18 results on '"Mechai S"'
Search Results
2. Diet of Crocidura pachyura (Küster, 1835) (Mammalia: Soricidae) in several localities of Algeria
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Amrouche-Larabi, L., Denys, C., Marniche, F., violaine nicolas, Messaoud, S., Khifer, L., Mechai, S., Boukhemza, M., NICOLAS COLIN, Violaine, Institut de Systématique, Evolution, Biodiversité (ISYEB ), Muséum national d'Histoire naturelle (MNHN)-École pratique des hautes études (EPHE), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)
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[SDV] Life Sciences [q-bio] ,[SDV]Life Sciences [q-bio] ,Ecology, Evolution, Behavior and Systematics - Abstract
Ecological information, including food habits, on African shrews is scarce. The aim of this study was to describe the diet of Crocidura pachyura (Küster, 1835) in Algeria. Its diet was studied by analysing stomach contents of 95 shrews collected in pitfall and Sherman traps, from June 2007 to September 2008 and from March 2012 to May 2014, in eight localities of North-Central Algeria, from the sea level until 1390 m (Tigzirt, Boukhalfa, Ouadias, El Misser, Darna, Tala Guilef, Zeralda and Reghaia). The diet was composed of 99 different prey taxa distributed in seven invertebrate classes (Clitellata, Nematelminthes, Gastropoda, Arachnida, Crustacea, Myriapoda and Insecta), one vertebrate (Squamata) and plants, particularly seeds. The most important components of the diet were invertebrates : their contribution was 77.05 % of the overall diet composition. Insects were the most frequent prey with 54.3 %. Crocidura pachyura feeds on small preys lower than 17 mm (average 4 mm) and the diversity index of Shannon-Weaver varied between 1.58 and 4.88 (average 2.4). Comparisons with similar studies in Algeria and Europe for C. russula showed some differences especially for Coleoptera, Hymenoptera and Diptera proportions., Régime alimentaire de Crocidura pachyura (Küster, 1835) (Mammalia, Soricidae) dans plusieurs localités d’Algérie. Le régime alimentaire de Crocidura pachyura (Küster, 1835) a été étudié grâce à l’analyse des contenus stomacaux de 95 spécimens collectés sur le terrain de juin 2007 à septembre 2008 et de mars 2012 à mai 2014. Ces individus ont été collectés au moyen de pièges Sherman et de pots-enterrés dans 8 localités d’Algérie du Nord et du Centre, du niveau de la mer à 1390 m d’altitude (Tigzirt, Boukhalfa, Ouadias, El Misser, Darna, Tala Guilef, Zeralda et Reghaia). On trouve 99 proies différentes distribuées dans 7 taxons d’invertébrés (Clitellates, Nématelminthes, Gastropodes, Arachnides, Crustacés, Myriapodes et Insectes), un vertébré (Squamate) et des plantes indéterminées, notamment des graines. Les invertébrés représentent 77,05 % du régime alimentaire et les insectes sont les proies les plus fréquentes avec 54,3 %. Crocidura pachyura se nourrit de petites proies de taille inférieure à 17 mm (moyenne 4 mm) et la diversité des proies (indice de diversité de Shannon-Weaver) varie de 1,58 à 4,88 (moyenne de 2,4). La comparaison avec les travaux similaires effectués en Algérie et en Europe sur C. russula montre quelques différences de régime, surtout en ce qui concerne les proportions des proies Coleoptères, Hyménoptères et Diptères., Amrouche-Larabi Lilya,Denys Christiane,Marniche Faiza,Nicolas Violaine,Messaoud Sidhoum,Khifer Larbi,Mechai Samir,Boukhemza Mohamed. Diet of Crocidura pachyura (Küster, 1835) (mammalia : soricidae) in several localities of Algeria . In: Revue d'Écologie (La Terre et La Vie), tome 73, n°4, 2018. pp. 504-513.
