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ARS Home » Plains Area » Kerrville, Texas » Knipling-Bushland U.S. Livestock Insects Research Laboratory » LAPRU » Research » Publications at this Location » Publication #348102

Research Project: Cattle Fever Tick Control and Eradication

Location: Livestock Arthropod Pests Research

Title: Molecular biology of amitraz resistance in cattle ticks of the genus Rhipicephalus

item JOHNSSON, NICHOLAS - University Of Glasgow
item KLAFKE, GUILHERME - Department Of Energy
item CORLEY, SEAN - University Of Queensland
item Tidwell, Jason
item BERRY, CHRISTINA - University Of Glasgow
item KOH-TAN, HH CALINE - University Of Glasgow

Submitted to: Frontiers in Bioscience
Publication Type: Abstract Only
Publication Acceptance Date: 6/5/2017
Publication Date: 1/1/2018
Citation: Johnsson, N.N., Klafke, G., Corley, S.W., Tidwell, J.P., Berry, C.M., Koh-Tan, H. 2018. Molecular biology of amitraz resistance in cattle ticks of the genus Rhipicephalus. Frontiers in Bioscience. 23:796-810.

Interpretive Summary: Amitraz is a widely used, affordable and relatively safe short-acting acaricide for use by spray or plunge dip. It has been available for over 40 years and resistance has been reported with increasing frequency in recent years. Research into the mechanisms of acaricide resistance has generated several lines of inquiry but so far none of the proposed mechanisms has been confirmed using functional studies. This review is intended to provide an overview of current knowledge and understanding of the possible mechanisms of amitraz resistance in tick species of the genus Rhipicephalus that affect cattle health, principally R. microplus.

Technical Abstract: Amitraz is an important product for the control of cattle ticks around the world. In comparison with other products for the control of ticks, it is quite affordable and it has a rapid knock-down effect. It binds with, and activates adrenergic neuro-receptors of animals and it inhibits the action of monoamine oxidases (MAO). Resistance to amitraz has been documented in Rhipicephalus microplus, R. decoloratus and R. appendiculatus. Four mechanisms of resistance have been proposed, each of which is supported by evidence but none of which has been definitively confirmed as the cause of resistance in the field. The proposed mechanisms include genetic target site insensitivity in two G protein-coupled receptors, the beta-adrenergic octopamine receptor (BAOR) and the octopamine/tyramine receptor (OCT/ Tyr), increased expression or activity of monoamine oxidases, and increased expression or activity of the ATP binding cassette transporter.