ABSTRACT
Ecotoxicity tests are key to predict environmental hazards resulting from chemical and biological pesticides in non-target species. In order to assess the effects of microbial pesticides it is important to determine if they cause infection in test organisms. At present the microbial elimination rate or clearance is not included in ecotoxicological regulatory protocols. This study evaluated the elimination of Bacillus thuringiensis and Bacillus sphaericus from fish and snails, after 30 days' exposure to commercial formulations of such entomopathogens. Data obtained showed that in clean water the tendency to eliminate microbial agents from the body of the exposed organisms is gradual over time but after 7 days the fish and snails were free of the two tested Bacillus spp.
Subject(s)
Bacillus/drug effects , Biomphalaria/microbiology , Characidae/microbiology , Pesticides/toxicity , Zebrafish/microbiology , Animals , Bacillus thuringiensis Toxins , Bacterial Proteins/toxicity , Bacterial Toxins/toxicity , Brazil , Colony-Forming Units Assay , Ecotoxicology , Endotoxins/toxicity , Hemolysin Proteins/toxicityABSTRACT
The environmental toxicology of chemical pesticides have increased interest in the development and use of microbial pest control agents. In the present study four new Brazilian strains of Bacillus and one fungus were tested to evaluate the acute oral toxicity and clearance of these microbials in C57BL6 mice. No mortality was observed after exposure for any of the microorganisms tested. Clearance was significant after 30 days but for one strain of B. thuringiensis and one of B. sphaericus this time was not enough to completely eliminate the spores.
