Journal of Mosquito Research 2015, Vol.5, No.15, 1-15
1
Research Article Open Access
Insecticide Confrontation in Dengue Vector: Enzymatic Characterization of
Tolerance Level in the Mysore Field Populations of
Aedes aegypti
Vasanth Patil H.B.
1,2
, Nithin K.S.
3
, Sathish Kumar B.Y.
1,
1. Postgraduate Department of Studies and Research in Bio-technology, University of Mysore, JSS College, Ooty Road, Mysore – 570 025, INDIA
2. JSS Research Foundation (University of Mysore), Sri Jayachamarajendra College of Engineering, Manasagangothri, Mysore, INDIA
3. Postgraduate Department of Studies and Research in Chemistry, University of Mysore, JSS College, Ooty Road, Mysore – 570 025, INDIA
Corresponding author email
Journal of Mosquito Research, 2015, Vol.5, No.15 doi: 10.5376/jmr.2015.05.0015
Received: 30 Apr., 2015
Accepted: 02 Jun, 2015
Published: 22 Sep., 2015
Copyright
©
2015 Vasanth Patil et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Vasanth Patil H.B., Nithin K.S., and Sathish Kumar B.Y., 2015, Insecticide Confrontation in Dengue Vector: Enzymatic Characterization of Tolerance Level in
the Mysore Field Populations of
Aedes aegypti
, Journal of Mosquito Research, Vol.5, No.15 1
-
14 (doi
Abstract
The susceptibility status of an insect population to any insecticide depends on several factors such includes genetic
constitution, ecology of breeding place, previous history of insecticide application if any in that area and the cross resistance spectra.
In view of the frequent outbreaks of dengue in different parts of the country and Karnataka state, in particular Mysore and
surrounding districts, it is felt essential to generate a base line data on the susceptibility of vectors of local importance and their
genetic differentiation through biochemical markers. Resistance to insecticides developed by
Aedes aegypti
was biochemically
detected among its population collected from five different urban areas of Mysore city and from four rural locations of Mysore,
Mandya and Hassan districts. Insect larvae exposed to different concentrations of insecticide - Deltamethrin for 24 hr. Insecticide
resistance/tolerance level in terms of LC
50
and LC
90
for the insecticide was high in rural population than urban. Correspondingly, the
reason for the resistance was detected through qualitative and quantitative analysis of three biochemical marker enzymes viz.,
A-Esterase, B-Esterase, Dehydrogenase (G6PD), and Phosphtases (Acid, Alkaline). The allelic frequency of Esterases and
Phosphatases was more in rural over urban populations and the same was implied in quantitative estimation also. Wherein the allelic
frequency of both the Phosphatases remains same in all the populations but the enzyme concentration was elevated in rural over the
urban populations. The inspection of the present study reveals that, the Mysore populations of
Ae. aegypti
shows much variation for
which their ecology was responsible.
Keywords
Deltamethrin; Esterases; G6PD-Glucose 6 phosphate dehydrogenase; Acid Phosphatase; Alkaline Phosphatase
Introduction
Arthropods being haematophagous (blood sucking)
have the ability to behave and demeanor as vector;
found to transmit human diseases, where many viruses,
bacteria, protozoa and helminths parasites make use of
such species for transmission between the vertebrate
hosts. Historically, major vector born diseases viz.,
malaria, dengue, chikungunya, yellow fever, and
plague were responsible for most life threatening
pathological conditions in humans (Gubler, 1991). Not
long after the discovery in 1877 that mosquitoes
transmitted filariasis from human to human, malaria
(1898), yellow fever (1900) and dengue (1903) were
shown to have similar transmission cycles. By 1910,
other major vector-borne diseases such as African
sleeping sickness, plague, Rocky Mountain spotted
fever, relapsing fever, chagas disease, sandfly fever
and louse-borne typhus had all been shown to require
a blood-sucking arthropod vector for transmission to
humans (Philip & Rozenboom, 1973).
Vector born Dengue viruses are flaviviruses and its
four serotypes DEN-1, 2, 3 and 4 sequentially causes
infections and are responsible for Dengue Haemorrhagic
Fever (DHF) and Dengue Shock Syndrome (DSS) in
humans. The viruses are transmitted to man by the bite
of infective mosquitoes, mainly
Aedes aegypti
and
secondarily by
Aedes albopictus
. DHF is characterized
by increased vascular permeability, hypovolaemia and
abnormal blood clotting mechanisms. Due to rapid
growth of urban centers the rainwater harvesting in
diverse types of containers resulting in multiple
storage practices and provided the place for breeding
vector species. Before the advent of DDT in 1939,
vectors were controlled by environmental sanitation
and with non-synthetic chemicals especially plant
