Amblyomma ticks

Mofokeng, Lehlohonolo S., Smit, Nico J. & Cook, Courtney A., 2021, Molecular screening of ticks of the genus Amblyomma (Acari: Ixodidae) infesting South African reptiles with comments on their potential to act as vectors for Hepatozoon fitzsimonsi (Dias, 1953) (Adeleorina: Hepatozoidae), International Journal for Parasitology: Parasites and Wildlife 16, pp. 163-167 : 165

3.2. Molecular analysis of Amblyomma ticks and their Hepatozoon spp .

The PCR analysis of the DNA isolates indicates amplification of 460bp for the 16S rRNA gene and ~700bp for the CO1 gene. BLASTn results for both mtDNA genes matched with the expected species, although notable divergence levels were observed in both cases ( Fig. 1 ). The CO1 gene was not able to amplify the A. latum . Based on the 16S rRNA phylogenetic analysis, the A. marmoreum from the current study constitutes a monophyletic clade (99% bootstrap value) closely affiliated to the same lineage group of A. marmoreum , while A. latum from this study formed a monophyletic clade with A. latum with 99% bootstrap value. Both A. marmoreum and A. latum formed a monophyletic group with other Amblyomma species of reptiles, clearly distinct from other Amblyomma species of mammals with a> 70% bootstrap value ( Fig. 2 ).

The overall prevalence of Hepatozoon was 10/100 (10%). It was detected from 1/4 (25%) A. marmoreum parasitizing Varanus albigularis and 9/94 (10%) A. marmoreum parasitizing tortoises. No Hepatozoon was detected from A. latum . The BLASTn analysis for the 430bp 18S rRNA of the Hepatozoon sequences had a 99% similarity with H. fitzsimonsi (KR069084.1) from South African tortoise Kinixys zombensis , and clustered in a single clade with H. fitzsimonsi from another South African tortoise, a tortoise collected from Nigeria and a tick collected from a tortoise in Kenya ( Fig. 2 ).

Figures

Fig. 1. Maximum likelihood analysis of Amblyomma tick species based on the 16S rRNA sequences. Bootstrap values at the major nodes are of percentage agreement among 1000 replicates. The branch scale represents substitutions per site.

Fig. 2. Maximum likelihood analysis of species of Hepatozoon based on the 18S rRNA sequences. Bootstrap values at the major nodes are of percentage agreement among 1000 replicates. The branch scale represents substitutions per site.