Advanced search
Start date
Betweenand
Related content
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Mutations in Rhipicephalus microplus GABA gated chloride channel gene associated with fipronil resistance

Full text
Author(s):
Castro Janer, E. [1] ; Klafke, G. M. [2] ; Fontes, F. [1] ; Capurro, M. L. [3] ; Schumaker, T. S. S. [3]
Total Authors: 5
Affiliation:
[1] UDELAR, Sch Vet, Dept Vet Parasitol, Av Lasplaces 1620, Montevideo 11600 - Uruguay
[2] Governo Estado Rio Grande do Sul, Inst Pesquisas Vet Desiderio Finamor, Estr Conde 6000, Eldorado Do Sul, RS - Brazil
[3] Univ Sao Paulo, Dept Parasitol, Inst Ciencias Biomed, Av Prof Lineu Prestes 1374, BR-05508000 Sao Paulo, SP - Brazil
Total Affiliations: 3
Document type: Journal article
Source: TICKS AND TICK-BORNE DISEASES; v. 10, n. 4, p. 761-765, JUN 2019.
Web of Science Citations: 0
Abstract

The tropical cattle tick, Rhipicephalus microplus, is one of the most damaging parasites that affects cattle in tropical and subtropical regions in the world. Tick resistance to acaricides is dispersed worldwide and a number of associated mutations in target site genes have been described. Phenylpyrazole (e.g. fipronil) and cyclodiene (e.g. lindane, dieldrin) insecticides both have the same mode of action blocking the GABA-gated chloride channel encoded by the GABA-Cl gene. A conserved mutation, rdl (resistance to dieldrin) is found across a number of arthropods resistant to cyclodienes and phenylpyrazoles. In ticks, the mutation T290 L, was identified in the second transmembrane (TM2) domain of the GABA-gated chloride channel of Australian cattle tick populations that are resistant to dieldrin. Recently, cross-resistance between fipronil and lindane was reported in R. microplus populations obtained from Uruguay and Brazil. The objective of the present study was to identify mutations in the GABA-Cl gene associated with fipronil resistance. Genomic DNA was obtained from engorged females from fipronil-susceptible and resistant populations sampled from Uruguay and Brazil (n = 166). Initially, it was searched the T290 L mutation described in Australia; however, this mutation was not detected in individuals from resistant populations from either country. The sequencing of a fragment of the GABA-Cl gene revealed nucleotide polymorphisms in fipronil- and lindane-resistant ticks in two populations from Uruguay and five from Brazil. Five amino acid substitutions were present in the resistant strains. Two different substitutions were found in an alanine residue (A286S and A286 L) that is homolog to rdl mutations in fipronil-resistant individuals of other arthropod species. Four other amino acid substitutions (S281 T, V317I, T328 A and A329S) were present in some resistant strains, always with the mutation A286S. This is the first documentation of mutations in the GABA-Cl gene associated with fipronil-resistant in R. microplus. (AU)

FAPESP's process: 12/21671-8 - Molecular diagnostic of fipronil resistance in Rhipicephalus (Boophilus) microplus
Grantee:Teresinha Tizu Sato Schumaker
Support Opportunities: Regular Research Grants