Isolation and curing of plasmid DNA from bacillus thuringiensis israelensis strains showing variable insecticidal activities

Bacillus thuringiensis israelensis 4Q1-WT [B. t. i.] have 9 plasmids. 14 mutates of this wild type were prepared with cured plasmids. The wild bacterial strain, the mutants and 14 industrial strains were compared according to the number, size of plasmids and their potential to induce mortality to Aedes caspius larvae. The 108 Kb plasmid is essential for B. t. israelensis to induce insect killing

Assignment of the crystal toxin genes of the mosquitocidal bacterium, bacillus thuringiensis israelensis to a specific plasmid

Bacillus thuringiensis 4Q1-WT and the prepared mutants, 4Q1-72 and 4Q1-81, were bioassayed against Aedes caspius larvae. The strain-4Q1-WT, which contains all plasmid arrays and the strain 4Q1-72 which contains the 108 kb plasmid gave 100% mortality, while stain 4Q1-81, which contains no plasmids, gave 0% mortality. Crystals from all tested strains were isolated, solubilized and characterized using PAGE to detect any homology or difference in crystal production, properties, and the relatedness to the plasmid profile

Bacterial contamination of the housefly, musca domestica, collected from 4 hospitals at Cairo

Four general hospitals were surveyed for bacterial contamination of the housefly, M. domestica which were caught inside the hospital sites and outside surroundings, especially, general garbages, Fly collections were made using the hanging sticky ribbon traps [spiralette]. Bacterial isolation was made from each sample both externally and internally during two successive years representing the different seasons of the year. Twenty-one bacterial isolates were identified from the 4 surveyed hospitals belonging to six families. Enterobacteriaceae [9 species each], Brucellaceae. [2 species]. Acromabacteriaceae and Pseudomonodaceae [one- species each]

Cloning and expression of the lepidoprotein toxin produced by bacillus thuringienesis var sotto in escherichia coli

During sporulation, Bacillus thuringiensis var. Sotto produces a parasporal crystalline protein which is toxic for the silk-worm, Bombyx mori and the cotton leaf worm, Spodoptera littoralis. The gene coding this crystal protein is present in a single plasmid. The plasmid DNA was isolated, purified and physically mapped using restriction endonuclease enzymes [R.E.]. The gene coding the sigma endotoxin was inserted into Escherichia coli -Jm103, using cloning vector pUC8. Transformed E. coli cells were found to synthesize the sigma endotoxin as demonstrated by the pathogenicity of the transformed cells against 4[th] instar larvae of S. littoralis

In situ inhibition of cholinesterase in anopheles pharoenisis and culex pipiens by malathion and fenitrothion

Inhibition of cholinesterase after poisoning of Anopheles pharoensis and Culex pipiens with 1c50[s] of malathion and fenitrothion was studied histochemically. The pattern of inhibition of both insecticides was similar. Inhibition was to a greater or less extent confined to the peripheral region of the thoracic ganglia, while the brain and abdominal ganglia showed partial inhibition of the neuropiles. The data provided evidence that if death is caused by inhibition of cholinesterase of the nervous system it is due to local inhibition and not to generalized inhibition

Histochemical localization of cholinesterases in some developmental stages of anopheles pharoensis and culex pipiens [Diptera: culicidae]

The distribution of cholinesterase in the larvae, pupae and adults of Anopheles pharoensis and Culex pipiens was investigated histochemically. Cholinesterase was found throughout the central nervous system and in peripheral nerves. Nonnervous tissues, such as gastric caeca, Malpighian tubules, longitudinal muscles, salivary glands sometimes exhibited faint cholinesterase reactions. Eserine sulphate and iso-OMPA were used as inhibitors in an attempt to characterize the enzyme as either acetylcholinesterase or pseudocholinesterase