Molecular analysis of Ixodes granulatus, a possible vector tick for Borrelia burgdorferi sensu lato in Taiwan

Abstract

The genetic identity of Ixodes granulatus ticks was determined for the first time in Taiwan. The phylogenetic relationships were analyzed by comparing the sequences of mitochondrial 16S ribosomal DNA gene obtained from 19 strains of ticks representing seven species of Ixodes and two outgroup species (Rhipicephalus sanguineus and Haemaphysalis inermis). Four major clades could be easily distinguished by neighbour-joining analysis and were congruent by maximum-parsimony method. All these I. granulatus ticks of Taiwan were genetically affiliated to a monophyletic group with highly homogeneous sequences (92.2-99.3% similarity), and can be discriminated from other Ixodes species and other genera of ticks with a sequence divergence ranging from 11.7 to 30.8%. Moreover, intraspecific analysis revealed that two distinct lineages are evident between the same species of I. granulatus ticks collected from Taiwan and Malaysia. Our results demonstrate that all these I. granulatus ticks of Taiwan represent a unique lineage distinct from the common vector ticks (I. ricinus complex) for Borrelia burgdorferi spirochetes.

Complete Mitochondrial Genome Sequence Data Provides Genetic Evidence That the Brown Dog Tick Rhipicephalus sanguineus (Acari: Ixodidae) Represents a Species Complex

“…For example, the intra-specific sequence variation in Dermacentor marginatus was 0.1-1.0% for p cox 1 (732 bp) and 0.2-1.2% for p nad 5 (519 bp) 43, and in Haemaphysalis punctata it was 0.4-1.9% for p cox 1 and 0.4-1.0% for p nad 5 43, and intra-specific sequence variation in Ixodes holocyclus and I. cornuatus was less than 0.86% for p cox 1 (640 bp) 46. However, comparison of the p cox 1 and p cyt b sequences between RSC and RSU revealed significantly high level of difference (10.8-11.5% for p cox 1 and 10.4-11.4% for p cyt b), consistent with previous studies of other Ixodes ticks, where inter-specific sequence variation was 9.1-16.0% for cox 1 46, and 13.0% for cox 1 47, and 4.2-14.1% for rrn L 48. In spite of the molecular evidence here supporting the RSC and RSU as distinct tick species, interpretation from present study needs to be somewhat caution until detailed population genetic studies have been carried out on samples from broader geographical localities to better illuminate the taxonomy and population genetic structures of R. sanguineus ticks.…”

Mitochondrial 16s rDNA based Analysis of some Hard Ticks Belonging to Genus Hyalomma Koch, 1844 (Acari: Ixodidae)

“…In contrast the H. asiaticum is more departed having 7.3% to 13.8% divergence from these species ( Table 5). As for H. dromedarii and H. detritum that cluster with H. asiaticum in the phylogenetic trees, H. asiaticum shows 7.65% and 7.84% divergence which is in agreement with between species differences reported earlier for Rhipicephalus and Ixodes species (Song et al, 2011;Apanaskevich et al, 2011;Chao et al, 2009).…”

Prevalence of on-host ticks (Acari: Ixodidae) in small mammals collected from forest near to human vicinity in Selangor, Malaysia

“…Ixodes granulatus was the most common tick species found in both study areas as this species was known to infest mammalian hosts such as rodents, and shrews (Nadchatram 2008;Chao et al 2009;2011;Madinah et al 2011;Ernieenor et al 2016). I. granulatus have been reported to host and possibly transmit a number of tick-borne pathogens, including Rickettsia and Borrelia (Kollars et al 2001;Graves & Stenos 2003;Chao et al 2010).…”