Experimental infections with different pathogen strains give insight into pathogen life history traits. The purpose of the present study was to compare variation in tissue infection prevalence and spirochete abundance among strains of Borrelia burgdorferi in a rodent host (Mus musculus, C3H/HeJ). Male and female mice were experimentally infected via tick bite with one of 12 strains. Ear tissue biopsies were taken at days 29, 59 and 89 postinfection, and seven tissues were collected at necropsy. The presence and abundance of spirochetes in the mouse tissues were measured by quantitative polymerase chain reaction. To determine the frequencies of our strains in nature, their multilocus sequence types were matched to published data sets. For the infected mice, 56.6% of the tissues were infected with B. burgdorferi. The mean spirochete load in the mouse necropsy tissues varied 4.8-fold between the strains. The mean spirochete load in the ear tissue biopsies decreased rapidly over time for some strains. The percentage of infected tissues in male mice (65.4%) was significantly higher compared to female mice (50.5%). The mean spirochete load in the seven tissues was 1.5× higher in male mice compared to female mice; this male bias was 15.3× higher in the ventral skin. Across the 11 strains, the mean spirochete loads in the infected mouse tissues were positively correlated with the strain-specific frequencies in their tick vector populations. The study suggests that laboratory-based estimates of pathogen abundance in host tissues can predict the strain composition of this important tick-borne pathogen in nature.

Biology Centre Institute of Parasitology Czech Academy of Sciences České Budějovice Czechia

Department of Biology University of Pennsylvania Philadelphia Pennsylvania USA

Department of Veterinary Microbiology Western College of Veterinary Medicine University of Saskatchewan Saskatoon Saskatchewan Canada

Faculty of Science University of South Bohemia České Budějovice Czechia

Groupe de Recherche en Épidémiologie des Zoonoses et Santé Publique Université de Montréal Montreal Quebec Canada

Public Health Risk Sciences National Microbiology Laboratory Public Health Agency of Canada St Hyacinthe Quebec Canada

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Acevedo, M. A., Dillemuth, F. P., Flick, A. J., Faldyn, M. J., & Elderd, B. D. (2019). Virulence-driven trade-offs in disease transmission: A meta-analysis. Evolution, 73(4), 636-647. https://doi.org/10.1111/evo.13692

Anderson, R. M., & May, R. M. (1982). Coevolution of hosts and parasites. Parasitology, 16, 411-426.

Arroyo-Mendoza, M., Peraza, K., Olson, J., Adler-Moore, J. P., & Buckley, N. E. (2020). Effect of testosterone and estrogen supplementation on the resistance to systemic Candida albicans infection in mice. Heliyon, 6(7), e04437. https://doi.org/10.1016/j.heliyon.2020.e04437

Balmer, O., & Tanner, M. (2011). Prevalence and implications of multiple-strain infections. The Lancet Infectious Diseases, 11(11), 868-878. https://doi.org/10.1016/S1473-3099(11)70241-9

Barbour, A. G. (2017). Infection resistance and tolerance in Peromyscus spp., natural reservoirs of microbes that are virulent for humans. Seminars in Cell and Developmental Biology, 61, 115-122. https://doi.org/10.1016/j.semcdb.2016.07.002

Barthold, S. W., Beck, D. S., Hansen, G. M., Terwilliger, G. A., & Moody, K. D. (1990). Lyme borreliosis in selected strains and ages of laboratory mice. The Journal of Infectious Diseases, 162(1), 133-138. https://doi.org/10.1093/infdis/162.1.133

Barthold, S. W., Persing, D. H., Armstrong, A. L., & Peeples, R. A. (1991). Kinetics of Borrelia burgdorferi dissemination and evolution of disease after intradermal inoculation of mice. The American Journal of Pathology, 139(2), 263-273.

