K P Bottjer

Learn More
The azasteroid, 25-azacoprostane (ASA-6), was evaluated for its effects on the growth, development and reproduction of the free-living nematodes, Caenorhabditis briggsae and Panagrellus redivivus. The axenic culture medium for either species of nematode consisted of Caenorhabditis briggsae Maintenance Medium (CbMM): formalin-killed Escherichia coli (1:1)(More)
25-Azasteroids were evaluated for their effects on the growth and development of the free-living stages of Nippostrongylus brasiliensis and Nematospiroides dubius. Increasing the concentration of 25-azasteroids in axenic cultures of either species resulted in a decrease in the percentage and mean length of larvae that developed to the third stage.(More)
Crystalline toxins from Bacillus thuringiensis israelensis and B.t. kurstaki were lethal in vitro to eggs of the nematode Trichostrongylus colubriformis. The LD50 values for the two toxins were 0.38 ng and 37.5 micrograms total protein/ml, respectively. After 1 week at ambient temperature, the LD50 of B.t. kurstaki decreased to less than 4 micrograms/ml.(More)
A toxin from the bacterium Bacillus thuringiensis israelensis is lethal to nematode eggs. Exposure of eggs of the ruminant nematode Trichostrongylus colubriformis to the toxin significantly increased the eggs' permeability to radiolabeled phenylalanine within 2 hr. Calcium chloride inhibited the toxin-induced change in egg permeability. Iodine staining of(More)
The cuticle of Haemonchus contortus, Nippostrongylus brasiliensis and Trichostrongylus colubriformis contained N-acetylgalactosamine and N-acetylglucosamine, based on the binding of fluorescein-labelled lectins. Binding of the lectins varied between the sexes and body regions of the nematodes. Treatment of male T. colubriformis with the lectin Lens(More)
Salmonella typhimurium within the 3rd stage larvae of Nematospiroides dubius was shown to infect mice, evidenced by prolonged shedding of salmonellae in the feces. Numbers of S typhimurium needed to infect mice were approximately 1,000- fold less if incorporated within the 3rd-stage larvae of N dubius. Results of these experiments demonstrate that nematode(More)
Bioassay of media fractions from cultivation of Bacillus thuringiensis israelensis revealed that ovicidal activity for eggs of the ruminant nematode Trichostrongylus colubriformis was found in microbial crystals, but was not released into culture medium. The purified delta-endotoxin of B. t. israelensis, composed of two 25 kDa proteins, had no effect on(More)