The document discusses the ecological, epidemiological, and molecular characteristics of Borrelia burgdorferi sensu lato, the causative agent of Lyme borreliosis. It highlights the complex interactions between the pathogen, tick vectors, and host species that contribute to the success of the Lyme disease system, including the presence of diverse tick species and their geographical distribution. The text also addresses factors influencing the spread of Lyme disease, such as climate change and migratory bird pathways.

1. The ecologic, epidemiologic and molecular aspects of
Borrelia burgdorferi sensu lato: consequence of
diversity, distribution and genome variations of Lyme
borreliosis spirochetes.
Biology Centre CAS,
Institute of Parasitology,
Laboratory of Molecular Ecology of Vectors and Pathogens
Branisovska 31, 37005, Ceske Budejovice, Czech Republic
natasha@paru.cas.cz
Natasha Rudenko
Susan Oliver

2. vector host
pathogen
What factors make the Lyme borreliosis system so successful?
Diverse interaction that occurs between spirochete, the
tick vector and the host makes Borrelia an elusive pathogen!!!

3. TICK FACTOIDS 
Approximately 900 tick species exists;
10% are of concern to humans.
All ticks are obligate, nonpermanent blood feeders;
hosts include all terrestrial vertebrates.
Ticks are vectors of more kinds of microorganisms
than any other arthropod taxon.
Worldwide distribution from arctic to antarctic.
The most important genera of hard ticks are:
Amblyomma, Boophilus, Dermacentor,
Haemaphysalis, Hyalomma, Ixodes and Rhipicephalus.

4. The worldwide distribution of major Ixodes tick species
of medical and veterinary importance
(“bridge” vectors)
I.pacificus
I.scapularis I.ricinus
I.persulcatus
adapted from B. Rosner 2006; www.lymebook.com

5. Ticks, important as “maintenance”
vectors of Borrelia burgdorferi
(usually non-human biting)
I. hexagonus, I. trianguliceps, I. uriae, H. concinna, –Europe
I. minor, I. affinis, I. dentatus, I. spinipalpis - USA
I. turdus, I. ovatus, I. columnae, I. tanuki – Japan
I. nipponensis –Korea, Japan
I. granulatus, I. monospinosus – China, Korea
I. moschiferi, H. concinna, H. longicornis, H. bispinosa - China
In some areas maintenance vectors appear to be more important in the enzootic cycle of
B. burgdorferi s.l. than the ‘bridge’ vectors that feed on the same hosts and bite humans
(Oliver, 1996).

6. Tick species experimentally confirmed as vectors of
Borrelia burgdorferi sensu lato (Eisen&Lane)
Tick specie Bb SL Bb ss B. afzelii B. garinii B. bissettii
I. affinis ☺
I. angustus ☺ ☺
I. dentatus ☺
I. hexagonus ☺
I. jellisoni ☺
I. minor ☺ ☺
I. muris ☺
I. pacificus ☺ ☺
I. persulcatus ☺
I. ricinus ☺ ☺ ☺ ☺ ☺
I. scapularis ☺ ☺ ☺ ☺ ☺
I. spinipalpis ☺ ☺
I. sinensis ☺

7. Tick species experimentally confirmed as vectors of
Borrelia burgdorferi sensu lato (Eisen&Lane)
Tick specie Bb SL Bb ss B. afzelii B. garinii B. bissettii
I. affinis ☺
I. angustus ☺ ☺
I. dentatus ☺
I. hexagonus ☺
I. jellisoni ☺
I. minor ☺ ☺
I. muris ☺
I. pacificus ☺ ☺
I. persulcatus ☺
I. ricinus ☺ ☺ ☺ ☺ ☺
I. scapularis ☺ ☺ ☺ ☺ ☺
I. spinipalpis ☺ ☺
I. sinensis ☺

8. Reservoir hosts of Borrelia burgdorferi sensu lato
Efficient reservoir hosts of B. burgdorferi s.l.
share several characteristics.
They are abundant, large number of them is naturally infected and
serves as hosts to numerous vector competent ticks.
They do not usually become resistant to repeated tick feeding.
They are readily infected and remain infected and infective to
competent tick vectors for long periods of time, often for life.
Lyme disease spirochetes infect diverse animal species, but not all of them serve as
competent hosts.

9. Reservoir Hosts
- mammals; -rodents; -birds; -lizards;

10. Pattern of response of vertebrate
serum complement to
B. burgdorferi s.l. spirochetes.
Ticha et al., 2016

11. 0
5
10
15
20
25
1982
1984
1992
1993
1995
1996
1997
1998
2001
2006
2007
2008
2009
2010
2011
2014
2016
Expanding complex of Borrelia burgdorferi sensu lato spirochetes

12. Currently known spirochete species from the Borrelia burgdorferi sensu lato complex

13. Spirochete species from the B. burgdorferi sensu lato complex involved in LB worldwide

17. Altering the level of gene expression in response to changes in temperature, pH, salts, nutrient
content, host and vector dependent factors spirochetes developed strategies to sense and
survive in these diverse environments, often changing their phenotypes….

