Culture-independent metagenomic methodologies have enabled detection and identification of microorganisms in various biological systems and often revealed complex and unknown microbiomes. In many organisms, the microbiome outnumbers the host cells and greatly affects the host biology and fitness. Ticks are hematophagous ectoparasites with a wide host range. They vector a number of human and animal pathogens and also directly cause major economic losses in livestock. Although several reports on a tick midgut microbiota show a diverse bacterial community, in most cases the size of the bacterial population has not been determined. In this study, the microbiome was quantified in the midgut and ovaries of the ticks Ixodes ricinus and Rhipicephalus microplus before, during, and after blood feeding. Although the size of bacterial community in the midgut fluctuated with blood feeding, it was overall extremely low in comparison to that of other hematophagous arthropods. In addition, the tick ovarian microbiome of both tick species exceeded the midgut 16S rDNA copy numbers by several orders of magnitude. This indicates that the ratio of a tick midgut/ovary microbiome represents an exception to the general biology of other metazoans. In addition to the very low abundance, the tick midgut diversity in I. ricinus was variable and that is in contrast to that found in the tick ovary. The ovary of I. ricinus had a very low bacterial diversity and a very high and stable bacterial abundance with the dominant endosymbiont, Midichloria sp. The elucidation of this aspect of tick biology highlights a unique tissue-specific microbial-invertebrate host interaction.

Biology Centre Institute of Parasitology Czech Academy of Sciences Ceske Budejovice Czechia

Central European Institute of Technology Center for Zoonoses University of Veterinary and Pharmaceutical Sciences Brno Czechia

Department of Chemistry and Biochemistry Mendel University Brno Czechia

Department of Entomology Kansas State University Manhattan KS United States

Faculdade de Veterinária Universidade Federal do Rio Grande do Sul Porto Alegre Brazil

Faculty of Science University of South Bohemia Ceske Budejovice Czechia

Laboratório de Bioquímica de Artrópodes Hematófagos Instituto de Bioquímica Médica Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil

Laboratório de Imunologia Aplicada a Sanidade Animal Centro de Biotecnologia Universidade Federal do Rio Grande do Sul Porto Alegre Brazil

Zobrazit více v PubMed

Altschul S. F., Madden T. L., Schäffer A. A., Zhang J., Zhang Z., Miller W., et al. . (1997). Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Res. 25, 3389–402. 10.1093/nar/25.17.3389 PubMed DOI PMC

Andreotti R., Pérez de León A. A., Dowd S. E., Guerrero F. D., Bendele K. G., Scoles G. A. (2011). Assessment of bacterial diversity in the cattle tick Rhipicephalus (Boophilus) microplus through tag-encoded pyrosequencing. BMC Microbiol. 11:6. 10.1186/1471-2180-11-6 PubMed DOI PMC

Benach J. L., Coleman J. L., Skinner R. A., Rosler E. M. (1987). Adult ixodes dammini on rabbits: a hypothesis for the development and transmission of borrelia burgdorferi. J. Infect. Dis. 155, 1300–6. 10.1093/infdis/155.6.1300 PubMed DOI

Binetruy F., Dupraz M., Buysse M., Duron O. (2019). Surface sterilization methods impact measures of internal microbial diversity in ticks. Parasit. Vectors 12:268. 10.1186/s13071-019-3517-5 PubMed DOI PMC

Bonnet S. I., Binetruy F., Hernández-Jarguín A. M., Duron O. (2017). The tick microbiome: why non-pathogenic microorganisms matter in tick biology and pathogen transmission. Front. Cell. Infect. Microbiol. 7:236. 10.3389/fcimb.2017.00236 PubMed DOI PMC

Budachetri K., Browning R. E., Adamson S. W., Dowd S. E., Chao C. C., Ching W. M., et al. . (2014). An insight into the microbiome of the Amblyomma maculatum (Acari: Ixodidae). J. Med. Entomol. 51, 119–29. 10.1603/me12223 PubMed DOI PMC

