Composition of the Midgut Microbiota Structure of Haemaphysalis longicornis Tick Parasitizing Tiger and Deer

Abstract

Haemaphysalis longicornis is a common tick species that carries several pathogens. There are few reports on the influence of different hosts on the structure of midgut microflora in H. longicornis. In this study, midgut contents of fully engorged female H. longicornis were collected from the surface of tiger (Panthera tigris) and deer (Dama dama). The bacterial genomic DNA of each sample was extracted, and the V3–V4 regions of the bacterial 16S rRNA were sequenced using the Illumina NovaSeq sequencing. The diversity of the bacterial community of the fully engorged female H. longicornis on the surface of tiger was higher than that of deer. In total, 8 phyla and 73 genera of bacteria annotations were detected in the two groups. At the phylum level, the bacterial phyla common to the two groups were Proteobacteria, Firmicutes, and Actinobacteriota. At the genus level, there were 20 common bacterial genera, among which the relative abundances of Coxiella, Morganella, Diplorickettsia, and Acinetobacter were high. The Morganella species was further identified to be Morganella morganii. The alpha diversity index indicated that the bacterial diversity of the tiger group was higher than that of the deer group. Bacteroidota, Patescibacteria, Desulfobacterota, Verrucomicrobiota, and Cyanobacteria were solely detected in the tiger group. A total of 52 bacterial genera were unique in the tiger group, while one bacterial genus was unique in the deer group. This study indicates that there are differences in the structure of the gut bacteria of the same tick species among different hosts. Further culture-based methods are needed to provide a more comprehensive understanding of the tick microbiota parasitizing different hosts.