Bacillus thuringiensis subsp. oswaldocruzi and Bacillus thuringiensis subsp. brasiliensis, two novel Brazilian strains which determine new serotype H38 and H39, respectively

Rabinovitch, Leon; Jesús, Fredy; Cavados, Clara F.G.; Zahner, Viviane; Momen, Hoomen; Silva, M. H. L. da; Dumanoir, V. Cosmao; Frachon, Emmanuel; Lecadet, Marguerite-M.

doi:10.1590/s0074-02761995000100009

Cited by 9 publications

(6 citation statements)

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“…Recently, the classification of Bt based on H antigen was revised (De Barjac and Franchon, 1990) (Table 11). More than 40 H-serotypes are now available and in many of these the array of Bt toxin genes present in isolates from a particular serovar are the same (Rabinovitch et al, 1995). A notable exception is the presence of very different Bt toxin genes in subspecies morrisoni and tenebrionis within serotype 8a,b.…”

Section: Classification Of Bt Toxinsmentioning

confidence: 99%

The Insecticidal Proteins of Bacillus thuringiensis

Kumar

Sharma

Malik³

1996

Advances in Applied Microbiology Volume 42

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Section: Classification Of Bt Toxinsmentioning

confidence: 99%

The Insecticidal Proteins of Bacillus thuringiensis

Kumar

Sharma

Malik³

1996

Advances in Applied Microbiology Volume 42

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“…In Brazil, Rabinovitch et al (1995), isolated two new B. thuringiensis serotypes from commercial peppers. These isolates belong to serotype H-38 and H-39, B. thuringiensis serovar oswaldocruzi and B. thuringiensis serovar brasiliensis, respectively.…”

mentioning

confidence: 99%

A new black fly isolate of Bacillus thuringiensis autoagglutinating strain highly toxic to Simulium pertinax (Kollar) (Diptera, Simuliidae) larvae

Cavados

Fonseca

Chaves

et al. 2005

Mem. Inst. Oswaldo Cruz

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Formulations containing the entomopathogenic Bacillus thuringiensis serovar israelensis strain Bacillus thuringiensis is a Gram-positive, spore-forming bacterium which produces a parasporal body during sporulation. The proteins contained in the parasporal crystal (delta-endotoxins) are specific insect gut toxins which have no significant effect on non-target organisms (Siegel 2001). The mode of action after ingestion involves solubilization of the protein in the alkaline conditions of the insect midgut, followed by activation of the protoxin into toxin through cleavage of specific regions by gut proteases. Then, the so called toxin binds to specific receptors in the brush border membrane vesicles of the midgut columnar cells. The binding is a two-step process, the second part being the insertion of the toxin into the cell membrane leading to pore formation, osmotic imbalance, disruption of the cell membrane and finally, death of the insect (Van Rie et al. 1990, Knowles 1994.The use of bioinsecticides based on B. thuringiensis to control insects from the orders Diptera, Coleoptera, and Lepidoptera and more recently against Hymenoptera, Orthoptera, and Mallophaga, has stimulated the search for other natural pathogens (Schenpf et al. 1998 Between 1995 to 1998, an isolation program was set up to obtain entomopathogenic Bacillus from Simulium larvae and adults in the Southeast region of Brazil. Eighteen strains of B. thuringiensis and one of B. sphaericus were isolated (Cavados et al. 2001). Preliminary bioassays were performed and one of the B. thuringiensis strains (LFB-FIOCRUZ 1035) showed promising activity against Aedes aegypti and Culex quinquefasciatus (Cavados et al. 2001).In the present study, the toxicity of the autoagglutinating strain LFB-FIOCRUZ 1035 was evaluated against two Dipteran species, S. pertinax and Ae. aegypti larvae, and compared with a standard powder formulation of the reference B. thuringiensis serovar israelensis strain IPS-82, which is used in commercially available bioinsecticides. MATERIALS AND METHODSBacterial strains -Two strains of B. thuringiensis were used, one of them IPS-82 (LFB-FIOCRUZ 584) serotype H-14, isolated from the standard powder prepared by the Pasteur Institute of Paris, and the other LFB-FIOCRUZ 1035, an autoagglutinating strain isolated from S. pertinax larvae collected in a natural breeding-site in Growth started with a pre-inoculum to reduce the duration of the lag phase of bacterial growth. After inoculation in 125 ml Erlenmeyer flasks containing 50 ml of the medium, the flasks were incubated in a New Brunswick Scientific agitator series 25D, at 175 opm and 30°C for 6 h. Subsequently, 3 ml were transferred to 500 ml Erlenmeyer flasks containing 150 ml of the soy flour and inorganic salts medium and incubated as previously described for a further 72 h period.Once sporulation had reached 95% of free spores and crystals, each culture was centrifuged (6000 g, 10°C), the supernatant removed and the remaining material was kept in an amber container with the pH adjus...