Baum, E., Hue, F., & Barbour, A. G. (2012). Experimental infections of the reservoir species Peromyscus leucopus with diverse strains of Borrelia burgdorferi, a Lyme disease agent. MBio, 3(6), e00434-12. https://doi.org/10.1128/mBio.00434-12

Belli, A., Sarr, A., Rais, O., Rego, R. O. M., & Voordouw, M. J. (2017). Ticks infected via co-feeding transmission can transmit Lyme borreliosis to vertebrate hosts. Scientific Reports, 7(1), 5006. https://doi.org/10.1038/s41598-017-05231-1

Benoit, V. M., Petrich, A., Alugupalli, K. R., Marty-Roix, R., Moter, A., Leong, J. M., & Boyartchuk, V. L. (2010). Genetic control of the innate immune response to Borrelia hermsii influences the course of relapsing fever in inbred strains of mice. Infection and Immunity, 78(2), 586-594. https://doi.org/10.1128/IAI.01216-09

Benten, W. P. M., Ulrich, P., Kühn-Velten, W. N., Vohr, H.-W., & Wunderlich, F. (1997). Testosterone-induced susceptibility to Plasmodium chabaudi malaria: Persistence after withdrawal of testosterone. Journal of Endocrinology, 153(2), 275-281. https://doi.org/10.1677/joe.0.1530275

Brisson, D., Baxamusa, N., Schwartz, I., & Wormser, G. P. (2011). Biodiversity of Borrelia burgdorferi strains in tissues of Lyme disease patients. PLoS ONE, 6(8), e22926. https://doi.org/10.1371/journal.pone.0022926

Brisson, D., & Dykhuizen, D. E. (2004). ospC diversity in Borrelia burgdorferi: Different hosts are different niches. Genetics, 168(2), 713-722. https://doi.org/10.1534/genetics.104.028738

Bockenstedt, L. K., Gonzalez, D., Mao, J., Li, M., Belperron, A. A., & Haberman, A. (2014). What ticks do under your skin: Two-photon intravital imaging of Ixodes scapularis feeding in the presence of the Lyme disease spirochete. The Yale Journal of Biology and Medicine, 87(1), 3-13.

Bockenstedt, L. K., Wooten, R. M., & Baumgarth, N. (2021). Immune response to Borrelia: Lessons from Lyme disease spirochetes. Current Issues in Molecular Biology, 42, 145-190. https://doi.org/10.21775/cimb.042.145

Bunikis, J., Garpmo, U., Tsao, J., Berglund, J., Fish, D., & Barbour, A. G. (2004). Sequence typing reveals extensive strain diversity of the Lyme borreliosis agents Borrelia burgdorferi in North America and Borrelia afzelii in Europe. Microbiology-SGM, 150, 1741-1755. https://doi.org/10.1099/mic.0.26944-0

Bunikis, J., Tsao, J., Luke, C. J., Luna, M. G., Fish, D., & Barbour, A. G. (2004). Borrelia burgdorferi infection in a natural population of Peromyscus leucopus mice: A longitudinal study in an area where Lyme borreliosis is highly endemic. Journal of Infectious Diseases, 189, 1515-1523.

Cabello, F. C., Godfrey, H. P., & Newman, S. A. (2007). Hidden in plain sight: Borrelia burgdorferi and the extracellular matrix. Trends in Microbiology, 15(8), 350-354. https://doi.org/10.1016/i.tim.2007.06.003

Casjens, S. R., Gilcrease, E. B., Vujadinovic, M., Mongodin, E. F., Luft, B. J., Schutzer, S. E., Fraser, C. M., & Qiu, W. G. (2017). Plasmid diversity and phylogenetic consistency in the Lyme disease agent Borrelia burgdorferi. BMC Genomics, 18, 165. https://doi.org/10.1186/s12864-017-3553-5

Casjens, S. R., Mongodin, E. F., Qiu, W. G., Luft, B. J., Schutzer, S. E., Gilcrease, E. B., Huang, W. M., Vujadinovic, M., Aron, J. K., Vargas, L. C., Freeman, S., Radune, D., Weidman, J. F., Dimitrov, G. I., Khouri, H. M., Sosa, J. E., Halpin, R. A., Dunn, J. J., & Fraser, C. M. (2012). Genome stability of Lyme disease spirochetes: Comparative genomics of Borrelia burgdorferi plasmids. PLoS ONE, 7(3), e33280. https://doi.org/10.1371/journal.pone.0033280

Cobey, S. (2014). Pathogen evolution and the immunological niche. Annals of the New York Academy of Sciences, 1320(1), 1-15. https://doi.org/10.1111/nyas.12493

