Applicability of in vitro bioassays for the diagnosis of ivermectin resistance in Rhipicephalus microplus (Acari: Ixodidae)


Autoria(s): Klafke, Guilherme Marcondes; Janer, Eleonor Adega Castro; Mendes, M. C.; Namindome, A.; Schumaker, Teresinha Tizu Sato
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

07/11/2013

07/11/2013

2012

Resumo

The applicability of laboratory bioassays to diagnose ivermectin (IVM) resistance in Rhipicephalus microplus was evaluated. Adult immersion tests (AITs), larval immersion tests (LITs) and larval packet tests (LPTs) were performed to characterise the effects of ivermectin toxicity on adults and larvae of a susceptible reference strain. The AIT was determined to be a reasonable assay but requires a large number of individuals to attain interpretable results. The LIT and LPT were validated with an IVM resistant strain, revealing resistance ratios (RRs) of 6.73 and 1.49, respectively. In a field survey, nine different populations of cattle tick from the states of Sao Paulo and Mato Grosso do Sul, Brazil, were analysed with the LIT. Populations without previous exposure to ivermectin exhibited RRs between 0.87 and 1.01. Populations previously exposed to IVM showed RRs between 1.83 and 4.62. The LIT was more effective at discriminating between resistant and susceptible populations than the LPT. The use of the LIT is recommended for the diagnosis of ivermectin resistance in R microplus. (C) 2011 Elsevier B.V. All rights reserved.

CNPq

FAPESP, Brazil [2007/56082-4]

INIA-FPTA, Uruguay [243]

Identificador

VETERINARY PARASITOLOGY, AMSTERDAM, v. 184, n. 41366, p. 212-220, 44986, 2012

0304-4017

http://www.producao.usp.br/handle/BDPI/43026

10.1016/j.vetpar.2011.09.018

http://dx.doi.org/10.1016/j.vetpar.2011.09.018

Idioma(s)

eng

Publicador

ELSEVIER SCIENCE BV

AMSTERDAM

Relação

VETERINARY PARASITOLOGY

Direitos

closedAccess

Copyright ELSEVIER SCIENCE BV

Palavras-Chave #RHIPICEPHALUS MICROPLUS #IVERMECTIN #ACARICIDE RESISTANCE #DIAGNOSIS #BOOPHILUS-MICROPLUS #CATTLE TICK #MACROCYCLIC LACTONES #MILK RESIDUES #TESTS #FIPRONIL #INSECTICIDES #BRAZIL #LC50 #PARASITOLOGY #VETERINARY SCIENCES
Tipo

article

original article

publishedVersion