Toxicity of Bacillus thuringiensis var. israelensis in aqueous suspension on the South American common frog Leptodactylus latrans (Anura: Leptodactylidae) tadpoles

LAJMANOVICH R.C.,; JUNGES C; CABAGNA ZENKLUSEN M.C; ATTADEMO A.M.; PELTZER P.M; M. MAGLIANESE; MÁRQUEZ V.E; BECCARIA A.

ENVIRONMENTAL RESEARCH

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2015 p. 205 - 212

0013-9351

The effectsofcommercialformulationsof Bacillus thuringiensisvar.israelensis (Bti) onnon-targetor-ganisms arestillamatterofdebate;inamphibians,therisksof Bti are littleknown.Toevaluatethetoxicityofacommercialliquid(aqueoussuspension,AS)formulationof Bti (Introbans) on Leptodactyluslatrans tadpoles, includingmedianlethalconcentration(LC50) andno-andlowest?observed-effect con-centrations (NOECandLOEC,respectively),aswellasthepossibleeffectsof Bti on oxidativeresponses,erythrocytesgenotoxicity,andhistologyoftheintestines.Inthelaboratory,tadpoleswereexposedtonominal concentrationsof0(control),2.5,5,10,20and40mg/Lofformulated Bti-AS. GlutathioneS-transferase(GST)andcatalase(CAT)activities,aswellasformationoferythrocytenuclearabnormal-ities (ENAs),andhistologicaleffectweremeasuredintadpolesdisplayingsurvivalrates 485%. L. latranstadpoles weresensitivetoexposureto Bti-AS, reaching100%mortalityafter48hofexposureatthehighest concentration. Bti-AS inducedGSTandCATenzymesandgenotoxicity(erythrocyte´snuclearabnormalities), andcausedintestine´shistopathology.Ourresultsdemonstratethattoxicityof Bti-AS isdose-dependent for L. latrans tadpoles andthatsublethalexposurealtersenzymesofoxidativestress,induces genotoxicity,andcausesintestinedamage.Furtherresearchisneededtoevaluatetheecotox-icological riskofthemassiveuseof Bti formulations onamphibianpopulationsthatcommonlyusedsuburban wastewaterorurbanwaterbodiestoreproduceandwherethisbiopesticideisfrequentlyap-plied.