Courtney, J. W., Kostelnik, L. M., Zeidner, N. S., & Massung, R. F. (2004). Multiplex real-time PCR for detection of Anaplasma phagocytophilum and Borrelia burgdorferi. Journal of Clinical Microbiology, 42(7), 3164-3168. https://doi.org/10.1128/JCM.42.7.3164-3168.2004

Dai, J., Wang, P., Adusumilli, S., Booth, C. J., Narasimhan, S., Anguita, J., & Fikrig, E. (2009). Antibodies against a tick protein, Salp15, protect mice from the Lyme disease agent. Cell Host and Microbe, 6(5), 482-492. https://doi.org/10.1016/j.chom.2009.10.006

De Roode, J. C., Yates, A. J., & Altizer, S. (2008). Virulence-transmission trade-offs and population divergence in virulence in a naturally occurring butterfly parasite. Proceedings of the National Academy of Sciences of the United States of America, 105(21), 7489-7494. https://doi.org/10.1073/pnas.0710909105

Derdáková, M., Dudiò, V., Brei, B., Brownstein, J. S., Schwartz, I., & Fish, D. (2004). Interaction and transmission of two Borrelia burgdorferi sensu stricto strains in a tick-rodent maintenance system. Applied and Environmental Microbiology, 70(11), 6783-6788. https://doi.org/10.1128/AEM.70.11.6783-6788.2004

Devevey, G., & Brisson, D. (2012). The effect of spatial heterogenity on the aggregation of ticks on white-footed mice. Parasitology, 139(7), 915-925. https://doi.org/10.1017/S003118201200008X

Devevey, G., Dang, T., Graves, C. J., Murray, S., & Brisson, D. (2015). First arrived takes all: Inhibitory priority effects dominate competition between co-infecting Borrelia burgdorferi strains. BMC Microbiology, 15, 61. https://doi.org/10.1186/s12866-015-0381-0

Dolan, M. C., Piesman, J., Schneider, B. S., Schriefer, M., Brandt, K., & Zeidner, N. S. (2004). Comparison of disseminated and nondisseminated strains of Borrelia burgdorferi sensu stricto in mice naturally infected by tick bite. Infection and Immunity, 72(9), 5262-5266. https://doi.org/10.1128/IAI.72.9.5262-5266.2004

Durand, J., Jacquet, M., Rais, O., Gern, L., & Voordouw, M. J. (2017). Fitness estimates from experimental infections predict the long-term strain structure of a vector-borne pathogen in the field. Scientific Reports, 7(1), 1851. https://doi.org/10.1038/s41598-017-01821-1

Embers, M. E., Ramamoorthy, R., & Philipp, M. T. (2004). Survival strategies of Borrelia burgdorferi, the etiologic agent of Lyme disease. Microbes and Infection, 6(3), 312-318. https://doi.org/10.1016/j.micinf.2003.11.014

Forbes, M. L., Horsey, E., Hiller, N. L., Buchinsky, F. J., Hayes, J. D., Compliment, J. M., Hillman, T., Ezzo, S., Shen, K., Keefe, R., Barbadora, K., Post, J. C., Hu, F. Z., & Ehrlich, G. D. (2008). Strain-specific virulence phenotypes of Streptococcus pneumoniae assessed using the Chinchilla laniger model of otitis media. PLoS ONE, 3(4), e1969. https://doi.org/10.1371/journal.pone.0001969

Genné, D., Rossel, M., Sarr, A., Battilotti, F., Rais, O., Rego, R. O. M., & Voordouw, M. J. (2021). Competition between strains of Borrelia afzelii in the host tissues and consequences for transmission to ticks. The ISME Journal, 15(8), 2390-2400. https://doi.org/10.1038/s41396-021-00939-5

Genné, D., Sarr, A., Gomez-Chamorro, A., Durand, J., Cayol, C., Rais, O., & Voordouw, M. J. (2018). Competition between strains of Borrelia afzelii inside the rodent host and the tick vector. Proceedings of the Royal Society B: Biological Sciences, 285(1890), 17-20. https://doi.org/10.1098/rspb.2018.1804