19. The geographical distribution of Borrelia burgdorferi sensu lato
10 years ago
(K. Kurtenbach et al., 2006)

20. The geographical distribution of Borrelia burgdorferi sensu lato
5 years ago
(G. Margos et al., 2011)

21. Map showing the updated distribution of the LB species based on published and unpublished results (2016)
The present geographical distribution of Borrelia burgdorferi sensu lato -updates

22. Map showing the updated distribution of the LB species based on published and unpublished results (2016)
The present geographical distribution of Borrelia burgdorferi sensu lato -updates

23. Borrelia finlandensis, 2011
Borrelia chilensis, 2014
Borrelia mayoni, 2016
New species from B. burgdorferi sensu lato complex

24. "The spread of Lyme disease is driven, in part, by climate change, as the tick vector spreads
northwards from endemic areas of the United States" (Steven Sternthal)

25. Main migration flyways
The Atlantic Flyway is a bird migration route that generally follows the Atlantic Coast of North
America and the Appalachian Mountains.
The migration route tends to narrow considerably in the southern U.S.A. in the states of Virginia,
North Carolina, South Carolina, Georgia, and Florida. It serves as avian superhighway’s for 500 +
bird species and millions of individual birds.

26. The diversity of spirochetes from B. burgdorferi sensu lato
in the United States
(adapted from G. Margos et al., 2010)
B. garinii
B. afzelii
B. kurtenbachii
B. mayonii

27. Worldwide frequency of B. burgdorferi ospC types
B. burgdorferi ospC alleles
detected in southeastern USA
Rudenko et al., 2013
B. burgdorferi ospC alleles
detected in Canada
Ogden et al., 2011
Rudenko et al., 2013

28. Some spirochete complexes were believed to be
restricted:
exclusively to North America
- B1, C, D, F, G, H, I, J, N, and U –
OR
exclusively to Europe:
- B2, S, L, Q, and V-
three ospC types - A, E, and K- were previously
detected on both continents

29. Geographic distribution of rare ospC allele in N. America
A significant spatial cluster of ticks infected with B. burgdorferi carrying rare allele L
was detected in Canada and in the southeastern USA (indicated by the black ellipses)

30. MLST
locus
sample
uvrA rplB pepX clpX ospC
allele
Bb316
PubMLST
Allele
distribution
GenBank
best match
(strains)
KU577579
allele 19
USA(CT,NY,
PA), Canada
M11p†,
CA382, B31
KU577578
allele 1
USA(CT,NY,
MA,MD,IL,
MN,MI,WI, CA),
Canada, Europe
M6p†, M11p†
KU577577
allele1
USA(CT,NY,
PA,VT,WI,
MA,ME,MN,
CA), Canada,
Europe
M11p†, M6p†
CA382, B31
KU577576
allele1
USA(CT,NY,
PA,WI, MI,
ME,MN,IN,
VT,MA,CA)
Canada,
Europe
M11p†, B31,
M6p†,CA382
A
Bb324
PubMLST
Allele
distribution
GenBank
best match
(strains)
KU598201
allele 1
USA(NY,CT,
ME, VT, PA,
MA, MD),
Canada,
Europe§
M11p†,
B31, CA382
KT598395
allele 1
as Bb316
M11p†,
CA382, B31
N/A N/A M
Bb327
PubMLST
Allele
distribution
GenBank
best match
(strains)
KU598202
allele 19
as Bb316
M11p†,
CA382, B31
KT598396
allele 1
as Bb316
as Bb324
M11p†,
CA382, B31
N/A N/A A
B. burgdorferi sensu stricto detected in A. americanum ticks
in the southeastern United States

31. A hypothesis for the migration route of Borrelia between the continents was proposed and the first evidences of trans-oceanic
dispersals of B. burgdorferi sensu stricto were presented almost 15 years ago.
(Foretz et al., 1997; Ras et al., 1997; Postic et al., 1999; Marti et al., 1997; Qiu et al., 2008).
The worldwide distribution of Borrelia is supported by long-distance transmission of
infected ticks by migrating hosts.

32. Marie Vancová
Libor Grubhoffer and James H. Oliver Jr.
Marina Golovchenko
ACKNOWLEDGEMENTS

33. Where Lyme disease is absent:
Is it the tick,
the vertebrate host,
or just a matter of time?
ESA, 2004
"Absence of proof is not proof of absence."
- Dr. Edwin J. Masters, M.D.

34. THANK YOU FOR YOUR ATTENTION!
natasha@paru.cas.cz