1. Genetic variability of Ehrlichia canis TRP36 in ticks, dogs, and red foxes from Eurasia.
- Author
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Bezerra-Santos MA, Nguyen VL, Iatta R, Manoj RRS, Latrofa MS, Hodžić A, Dantas-Torres F, Mendoza-Roldan JA, and Otranto D
- Subjects
- Animals, Asia epidemiology, Bacterial Proteins genetics, Dogs, Ehrlichia canis classification, Ehrlichiosis epidemiology, Ehrlichiosis microbiology, Ehrlichiosis veterinary, Europe epidemiology, Gene Expression Regulation, Bacterial, Global Health, Phylogeny, RNA, Bacterial genetics, RNA, Ribosomal, 16S genetics, Bacterial Proteins metabolism, Dog Diseases microbiology, Ehrlichia canis genetics, Foxes microbiology, Genetic Variation, Rhipicephalus sanguineus microbiology
- Abstract
Ehrlichia canis is among the most prevalent tick-borne pathogens infecting dogs worldwide, being primarily vectored by brown dog ticks, Rhipicephalus sanguineus sensu lato (s.l.). The genetic variability of E. canis has been assessed by analysis of different genes (e.g., disulfide bond formation protein gene, glycoprotein 19, tandem repeat protein 36 - TRP36) in the Americas, Africa, Asia, and in a single dog sample from Europe (i.e., Spain). This study was aimed to assess the variations in the TRP36 gene of E. canis detected in naturally infected canids and R. sanguineus s.l. ticks from different countries in Asia and Europe. DNA samples from dogs (n = 644), foxes (n = 146), and R. sanguineus s.l. ticks (n = 658) from Austria, Italy, Iran, Pakistan, India, Indonesia, Malaysia, the Philippines, Singapore, Thailand, Vietnam, and Taiwan were included in this study. Ehrlichia canis 16S rRNA positive samples (n = 115 from the previous studies; n = 14 from Austria in this study) were selected for molecular examination by analyses of TRP36 gene. Out of 129 E. canis 16S rRNA positive samples from dogs (n = 88), foxes (n = 7), and R. sanguineus s.l. ticks (n = 34), the TRP36 gene was successfully amplified from 52. The phylogenetic analysis of the TRP36 pre-repeat, tandem repeat, and post repeat regions showed that most samples were genetically close to the United States genogroup, whereas two samples from Austria and one from Pakistan clustered within the Taiwan genogroup. TRP36 sequences from all samples presented a high conserved nucleotide sequence in the tandem repeat region (from 6 to 20 copies), encoding for nine amino acids (i.e., TEDSVSAPA). Our results confirm the US genogroup as the most frequent group in dogs and ticks tested herein, whereas the Taiwan genogroup was present in a lower frequency. Besides, this study described for the first time the US genogroup in red foxes, thus revealing that these canids share identical strains with domestic dogs and R. sanguineus s.l. ticks., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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