Organ-specific bacterial microbiota in the engorged female Haemaphysalis longicornis ticks

ABSTRACT

Bacterial microbiota are involved in tick physiology and varies with various factors. The variation of bacterial microbiota among tick organs is less investigated. In this study, the bacterial microbiota of four organs (ovaries, salivary glands, midgut, and Malpighian tubules) from the engorged female Haemaphysalis longicornis were surveyed using 16S rRNA high-throughput sequencing. Results indicated that the bacterial richness and diversity varied among tick organs, and ovaries had the lowest level of bacterial richness and diversity. The ovaries and salivary glands had relatively stable bacterial compositions when considering bacterial abundance. Proteobacteria was the dominant bacterial phylum in the four organs, followed by Firmicutes, Bacteroidota and Actinobacteriota. The ovaries carried more Proteobacteria, while the Firmicutes abundance was higher in salivary glands. The environmental bacteria including Staphylococcus, Pseudomonas, Brevundimonas, Acinetobacter, Enterobacter, and Stenotrophomonas had high abundance in the midgut and salivary glands, suggesting that ticks can acquire environmental bacteria through blood meals or host skin. The predominant proportion of Coxiella in ovaries ensures its vertical transmission, and Coxiella in Malpighian tubules can provide nutrients to the host. In conclusion, organ-specific bacterial microbiota was observed in the engorged female H. longicornis, and the functions of these bacteria in organs remain to be investigated.

KEYWORDS:

• Tick organ
• bacterial function
• 16S rRNA high-throughput sequencing

Acknowledgments

We thank Professor Zhijun Yu of Hebei Normal University for his help in sample collection.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The raw data are available on the NCBI Sequence Read Archive (SRA) archive under the accession number PRJNA661974.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/01647954.2024.2323549

Additional information

Funding

This study was supported by Natural Science Foundation of Hebei province [C2022205019], China Postdoctoral Science Foundation [2020M670686], and the National Natural Science Foundation of China [31802008].