RESEARCH ARTICLE
Permethrin Resistance Due to Knockdown Gene Mutations is Prevalent in Human Head Louse Populations
J. Marshall Clark*
Article Information
Identifiers and Pagination:
Year: 2010Volume: 4
First Page: 63
Last Page: 68
Publisher ID: TODJ-4-63
DOI: 10.2174/1874372201004010063
Article History:
Received Date: 24/02/2010Revision Received Date: 10/03/2010
Acceptance Date: 10/03/2010
Electronic publication date: 14/7/2010
Collection year: 2010
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
Permethrin resistance in head lice is mainly conferred by the knockdown resistance (kdr) trait, a voltagesensitive sodium channel (VSSC) insensitivity factor. Three VSSC mutations have been identified and confirmed to reduce the sensitivity of VSSC to permethrin. A step-wise resistance monitoring system has been established based on molecular resistance detection techniques. Quantitative sequencing (QS) predicts the kdr allele frequency in head lice on a population basis. The speed, simplicity and accuracy of QS made it an ideal candidate for a routine primary resistance monitoring tool to screen a large number of wild louse populations as an alternative to conventional bioassay. As a secondary monitoring method, real-time PASA (rtPASA) provides a more precise determination of low resistance allele frequencies. To obtain more detailed information on resistance allele zygosity, as well as allele frequency, serial invasive signal amplification reaction (SISAR) is utilized as an individual genotyping method. Using this approach, kdr alleles were detected in head lice from 10 of the 14 countries examined and an overall kdr allele frequency of 73.8% determined.
