Diversidad genético molecular de cepas de Bacillus thuringiensis con potencial tóxico contra Aedes aegypti

Abstract

ResumenObjetivos: Evaluar la diversidad genético molecular de cepas nativas aisladas de B. thuringiensis tóxicas contra Aedes aegypti, vector del dengue. Diseño: Estudio descriptivo, analítico. Institución: Centro de Investigación de Bioquímica y Nutrición, Facultad de Medicina, UNMSM. Material biológico: Cepas nativas y estándar de B. thuringiensis. Intervenciones: Se extrajo el ADN genómico de 53 cepas nativas y 10 cepas estándar de B. thuringiensis aisladas del suelo de distintas regiones geográficas del Perú. Para el análisis de diversidad, se evaluó secuencias repetitivas de ADN mediante la técnica REP-PCR, siendo visualizados en geles de agarosa teñidos con bromuro de etidio. Se hizo el análisis de clúster con el dendograma de similaridad de cepas estándares y nativas de B. thuringiensis, utilizando programas bioinformáticos. Principales medidas de resultados: Diversidad evaluada mediante los perfiles genéticos (bandas de ADN repetitivas) en geles de agarosa y dendograma de cepas B. thuringiensis. Resultados: Las cepas procedentes de Junín, Huaral, Ica, Cusco, Arequipa y Cajamarca tendieron a formar grupos según procedencia, destacándose dos caracterizadas como potencialmente tóxicas contra Aedes aegypti (de Ica y de Cajamarca), formando un subgrupo con cepas estándar tóxicas HD-968 y GM 33. Conclusiones: Se observa gran diversidad de cepas nativas de B. thuringiensis procedentes de diferentes lugares del país, con cierta tendencia a formar subgrupos según procedencia geográfica y en relación de similaridad con las cepas B. thuringiensis estándares, algunas con potencial para ser utilizadas contra Aedes aegypti, vector del virus del dengue. Palabras clave: Bacillus thuringiensis, variación (genética), genes bacterianos, virus del dengue. Abstract Objectives: To determine the molecular genetic diversity of native B. thuringiensis strains toxic against Aedes aegypti, vector of dengue. Design: Descriptive, analytical study. Setting: Biochemistry and Nutrition Research Center, Faculty of Medicine, San Marcos University, Lima, Peru. Participants: Native and standard strains of B. thuringiensis. Interventions: Extraction of B. thuringiensis genomic DNA from 53 native strains and 10 standard strains isolated from different Peruvian regions soil samples. Diversity was determined by repetitive DNA sequences using REP-PCR technique, visualized in agarose gels stained with ethidium bromide. B. thuringiensis standard and native strains cluster analysis was performed by dendrogram of similarity using bioinformatic programs. Main outcome measures: Diversity of B. thuringiensis strains. Results: Strains from Junin, Huaral, Ica, Cusco, Arequipa, and Cajamarca tended to form groups according to source, highlighting two strains characterized as potentially toxic against Aedes aegypti (Ica and Cajamarca), and outlining a subgroup or cluster with toxic standard strains HD-968 and GM 33. Conclusions: A great diversity of B. thuringiensis native strains coming from different regions of the country have a tendency to form sub-gr...

Genetic diversity of Brazilian Bacillus thuringiensis isolates with toxicity against Aedes aegypti (Diptera: Culicidae)

“…When correlating the mortality of the BtMA isolates and the site of origin, only group VI, constituted by the isolates BtMA-684, BtMA-685, BtMA-688, BtMA-689 and BtMA-679, showed a genetic relationship. This low correlation was also verified by Huerta et al 21 when verifying subgroups of Bt formed according to the geographical origin and potential use against A. aegypti. Likewise, Da Silva and Valicente 9 and Machado et al 35 , comparing the genetic relationship of Bt isolates toxic to Spodoptera spp.…”

“…The repetitive element palindromic-polymerase chain reaction (rep-PCR) technique has been used to investigate the interspecific and intraspecific genetic diversity of Bt isolates, allowing us to correlate them with the geographic regions of collection, the origin of the substrate, morphological, biochemical and genetic characteristics, and rates of mortality and toxicity against insect pests and vectors 32,50,21,19,35 .…”

“…Huerta et al 21 , using REP primers, evaluated the genetic diversity of 53 Bt isolates collected in soil from different geographical regions of Peru and correlated the similarity of these isolates according to geographic origin. Similarly, Da Silva and Valicente 9 pointed out that the similarity of Bt isolates may be related to geographic location when they used the ERIC, REP and BOX primers simultaneously.…”

Genetic diversity of Brazilian Bacillus thuringiensis isolates with toxicity against Aedes aegypti (Diptera: Culicidae)

“…The repetitive element palindromic-polymerase chain reaction (rep-PCR) technique has been used to investigate the interspecific and intraspecific genetic diversity of Bt isolates, allowing us to correlate them with the geographic regions of collection, the origin of the substrate, genetic characteristics, and rates of mortality and toxicity against insect 22 , 23 , 29 , 38 , 39 .…”

“…Huerta et al 38 , using REP primers, evaluated the genetic diversity of 53 Bt isolates collected in soil from different geographical regions of Peru and correlated the similarity of these isolates according to geographic origin. Similarly, Da Silva and Valicente 20 pointed out that the similarity of Bt isolates may be related to geographic location when they used the ERIC, REP and BOX primers simultaneously.…”