Microbiome of two adult tick species and their laboratory-reared offspring shows intra- and inter-species differences

Tick-borne pathogens are a significant threat to human and animal health. Exposing the microbial composition of ticks elucidates their potential role in transmitting pathogens and causing disease as well as uncovering their potential interaction with the hosting tick. Our study focused on characterizing the tick microbiome of adult females and their lab-reared larval offspring of two prevalent tick species found on dogs in Nigeria [Rhipicephalus sanguineus s.l. tropical lineage (R. linnaei) and Haemaphysalis leachi]. We investigated the relative phyla abundance, the alpha and beta diversities of microbial communities comparing tick species, and different development stages (adults versus larvae). To the best of our knowledge, this is the first analysis on H. leachi microbiome described from West Africa. Our findings revealed a diverse microbiome with significant differences across species and their developmental stages, highlighting the dominance of the Proteobacteria phylum, followed by Firmicutes and Actinobacteriota. In contrast to H. leachi, for R. linnaei we observed significant differences in the alpha and beta diversities of the microbiome of larvae and adult females. Predominant bacterial genera were identified in R. linnaei, particularly Arsenophonus and Coxiella, which showed increased abundance in adult ticks. In H. leachi, other predominant genera were detected, including Sphingomonas, Comamonas, and Williamsia. Our results contribute to the understanding of microbiome dynamics within ticks and offers insights of tick physiology for addressing public health concerns and developing effective strategies for pathogen control.