avian infectious bronchitis virus, was discovered in 1937 by Fred Beaudette and Charles Hudson. In 1967, June Almeida and David Tyrrell performed electron microscopy on specimens from cultures of viruses known to cause colds in humans and identified particles that resembled avian infectious bronchitis virus. Almeida coined the term “coronavirus,” from the Latin corona (“crown”), because the glycoprotein spikes of these viruses created an image similar to a solar corona (Figure). |
The concept of the crown and its potential role in the downfall of coronavirus
Chorba T . Emerg Infect Dis 2020 26 (9) 2302-2305 Coronavirus virions are spherical or variable in shape and composed of an outer layer of lipid covered with a crown of club-shaped peplomers or spikes. Within each spike is a helical single-stranded RNA-containing structural protein. Although the term corona was first used in English in the 1500s, it was borrowed directly from the Latin word for “crown.” Corona is derived from the Ancient Greek κορώνη (korōnè), meaning “garland” or “wreath,” coming from a proto-Indo-European root, sker- or ker-, meaning “to turn” or “to bend.” | | In the 1967 initial description of an electron microscopic image of a human common cold virus, June Almeida (née Hart) and David Tyrrell described the surface of coronavirus particles as being “covered with a distinct layer of projections roughly 200Ǻ [20 nm] long….[with] a narrow stalk just in the limit of resolution of the microscope and a ‘head’ roughly 100Ǻ across”. In micrographs, the club-shaped spikes that stud the surface of coronaviruses are glycoproteins that give the appearance of a radiate crown. |
Using reduced inoculum densities of Mycobacterium tuberculosis in MGIT Pyrazinamide Susceptibility Testing to prevent false-resistant results and improve accuracy: A multicenter evaluation
Morlock GP , Tyrrell FC , Baynham D , Escuyer VE , Green N , Kim Y , Longley-Olson PA , Parrish N , Pennington C , Tan D , Austin B , Posey JE . Tuberc Res Treat 2017 2017 3748163 The primary platform used for pyrazinamide (PZA) susceptibility testing of Mycobacterium tuberculosis is the MGIT culture system (Becton Dickinson). Since false-resistant results have been associated with the use of this system, we conducted a multicenter evaluation to determine the effect of using a reduced cell density inoculum on the rate of false resistance. Two reduced inoculum densities were compared with that prescribed by the manufacturer (designated as "BD" method). The reduced inoculum methods (designated as "A" and "C") were identical to the manufacturer's protocol in all aspects with the exception of the cell density of the inoculum. Twenty genetically and phenotypically characterized M. tuberculosis isolates were tested in duplicate by ten independent laboratories using the three inoculum methods. False-resistant results declined from 21.1% using the standard "BD" method to 5.7% using the intermediate ("A") inoculum and further declined to 2.8% using the most dilute ("C") inoculum method. The percentages of the resistant results that were false-resistant declined from 55.2% for the "BD" test to 28.8% and 16.0% for the "A" and "C" tests, respectively. These results represent compelling evidence that the occurrence of false-resistant MGIT PZA susceptibility test results can be mitigated through the use of reduced inoculum densities. |
Trends in testing for Mycobacterium tuberculosis complex from US Public Health Laboratories, 2009-2013
Tyrrell F , Stafford C , Yakrus M , Youngblood M , Hill A , Johnston S . Public Health Rep 2017 132 (1) 56-64 OBJECTIVE: We investigated data from US public health laboratories funded through the Centers for Disease Control and Prevention's Tuberculosis Elimination and Laboratory Cooperative Agreement to document trends and challenges in meeting national objectives in tuberculosis (TB) laboratory diagnoses. METHODS: We examined data on workload and turnaround time from public health laboratories' progress reports during 2009-2013. We reviewed methodologies, laboratory roles, and progress toward rapid detection of Mycobacterium tuberculosis complex through nucleic acid amplification (NAA) testing. We compared selected data with TB surveillance reports to estimate public health laboratories' contribution to national diagnostic services. RESULTS: During the study period, culture and drug susceptibility tests