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- 2018
3. Evolutionary Aspects of Emerging Lyme Disease in Canada
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Ogden, N. H., primary, Feil, E. J., additional, Leighton, P. A., additional, Lindsay, L. R., additional, Margos, G., additional, Mechai, S., additional, Michel, P., additional, and Moriarty, T. J., additional
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- 2015
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4. Complex Population Structure of Borrelia burgdorferi in Southeastern and South Central Canada as Revealed by Phylogeographic Analysis
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Mechai, S., primary, Margos, G., additional, Feil, E. J., additional, Lindsay, L. R., additional, and Ogden, N. H., additional
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- 2015
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5. Investigation of the Population Structure of the Tick Vector of Lyme DiseaseIxodes scapularis(Acari: Ixodidae) in Canada Using Mitochondrial Cytochrome C Oxidase Subunit I Gene Sequences
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Mechai, S., primary, Feil, E. J., additional, Gariepy, T. D., additional, Gregory, T. R., additional, Lindsay, L. R., additional, Millien, V., additional, and Ogden, N. H., additional
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- 2013
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6. Investigation of the Population Structure of the Tick Vector of Lyme Disease Ixodes scapularis (Acari: Ixodidae) in Canada using Mitochondrial Cytochrome C Oxidase Subunit I Gene Sequences
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Mechai, S., Feil, E. J., Gariepy, T. D., Gregory, T. R., Lindsay, L. R., Millien, V., and Ogden, N. H.
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- 2013
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7. Hepatitis C virus genotypes in France: comparison of clinical features of patients infected with HCV type I and type II
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Qu, D., Li, J.-S., Vitvitski, L., and Mechai, S.
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- 1994
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8. Evolutionary Aspects of Emerging Lyme Disease in Canada.
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Ogden, N. H., Feil, E. J., Leighton, P. A., Lindsay, L. R., Margos, G., Mechai, S., Michel, P., and Moriarty, T. J.
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LYME disease , *TICKS , *BORRELIA burgdorferi , *EPIDEMIOLOGY , *BACTERIAL diseases - Abstract
In North America, Lyme disease (LD) is a tick-borne zoonosis caused by the spirochete bacterium Borrelia burgdorferi sensu stricto, which is maintained by wildlife. Tick vectors and bacteria are currently spreading into Canada and causing increasing numbers of cases of LD in humans and raising a pressing need for public health responses. There is no vaccine, and LD prevention depends on knowing who is at risk and informing them how to protect themselves from infection. Recently, it was found in the United States that some strains of B. burgdorferi sensu stricto cause severe disease, whereas others cause mild, self-limiting disease. While many strains occurring in the United States also occur in Canada, strains in some parts of Canada are different from those in the United States. We therefore recognize a need to identify which strains specific to Canada can cause severe disease and to characterize their geographic distribution to determine which Canadians are particularly at risk. In this review, we summarize the history of emergence of LD in North America, our current knowledge of B. burgdorferi sensu stricto diversity, its intriguing origins in the ecology and evolution of the bacterium, and its importance for the epidemiology and clinical and laboratory diagnosis of LD. We propose methods for investigating associations between B. burgdorferi sensu stricto diversity, ecology, and pathogenicity and for developing predictive tools to guide public health interventions. We also highlight the emergence of B. burgdorferi sensu stricto in Canada as a unique opportunity for exploring the evolutionary aspects of tick-borne pathogen emergence. [ABSTRACT FROM AUTHOR]
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- 2015
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9. Possible effect of mutations on serological detection of Borrelia burgdorferi sensu stricto ospC major groups: An in-silico study.
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Mechai S, Coatsworth H, and Ogden NH
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- Humans, Phylogeny, Prospective Studies, Amino Acid Sequence, Antigens, Bacterial genetics, Bacterial Outer Membrane Proteins, Mutation, Borrelia burgdorferi Group genetics, Borrelia burgdorferi genetics, Lyme Disease diagnosis
- Abstract
The outer surface protein C (OspC) of the agent of Lyme disease, Borrelia burgdorferi sensu stricto, is a major lipoprotein surface-expressed during early-phase human infections. Antibodies to OspC are used in serological diagnoses. This study explored the hypothesis that serological test sensitivity decreases as genetic similarity of ospC major groups (MGs) of infecting strains, and ospC A (the MG in the strain B31 used to prepare antigen for serodiagnosis assays) decreases. We used a previously published microarray dataset to compare serological reactivity to ospC A (measured as pixel intensity) versus reactivity to 22 other ospC MGs, within a population of 55 patients diagnosed by two-tier serological testing using B. burgdorferi s.s. strain B31 as antigen, in which the ospC MG is OspC A. The difference in reactivity of sera to ospC A and reactivity to each of the other 22 ospC MGs (termed 'reactivity difference') was the outcome variable in regression analysis in which genetic distance of the ospC MGs from ospC A was the explanatory variable. Genetic distance was computed for the whole ospC sequence, and 9 subsections, from Neighbour Joining phylogenetic trees of the 23 ospC MGs. Regression analysis was conducted using genetic distance for the full ospC sequence, and the subsections individually. There was a significant association between the reactivity difference and genetic distance of ospC MGs from ospC A: increased genetic distance reduced reactivity to OspC A. No single ospC subsection sequence fully explained the relationship between genetic distance and reactivity difference. An analysis of single nucleotide polymorphisms supported a biological explanation via specific amino acid modifications likely to change protein binding affinity. This adds support to the hypothesis that genetic diversity of B. burgdorferi s.s. (here specifically OspC) may impact serological diagnostic test performance. Further prospective studies are necessary to explore the clinical implications of these findings., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Mechai et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
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- 2023
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10. The origins and potential future of SARS-CoV-2 variants of concern in the evolving COVID-19 pandemic.