Carpi G., Cagnacci F., Wittekindt N. E., Zhao F., Qi J., Tomsho L. P., et al. . (2011). Metagenomic profile of the bacterial communities associated with Ixodes ricinus ticks. PLoS ONE 6:e25604. 10.1371/journal.pone.0025604 PubMed DOI PMC

Clayton K. A., Gall C. A., Mason K. L., Scoles G. A., Brayton K. A. (2015). The characterization and manipulation of the bacterial microbiome of the Rocky mountain wood tick, Dermacentor andersoni. Parasit. Vectors 8:632. 10.1186/s13071-015-1245-z PubMed DOI PMC

Comeau A. M., Douglas G. M., Langille M. G. I. (2017). Microbiome helper: a custom and streamlined workflow for microbiome research. mSystems 2:e00127-16. 10.1128/msystems.00127-16 PubMed DOI PMC

Comeau A. M., Li W. K. W., Tremblay J. É., Carmack E. C., Lovejoy C. (2011). Arctic ocean microbial community structure before and after the 2007 record sea ice minimum. PLoS ONE 6:e27492. 10.1371/journal.pone.0027492 PubMed DOI PMC

Dennison N. J., Jupatanakul N., Dimopoulos G. (2014). The mosquito microbiota influences vector competence for human pathogens. Curr. Opin. Insect Sci. 3, 6–13. 10.1016/j.cois.2014.07.004 PubMed DOI PMC

Dimitriu P. A., Iker B., Malik K., Leung H., Mohn W. W., Hillebrand G. G. (2019). New insights into the intrinsic and extrinsic factors that shape the human skin microbiome. MBio 10:e00839-19. 10.1128/mBio.00839-19 PubMed DOI PMC

Duron O., Binetruy F., Noël V., Cremaschi J., McCoy K. D., Arnathau C., et al. . (2017). Evolutionary changes in symbiont community structure in ticks. Mol. Ecol. 26, 2905–2921. 10.1111/mec.14094 PubMed DOI

Duron O., Morel O., Noël V., Buysse M., Binetruy F., Lancelot R., et al. . (2018). Tick-bacteria mutualism depends on B vitamin synthesis pathways. Curr. Biol. 28, 1896–1902.e5. 10.1016/j.cub.2018.04.038 PubMed DOI

Eichler S., Schaub G. A. (2002). Development of symbionts in triatomine bugs and the effects of infections with trypanosomatids. Exp. Parasitol. 100, 17–27. 10.1006/expr.2001.4653 PubMed DOI

Elliott D. R., Wilson M., Buckley C. M. F., Spratt D. A. (2005). Cultivable oral microbiota of domestic dogs. J. Clin. Microbiol. 43, 5470–6. 10.1128/JCM.43.11.5470-5476.2005 PubMed DOI PMC

Engel P., Moran N. A. (2013). The gut microbiota of insects - diversity in structure and function. FEMS Microbiol. Rev. 37, 699–735. 10.1111/1574-6976.12025 PubMed DOI

Estrada-Peña A. (2015). Ticks as vectors: taxonomy, biology and ecology. Rev. Sci. Tech. 34, 53–65. 10.20506/rst.34.1.2345 PubMed DOI

Fogaça A. C., Da Silva P. I., Miranda M. T. M., Bianchi A. G., Miranda A., Ribolla P. E. M., et al. . (1999). Antimicrobial activity of a bovine hemoglobin fragment in the tick Boophilus microplus. J. Biol. Chem. 274, 25330–4. 10.1074/jbc.274.36.25330 PubMed DOI

Goodrich J. K., Di Rienzi S. C., Poole A. C., Koren O., Walters W. A., Caporaso J. G., et al. . (2014). Conducting a microbiome study. Cell 158, 250–262. 10.1016/j.cell.2014.06.037 PubMed DOI PMC

Greay T. L., Gofton A. W., Paparini A., Ryan U. M., Oskam C. L., Irwin P. J. (2018). Recent insights into the tick microbiome gained through next-generation sequencing. Parasit. Vectors 11:12. 10.1186/s13071-017-2550-5 PubMed DOI PMC

