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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Detoxification mechanisms involved in ivermectin resistance in the cattle tick, Rhipicephalus (Boophilus) microplus

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Le Gall, Valeria Lis [1] ; Klafke, Guilherme Marcondes [1, 2] ; Torres, Tatiana Teixeira [1]
Total Authors: 3
[1] Univ Sao Paulo, Dept Genet & Biol Evolut, Rua Matao, BR-05508090 Sao Paulo - Brazil
[2] Inst Pesquisas Vet Desiderio Finamor, Estr Municipal do Conde 6000, BR-92990000 Eldorado Do Sul - Brazil
Total Affiliations: 2
Document type: Journal article
Source: SCIENTIFIC REPORTS; v. 8, AUG 17 2018.
Web of Science Citations: 3

The cattle tick Rhipicephalus microplus is one of the most important ectoparasites with great sanitary and economic impact for cattle rearing worldwide. Ivermectin is commonly used to control tick populations, but its use over the last 30 years has led to the development of resistant populations of R. microplus, and a concomitant loss of efficacy. In this context, we aimed to determine the metabolic mechanisms that contribute to ivermectin resistance in a resistant strain of this species. We performed lethal time bioassays with inhibitors of detoxifying enzymes and xenobiotic transporters (four detoxification pathways) using two strains of ticks: a susceptible strain, Mozo, and a resistant strain, Juarez. We used four inhibitors to test the involvement of different families of proteins responsible for detoxification of ivermectin, namely cytochrome P450, esterases, glutathione-S-transferase, and ATP Binding Cassette Transporters. We calculated the synergistic factor for each inhibitor and strain. To different degrees, all tested inhibitors altered the mortality rates in the strain Juarez, indicating that multiple mechanisms are responsible for the resistant phenotype. Detoxification mechanisms mediated by ABC transporters were observed to be the most important. Esterases, glutathione-S-transferases, and cytochrome-oxidases played less important roles in detoxification. (AU)

FAPESP's process: 12/06819-9 - Investigation of the molecular basis of parasiticide resistance in Rhipicephalus microplus and Cochliomyia hominivorax
Grantee:Tatiana Teixeira Torres
Support type: Regular Research Grants