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Otto SP, Day T, Arino J, Colijn C, Dushoff J, Li M, Mechai S, Van Domselaar G, Wu J, Earn DJD, and Ogden NH
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- Animals, Biological Evolution, COVID-19 mortality, COVID-19 Vaccines pharmacology, Humans, Infection Control, Mutation, SARS-CoV-2 genetics, Selection, Genetic, COVID-19 transmission, COVID-19 virology, COVID-19 Vaccines administration & dosage, SARS-CoV-2 pathogenicity
- Abstract
One year into the global COVID-19 pandemic, the focus of attention has shifted to the emergence and spread of SARS-CoV-2 variants of concern (VOCs). After nearly a year of the pandemic with little evolutionary change affecting human health, several variants have now been shown to have substantial detrimental effects on transmission and severity of the virus. Public health officials, medical practitioners, scientists, and the broader community have since been scrambling to understand what these variants mean for diagnosis, treatment, and the control of the pandemic through nonpharmaceutical interventions and vaccines. Here we explore the evolutionary processes that are involved in the emergence of new variants, what we can expect in terms of the future emergence of VOCs, and what we can do to minimise their impact., Competing Interests: Declaration of interests The authors declare no competing interests., (Crown Copyright © 2021. Published by Elsevier Inc. All rights reserved.)
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- 2021
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11. Genetic diversity of Borrelia garinii from Ixodes uriae collected in seabird colonies of the northwestern Atlantic Ocean.
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Munro HJ, Ogden NH, Mechai S, Lindsay LR, Robertson GJ, Whitney H, and Lang AS
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- Animals, Multilocus Sequence Typing, Newfoundland and Labrador, Borrelia burgdorferi Group genetics, Charadriiformes parasitology, Genetic Variation, Ixodes microbiology
- Abstract
The occurrence of Borrelia garinii in seabird ticks, Ixodes uriae, associated with different species of colonial seabirds has been studied since the early 1990s. Research on the population structure of this bacterium in ticks from seabird colonies in the northeastern Atlantic Ocean has revealed admixture between marine and terrestrial tick populations. We studied B. garinii genetic diversity and population structure in I. uriae collected from seabird colonies in the northwestern Atlantic Ocean, in Newfoundland and Labrador, Canada. We applied a multi-locus sequence typing (MLST) scheme to B. garinii found in ticks from four species of seabirds. The B. garinii strains found in this seabird colony ecosystem were diverse. Some were very similar to strains from Asia and Europe, including some obtained from human clinical samples, while others formed a divergent group specific to this region of the Atlantic Ocean. Our findings highlight the genetic complexity of B. garinii circulating in seabird ticks and their avian hosts but also demonstrate surprisingly close connections between B. garinii in this ecosystem and terrestrial sources in Eurasia. Genetic similarities among B. garinii from seabird ticks and humans indicate the possibility that B. garinii circulating within seabird tick-avian host transmission cycles could directly, or indirectly via connectivity with terrestrial transmission cycles, have consequences for human health., (Crown Copyright © 2019. Published by Elsevier GmbH. All rights reserved.)
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- 2019
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12. Detection of municipalities at-risk of Lyme disease using passive surveillance of Ixodes scapularis as an early signal: A province-specific indicator in Canada.