decreased, but NAA testing increased. Public health laboratories achieved turnaround time benchmarks for drug susceptibility tests at lower levels than for acid-fast bacilli smear and identification from culture. NAA positivity in laboratories among surveillance-reported culture-positive TB cases increased from 26.6% (2355 of 8876) in 2009 to 40.0% (2948 of 7358) in 2013. Public health laboratories provided an estimated 50.9% (4285 of 8413 in 2010) to 57.2% (4210 of 7358 in 2013) of culture testing and 88.3% (6822 of 7727 in 2011) to 94.4% (6845 of 7250 in 2012) of drug susceptibility tests for all US TB cases. CONCLUSIONS: Public health laboratories contribute substantially to TB diagnoses in the United States. Although testing volumes mostly decreased, the increase in NAA testing indicates continued progress in rapid M tuberculosis complex detection. |
Epidemiology of bacterial meningitis in the North American Arctic, 2000-2010
Gounder PP , Zulz T , Desai S , Stenz F , Rudolph K , Tsang R , Tyrrell GJ , Bruce MG . J Infect 2015 71 (2) 179-87 OBJECTIVE: To determine the incidence of meningitis caused by Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pneumoniae in the North American Arctic during 2000-2010. METHODS: Surveillance data were obtained from the International Circumpolar Surveillance network. We defined a case of bacterial meningitis caused by H. influenzae, N. meningitidis, or S. pneumoniae as a culture-positive isolate obtained from a normally sterile site in a resident with a meningitis diagnosis. RESULTS: The annual incidence/100,000 persons for meningitis caused by H. influenzae, N. meningitidis, and S. pneumoniae among all North American Arctic residents was: 0.6, 0.5, and 1.5, respectively; the meningitis incidence among indigenous persons in Alaska and Canada (indigenous status not recorded in Greenland) for those three bacteria was: 2.1, 0.8, and 2.4, respectively. The percentage of pneumococcal isolates belonging to a 7-valent pneumococcal conjugate vaccine serotype declined from 2000-2004 to 2005-2010 (31% to 2%, p-value <0.01). During 2005-2010, serotype a caused 55% of H. influenzae meningitis and serogroup B caused 86% of meningococcal meningitis. CONCLUSIONS: Compared with all North American Arctic residents, indigenous people suffer disproportionately from bacterial meningitis. Arctic residents could benefit from the development of a H. influenzae serotype a vaccine and implementation of a meningococcal serogroup B vaccine. |
Probability of negative Mycobacterium tuberculosis complex cultures based on time-to-detection of positive cultures: a multi-center evaluation of commercial broth-based culture systems
Tyrrell FC , Budnick GE , Elliott T , Gillim-Ross L , Hildred MV , Mahlmeister P , Parrish N , Pentella M , Vanneste J , Wang YF , Starks AM . J Clin Microbiol 2012 50 (10) 3275-82 We conducted a multicenter study to determine whether Mycobacterium tuberculosis complex (MTBC) cultures in automated broth-based systems could reliably be considered as negative sooner than six weeks. Laboratory sites used MGIT or BacT/ALERT and tracked results of time to detection of mycobacteria (TTD-all, n = 1547) and MTBC (TTD-MTBC, n = 466) over six-month periods from primarily (93%) respiratory specimens. Cumulative percentages by day detected and median TTD of initial and follow-up specimens were analyzed. The median TTD-MTBC for MGIT (n = 6 sites) was 14 days. For laboratories using standard processing procedures, 100% of MTBC were detected from initial and follow-up specimens in 28 and 35 days, respectively, and no yield of MTBC on solid or MGIT liquid media was observed after five weeks. The median TTD-MTBC for BacT/ALERT (n = 3 sites) was 18 days, with 95% and 100% detected within 37 and 42 days respectively. Analysis of TTD of positive MTBC cultures in broth can predict the probability of culture negativity at defined time points. Receipt of interim negative reports earlier than six weeks could assist clinicians in considering alternative diagnoses, and could alter timing and prioritization of public health interventions. Laboratories should analyze their own TTD data to inform protocol decisions. Laboratories using MGIT could issue no growth of MTBC reports on initial specimens as early as four weeks and on patients undergoing treatment as early as five weeks post-inoculation. |
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