Guizzo M. G., Parizi L. F., Nunes R. D., Schama R., Albano R. M., Tirloni L., et al. . (2017). A Coxiella mutualist symbiont is essential to the development of Rhipicephalus microplus. Sci. Rep. 7:17554. 10.1038/s41598-017-17309-x PubMed DOI PMC

Hammer T. J., Sanders J. G., Fierer N. (2019). Not all animals need a microbiome. FEMS Microbiol. Lett. 366:fnz117. 10.1093/femsle/fnz117 PubMed DOI

Heintz-Buschart A., Wilmes P. (2018). Human gut microbiome: function matters. Trends Microbiol. 26, 563–574. 10.1016/j.tim.2017.11.002 PubMed DOI

Henning K., Greiner-Fischer S., Hotzel H., Ebsen M., Theegarten D. (2006). Isolation of spiroplasma sp. from an ixodes tick. Int. J. Med. Microbiol. 40, 157–61. 10.1016/j.ijmm.2006.01.012 PubMed DOI

Hornok S., Szoke K., Meli M. L., Sándor A. D., Görföl T., Estók P., et al. (2019). Molecular detection of vector-borne bacteria in bat ticks (acari: ixodidae, argasidae) from eight countries of the old and new worlds 06 biological sciences 0604 genetics. Parasit. Vectors. 12:50 10.1186/s13071-019-3303-4 PubMed DOI PMC

Huttenhower C., Knight R., Brown C. T., Caporaso J. G., Clemente J. C., Gevers D., et al. . (2014). Advancing the microbiome research community. Cell 159, 227–30. 10.1016/j.cell.2014.09.022 PubMed DOI PMC

Kopáček P., Hajdušek O., Burešová V., Daffre S. (2010). Tick innate immunity. Adv. Exp. Med. Biol. 708, 137–162. 10.1007/978-1-4419-8059-5-8 PubMed DOI

Lane R. S., Piesman J., Burgdorfer W. (1991). Lyme borreliosis: relation of its causative agent to its vectors and hosts in North America and Europe. Annu. Rev. Entomol. 36, 587–609. 10.1146/annurev.ento.36.1.587 PubMed DOI

Lara F. A. (2005). Tracing heme in a living cell: hemoglobin degradation and heme traffic in digest cells of the cattle tick Boophilus microplus. J. Exp. Biol. 208, 3093–3101. 10.1242/jeb.01749 PubMed DOI

Moreno C. X., Moy F., Daniels T. J., Godfrey H. P., Cabello F. C. (2006). Molecular analysis of microbial communities identified in different developmental stages of Ixodes scapularis ticks from westchester and dutchess counties, New York. Environ. Microbiol. 8, 761–72. 10.1111/j.1462-2920.2005.00955.x PubMed DOI

Nadkarni M. A., Martin F. E., Jacques N. A., Hunter N. (2002). Determination of bacterial load by real-time PCR using a broad-range (universal) probe and primers set. Microbiology 148(Pt 1), 257–266. 10.1099/00221287-148-1-257 PubMed DOI

Nakajima Y., Ogihara K., Taylor D., Yamakawa M. (2009). Antibacterial hemoglobin fragments from the midgut of the soft tick, Ornithodoros moubata (Acari: Argasidae). J. Med. Entomol. 40, 78–81. 10.1603/0022-2585-40.1.78 PubMed DOI

Narasimhan S., Fikrig E. (2015). Tick microbiome: the force within. Trends Parasitol. 31, 315–323. 10.1016/j.pt.2015.03.010 PubMed DOI PMC

Narasimhan S., Rajeevan N., Liu L., Zhao Y. O., Heisig J., Pan J., et al. . (2014). Gut microbiota of the tick vector Ixodes scapularis modulate colonization of the Lyme disease spirochete. Cell Host Microbe 15, 58–71. 10.1016/j.chom.2013.12.001 PubMed DOI PMC

Needleman S. B., Wunsch C. D. (1970). A general method applicable to the search for similarities in the amino acid sequence of two proteins. J. Mol. Biol. 48, 443–53. 10.1016/0022-2836(70)90057-4 PubMed DOI

Nijhof A. M., Balk J. A., Postigo M., Jongejan F. (2009). Selection of reference genes for quantitative RT-PCR studies in Rhipicephalus (Boophilus) microplus and Rhipicephalus appendiculatus ticks and determination of the expression profile of Bm86. BMC Mol. Biol. 10:112. 10.1186/1471-2199-10-112 PubMed DOI PMC

Oksanen J., Blanchet F. G., Friendly M., Kindt R., Legendre P., McGlinn D., et al. (2019). vegan: Community Ecology Package. R package version 2.5-2. Cran R.