Genné, D., Sarr, A., Rais, O., & Voordouw, M. J. (2019). Competition between strains of Borrelia afzelii in immature Ixodes ricinus ticks is not affected by season. Frontiers in Cellular and Infection Microbiology, 9, 431. https://doi.org/10.3389/fcimb.2019.00431

Gern, L., Schaible, U. E., & Simon, M. M. (1993). Mode of inoculation of the Lyme disease agent Borrelia burgdorferi influences infection and immune responses in inbred strains of mice. Journal of Infectious Diseases, 167(4), 971-975. https://doi.org/10.1093/infdis/167.4.971

Golde, W. T., Gollobin, P., & Rodriguez, L. L. (2005). A rapid, simple, and humane method for submandibular bleeding of mice using a lancet. Lab Animal, 34(9), 39-43. https://doi.org/10.1038/laban1005-39

Gomez-Chamorro, A., Battilotti, F., Cayol, C., Mappes, T., Koskela, E., Boulanger, N., Genné, D., Sarr, A., & Voordouw, M. J. (2019). Susceptibility to infection with Borrelia afzelii and TLR2 polymorphism in a wild reservoir host. Scientific Reports, 9, 6711. https://doi.org/10.1038/s41598-019-43160-3

Gomez-Chamorro, A., Heinrich, V., Sarr, A., Roethlisberger, O., Genné, D., Bregnard, C., Jacquet, M., & Voordouw, M. J. (2019). Maternal antibodies provide bank voles with strain-specific protection against infection by the Lyme disease pathogen. Applied and Environmental Microbiology, 85(23), e01887-19. https://doi.org/10.1128/AEM.01887-19

Grillon, A., Westermann, B., Cantero, P., Jaulhac, B., Voordouw, M. J., Kapps, D., Collin, E., Barthel, C., Ehret-Sabatier, L., & Boulanger, N. (2017). Identification of Borrelia protein candidates in mouse skin for potential diagnosis of disseminated Lyme borreliosis. Scientific Reports, 7(16719), 1-13. https://doi.org/10.1038/s41598-017-16749-9

Grimm, D., Tilly, K., Bueschel, D. M., Fisher, M. A., Policastro, P. F., Gherardini, F. C., Schwan, T. G., & Rosa, P. A. (2005). Defining plasmids required by Borrelia burgdorferi for colonization of tick vector Ixodes scapularis (Acari: Ixodidae). Journal of Medical Entomology, 42(4), 676-684. https://doi.org/10.1603/0022-2585(2005)042[0676:dprbbb]2.0.co;2

Hanincová, K., Ogden, N. H., Diuk-Wasser, M., Pappas, C. J., Iyer, R., Fish, D., Schwartz, I., & Kurtenbach, K. (2008). Fitness variation of Borrelia burgdorferi sensu stricto strains in mice. Applied and Environmental Microbiology, 74(1), 153-157. https://doi.org/10.1128/AEM.01567-07

Hamer, S. A., Hickling, G. J., Sidge, J. L., Walker, E. D., & Tsao, J. I. (2012). Synchronous phenology of juvenile Ixodes scapularis, vertebrate host relationships, and associated patterns of Borrelia burgdorferi ribotypes in the midwestern United States. Ticks and Tick-borne Diseases, 3, 65-74.

Haven, J., Magori, K., & Park, A. W. (2012). Ecological and inhost factors promoting distinct parasite life-history strategies in Lyme borreliosis. Epidemics, 4(3), 152-157. https://doi.org/10.1016/j.epidem.2012.07.001

Hellgren, O., Andersson, M., & Raberg, L. (2011). The genetic structure of Borrelia afzelii varies with geographic but not ecological sampling scale. Journal of Evolutionary Biology, 24(1), 159-167.

Hill, M. A., Kwon, J. H., Gerry, B., Hardy, W. A., Walkowiak, O. A., Kavarana, M. N., Nadig, S. N., & Rajab, T. K. (2021). Immune privilege of heart valves. Frontiers in Immunology, 12, 731361. https://doi.org/10.3389/fimmu.2021.731361

Hoen, A. G., Margos, G., Bent, S. J., Diuk-Wasser, M. A., Barbour, A., Kurtenbach, K., & Fish, D. (2009). Phylogeography of Borrelia burgdorferi in the eastern United States reflects multiple independent Lyme disease emergence events. Proceedings of the National Academy of Sciences of the United States of America, 106(35), 15013-15018. https://doi.org/10.1073/pnas.0903810106

Hofmeister, E. K., Ellis, B. A., Glass, G. E., & Childs, J. E. (1999). Longitudinal study of infection with Borrelia burgdorferi in a population of Peromyscus leucopus at a Lyme disease-enzootic site in Maryland. American Journal of Tropical Medicine and Hygiene, 60(4), 589-609.

