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Author Barrios, Silvia ♦ Zerba, Eduardo ♦ Picollo, Maria I. ♦ Audi, Paola Gonzalez
Source SpringerLink
Content type Text
Publisher Springer-Verlag
File Format PDF
Copyright Year ©2009
Language English
Subject Domain (in DDC) Technology ♦ Medicine & health
Subject Keyword Immunology ♦ Microbiology ♦ Medical Microbiology
Abstract Enhanced metabolism by oxidative enzymes is a major cause of pyrethroid resistance in insects. In this work, we evaluated the role of specific and non-specific esterases in head louse populations from Buenos Aires with different levels of resistance to permethrin. As esterase activity is substrate-dependent, four different esters were used as unspecific substrates in order to obtain a better characterization of the possible role of these enzymes in the resistance phenomenon. The unspecific substrates were phenylthioacetate, 1- and 2-naphtyl-acetate, and p-nitrophenyl acetate. A 7-coumaryl permethrate was synthesized and used as a specific substrate to measure pyrethroid esterases by a very sensitive microfluorometric method. The results on pyrethroid esterase activity obtained with this substrate showed that these enzymes contribute to the detoxifying activity in resistant populations, although no correlation was found between pyrethroid esterase activity and resistance ratios. In this study, we established that the activity of esterase against specific and non-specific substrates is increased in pyrethroid-resistant populations of head lice from Buenos Aires. Also, dichlorodiphenyltrichloroethane (DDT) resistance values demonstrated that there is a DDT cross-resistance phenomenon in pyrethroid-resistant head louse populations and suggested that an alteration in the receptor of the nervous system (kdr gen) is a key factor of the resistance phenomena in these head louse populations.
ISSN 09320113
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2009-11-17
Publisher Place Berlin/Heidelberg
e-ISSN 14321955
Journal Parasitology Research
Volume Number 106
Issue Number 2
Page Count 7
Starting Page 415
Ending Page 421


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Source: SpringerLink