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Presented by: Najmeh Parhizgari PhD student of medical virology at TUMS

Insights to Genetic Characterization Tools for Epidemiological Tracking of Francisella tularensis in Sweden. Presented by: Najmeh Parhizgari PhD student of medical virology at TUMS. Introduction. 1. Introduction Francisella tularensis Highly virulent Facultative intracellular pathogen

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Presented by: Najmeh Parhizgari PhD student of medical virology at TUMS

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  1. Insights to Genetic Characterization Tools for Epidemiological Tracking of Francisellatularensisin Sweden Presented by: NajmehParhizgari PhD student of medical virology at TUMS

  2. Introduction 1

  3. Introduction • Francisellatularensis • Highly virulent • Facultative intracellular pathogen • Tularaemia in humans and animals • Transmission • Arthropod bites (Vector Born Disease) • Inhalation of contaminated dust • Ingestion of contaminated food or water 2

  4. Introduction • Main form of disease • Ulceroglandular tularemia • Glandular tularemia • Oculoglandular tularemia • Oropharyngeal tularemia • Pneumonic tularemia • Typhoidal tularemia 3

  5. Introduction • F. tularensissubspecies: • tularensis • holarctica • mediasiatica • novicida • Difference in : • Virulence • Geographic distribution • Host/vector associations • Genetic diversity Type A Tularemia Type B Tularemia 4

  6. High-resolution molecular methods Pulsed-field gel electrophoresis (PFGE) Multi-locus variable-number of tandem repeat (VNTR) analysis (MLVA) canonical Single Nucleotide Polymorphism (canSNP) Insertion-deletion markers (INDELs) Whole genome microarrays 5

  7. Evaluate canSNPs, MLVA, and PmeI-PFGE for practical uses in epidemiological investigation 6

  8. Method Clinical samples Genotyping tools: canSNP MLVA PFGE Geomappingg 7

  9. Clinical samples • F. tularensissubspecies holarctica • From 1994 to 2010 • Diverse regions in Sweden • Three ulceroglandulartularaemia • One hundred twenty four cultured samples 8

  10. Genotyping tools • canSNP: • Using 26 assays • MLVA: • Ft-M3, Ft-M6, Ft-M20, Ft-M22 and Ft-M24 • PFGE: • PmeI GTTT_^AAAC 9

  11. Results 10

  12. MLVA canSNP PFGE n:97, B12 Tul-I Type 1 Tul-II n:24, B7/8 Type 2 M22 M24 Tul-III Type 3 canSNP, MLVA, and PFGE were in general agreement when classifying samples into major groups 11

  13. MLVA 12

  14. Pulsed- Field Gel Electrophoresis (PFGE) patterns 13

  15. canSNP 14

  16. Geographic distribution of SNP groups A highly complex geographic pattern among the phylogroups exists at a national and regional scale in Sweden 15

  17. Relationships among groups canSNP MLVA Discrimination among samples withinthe same phylogroup 16

  18. Discussion 17

  19. Discussion Despite the phylogeographic complexity, patterns emerge that suggest the possibility of identifying SNP markers that could be meaningfully linked to geographic regions or at least narrow the geographic range of possible places This B.22 SNP was highly specific to FSC200 genome. All other phylogroups are defined by SNPs discovered from genomes found in other nations (USA, Russia, and Hungary) The striking genetic similarity suggests that they all recently emerged from a common ancestor. The temporal pattern rules out a single outbreak season and provides insight into the stability of this genotype. The results of the present study indicate that SNP typing schemes, designed from geographically informative SNPs, combined with a MLVA typing scheme have the potential to be used as a standalone typing method in outbreak investigations Complex phylogeographic pattern of tularemia distribution in Sweden poses a great challenge to accurately identify a source and place of infection for any given F. tularensisspecimen The broad distribution of closely related phylogroupsis central to the argument that F.tularensis is a rapidly dispersed organism All phylogroups identified in Sweden have also been found in distant nations abroad, except B.22, which is restricted to Sweden whole-genome sequencing (WGS) would be the most appropriate tool for effectively linking specific genetic type to geography 18

  20. Thank you for your attention Question?

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