Bacillus thuringiensis in Fecal Samples from Greenhouse Workers after Exposure to B. thuringiensis -Based Pesticides

Abstract

In a study of occupational exposure to Bacillus thuringiensis, 20 exposed greenhouse workers were examined for Bacillus cereus-like bacteria in fecal samples and on biomonitoring filters. Bacteria with the following characteristics were isolated from eight individuals: intracellular crystalline inclusions characteristic of B. thuringiensis, genes for and production of B. cereus enterotoxins, and positivity for cry11 as determined by PCR. DNA fingerprints of the fecal isolates were identical to those of strains isolated from the commercial products used. Work processes (i.e., spraying) correlated with the presence of B. thuringiensis in the fecal samples (10 2 to 10 3 CFU/g of feces). However, no gastrointestinal symptoms correlated with the presence of B. thuringiensis in the fecal samples.

Toxicity studies for indigenous Bacillus thuringiensis isolates from Malang city, East Java on Aedes aegypti larvae

“…A total of 0.1 mL of the stock bacterial suspension from each dilution was inoculated on nutrient agar and incubated at 30 °C . The number of B. thuringiensis was based on the number of colonies that grew after incubating for 12,24,36,48,72 and 96 h.…”

Characterization of polyvalent and safe Bacillus thuringiensis strains with potential use for biocontrol

“…Indeed, although Bt-based insecticide has been used for many years, only one report described the implication of Bt in food-borne disease [46], despite its detection in faecal samples of exposed greenhouse workers [47]. Nevertheless, it is important for the bioinsecticide industry to consider that introduction of Bt spores into the human food chain through the application of this bacterial species to crops, followed by spore germination, may cause a risk of food-borne poisoning cases.…”

Evolution of the Bacillus cereus Group

“…Held together with the fact that genes encoding the non-hemolytic enterotoxin complex (Nhe) are found ubiquitously among B. cereus group organisms and that B. cereus group species other than B. cereus sensu stricto have been characterized as the cause of gastroenteritis (McIntyre et al 2008), this emphasizes the opportunistic nature of B. cereus group bacteria, and the potential for other B. cereus group species to cause food-borne disease. It should be noted however, that in a study of greenhouse workers with occupational exposure to B. thuringiensis, although detecting human gastrointestinal carriage of B. thuringiensis, no gastrointestinal symptoms correlated with the presence of B. thuringiensis in fecal samples (Jensen et al 2002).…”