Bacterial microbiome of Dermacentor hunteri ticks from bighorn sheep of Sonora, Mexico

Abstract

ABSTRACT Dermacentor hunteri is a tick species that parasitizes bighorn sheep (Ovis canadiensis) and is an important vector of pathogens such as Anaplasma marginale Bartonella, Borrelia, Rickettsia, and Francisella; however, other obligate endosymbionts have been reported in this genus. We aimed to investigate the bacterial microbiome of D. hunteri males and females by next-generation sequencing (NGS) to identify their endosymbionts and possible bacteria pathogenic to humans or animals. Thus, 183 adult ticks were collected from four bighorn sheep from Sonora, Mexico. The final library was sequenced using Illumina MiSeq. Alpha-diversity analyses were performed using QIIME. Francisella tularensis represented 73.4% and 99.8% of the tick microbiome in males and females, respectively. Other species with a significant percentage in the male D. hunteri microbiome were Sphingobium yanoikuyae (5.3%), Sphingomonas adhaesiva-ginsenosidimutans (2.7%), Janthinobacterium agaricidamnosum (4.1%), and Vibrio alginolyticus-proteolyticus (4.7%). Vibrio parahaemolyticus represented 0.1% in females and 1.6% in males. This study provided the first overview of the complex microbiota associated with D. hunteri collected from bighorn sheep, characterized by F. tularensis. However, more research is needed to assess the presence of zoonotic cycles and O. canadensis as possible wild reservoirs that may endanger local wild mammals or human population health.