Format

Send to

Choose Destination
Ticks Tick Borne Dis. 2018 Sep;9(6):1407-1415. doi: 10.1016/j.ttbdis.2018.07.001. Epub 2018 Jul 2.

Evidence for an effect of landscape connectivity on Borrelia burgdorferi sensu stricto dispersion in a zone of range expansion.

Author information

1
Public Health Risk Sciences Division, National Microbiology Laboratory, Public Health Agency of Canada, 3200 Sicotte, Saint-Hyacinthe, Québec, J2S 2M2, Canada; Groupe de Recherche en Épidémiologie des Zoonoses et Santé Publique, Faculté de médecine vétérinaire, Université de Montréal, 3200 Sicotte, Saint-Hyacinthe, Québec, J2S 2M2, Canada. Electronic address: samir.mechai@canada.ca.
2
Ludwig Maximilians Universität München, Department for Infectious Diseases and Zoonoses, Munich, Germany; National Reference Centre for Borrelia, Oberschleissheim, Germany; Bavarian Health and Food Safety Authority, Oberschleissheim, Germany.
3
Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, United Kingdom.
4
Zoonotic Diseases and Special Pathogens Division, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada.
5
Office of the Chief Science Officer, Public Health Agency of Canada, Ottawa, Ontario, K1A 0K9, Canada.
6
Groupe de Recherche en Épidémiologie des Zoonoses et Santé Publique, Faculté de médecine vétérinaire, Université de Montréal, 3200 Sicotte, Saint-Hyacinthe, Québec, J2S 2M2, Canada; Public Health Risk Sciences Division, National Microbiology Laboratory, Public Health Agency of Canada, 3200 Sicotte, Saint-Hyacinthe, Québec, J2S 2M2, Canada.

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.

KEYWORDS:

Borrelia burgdorferi; Connectivity; Landscape; Lyme disease

PMID:
30006200
DOI:
10.1016/j.ttbdis.2018.07.001
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center