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Gasmi S, Ogden NH, Ripoche M, Leighton PA, Lindsay RL, Nelder MP, Rees E, Bouchard C, Vrbova L, Rusk R, Russell C, Pelcat Y, Mechai S, Kotchi SO, and Koffi JK
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- Animals, Female, Humans, Lyme Disease diagnosis, Male, Manitoba epidemiology, Ontario epidemiology, Risk Assessment, Arachnid Vectors microbiology, Borrelia burgdorferi isolation & purification, Ixodes microbiology, Lyme Disease epidemiology
- Abstract
Lyme disease, the most commonly reported vector-borne disease in North America, is caused by the spirochete Borrelia burgdorferi sensu stricto, which is transmitted by Ixodes scapularis in eastern Canada and Ixodes pacificus in western Canada. Recently, the northward range expansion of I. scapularis ticks, in south-eastern Canada, has resulted in a dramatic increase in the incidence of human Lyme disease. Detecting emerging areas of Lyme disease risk allows public health to target disease prevention efforts. We analysed passive tick surveillance data from Ontario and Manitoba to i) assess the relationship between the total numbers of I. scapularis submissions in passive surveillance from humans, and the number of human Lyme disease cases, and ii) develop province-specific acarological indicators of risk that can be used to generate surveillance-based risk maps. We also assessed associations between numbers of nymphal I. scapularis tick submissions only and Lyme disease case incidence. Using General Estimating Equation regression, the relationship between I. scapularis submissions (total numbers and numbers of nymphs only) in each census sub-division (CSD) and the number of reported Lyme disease cases was positively correlated and highly significant in the two provinces (P ≤ 0.001). The numbers of I. scapularis submissions over five years discriminated CSDs with ≥ 3 Lyme disease cases from those with < 3 cases with high accuracy when using total numbers of tick submission (Receiver Operating Characteristics area under the curve [AUC] = 0.89) and moderate accuracy (AUC = 0.78) when using nymphal tick submissions only. In Ontario the optimal cut-off point was a total 12 tick submissions from a CSD over five years (Sensitivity = 0.82, Specificity = 0.84), while in Manitoba the cut-off point was five ticks (Sensitivity = 0.71, Specificity = 0.79) suggesting regional variability of the risk of acquiring Lyme disease from an I. scapularis bite. The performances of the acarological indicators developed in this study for Ontario and Manitoba support the ability of passive tick surveillance to provide an early signal of the existence Lyme disease risk areas in regions where ticks and the pathogens they transmit are expanding their range., Competing Interests: The authors have declared that no competing interests exist.
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- 2019
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13. Evidence for an effect of landscape connectivity on Borrelia burgdorferi sensu stricto dispersion in a zone of range expansion.
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Mechai S, Margos G, Feil EJ, Lindsay LR, Michel P, Kotchi SO, and Ogden NH
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- Animal Distribution, Animals, Multilocus Sequence Typing, Quebec epidemiology, Rodent Diseases epidemiology, Rodent Diseases parasitology, Tick Infestations epidemiology, Tick Infestations parasitology, Borrelia burgdorferi isolation & purification, Deer, Environment, Ixodes microbiology, Ixodes physiology, Rodentia, Tick Infestations veterinary
- Abstract
In North America, different strains of the Lyme disease-causing bacterium Borrelia burgdorferi sensu stricto cluster into phylogenetic groups that are associated with different levels of pathogenicity and, for some, specific rodent reservoir hosts. Here we explore whether landscape connectivity, by impacting host dispersal, influences B. burgdorferi s.s. spread patterns. This question is central to modelling spatial patterns of the spread of Lyme disease risk in the zone of northward range-expansion of B. burgdorferi s.s. in southeastern Canada where the study was conducted. We used multi-locus sequence typing (MLST) to characterise B. burgdorferi s.s. in positive ticks collected at 13 sites in southern Quebec, Canada during the early stages of B. burgdorferi s.s. invasion. We used mixed effects logistic regression to investigate whether landscape connectivity (probability of connectivity; PC) affected the probability that samples collected at different sites were of the same strain (MLST sequence type: ST). PC was calculated from a habitat map based on high spatial resolution (15 m) Landsat 8 imagery to identify woodland habitat that are preferred by rodent hosts of B. burgdorferi s.s. There was a significant positive association between the likelihood that two samples were of the same ST and PC, when PC values were grouped into three categories of low, medium and high. When analysing data for individual STs, samples at different sites were significantly more likely to be the same when PC was higher for the rodent-associated ST1. These findings support the hypothesis that dispersion trajectories of B. burgdorferi s.s. in general, and some rodent-associated strains in particular, are at least partly determined by landscape connectivity. This may suggest that dispersion of B. burgdorferi s.s. is more common by terrestrial mammal hosts (which would likely disperse according to landscape connectivity) than by birds, the dispersal of which is likely less constrained by landscape. This study suggests that accounting for landscape connectivity may improve model-based predictions of spatial spread patterns of B. burgdorferi s.s. The findings are consistent with possible past dispersal patterns of B. burgdorferi s.s. as determined by phylogeographic studies., (Crown Copyright © 2018. Published by Elsevier GmbH. All rights reserved.)
