Tick-borne diseases, such as boreliosis (Lyme disease) or anaplasmosis, are on the rise globally. While it is well known that ticks transmit harmful pathogen to humans and animals, less is understood about the microbiome changes that occur during tick bites not just in the tick, but also in the host’s skin. This interaction between the tick’s microbiome and the host’s skin bacteria may play a crucial role in the transmission of diseases.
Major Discoveries from tick and skin microbiome interaction Study:
A new study conducted by researchers from Vaiomer, University of Strasbourg and CNRS explores the dramatic microbial shifts that occur during the tick-feeding process:
• The skin bacteria in mice deeply impacted by the tick bitemostly replaced by bacteria coming from the tick.
• Pathogens such as Borrelia, Anaplasma, Rickettsia, and Neoehrlichia are transmitted from tick to host and can spread beyond the skin to internal organs.
• The tick’s own microbiome also changes when it feeds on the host’s blood.
• These changes depend on whether the biting tick is a nymph or an adult female.
These results reveal that the skin microbiome is not just a passive bystander during a tick bite. Instead, it actively participates in—and is affected by—the tick’s feeding and pathogen transmission processes. This research area opens up new insights into understanding tick feeding mechanism (in particular how tick escape of the host immune system), tick-borne disease dynamics and potential microbiome-based intervention strategies.
This research highlights the importance of studying both the vector (tick) and the host microbiota.
By understanding this microbial dialogue, we can better comprehend how pathogens enter hosts and potentially develop strategies to prevent them.
Read the Full Study: Cross-alteration of murine skin and tick microbiome concomitant with pathogen transmission after Ixodes ricinus bite
CITATIONS
Cross-alteration of murine skin and tick microbiome concomitant with pathogen transmission after Ixodes ricinus bite
Nathalie Boulanger, Jean-Louis-Marie Insonere, Sebastian Van Blerk, Cathy Barthel, Céline Serres, Olivier Rais, Alain Roulet, Florence Servant, Olivier Duron, Benjamin Lelouvier. Microbiome.Nov 11;11(1):250. doi: 10.1186/s40168-023-01696-7. PMID: 37952001 PMCID: PMC10638774
Abstract :
Background: Ticks are major vectors of diseases affecting humans such as Lyme disease or domestic animals such as anaplasmosis. Cross-alteration of the vertebrate host skin microbiome and the tick microbiome may be essential during the process of tick feeding and for the mechanism of pathogen transmission. However, it has been poorly investigated.
Methods: We used mice bitten by field-collected ticks (nymphs and adult ticks) in different experimental conditions to investigate, by 16S rRNA gene metabarcoding, the impact of blood feeding on both the mouse skin microbiome and the tick microbiome. We also investigated by PCR and 16S rRNA gene metabarcoding, the diversity of microorganisms transmitted to the host during the process of tick bite at the skin interface and the dissemination of the pathogen in host tissues (blood, heart, and spleen).
Results: Most of the commensal bacteria present in the skin of control mice were replaced during the blood-feeding process by bacteria originating from the ticks. The microbiome of the ticks was also impacted by the blood feeding. Several pathogens including tick-borne pathogens (Borrelia/Borreliella, Anaplasma, Neoehrlichia, Rickettsia) and opportunistic bacteria (Williamsia) were transmitted to the skin microbiome and some of them disseminated to the blood or spleen of the mice. In the different experiments of this study, skin microbiome alteration and Borrelia/Borreliella transmission were different depending on the tick stages (nymphs or adult female ticks).
Conclusions: Host skin microbiome at the bite site was deeply impacted by the tick bite, to an extent which suggests a role in the tick feeding, in the pathogen transmission, and a potentially important impact on the skin physiopathology. The diversified taxonomic profiles of the tick microbiome were also modified by the blood feeding. Video Abstract.
Keywords: 16S targeted sequencing; Anaplasma; Borrelia; Borreliella; Lyme disease; Metagenome; Metagenomic; Microbiota.
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