title: Toxicity of Bacillus thuringiensis var. israelensis in aqueous suspension on the South American common frog Leptodactylus latrans (Anura: Leptodactylidae) tadpoles.
abstract: The effects of commercial formulations of Bacillus thuringiensisvar.israelensis (Bti) on non-target organisms are still a matter of debate; in amphibians, the risks of Bti are little known. To evaluate the toxicity of a commercial liquid (aqueous suspension, AS) formulation of Bti (Introban(®)) on Leptodactylus latrans tadpoles, including median lethal concentration (LC50) and no-and lowest-observed-effect concentrations (NOEC and LOEC, respectively), as well as the possible effects of Bti on oxidative responses, erythrocytes genotoxicity, and histology of the intestines. In the laboratory, tadpoles were exposed to nominal concentrations of 0 (control), 2.5, 5, 10, 20 and 40 mg/L of formulated Bti-AS. Glutathione S-transferase (GST) and catalase (CAT) activities, as well as formation of erythrocyte nuclear abnormalities (ENAs), and histological effect were measured in tadpoles displaying survival rates >85%. L. latrans tadpoles were sensitive to exposure to Bti-AS, reaching 100% mortality after 48 h of exposure at the highest concentration. Bti-AS induced GST and CAT enzymes and genotoxicity (erythrocyte's nuclear abnormalities), and caused intestine's histopathology. Our results demonstrate that toxicity of Bti-AS is dose-dependent for L. latrans tadpoles and that sublethal exposure alters enzymes of oxidative stress, induces genotoxicity, and causes intestine damage. Further research is needed to evaluate the ecotoxicological risk of the massive use of Bti formulations on amphibian populations that commonly used suburban wastewater or urban waterbodies to reproduce and where this biopesticide is frequently applied.
authors.affiliation: National Council for Scientific and Technical Research (CONICET), Buenos Aires, Argentina; Faculty of Biochemistry and Biological Sciences (FBCB-UNL), Ciudad Universitaria Paraje el Pozo s/n, 3000 Santa Fe, Argentina. Electronic address: lajmanovich@hotmail.com.
authors.forename: Rafael C
authors.initials: RC
authors.lastname: Lajmanovich
authors.affiliation: National Council for Scientific and Technical Research (CONICET), Buenos Aires, Argentina; Faculty of Biochemistry and Biological Sciences (FBCB-UNL), Ciudad Universitaria Paraje el Pozo s/n, 3000 Santa Fe, Argentina.
authors.forename: Celina M
authors.initials: CM
authors.lastname: Junges
authors.affiliation: Faculty of Biochemistry and Biological Sciences (FBCB-UNL), Ciudad Universitaria Paraje el Pozo s/n, 3000 Santa Fe, Argentina.
authors.forename: Mariana C
authors.initials: MC
authors.lastname: Cabagna-Zenklusen
authors.affiliation: National Council for Scientific and Technical Research (CONICET), Buenos Aires, Argentina; Faculty of Biochemistry and Biological Sciences (FBCB-UNL), Ciudad Universitaria Paraje el Pozo s/n, 3000 Santa Fe, Argentina.
authors.forename: Andrés M
authors.initials: AM
authors.lastname: Attademo
authors.affiliation: National Council for Scientific and Technical Research (CONICET), Buenos Aires, Argentina; Faculty of Biochemistry and Biological Sciences (FBCB-UNL), Ciudad Universitaria Paraje el Pozo s/n, 3000 Santa Fe, Argentina.
authors.forename: Paola M
authors.initials: PM
authors.lastname: Peltzer
authors.affiliation: Faculty of Biochemistry and Biological Sciences (FBCB-UNL), Ciudad Universitaria Paraje el Pozo s/n, 3000 Santa Fe, Argentina.
authors.forename: Mariana
authors.initials: M
authors.lastname: Maglianese
authors.affiliation: Faculty of Biochemistry and Biological Sciences (FBCB-UNL), Ciudad Universitaria Paraje el Pozo s/n, 3000 Santa Fe, Argentina.
authors.forename: Vanina E
authors.initials: VE
authors.lastname: Márquez
authors.affiliation: Faculty of Biochemistry and Biological Sciences (FBCB-UNL), Ciudad Universitaria Paraje el Pozo s/n, 3000 Santa Fe, Argentina.
authors.forename: Alejandro J
authors.initials: AJ
authors.lastname: Beccaria
mesh_terms: D000818:Animals; D001001:Anura / Q000254:growth & development*; D001413:Bacillus thuringiensis; D007814:Larva / Q000187:drug effects*; D010084:Oxidation-Reduction; D014867:Water
chemical_list: D014867:Water
keywords: Amphibians; Biomarkers; Biopesticides; Mortality