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- 2018
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14. Whole genome sequencing and phylogenetic analysis of strains of the agent of Lyme disease Borrelia burgdorferi from Canadian emergence zones.
- Author
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Tyler S, Tyson S, Dibernardo A, Drebot M, Feil EJ, Graham M, Knox NC, Lindsay LR, Margos G, Mechai S, Van Domselaar G, Thorpe HA, and Ogden NH
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- Animals, Borrelia burgdorferi isolation & purification, Canada epidemiology, Chromosomes, Bacterial genetics, Communicable Diseases, Emerging epidemiology, Genetic Variation, Genotyping Techniques, Ixodes microbiology, Lyme Disease epidemiology, Phenotype, Sequence Analysis, DNA, Whole Genome Sequencing, Borrelia burgdorferi genetics, Communicable Diseases, Emerging parasitology, Lyme Disease microbiology, Phylogeny
- Abstract
Lyme disease is emerging in southern Canada due to range expansion of the tick vector, followed by invasion of the agent of Lyme disease Borrelia burgdorferi sensu stricto. Strain diversity, as determined by Multi Locus Sequence Typing, occurs in this zone of emergence, and this may have its origins in adaptation to ecological niches, and have phenotypic consequences for pathogenicity and serological test performance. Sixty-four unique strains were cultured from ticks collected in southern Canada and the genomes sequenced using the Illumina MiSeq platform. A maximum likelihood phylogenetic tree of the chromosome revealed two large clades with multiple subclades. Consistent with previous studies on this species, the clades were not geographically defined, and some Canadian strains were highly divergent from previously sequenced US strains. There was evidence for recombination in the chromosome but this did not affect the phylogeny. Analysis of chromosomal genes indicated that these are under intense purifying selection. Phylogenies of the accessory genome and chromosome were congruent. Therefore strain differences identified in the phylogeny of chromosomal genes likely act as a proxy for genetic determinants of phenotypic differences amongst strains that are harboured in the accessory genome. Further studies on health implications of strain diversity are needed.
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- 2018
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15. Antibody responses to Borrelia burgdorferi detected by western blot vary geographically in Canada.
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Ogden NH, Arsenault J, Hatchette TF, Mechai S, and Lindsay LR
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- Antibodies, Bacterial metabolism, Antibody Formation, Canada epidemiology, Enzyme-Linked Immunosorbent Assay, Geography, Humans, Lyme Disease diagnosis, Lyme Disease epidemiology, Lyme Disease immunology, Lyme Disease microbiology, Manitoba epidemiology, Nova Scotia epidemiology, Retrospective Studies, Serologic Tests methods, Antibodies, Bacterial analysis, Blotting, Western, Borrelia burgdorferi immunology
- Abstract
Lyme disease is emerging in eastern and central Canada, and most cases are diagnosed using the two-tier serological test (Enzyme Immuno Assay [EIA] followed by Western blot [WB]). Simplification of this algorithm would be advantageous unless it impacts test performance. In this study, accuracy of individual proteins of the IgG WB algorithm in predicting the overall test result in samples from Canadians was assessed. Because Borrelia burgdorferi strains vary geographically in Canada, geographic variations in serological responses were also explored. Metrics of relative sensitivity, specificity and the kappa statistic measure of concordance were used to assess the capacity of responses to individual proteins to predict the overall IgG WB result of 2524 EIA (C6)-positive samples from across Canada. Geographic and interannual variations in proportions of samples testing positive were explored by logistic regression. No one protein was highly concordant with the IgG WB result. Significant variations were found amongst years and geographic regions in the prevalence of samples testing positive using the overall IgG WB algorithm, and for individual proteins of the algorithm. In most cases the prevalence of samples testing positive were highest in Nova Scotia, and lower in samples from Manitoba westwards. These findings suggest that the current two tier test may not be simplified and continued use of the current two-tier test method and interpretation is recommended. Geographic and interannual variations in the prevalence of samples testing positive may be consistent with B. burgdorferi strain variation in Canada, and further studies are needed to explore this., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2017
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16. Evidence for Host-Genotype Associations of Borrelia burgdorferi Sensu Stricto.
