Comparative analysis of the midgut microbiota of two natural tick vectors of Rickettsia rickettsii

Although the ticks Amblyomma sculptum and Amblyomma aureolatum are important vectors of Rickettsia rickettsii, causative agent of the life-threatening Rocky Mountain spotted fever, A. aureolatum is considerably more susceptible to infection than A. sculptum. As the microbiota can interfere with the colonization of arthropod midgut (MG) by pathogens, in the current study we analyzed the MG microbiota of both tick species. Our results revealed that the MG of A. aureolatum harbors a prominent microbiota, while A. sculptum does not. Remarkably, a significant reduction of the bacterial load was recorded in R. rickettsii-infected A. aureolatum. In addition, the taxonomy analysis of the MG bacterial community of A. aureolatum revealed a dominance of the genus Francisella, suggesting an endosymbiosis. This study is the first step in getting insights into the mechanisms underlying the interactions among Amblyomma species, their microbiota and R. rickettsii. Additional studies to better understand these mechanisms are required and may help the development of novel alternatives to block rickettsial transmission.

Instituto de Biotecnología

Fil: Pavanelo, Daniel Brisotto. University of São Paulo. Institute of Biomedical Sciences. Department of Parasitology; Brasil

Fil: Schröder, Nicolas C.H. University of São Paulo. Institute of Biomedical Sciences. Department of Parasitology; Brasil

Fil: Pin Viso, Natalia Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina

Fil: Martins, Larissa A. University of São Paulo. Institute of Biomedical Sciences. Department of Parasitology; Brasil

Fil: Malossi, Camila Dantas. University of São Paulo. Institute of Biomedical Sciences. Department of Parasitology; Brasil

Fil: Galletti, Maria Fernanda B.M. University of São Paulo. Institute of Biomedical Sciences. Department of Parasitology; Brasil

Fil: Labruna, Marcelo B. University of São Paulo. Faculty of Veterinary Medicine and Husbandry. Department of Preventive Veterinary Medicine and Animal Health; Brasil

Fil: Daffre, Sirlei. University of São Paulo. Institute of Biomedical Sciences. Department of Parasitology; Brasil

Fil: Farber, Marisa Diana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina

Fil: Fogaça, Andréa C. University of São Paulo. Institute of Biomedical Sciences. Department of Parasitology; Brasil