Hughes, V. L., & Randolph, S. E. (2001). Testosterone increases the transmission potential of tick-borne parasites. Parasitology, 123(4), 365-371. https://doi.org/10.1017/S0031182001008599

Hyde, J. A. (2017). Borrelia burgdorferi keeps moving and carries on: A review of borrelial dissemination and invasion. Frontiers in Immunology, 8, 114. https://doi.org/10.3389/fimmu.2017.00114

Jacquet, M., Durand, J., Rais, O., & Voordouw, M. J. (2015). Cross-reactive acquired immunity influences transmission success of the Lyme disease pathogen, Borrelia afzelii. Infection, Genetics and Evolution, 36, 131-140. https://doi.org/10.1016/j.meegid.2015.09.012

Jacquet, M., Margos, G., Fingerle, V., & Voordouw, M. J. (2016). Comparison of the lifetime host-to-tick transmission between two strains of the Lyme disease pathogen Borrelia afzelii. Parasites & Vectors, 9(1), 645. https://doi.org/10.1186/s13071-016-1929-z

Jolley, K. A., Bray, J. E., & Maiden, M. C. J. (2018). Open-access bacterial population genomics: BIGSdb software, the PubMLST.org website and their applications. Wellcome Open Research, 3, 124. https://doi.org/10.12688/wellcomeopenres.14826.1

Jutras, B. L., Chenail, A. M., & Stevenson, B. (2013). Changes in bacterial growth rate govern expression of the Borrelia burgdorferi OspC and Erp infection-associated surface proteins. Journal of Bacteriology, 195(4), 757-764. https://doi.org/10.1128/jb.01956-12

Klein, S. L. (2004). Hormonal and immunological mechanisms mediating sex differences in parasite infection. Parasite Immunology, 26(6-7), 247-264. https://doi.org/10.1111/j.0141-9838.2004.00710.x

Klein, S. L., & Flanagan, K. L. (2016). Sex differences in immune responses. Nature Reviews Immunology, 16(10), 626-638. https://doi.org/10.1038/nri.2016.90

Kurtenbach, K., Hanincová, K., Tsao, J. I., Margos, G., Fish, D., & Ogden, N. H. (2006). Fundamental processes in the evolutionary ecology of Lyme borreliosis. Nature Reviews Microbiology, 4(9), 660-669. https://doi.org/10.1038/nrmicro1475

Liang, F. T., Yan, J., Mbow, M. L., Sviat, S. L., Gilmore, R. D., Mamula, M., & Fikrig, E. (2004). Borrelia burgdorferi changes its surface antigenic expression in response to host immune responses. Infection and Immunity, 72(10), 5759-5767. https://doi.org/10.1128/iai.72.10.5759-5767.2004

Lin, Y. P., Tan, X., Caine, J. A., Castellanos, M., Chaconas, G., Coburn, J., & Leong, J. M. (2020). Strain-specific joint invasion and colonization by Lyme disease spirochetes is promoted by outer surface protein C. PLoS Pathogens, 16(5), 1-29. https://doi.org/10.1371/journal.ppat.1008516

Ma, Y., Seiler, K. P., Eichwald, E. J., Weis, J. H., Teuscher, C., & Weis, J. J. (1998). Distinct characteristics of resistance to Borrelia burgdorferi-induced arthritis in C57BL/6N mice. Infection and Immunity, 66(1), 161-168.