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Mechai S, Margos G, Feil EJ, Barairo N, Lindsay LR, Michel P, and Ogden NH
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- Animals, Borrelia burgdorferi pathogenicity, Genotype, Host-Pathogen Interactions, Humans, Ixodes microbiology, Lyme Disease microbiology, Lyme Disease transmission, Multilocus Sequence Typing, Borrelia burgdorferi genetics
- Abstract
Different genotypes of the agent of Lyme disease in North America, Borrelia burgdorferi sensu stricto, show varying degrees of pathogenicity in humans. This variation in pathogenicity correlates with phylogeny and we have hypothesized that the different phylogenetic lineages in North America reflect adaptation to different host species. In this study, evidence for host species associations of B. burgdorferi genotypes was investigated using 41 B. burgdorferi-positive samples from five mammal species and 50 samples from host-seeking ticks collected during the course of field studies in four regions of Canada: Manitoba, northwestern Ontario, Quebec, and the Maritimes. The B. burgdorferi genotypes in the samples were characterized using three established molecular markers (multi-locus sequence typing [MLST], 16S-23S rrs-rrlA intergenic spacer, and outer surface protein C sequence [ospC] major groups). Correspondence analysis and generalized linear mixed effect models revealed significant associations between B. burgdorferi genotypes and host species (in particular chipmunks, and white-footed mice and deer mice), supporting the hypotheses that host adaptation contributes to the phylogenetic structure and possibly the observed variation in pathogenicity in humans.
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- 2016
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17. Changing geographic ranges of ticks and tick-borne pathogens: drivers, mechanisms and consequences for pathogen diversity.
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Ogden NH, Mechai S, and Margos G
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- Animals, Basic Reproduction Number, Humans, Tick-Borne Diseases epidemiology, Tick-Borne Diseases transmission, Arthropod Vectors classification, Arthropod Vectors growth & development, Phylogeography, Ticks classification, Ticks growth & development
- Abstract
The geographic ranges of ticks and tick-borne pathogens are changing due to global and local environmental (including climatic) changes. In this review we explore current knowledge of the drivers for changes in the ranges of ticks and tick-borne pathogen species and strains via effects on their basic reproduction number (R 0), and the mechanisms of dispersal that allow ticks and tick-borne pathogens to invade suitable environments. Using the expanding geographic distribution of the vectors and agent of Lyme disease as an example we then investigate what could be expected of the diversity of tick-borne pathogens during the process of range expansion, and compare this with what is currently being observed. Lastly we explore how historic population and range expansions and contractions could be reflected in the phylogeography of ticks and tick-borne pathogens seen in recent years, and conclude that combined study of currently changing tick and tick-borne pathogen ranges and diversity, with phylogeographic analysis, may help us better predict future patterns of invasion and diversity.
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- 2013
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18. Characterization of the third most common genotype of hepatitis C virus in France.
- Author
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Li JS, Vitvitski L, Tong SP, Mechai S, Berthillon P, and Trépo C
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- Amino Acid Sequence, Base Sequence, France epidemiology, Genotype, Hepatitis C epidemiology, Humans, Molecular Sequence Data, Prevalence, Sequence Homology, Amino Acid, Sequence Homology, Nucleic Acid, Genetic Variation, Hepacivirus genetics
- Abstract
We have previously identified the two major hepatitis C virus (HCV) genotypes prevalent in France (type I and type II). We report here the identification and partial characterization of a new HCV genotype with a highly divergent 5' noncoding (NC) region and a structural protein region. This genotype showed only 93-94% sequence identity with either type I or type II HCV in the 5' NC region. Sequence analysis of the structural protein region revealed extremely low sequence homology with all the four major HCV genotypes: 86-89% for the core protein and 56-69% for the envelope protein. However, further analysis revealed that this new genotype was very similar to the genotype 3a described most recently. Screening of 150 clinical samples with genotype-specific oligoprobes revealed prevalence of this genotype in 12% of the French samples with a significant association with drug addiction and a good response to interferon therapy. These results may have implications for the diagnosis of HCV infection and the design of HCV vaccines.
- Published
- 1995
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