Oliveira J. H. M., Gonçalves R. L. S., Lara F. A., Dias F. A., Gandara A. C. P., Menna-Barreto R. F. S., et al. . (2011). Blood meal-derived heme decreases ROS levels in the midgut of Aedes aegypti and allows proliferation of intestinal microbiota. PLoS Pathog. 7:e1001320. 10.1371/journal.ppat.1001320 PubMed DOI PMC

Olivieri E., Epis S., Castelli M., Varotto Boccazzi I., Romeo C., Desirò A., et al. . (2019). Tissue tropism and metabolic pathways of Midichloria mitochondrii suggest tissue-specific functions in the symbiosis with Ixodes ricinus. Ticks Tick. Borne. Dis. 10, 1070–1077. 10.1016/j.ttbdis.2019.05.019 PubMed DOI

Perner J., Provazník J., Schrenková J., Urbanová V., Ribeiro J. M. C., Kopáček P. (2016). RNA-seq analyses of the midgut from blood- and serum-fed Ixodes ricinus ticks. Sci. Rep. 6:36695. 10.1038/srep36695 PubMed DOI PMC

Quast C., Pruesse E., Yilmaz P., Gerken J., Schweer T., Yarza P., et al. . (2013). The SILVA ribosomal RNA gene database project: Improved data processing and web-based tools. Nucleic Acids Res. 41, D590–D596. 10.1093/nar/gks1219 PubMed DOI PMC

R Core Team (2018). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna. Available online at: https://www.R-project.org/

Reck J., Berger M., Terra R. M. S., Marks F. S., da Silva Vaz I., Guimarães J. A., et al. . (2009). Systemic alterations of bovine hemostasis due to Rhipicephalus (Boophilus) microplus infestation. Res. Vet. Sci. 86, 56–62. 10.1016/j.rvsc.2008.05.007 PubMed DOI

Regassa L. B., Gasparich G. E. (2006). Spiroplasmas: evolutionary relationships and biodiversity. Front. Biosci. 11, 2983–3002. 10.2741/2027 PubMed DOI

Rognes T., Flouri T., Nichols B., Quince C., Mahé F. (2016). VSEARCH: a versatile open source tool for metagenomics. PeerJ. 4:e2584. 10.7717/peerj.2584 PubMed DOI PMC

Ross B. D., Hayes B., Radey M. C., Lee X., Josek T., Bjork J., et al. (2018). Ixodes scapularis does not harbor a stable midgut microbiome. ISME J. 12, 2596–2607. 10.1038/s41396-018-0161-6 PubMed DOI PMC

Sassera D., Lo N., Bouman E. A. P., Epis S., Mortarino M., Bandi C. (2008). “Candidatus midichloria” endosymbionts bloom after the blood meal of the host, the hard tick Ixodes ricinus. Appl. Environ. Microbiol. 74, 6138–40. 10.1128/AEM.00248-08 PubMed DOI PMC

Sassera D., Lo N., Epis S., D'Auria G., Montagna M., Comandatore F., et al. . (2011). Phylogenomic evidence for the presence of a flagellum and cbb 3 oxidase in the free-living mitochondrial ancestor. Mol. Biol. Evol. 28, 3285–96. 10.1093/molbev/msr159 PubMed DOI

Schloss P. D., Westcott S. L., Ryabin T., Hall J. R., Hartmann M., Hollister E. B., et al. . (2009). Introducing mothur: open-source, platform-independent, community-supported software for describing and comparing microbial communities. Appl. Environ. Microbiol. 75, 7537–7541. 10.1128/AEM.01541-09 PubMed DOI PMC