Margos, G., Gatewood, A. G., Aanensen, D. M., Hanincova, K., Terekhova, D., Vollmer, S. A., Cornet, M., Piesman, J., Donaghy, M., Bormane, A., Hurn, M. A., Feil, E. J., Fish, D., Casjens, S., Wormser, G. P., Schwartz, I., & Kurtenbach, K. (2008). MLST of housekeeping genes captures geographic population structure and suggests a European origin of Borrelia burgdorferi. Proceedings of the National Academy of Sciences of the United States of America, 105(25), 8730-8735. https://doi.org/10.1073/pnas.0800323105

Margos, G., Tsao, J. I., Castillo-Ramírez, S., Girard, Y. A., Hamer, S. A., Hoen, A. G., Lane, R. S., Raper, S. L., & Ogden, N. H. (2012). Two boundaries separate Borrelia burgdorferi populations in North America. Applied and Environmental Microbiology, 78(17), 6059-6067. https://doi.org/10.1128/AEM.00231-12

Margos, G., Vollmer, S. A., Ogden, N. H., & Fish, D. (2011). Population genetics, taxonomy, phylogeny and evolution of Borrelia burgdorferi sensu lato. Infection, Genetics and Evolution, 11(7), 1545-1563. https://doi.org/10.1016/j.meegid.2011.07.022

Massad, E. (1987). Transmission rates and the evolution of pathogenicity. Evolution, 41(5), 1127-1130. https://doi.org/10.2307/2409198

McCall, L. I., Siqueira-Neto, J. L., & McKerrow, J. H. (2016). Location, location, location: Five facts about tissue tropism and pathogenesis. PLoS Pathogens, 12(5), e1005519. https://doi.org/10.1371/journal.ppat.1005519

Mechai, S., Margos, G., Feil, E. J., Lindsay, L. R., & Ogden, N. H. (2015). Complex population structure of Borrelia burgdorferi in southeastern and south central Canada as revealed by phylogeographic analysis. Applied and Environmental Microbiology, 81(4), 1309-1318. https://doi.org/10.1128/aem.03730-14

Motaleb, M. A., Liu, J., & Wooten, R. M. (2015). Spirochetal motility and chemotaxis in the natural enzootic cycle and development of Lyme disease. Current Opinion in Microbiology, 28, 106-113. https://doi.org/10.1016/j.mib.2015.09.006

Ogden, N. H., Feil, E. J., Leighton, P. A., Lindsay, L. R., Margos, G., Mechai, S., Michel, P., & Moriarty, T. J. (2015). Evolutionary aspects of emerging Lyme disease in Canada. Applied and Environmental Microbiology, 81(21), 7350-7359. https://doi.org/10.1128/AEM.01671-15

Ogden, N. H., Margos, G., Aanensen, D. M., Drebot, M. A., Feil, E. J., Hanincová, K., Schwartz, I., Tyler, S., & Lindsay, L. R. (2011). Investigation of genotypes of Borrelia burgdorferi in Ixodes scapularis ticks collected during surveillance in Canada. Applied and Environmental Microbiology, 77(10), 3244-3254. https://doi.org/10.1128/aem.02636-10

Ostfeld, R. S., Brisson, D., Oggenfuss, K., Devine, J., Levy, M. Z., & Keesing, F. (2018). Effects of a zoonotic pathogen, Borrelia burgdorferi, on the behavior of a key reservoir host. Ecology and Evolution, 8, 4074-4083. https://doi.org/10.1002/ece3.3961

Perkins, S. E., Cattadori, I. M., Tagliapietra, V., Rizzoli, A. P., & Hudson, P. J. (2003). Empirical evidence for key hosts in persistence of a tick-borne disease. International Journal for Parasitology, 33(9), 909-917. https://doi.org/10.1016/s0020-7519(03)00128-0

Piesman, J., & Gern, L. (2004). Lyme borreliosis in Europe and North America. Parasitology, 129(S1), S191-S220. https://doi.org/10.1017/s0031182003004694

Qiu, W. G., Schutzer, S. E., Bruno, J. F., Attie, O., Yun, X., Dunn, J. J., Fraser, C. M., Casjens, S. R., & Luft, B. J. (2004). Genetic exchange and plasmid transfers in Borrelia burgdorferi sensu stricto revealed by three-way genome comparisons and multilocus sequence typing. Proceedings of the National Academy of Sciences of the United States of America, 101(39), 14150-14155. https://doi.org/10.1073/pnas.0402745101

R Core Team. (2021). R: A language and environment for statistical computing. R Foundation for Statistical Computing. https://www.R-project.org/

