title: Toxicological and biochemical analysis of the susceptibility of sylvatic Triatoma infestans from the Andean Valley of Bolivia to organophosphate insecticide.
abstract: To increase our knowledge of the natural susceptibility of Triatoma infestans to an organophosphate insecticide, we performed toxicological and biochemical studies on three sylvatic populations from Bolivia and two populations from domestic dwellings from Bolivia and Argentina. Fifty-per-cent lethal doses (LD50) were determined based on the topical application of fenitrothion on first instar nymphs and mortality was assessed at 24 h. Both type of populations exhibited LD50ratios significantly higher than 1 with a range of the values (1.42-2.47); the maximum value were found in a sylvatic (-S) population, Veinte de Octubre-S. Samples were biochemically analysed using a glutathione S-transferase activity assay. The highest significant activity was obtained for Veinte de Octubre-S and the lowest activity was obtained for the reference population (102.69 and 54.23 pmol per minute per mg of protein respectively). Two out of the three sylvatic populations (Veinte de Octubre-S and Kirus Mayu-S) exhibited significantly higher glutathione S-transferase activity than that of the reference population. Based on this analysis of the natural susceptibility of this organism to organophosphate insecticides, continental and focal surveys of organophosphate susceptibility should be conducted to evaluate the evolution and distribution of this phenomenon.
authors.forename: Pablo Luis
authors.initials: PL
authors.lastname: Santo-Orihuela
authors.forename: Guillermo
authors.initials: G
authors.lastname: Carvajal
authors.forename: María Inés
authors.initials: MI
authors.lastname: Picollo
authors.forename: Claudia Viviana
authors.initials: CV
authors.lastname: Vassena
mesh_terms: D000818:Animals; D001838:Bolivia; D005278:Fenitrothion; D005982:Glutathione Transferase / Q000378:metabolism*; D006798:Housing; D007305:Insecticide Resistance / Q000502:physiology*; D007306:Insecticides; D007928:Lethal Dose 50; D009758:Nymph / Q000187:drug effects; D014197:Trees; D014224:Triatoma / Q000187:drug effects* / Q000201:enzymology
chemical_list: D007306:Insecticides; D005982:Glutathione Transferase; D005278:Fenitrothion
references.citation: Infect Genet Evol. 2006 Jan;6(1):46-62
references.pmid: 16376840
references.citation: Pest Manag Sci. 2001 Jun;57(6):501-8
references.pmid: 11407025
references.citation: J Med Entomol. 2010 Nov;47(6):1077-81
references.pmid: 21175056
references.citation: J Econ Entomol. 2011 Apr;104(2):636-45
references.pmid: 21510216
references.citation: Proc Natl Acad Sci U S A. 2007 Oct 9;104(41):16194-9
references.pmid: 17913895
references.citation: J Med Entomol. 2009 Sep;46(5):1195-202
references.pmid: 19769054
references.citation: PLoS Negl Trop Dis. 2011 Oct;5(10):e1365
references.pmid: 22039559
references.citation: Mem Inst Oswaldo Cruz. 2004 May;99(3):335-9
references.pmid: 15273811
references.citation: Am J Trop Med Hyg. 2010 Apr;82(4):574-9
references.pmid: 20348501
references.citation: Mem Inst Oswaldo Cruz. 2009 Jul;104 Suppl 1:17-30
references.pmid: 19753454
references.citation: J Med Entomol. 2005 Jul;42(4):637-42
references.pmid: 16119553
references.citation: Mem Inst Oswaldo Cruz. 2010 Sep;105(6):752-6
references.pmid: 20944988
references.citation: J Med Entomol. 2008 May;45(3):421-6
references.pmid: 18533435
references.citation: Infect Genet Evol. 2011 Jul;11(5):1045-57
references.pmid: 21463708
references.citation: J Med Entomol. 2011 Jul;48(4):828-35
references.pmid: 21845942
references.citation: J Pharmacol Exp Ther. 1949 Jun;96(2):99-113
references.pmid: 18152921
references.citation: Trop Med Int Health. 2010 Sep;15(9):1037-48
references.pmid: 20545921
references.citation: Am J Trop Med Hyg. 2012 Mar;86(3):455-8
references.pmid: 22403316
references.citation: Anal Biochem. 1976 May 7;72:248-54
references.pmid: 942051
references.citation: Med Vet Entomol. 2000 Mar;14(1):51-5
references.pmid: 10759312
references.citation: Trends Parasitol. 2006 Dec;22(12):583-8
references.pmid: 17049308
references.citation: J Med Entomol. 2008 Mar;45(2):298-306
references.pmid: 18402146
references.citation: Insect Mol Biol. 2005 Jan;14(1):3-8
references.pmid: 15663770
references.citation: Mem Inst Oswaldo Cruz. 2012 Dec;107(8):1042-7
references.pmid: 23295756
references.citation: Mem Inst Oswaldo Cruz. 2000;95 Suppl 1:119-22
references.pmid: 11142700
references.citation: Trans R Soc Trop Med Hyg. 1999 Jan-Feb;93(1):13-4
references.pmid: 10492778
references.citation: Trends Parasitol. 2005 Jan;21(1):7-10
references.pmid: 15639733
references.citation: PLoS Negl Trop Dis. 2011 May 03;5(5):e1026
references.pmid: 21572522
references.citation: Infect Genet Evol. 2010 Mar;10(2):350-3
references.pmid: 20060504
references.citation: J Med Entomol. 2012 Nov;49(6):1379-86
references.pmid: 23270166
references.citation: Mem Inst Oswaldo Cruz. 2002 Jul;97(5):603-12
references.pmid: 12219120
references.citation: J Med Entomol. 2012 Nov;49(6):1355-60
references.pmid: 23270163
references.citation: Mem Inst Oswaldo Cruz. 2009 Jul;104 Suppl 1:60-4
references.pmid: 19753459
references.citation: Am J Trop Med Hyg. 2007 Sep;77(3):467-77
references.pmid: 17827362
references.citation: Comp Biochem Physiol B. 1986;84(4):607-17
references.pmid: 3530629
references.citation: J Biol Chem. 1974 Nov 25;249(22):7130-9
references.pmid: 4436300