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

Toxicity of Bacillus Thuringiensis Var. Kurstaki to Aquatic Insects

The Canadian Entomologist, 1985

Representative aquatic insects, larvae of Simuliidae, Chironomidae, Trichoptera, Megaloptera, and nymphs of Ephemeroptera and Plecoptera, were tested for susceptibility to continuous exposure toBacillus thuringiensisBerliner var.kurstakiat 4.3, 43, and 430 IU/mL. OnlySimulium vittatumwas affected, and at the highest concentration. Effects on other organisms, particularlyProsimulium fuscum/mixtum, were suggested. The lowest of the concentrations tested was twice the worst-case transitory concentration peaks expected in water from aerial forest spraying at 30 BIU/ha. Spray buffer zones around water bodies are unnecessary at this spray rate.

Stress Response of European Common Frog (Rana temporaria) Tadpoles to Bti Exposure in an Outdoor Pond Mesocosm

Bulletin of Environmental Contamination and Toxicology

The biocide Bacillus thuringiensis var. israelensis (Bti) is applied to wetlands to control nuisance by mosquitoes. Amphibians inhabiting these wetlands can be exposed to Bti multiple times, potentially inducing oxidative stress in developing tadpoles. For biochemical stress responses, ambient water temperature plays a key role. Therefore, we exposed tadpoles of the European common frog (Rana temporaria) three times to field-relevant doses of Bti in outdoor floodplain pond mesocosms (FPM) under natural environmental conditions. We sampled tadpoles after each Bti application over the course of a 51-day experiment (April to June 2021) and investigated the activity of the glutathione-S-transferase (GST) and protein carbonyl content as a measure for detoxification activity and oxidative damage. GST activity increased over the course of the experiment likely due to a general increase of water temperature. We did not observe an effect of Bti on either of the investigated biomarkers under ...

Efeitos toxicológicos de ?-endotoxinas e ?-exotoxinas de Bacillus thuringiensis em ratos Wistar

2021

Bacillus thuringiensis is an entomopathogen consisting of toxic proteins, such as the ?- endotoxins specific to insects. However, some subspecies can produce ?-exotoxins that are nonspecifi c and toxic to the vertebrates. So, in this research the toxicology effect of two isolates of B. thuringiensis in Wistar rats have been assessed. In the in vivo assays the animals have been given 3.1010UFC/mL of B. thuringiensis thuringiensis and B. thuringiensis aizawai and supernatant bacterial suspensions orally. The excrements and the stomachic content of the animals have been collected and analyzed in SDS-PAGE (10%). The analyzed data show protein fragments between 151 kDa and 28 kDa, seeing that the fecal samples show only one track of peptides in the treatments when compared with the control group. The assessments of the stomach of the treated rats carried out under stereomicroscope have not shown alterations when compared with the control. These results indicate that the toxins which can ...