Råberg, L. (2012). Infection intensity and infectivity of the tick-borne pathogen Borrelia afzelii. Journal of Evolutionary Biology, 25(7), 1448-1453. https://doi.org/10.1111/j.1420-9101.2012.02515.x

Råberg, L., Hagström, A., Andersson, M., Bartkova, S., Scherman, K., Strandh, M., & Tschirren, B. (2017). Evolution of antigenic diversity in the tick-transmitted bacterium Borrelia afzelii: A role for host specialization? Journal of Evolutionary Biology, 30(5), 1034-1041. https://doi.org/10.1111/jeb.13075

Roehrig, J. T., Piesman, J., Hunt, A. R., Keen, M. G., Happ, C. M., & Johnson, B. J. B. (1992). The hamster immune response to tick-transmitted Borrelia burgdorferi differs from the response to needle-inoculated, cultured organisms. Journal of Immunology, 149(11), 3648-3653.

Rynkiewicz, E. C., Brown, J., Tufts, D. M., Huang, C.-I., Kampen, H., Bent, S. J., Fish, D., & Diuk-Wasser, M. A. (2017). Closely-related Borrelia burgdorferi (sensu stricto) strains exhibit similar fitness in single infections and asymmetric competition in multiple infections. Parasites & Vectors, 10(1), 64. https://doi.org/10.1186/s13071-016-1964-9

Sasaki, M., Fujii, Y., Iwamoto, M., & Ikadai, H. (2013). Effect of sex steroids on Babesia microti infection in mice. The American Journal of Tropical Medicine and Hygiene, 88(2), 367-375. https://doi.org/10.4269/ajtmh.2012.12-0338

Schmid-Hempel, P. (2021). Evolutionary parasitology: The integrated study of infections, immunology, ecology, and genetics (2nd ed.). Oxford University Press. https://doi.org/10.1093/oso/9780198832140.001.0001

Sertour, N., Cotté, V., Garnier, M., Malandrin, L., Ferquel, E., & Choumet, V. (2018). Infection kinetics and tropism of Borrelia burgdorferi sensu lato in mouse after natural (via ticks) or artificial (needle) infection depends on the bacterial strain. Frontiers in Microbiology, 9, 1722. https://doi.org/10.3389/fmicb.2018.01722

Shih, C.-M., Pollack, R. J., Telford, S. R., & Spielman, A. (1992). Delayed dissemination of Lyme disease spirochetes from the site of deposition in the skin of mice. Journal of Infectious Diseases, 166(4), 827-831. https://doi.org/10.1093/infdis/166.4.827

Stanek, G., & Reiter, M. (2011). The expanding Lyme Borrelia complex-clinical significance of genomic species? Clinical Microbiology and Infection, 17(4), 487-493. https://doi.org/10.1111/j.1469-0691.2011.03492.x

Stanek, G., Wormser, G. P., Gray, J., & Strle, F. (2012). Lyme borreliosis. Lancet, 379(9814), 461-473. https://doi.org/10.1016/s0140-6736(11)60103-7

Steere, A. C., Strle, F., Wormser, G. P., Hu, L. T., Branda, J. A., Hovius, J. W. R., Li, X., & Mead, P. S. (2016). Lyme borreliosis. Nature Reviews Disease Primers, 2(1), 1-19. https://doi.org/10.1038/nrdp.2016.90

Stewart, P. E., Byram, R., Grimm, D., Tilly, K., & Rosa, P. A. (2005). The plasmids of Borrelia burgdorferi: Essential genetic elements of a pathogen. Plasmid, 53(1), 1-13. https://doi.org/10.1016/j.plasmid.2004.10.006

Tonetti, N., Voordouw, M. J., Durand, J., Monnier, S., & Gern, L. (2015). Genetic variation in transmission success of the Lyme borreliosis pathogen Borrelia afzelii. Ticks and Tick-Borne Diseases, 6(3), 334-343. https://doi.org/10.1016/j.ttbdis.2015.02.007

Travinsky, B., Bunikis, J., & Barbour, A. G. (2010). Geographic differences in genetic locus linkages for Borrelia burgdorferi. Emerging Infectious Diseases, 16(7), 1147-1150. https://doi.org/10.3201/eid1607.091452