Sojka D., Franta Z., Horn M., Caffrey C. R., Mareš M., Kopáček P. (2013). New insights into the machinery of blood digestion by ticks. Trends Parasitol. 29, 276–285. 10.1016/j.pt.2013.04.002 PubMed DOI

Sonenshine D. E., Ceraul S. M., Hynes W. E., Macaluso K. R., Azad A. F. (2002). Expression of defensin-like peptides in tick hemolymph and midgut in response to challenge with Borrelia burgdorferi, Escherichia coli and Bacillus subtilis. Exp. Appl. Acarol. 28, 127–34. 10.1023/A:1025354326877 PubMed DOI

Sonenshine D. E., Macaluso K. R. (2017). Microbial invasion vs. tick immune regulation. Front. Cell. Infect. Microbiol. 7:390. 10.3389/fcimb.2017.00390 PubMed DOI PMC

Strnad M., Hönig V., RuŽek D., Grubhoffer L., Rego R. O. M. (2017). Europe-wide meta-analysis of Borrelia burgdorferi sensu lato prevalence in questing Ixodes ricinus ticks. Appl. Environ. Microbiol. 83:e00609-17. 10.1128/AEM.00609-17 PubMed DOI PMC

Strong M. J., Xu G., Morici L., Splinter Bon-Durant S., Baddoo M., Lin Z., et al. . (2014). Microbial contamination in next generation sequencing: implications for sequence-based analysis of clinical samples. PLoS Pathog. 10:e1004437. 10.1371/journal.ppat.1004437 PubMed DOI PMC

Vayssier-Taussat M., Kazimirova M., Hubalek Z., Hornok S., Farkas R., Cosson J. F., et al. . (2015). Emerging horizons for tick-borne pathogens: From the “one pathogen-one disease” vision to the pathobiome paradigm. Future Microbiol. 10, 2033–43. 10.2217/fmb.15.114 PubMed DOI PMC

Weiss B., Aksoy S. (2011). Microbiome influences on insect host vector competence. Trends Parasitol. 27, 514–22. 10.1016/j.pt.2011.05.001 PubMed DOI PMC

Yilmaz P., Parfrey L. W., Yarza P., Gerken J., Pruesse E., Quast C., et al. . (2014). The SILVA and “all-species living tree project (LTP)” taxonomic frameworks. Nucleic Acids Res. 42, D643–D648. 10.1093/nar/gkt1209 PubMed DOI PMC

Zhang C. M., Li N. X., Zhang T. T., Qiu Z. X., Li Y., Li L. W., et al. . (2017). Endosymbiont CLS-HI plays a role in reproduction and development of Haemaphysalis longicornis. Exp. Appl. Acarol. 73, 429–438. 10.1007/s10493-017-0194-y PubMed DOI

Zhong J., Jasinskas A., Barbour A. G. (2007). Antibiotic treatment of the tick vector Amblyomma americanum reduced reproductive fitness. PLoS ONE 2:e405. 10.1371/journal.pone.0000405 PubMed DOI PMC

The immune factors involved in the rapid clearance of bacteria from the midgut of the tick Ixodes ricinus

Significant role of symbiotic bacteria in the blood digestion and reproduction of Dermanyssus gallinae mites

Insight Into the Dynamics of the Ixodes ricinus Nymphal Midgut Proteome

Variation of bacterial community assembly over developmental stages and midgut of Dermanyssus gallinae

Characterization and manipulation of the bacterial community in the midgut of Ixodes ricinus

Ixodes ricinus ticks have a functional association with Midichloria mitochondrii

Spiroplasma Isolated From Third-Generation Laboratory Colony Ixodes persulcatus Ticks

Tick Immune System: What Is Known, the Interconnections, the Gaps, and the Challenges

Identification of Tick Ixodes ricinus Midgut Genes Differentially Expressed During the Transmission of Borrelia afzelii Spirochetes Using a Transcriptomic Approach