title: Massive infection of seabird ticks with bacterial species related to Coxiella burnetii.
abstract: Seabird ticks are known reservoirs of bacterial pathogens of medical importance; however, ticks parasitizing tropical seabirds have received less attention than their counterparts from temperate and subpolar regions. Recently, Rickettsia africae was described to infect seabird ticks of the western Indian Ocean and New Caledonia, constituting the only available data on bacterial pathogens associated with tropical seabird tick species. Here, we combined a pyrosequencing-based approach with a classical molecular analysis targeting bacteria of potential medical importance in order to describe the bacterial community in two tropical seabird ticks, Amblyomma loculosum and Carios (Ornithodoros) capensis. We also investigated the patterns of prevalence and host specificity within the biogeographical context of the western Indian Ocean islands. The bacterial community of the two tick species was characterized by a strong dominance of Coxiella and Rickettsia. Our data support a strict Coxiella-host tick specificity, a pattern resembling the one found for Rickettsia spp. in the same two seabird tick species. Both the high prevalence and stringent host tick specificity suggest that these bacteria may be tick symbionts with probable vertical transmission. Detailed studies of the pathogenicity of these bacteria will now be required to determine whether horizontal transmission can occur and to clarify their status as potential human pathogens. More generally, our results show that the combination of next generation sequencing with targeted detection/genotyping approaches proves to be efficient in poorly investigated fields where research can be considered to be starting from scratch.
authors.affiliation: Centre de Recherche et de Veille sur les Maladies Émergentes dans l'Océan Indien (CRVOI), GIP CYROI, Ste Clotilde, La Réunion, France.
authors.forename: David A
authors.initials: DA
authors.lastname: Wilkinson
authors.forename: Muriel
authors.initials: M
authors.lastname: Dietrich
authors.forename: Camille
authors.initials: C
authors.lastname: Lebarbenchon
authors.forename: Audrey
authors.initials: A
authors.lastname: Jaeger
authors.forename: Céline
authors.initials: C
authors.lastname: Le Rouzic
authors.forename: Matthieu
authors.initials: M
authors.lastname: Bastien
authors.forename: Erwan
authors.initials: E
authors.lastname: Lagadec
authors.forename: Karen D
authors.initials: KD
authors.lastname: McCoy
authors.forename: Hervé
authors.initials: H
authors.lastname: Pascalis
authors.forename: Matthieu
authors.initials: M
authors.lastname: Le Corre
authors.forename: Koussay
authors.initials: K
authors.lastname: Dellagi
authors.forename: Pablo
authors.initials: P
authors.lastname: Tortosa
mesh_terms: D000818:Animals; D058448:Biota; D001717:Birds / Q000469:parasitology*; D016000:Cluster Analysis; D003381:Coxiella / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D026863:Ixodidae / Q000382:microbiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012281:Rickettsia / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D017422:Sequence Analysis, DNA; D014329:Tropical Climate