Trigunaite, A., Dimo, J., & Jørgensen, T. N. (2015). Suppressive effects of androgens on the immune system. Cellular Immunology, 294(2), 87-94. https://doi.org/10.1016/j.cellimm.2015.02.004

Tsao, J. (2009). Reviewing molecular adaptations of Lyme borreliosis spirochetes in the context of reproductive fitness in natural transmission cycles. Veterinary Research (Paris), 40(2), 36. https://doi.org/10.1051/vetres/2009019

Tschirren, B., Andersson, M., Scherman, K., Westerdahl, H., Mittl, P. R. E., & Råberg, L. (2013). Polymorphisms at the innate immune receptor TLR2 are associated with Borrelia infection in a wild rodent population. Proceedings of the Royal Society B: Biological Sciences, 280(1759), 20130364. https://doi.org/10.1098/rspb.2013.0364

Tyler, S., Tyson, S., Dibernardo, A., Drebot, M., Feil, E. J., Graham, M., Knox, N. C., Lindsay, L. R., Margos, G., Mechai, S., Van Domselaar, G., Thorpe, H. A., & Ogden, N. H. (2018). Whole genome sequencing and phylogenetic analysis of strains of the agent of Lyme disease Borrelia burgdorferi from Canadian emergence zones. Scientific Reports, 8(1), 1-12. https://doi.org/10.1038/s41598-018-28908-7

Voordouw, M. J., Lachish, S., & Dolan, M. C. (2015). The Lyme disease pathogen has no effect on the survival of its rodent reservoir host. PLoS ONE, 10(2), e0118265. https://doi.org/10.1371/journal.pone.0118265

Wang, G., Ojaimi, C., Wu, H., Saksenberg, V., Iyer, R., Liveris, D., McClain, S. A., Wormser, G. P., & Schwartz, I. (2002). Disease severity in a murine model of Lyme borreliosis is associated with the genotype of the infecting Borrelia burgdorferi sensu stricto strain. The Journal of Infectious Diseases, 186(6), 782-791. https://doi.org/10.1086/343043

Wang, G., Ojaimi, C., Wu, H., Saksenberg, V., Iyer, R., McClain, S. A., Wormser, G. P., & Schwartz, I. (2001). Impact of genotypic variation of Borrelia burgdorferi sensu stricto on kinetics of dissemination and severity of disease in C3H/HeJ mice. Abstracts of the General Meeting of the American Society for Microbiology, 101(7), 294-295. https://doi.org/10.1128/IAI.69.7.4303

Wang, I. N., Dykhuizen, D. E., Qiu, W., Dunn, J. J., Bosler, E. M., & Luft, B. J. (1999). Genetic diversity of ospC in a local population of Borrelia burgdorferi sensu stricto. Genetics, 151(1), 15-30. https://doi.org/10.1093/genetics/151.1.15

Wooten, R. M., & Weis, J. J. (2001). Host-pathogen interactions promoting inflammatory Lyme arthritis: Use of mouse models for dissection of disease processes. Current Opinion in Microbiology, 4(3), 274-279. https://doi.org/10.1016/S1369-5274(00)00202-2

Yang, L., Weis, J. H., Eichwald, E., Kolbert, C. P., Persing, D. H., & Weis, J. J. (1994). Heritable susceptibility to severe Borrelia burgdorferi-induced arthritis is dominant and is associated with persistence of large numbers of spirochetes in tissues. Infection and Immunity, 62(2), 492-500. https://doi.org/10.1128/iai.62.2.492-500.1994

Zawada, S. G., von Fricken, M. E., Weppelmann, T. A., Sikaroodi, M., & Gillevet, P. M. (2020). Optimization of tissue sampling for Borrelia burgdorferi in white-footed mice (Peromyscus leucopus). PLoS ONE, 15(1), e0226798. https://doi.org/10.1371/journal.pone.0226798

Zhong, X., Nouri, M., & Råberg, L. (2019). Colonization and pathology of Borrelia afzelii in its natural hosts. Ticks and Tick-Borne Diseases, 10(4), 822-827. https://doi.org/10.1016/j.ttbdis.2019.03.017

Variation among strains of Borrelia burgdorferi in host tissue abundance and lifetime transmission determine the population strain structure in nature