Borrelia burgdorferi sensu stricto and Borrelia afzelii: Population structure and differential pathogenicity.
MultiLocus sequence typing (MLST) is considered a powerful method to unveil relationships within bacterial populations and it constitutes an economical and fast alternative to whole genome sequencing. We used this method to understand whether there are differences in human pathogenicity within and between different Borrelia burgdorferi sensu lato species. Therefore, 136 strains from human patients or ticks from Europe were included in MLST analyses. The scheme employed used eight chromosomally located housekeeping genes (i.e. clpA, clpX, nifS, pepX, pyrG, recG, rplB and uvrA). We investigated Borrelia afzelii, one of the predominant species in Europe, and B. burgdorferi sensu stricto (s.s.), because it allowed comparative analysis to strains from the USA. We typed 113 patient isolates as well as 23 tick isolates. For further comparative purposes an additional 746 strains from Europe and the USA were included from the MLST website http://borrelia.mlst.net. We observed an overlap of the B. burgdorferi s.s. populations from Europe and the USA isolated from human patients while there was no overlap of the populations found in tick vectors. Further results indicate that B. afzelii was significantly less associated with disseminated infection than B. burgdorferi s.s. and that B. burgdorferi s.s. from Europe caused neuroborreliosis to a significantly greater extent than B. afzelii or B. burgdorferi s.s. in the USA. Our data suggest that there may be an evolutionary basis of differential interspecies pathogenicity in Borrelia. This was not evident within Borrelia species: we found the same sequence types in patients with disseminated or localized symptoms when the number of strains was sufficiently high. We hypothesize that the finding that B. burgdorferi s.s. in Europe is much more associated with neuroborreliosis than in the USA maybe linked to factor(s) related to the human host, the tick vector or the bacterium itself (e.g. plasmid content and structure).
Bavarian Health and Food Safety Authority, Branch Oberschleißheim, Veterinärstr. 2, 85764 Oberschleißheim, Germany; National Reference Centre for Borrelia, Veterinärstr. 2, 85764 Oberschleißheim, Germany.
Sabrina
S
Jungnick
Bavarian Health and Food Safety Authority, Branch Oberschleißheim, Veterinärstr. 2, 85764 Oberschleißheim, Germany; National Reference Centre for Borrelia, Veterinärstr. 2, 85764 Oberschleißheim, Germany. Electronic address: gabriele.margos@lgl.bayern.de.
Gabriele
G
Margos
Bavarian Health and Food Safety Authority, Branch Oberschleißheim, Veterinärstr. 2, 85764 Oberschleißheim, Germany; National Reference Centre for Borrelia, Veterinärstr. 2, 85764 Oberschleißheim, Germany.
Melissa
M
Rieger
Bavarian Health and Food Safety Authority, Branch Oberschleißheim, Veterinärstr. 2, 85764 Oberschleißheim, Germany; National Reference Centre for Borrelia, Veterinärstr. 2, 85764 Oberschleißheim, Germany.
Eldina
E
Dzaferovic
The Robinson Research Institute, School of Paediatrics and Reproductive Health, The University of Adelaide, Adelaide 5005, SA, Australia.
Stephen J
SJ
Bent
Comparative Tropical Medicine and Parasitology, LMU Munich, Munich, Germany.
Evelyn
E
Overzier
Comparative Tropical Medicine and Parasitology, LMU Munich, Munich, Germany.
Cornelia
C
Silaghi
Dr. Gernot Walder GmbH, Unterwalden 30, 9931 Ausservillgraten, Austria.
Gernot
G
Walder
Department of Hygiene, Medical Microbiology and Social Medicine, Innsbruck Medical University, Fritz Pregl Str. 3, 6020 Innsbruck, Austria.
Franziska
F
Wex
Bavarian Health and Food Safety Authority, Branch Oberschleißheim, Veterinärstr. 2, 85764 Oberschleißheim, Germany.
Johannes
J
Koloczek
Bavarian Health and Food Safety Authority, Branch Oberschleißheim, Veterinärstr. 2, 85764 Oberschleißheim, Germany.
Andreas
A
Sing
Bavarian Health and Food Safety Authority, Branch Oberschleißheim, Veterinärstr. 2, 85764 Oberschleißheim, Germany; National Reference Centre for Borrelia, Veterinärstr. 2, 85764 Oberschleißheim, Germany.
Volker
V
Fingerle
D000818:Animals; D025065:Borrelia burgdorferi / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D015748:Borrelia burgdorferi Group / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D005060:Europe; D005798:Genes, Bacterial; D020043:Genes, Essential; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008193:Lyme Disease / Q000382:microbiology; D058885:Multilocus Sequence Typing; D013987:Ticks / Q000382:microbiology; D014481:United States
Borrelia afzelii; Borrelia burgdorferi sensu stricto; Human pathogenesis; Lyme borreliosis; Multilocus sequence analysis; Population structure