Huguette de Barjac

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Le nouveau sérotype H14 individualisé dans le groupe desBacillus thuringiensis Berliner, sous le nom de variétéisraelensis est un pathogène puissant et essentiel des larves de moustiques. Son pouvoir larvicide n'a aucun équivalent chez les autres sérotypes connus deB. thuringiensis et apparaît très compétitif avec celui deB. sphaericus. A dose forte,B.(More)
Guidelines have been formulated for safety tests and registration of new microbial pesticides containing pathogenic or inhibitory bacteria. These guidelines are intended for the advice of interested firms and governmental agencies. They are based on over a decade's experience and intense recent activity in this field. For the registration of a new microbial(More)
A new medium (MBS) for optimal sporulation of Bacillus sphaericus was defined. With the two main mosquito pathogenic strains grown in this medium, 1593-4 and 2297, highest cell and spore yields were obtained, concomitantly with an highest larvicidal activity against Culex pipiens. Study of both strains asporulated mutants showed a decrease in larvicidal(More)
The larvicidal power of more than 180 Bacillus sphaericus strains belonging to six H serotypes has been assayed on Culex pipiens, Anopheles stephensi and Aedes aegypti under standardized conditions. The most potent strains are distributed into serotype H5a5b, generally toxic to the three mosquito species, and serotypes H6 and H25, toxic to C. pipiens and A.(More)
Après avoir rappelé les classifications précédemment proposées pour lesBacillus thuringiensis, les auteurs indiquent l'état actuel de leur classification qui est maintenant la plus utilisée et qui comporte 12 sérotypes et 17 souches-types. La prise en considération de caractères enzymatiques tels que la DNase, la RNase, l'arginine-dihydrolase fournit une(More)
A toxicity study of 54 Bacillus sphaericus strains isolated from vectors or breeding sites has led to a relatively homogeneous grouping of mosquito pathogenic strains into five H-serotypes among the nine serotypes determined. Each serotype seems to be characterized by a different level of toxicity and a classification of these five serotypes can be made on(More)
A screening of the larvicidal activity of the more than 900 strains ofBacillus thuringiensis strains, combining the Institut Pasteur collection was realized. A quick bioassay using 1st instar larvae and semi-synthetic medium was developed. Many strains were toxic toSpodoptera littoralis, but only a few belonging mainly to serovarsaizawai, kenyae(More)
24 strains ofBacillus thuringiensis type are studied by the determination of 35 cultural and biochemical characters. About 10 different biochmeical characters make it possible to classify these strains into six major biochemical groups represented by one or two type-strains (biotypes). On the other hand, the study of these 24 strains by the flagellate(More)
Clostridium bifermentans serovar malaysia is toxic to mosquito larvae. During large-scale preparation in a fermentor, the bacteria enter the sporulation stage after 5 h culture, whereupon high larvicidal activity is obtained (LC50 48 h on Anopheles stephensi = 3.1 × 10−5). The toxicity becomes maximal around 3–5 h later (LC50 48 h = 1.3 × 10−5) and remains(More)