Investigation of rickettsial genus carried by vector ticks in Luodian County, Guizhou Province
- Author:
CHEN Qiu
;
TANG Jixia
;
MENG Jiao
- Publication Type:Case Reports
- Keywords:
Rickettsia;
16S sequencing；tick;
Guizhou
- From:
China Tropical Medicine
2024;24(11):1419-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To understand the basic characteristics of Rickettsia bacteria carried by parasitic ticks on the surface of free-range goats in the mountainous areas of Luodian County, Guizhou Province. Methods Ticks were collected from the free-range goats raised in the mountainous areas of Luodian County, Guizhou Province, China. DNA was extracted from individual ticks to prepare pooled DNA samples for full-length 16S rRNA sequencing. Quality-controlled sequences were annotated and classified using the Kraken2 database. The best-quality sequence for each species was selected as the representative sequence, and the consistency of each obtained representative sequence with Rickettsia sequences was assessed using the Basic Local Alignment Search Tool (BLAST) on the National Center for Biotechnology Information (NCBI) website to evaluate the identity of the obtained representative sequence with the Rickettsia sequence. Based on the results of the genetic consistency analysis, the representative sequence with the highest consistency with registered Rickettsia genes on NCBI and other sequences of the same Rickettsia species were selected, then, using the Orientia within the family Rickettsiaceae as the outgroup to construct the phylogenetic tree by MEGA 7.0 software. Results A total of 66 ticks were collected, of which 63 were Haemaphysalis longicornis and 3 were Rhipicephalus microplus. A total of 499 representative sequences were obtained in this study. BLAST analysis revealed that 21 representative sequences had more than 85% gene identity with 16S rRNA genes of Rickettsia in the NCBI nucleotide database. Among them, 9 sequences were more than 89% gene identity to Rickettsia (KU758903 and KY433580) isolated in China, with OTU47 showing the highest consistency at 95.76% with KU758903. Six sequences were more than 90% identity to the genes of Rickettsia (LC388776 and MT434769) isolated in China and Japan; three sequences were more than 89% identity to the genes of Rickettsia symbionts (KY617772) isolated in Henan Province, China; two sequences had more than 85% genetic identity with Rickettsia japonica (MF496167 and MF496155) isolated in Shandong Province, China; one sequence had more 85% genetic identity with Rickettsia vini isolated in Belgium. Phylogenetic analysis suggests that Rickettsia (OTU47) identified in this study belongs to the same branch as an unidentified Rickettsia species isolated in China (GenBank accession number: KU758903) and is closely related to Rickettsia longicornis isolated in Yunnan, China (GenBank accession number: KY433580).Conclusions The ticks parasitizing free-range goats in Luodian County, Guizhou, carry mostly unidentified Rickettsia species, and their pathogenicity and public health significance need to be further studied.
- Full text:202511121029074768620.Investigation of rickettsial genus carried by vector ticks in Luodian County, Guizhou Province.pdf
