Investigating the Insecticide Resistance Mechanisms in a Pyrethroid Resistance Aedes Aegypti Population from Mexico

• Main Author: Zarini Ismail
• Format: Thesis
• Language: English
• Published: Universiti Sains Islam Malaysia 2012
• Subjects: Dengue > Prevention & Control; Aedes; tes WC528 Z37i 2009; Insecticides; Insect Vectors; Mexico
• Online Access: http://ddms.usim.edu.my/handle/123456789/5684

The mosqirito Aedes ae5vyti is the primary vector for arboviruses such as Dengue, which can gave rises to serious complications such as dengue haemorrhagic fever and dengue shock syndrome which can threatened human life. Since the control of this disease mainly relies on targeting the mosquito vector by using insecticides, the emergence of resistance to insecticide threatens the success of control programmes and hence increases disease transmission. As there are limited numbers of insecticides used in vector control programmes, monitoring and early detection of insecticide resistance mechanism in mosquito population is a crucial step i~ determined the appropriate resistance management. Here we investigated the resistance mechanisms for both target site and metabolic resistance in pyrethroid resistance Ae. aegypti popillation from Mexico, the Merida strain using a number of molecular techniques. Allele-specific PCR was employed to determine an as yet unpublished novel kdr mutation, whilst the Heated Oligonucleotide Ligation Assay (HOLA) was used to determine the previously reported kdr. mutation Valine 10 16Isoleucine and Isoleucine 10 1 1 Valine. Finally metabolic resistance was assessed using multiplex quantitative PCR to determine whether a selection of cytochrome P450s and Glutathione-S transferases (GSTs) were contributing to the resistance phenotype. Here we reported the association of both target site and metabolic resistance conferring the resistance status to Ae .aegypti Merida. Presented is evidence of a novel kdr. mutation in exon 29, segment 6 domain 111 and in addition to the presence of a kdr mutation ValinelOl6Isoleucine at segment 6 domain 11 of voltage gated sodium channel gene. Furthermore, members of the epsilon GST class (GSTe2, GSTe4 and GSTe7) and members of CYP9 P450 family (CI'P9JZ.l and CYP9J32) were highly expressed. These findings will provide a basis for identifying the resistance associated enzymes within these strain of mosquito and enable resistance status to be monitored and managed appropriately.