Cross-resistance between macrocyclic lactones in populations of Rhipicephalus microplus in Brazil's semiarid region.
Exp Appl Acarol
; 87(1): 109-117, 2022 May.
Article
em En
| MEDLINE
| ID: mdl-35817880
ABSTRACT
Rhipicephalus microplus, also known as the cattle tick, is the parasite with the greatest impact on cattle in Brazil. The most common method for controlling this tick is the application of synthetic chemical acaricides, especially ivermectin, which belongs to the group of macrocyclic lactones (MLs). However, because ivermectin is widely used, there is concern about the development of cross-resistance within this chemical class. Thus, engorged females were collected from farms with a history of resistance to ivermectin, which was the only one among the MLs that was used as an endectocide drug. Using larval immersion tests (LIT), bioassays were performed with ivermectin, moxidectin and eprinomectin on populations of R. microplus from the semiarid region of the states of Paraíba and Ceará, Brazil. Epidemiological questionnaires were applied to collect information about tick control management. All the evaluated populations showed cross-resistance between ivermectin and moxidectin, but only one population showed cross-resistance between ivermectin and eprinomectin. Weekly or monthly administration of injectable 1% ivermectin on farms was reported. It was concluded that the frequent use of ivermectin may lead to the development of cross-resistance to moxidectin. For eprinomectin, despite the structural similarity, cross-resistance was not observed in three tick populations.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Infestações por Carrapato
/
Doenças dos Bovinos
/
Rhipicephalus
/
Acaricidas
Limite:
Animals
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article