<p><strong>Introducción.</strong> La principal estrategia para el control de <em>Aedes aegypti</em>, vector de los virus dengue, chikungunya y Zika, se basa en la utilización de insecticidas con el fin de disminuir las poblaciones del vector. Sin embargo, su uso ha conllevado a que el insecto desarrolle resistencia a estos químicos.</p><p><strong>Objetivo.</strong> Determinar la presencia de la mutación F1534C, asociada con resistencia cruzada a DDT y piretroides, en mosquitos de la especie <em>Ae. aegypti</em> de la ciudad de Sincelejo, Colombia.</p><p><strong>Materiales y métodos.</strong> El estudio se desarrolló con nueve ejemplares de <em>Ae. aegypti</em> que mostraron resistencia<strong> </strong>a lambdacialotrina en bioensayos desarrollados por la Secretaría de Salud de Sucre. Se realizó una PCR semi-anidada, según la la metodología descrita por Harris y colaboradores (2010), con el fin de amplificar el exón 31 del gen <em>para</em> del canal de sodio dependiente de voltaje de <em>Ae. aegypti</em>. Los productos de PCR se secuenciaron, editaron y analizaron con el programa MEGA 5.<strong></strong></p><p><strong>Resultados.</strong> En todos los mosquitos evaluados se detectó la presencia del alelo silvestre y mutante del exón 31. En la secuencia nucleotídica del alelo mutante, se observó una sustitución de timina por guanina, que produce el cambio del codón UUC por UGC y conlleva al reemplazo del aminoácido fenilalanina por cisteína en el residuo 1534 de la proteína.</p><p><strong>Conclusión.</strong> Los nueve mosquitos analizados presentaron un genotipo heterocigoto para la mutación F1534C, cuyo efecto fenotípico es la resistencia al derribo (<em>kdr</em>) por los insecticidas DDT y piretroides.</p>

Introduction. Aedes aegypti is the most important mosquito species in America for the transmission of viruses of dengue, Zika, Chikungunya and yellow fever. Ecological factors as well as chemical controls can affect the genetic composition of Ae. aegypti populations, which is why its genetic characterization is necessary. Objective. To determine the genetic variability of Ae. aegypti populations in four municipalities of Sucre department, Colombia. Materials and methods. Larvae of Ae. aegypti, collected in the municipalities of Sincelejo, Sampués, Corozal and Guaranda, Sucre department, were reared under laboratory conditions to adult stage. A segment of the mitochondrial ND4 gene which codes for the subunit 4 of the enzyme NADH-dehydrogenase was used as genetic marker. The genetic analysis included the estimation of parameters of nucleotide and haplotype diversity, genetic structure and gene flow. Results. One hundred and eight partial sequences of 357 nucleotides and four nucleotide haplotypes of the ND4 gene of Ae. aegypti were obtained. A significantly high genetic differentiation was found between the Sampués and Guaranda populations (FST=0.59467), Sincelejo and Sampués (FST=0.25637), and Corozal and Guaranda (FST=0.22237). A high gene flow (Nm=infinite) was observed among the populations of Sincelejo and Corozal. Conclusion. There are genetic differences between the Ae. aegypti populations from the municipalities of Sucre department. The presence of a new haplotype of the mitochondrial ND4 gene of Ae. aegypti in Colombia was recorded, detected in the municipality of Sincelejo.

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The austempered ductile iron (ADI) is a material with great potential while talking about applications involving toughness, high strength, ductility or wear resistance. In most applications where ADI is employed, its corrosion resistance might be a transcendental property, nevertheless, due to its structure, the ADI doesn't possess resistance very marked to corrosion. Even so, it's of great interest to know how different parameters on heat treatment could affect the ADI microstructure's, and it can disturb its behavior against various variables, and in consequence its properties as its applications areas could be reduced. In this paper we evaluate the corrosion resistance presented by ADI irons, after having been subjected to different Austempered treatments. The results show that the waiting times of the ADI in the salt bath as well as in the furnace austenitizing, play a crucial role in evaluating the corrosion resistance of these irons.