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“…The frequent and intensive attacks by simuliids on the transitory population in this area can reduce tourism in summer months, a fact that could negatively impact the economies of affected municipalities. To decrease the presence of these insects in these areas, a full-scale programme, based on Bacillus thuringiensis serovar israelensis, has been carried out in the north littoral zone of the State of São Paulo since 1990 (Araújo-Coutinho 1995).Recent findings of B. thuringiensis serovar oswaldocruzi and B. thuringiensis serovar braziliensis from unusual habitats (Rabinovitch et al 1995) encourage the continued search for other endemic entomopathogens. For that purpose, Simulium larvae and adults from the north littoral zone of São Paulo and some other rivers in the State of Rio de Janeiro were evaluated for the presence of entomopathogenic bacteria.…”

mentioning

confidence: 99%

“…Recent findings of B. thuringiensis serovar oswaldocruzi and B. thuringiensis serovar braziliensis from unusual habitats (Rabinovitch et al 1995) encourage the continued search for other endemic entomopathogens. For that purpose, Simulium larvae and adults from the north littoral zone of São Paulo and some other rivers in the State of Rio de Janeiro were evaluated for the presence of entomopathogenic bacteria.…”

mentioning

confidence: 99%

Identification of entomopathogenic Bacillus isolated from Simulium (Diptera, Simuliidae) larvae and adults

Cavados¹,

Fonseca²,

Chaves³

et al. 2001

Mem. Inst. Oswaldo Cruz

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Entomopathogenic bacteria isolated fromSimuliids are hematophagus insects naturally occurring in waterways throughout Brazil. Although some species have been involved in the transmission of human onchocerciasis in other regions (Gerais & Ribeiro 1986, Maia-Herzog et al. 1999) the main importance of these insects in the southeast of Brazil is socio-economic. The frequent and intensive attacks by simuliids on the transitory population in this area can reduce tourism in summer months, a fact that could negatively impact the economies of affected municipalities. To decrease the presence of these insects in these areas, a full-scale programme, based on Bacillus thuringiensis serovar israelensis, has been carried out in the north littoral zone of the State of São Paulo since 1990 (Araújo-Coutinho 1995).Recent findings of B. thuringiensis serovar oswaldocruzi and B. thuringiensis serovar braziliensis from unusual habitats (Rabinovitch et al. 1995) encourage the continued search for other endemic entomopathogens. For that purpose, Simulium larvae and adults from the north littoral zone of São Paulo and some other rivers in the State of Rio de Janeiro were evaluated for the presence of entomopathogenic bacteria. MATERIALS AND METHODSCollection of simuliids -Black fly larvae and adults were collected from breeding sites in Pau d'Alho river, State of São Paulo. This river was divided into two regions, one downstream of B. thuringiensis serovar israelensis applications and another, upstream. Another collection point was the Soberbo river, Guapimirim, State of Rio de Janeiro (Fonseca et al. 1998). This river has never been exposed to commercial formulations based on B. thuringiensis serovar israelensis. Only larvae were collected in this waterway. The third point where larvae were collected was in Rio das Pedras, Mangaratiba, State of Rio de Janeiro.Isolation of Bacillus -To eliminate external contamination, the insects were sterilized following the methodology described by Alves (1986) with a slight modification; "Superbonder" glue (cyanoacrilate ester) was used to close both oral and anal cavities. This modification was adopted because Simulium larvae are very small and the dental floss used in the original technique was not applicable. After this step, the original method was performed passing the larvae through three solutions, first in 70% alcohol for 2 sec, second in 5% sodium hypoclorite for 3 min and finally in sterile 10% sodium thiossulfate for 5 min. The specimens were then washed three times in sterile distilled water.Two different methods were used to isolate B. thuringiensis samples. In both, Simulium larvae were transferred aseptically into a sterile mortar and macerated with a sterile pestle. In the first method, the macerate was placed in tubes containing distilled water (10 ml). The suspension was heated (65ºC) for 12 min, and immediately diluted (1x10 -2

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Bacillus thuringiensis subsp. oswaldocruzi and Bacillus thuringiensis subsp. brasiliensis, two novel Brazilian strains which determine new serotype H38 and H39, respectively

Cited by 9 publications

References 0 publications

The Insecticidal Proteins of Bacillus thuringiensis

The Insecticidal Proteins of Bacillus thuringiensis

A new black fly isolate of Bacillus thuringiensis autoagglutinating strain highly toxic to Simulium pertinax (Kollar) (Diptera, Simuliidae) larvae

Identification of entomopathogenic Bacillus isolated from Simulium (Diptera, Simuliidae) larvae and adults

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