Biology subjects

Duque, J. E.

Publications and source records attributed to Duque, J. E..

7 recordsLinked to original sources

bioRxiv2026

Carvacrol as a dual-target acaricidal candidate against the cattle tick Rhipicephalus (Boophilus) microplus: molecular docking, mechanistic validation, and early field testing

The blood-sucking ectoparasite Rhipicephalus B. microplus represents one of the greatest economic threats to livestock worldwide. The discovery of novel acaricidal molecules based on environmentally sustainable technologies is therefore required, particularly those suitable for use in dairy and meat-producing livestock without generating contaminant residues. This study aimed to identify and validate plant-derived metabolites with dual activity on acetylcholinesterase and mitochondrial targets as sustainable acaricidal agents against R. microplus, integrating computational screening, biochemical assays and field evaluation. Following in silico screening of 1.300 plant metabolites targeting acetylcholinesterase and mitochondrial function, fourteen compounds were selected for in vitro and in vivo mortality assays using immersion and larval vessel methods. Carvacrol was identified as the most promising metabolite and showed an inhibitory mechanism of action on acetylcholinesterase and mitochondrial complexes I, III, and IV. Its acaricidal efficacy was subsequently confirmed under field conditions using ethanolic and oily formulations (spray and pour-on) applied to cattle (Bos taurus). The spray formulation significantly reduced tick infestation, decreasing tick counts by 20% every 10 days (p < 0.001), whereas the pour-on formulation showed no significant reduction (p = 0.093). These results demonstrate that an integrated discovery pipeline from computational screening to field validation provides a robust strategy for identifying plant-derived acaricidal agents targeting key physiological pathways in R. microplus. HighlightsO_LIStructured and sequential workflow (pipeline) from in silico to Bos taurus C_LIO_LIIdentification and validation of phytometabolites against R. microplus C_LIO_LICarvacrol multitarget activity on acetylcholinesterase and bioenergetic in ticks C_LIO_LIThe spray formulation reduces tick infestation by 20% every 10 days C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=91 SRC="FIGDIR/small/727743v1_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@11c9931org.highwire.dtl.DTLVardef@8d6088org.highwire.dtl.DTLVardef@1bcc09aorg.highwire.dtl.DTLVardef@108d1d1_HPS_FORMAT_FIGEXP M_FIG C_FIG Created in BioRender. Avendano, G. (2026) https://BioRender.com/7pm1ffj

biochemistry↗

bioRxiv2026

Electroantennographic and behavioral responses of Rhodnius prolixus (Stal 1872) to xenobiotics reveal carvone and IR3535 as potential repellent candidates

Electroantennography (EAG) is a valuable approach for monitoring the sensory responses of insects to insecticidal and repellent molecules and an effective tool for early screening of compounds aimed at controlling and protecting against medically important insect vectors. However, its predictive potential for repellent efficacy in triatomine vectors remains poorly explored. The objective of this study was to evaluate the EAG responses to different xenobiotics as a preliminary selection strategy for compounds with potential repellent action against triatomines. For this purpose, the antennae of adult triatomines subjected to prolonged fasting ([≥]30 days) were exposed to repellent molecules. In parallel, repellency bioassays were conducted using a live bait (Gallus gallus) and a newly designed laboratory device to validate the electroantennographic results. EAG recordings showed a significant reduction in olfactory capacity of> 60% in response to the chemical compounds IR3535 and carvone, consistent with the protection times observed in the repellency tests (135.6 {+/-} 43.29 min and 108 {+/-} 26.33 min, respectively). In conclusion, the compounds with the highest repellent activity were clearly discriminated by the insects olfactory system, a finding corroborated by the decrease in electrical signals recorded in the EAG bioassays.

animal behavior and cognition↗

bioRxiv2025

Baseline bioenergetic profile of mitochondria and permeabilized tissue of Aedes aegypti (Diptera: Culicidae) throughout its life cycle

Cellular respiration parameters provide information on the energy metabolism of an organism under physiological or non-conditions and can be determined by isolating mitochondria or even using their permeabilized tissue. The present study aimed to describe the mitochondrial activity of Ae. aegypti throughout its life cycle. For this purpose, we isolated mitochondria and permeabilized tissue (1 and 5 individuals) from larvae (L4), pupae, and adults (female thorax) to estimate oxygen consumption using different oxidizable substrates (glutamate, malate, proline + pyruvate, succinate, and glycerol-3-phosphate). The Respiratory Control Coefficient (RCC) was calculated, and the specific enzyme activity of the Electron Transport Chain (ETC) was quantified. The highest values of oxygen consumption (state 3) were obtained when succinate was used as the oxidizable substrate in all developmental stages of Ae. aegypti, with a progressive increase in the values recorded from larva (isolated mitochondria: 30.3 {+/-} 5.0 pmol/(s*mL), permeabilized tissue/ 5 individuals: 48.8{+/-}1.8 pmol/(s*mL)), through pupa (isolated mitochondria: 42.8{+/-}3.6 pmol/(s*mL); permeabilized tissue/5 individuals: 47.4{+/-}2.2 pmol/(s*mL)), through adult (isolated mitochondria: 53.4{+/-}6.0 pmol/(s*mL); permeabilized tissue/5 thorax: 27.4{+/-}2.4 pmol/(s*mL)). These results are congruent with the values obtained for enzyme activity, with higher activity of succinate oxidase and succinate dehydrogenase enzymes (Complex II). The CCR values for isolated mitochondria and permeabilized tissue ranged from 1 to 1.8. The results allow us to conclude that there are changes in mitochondrial respiration throughout the life cycle of the Ae. aegypti mosquito.

biochemistry↗

bioRxiv2024

TropD-Detector: A CRISPR/LbCas12a-Based system for rapid and sensitive screening of Trypanosoma cruzi in Chagas vectors and reservoirs

Chagas disease, also known as American Trypanosomiasis, is a zoonosis with global distribution caused by the parasite Trypanosoma cruzi, primarily transmitted through the feces of infected triatomines. The emergence of new cases in non-endemic areas highlights the importance of early pathogen detection in vectors and reservoirs to generate effective control strategies and establish preventive policies. The objective of this study was to design and validate a detection system of T. cruzi based on specific DNA cleavage and collateral activation using the CRISPR/LbCas12a system, targeting the genes Cytochrome B (Cytb), 18S ribosomal subunit (SR18s), and histone (H2A). This system was validated for their uses in both vectors and reservoirs of the parasite. The first step was to conduct a bioinformatic analysis of the target genes and design RNA guides for each cleavage site and primers to amplify the target region through PCR. Subsequently, we sequenced the amplified DNA target and validated the detection system using T. cruzi DNA extracted from naturally infected Rhodnius pallescens in the metropolitan area of Bucaramanga, Colombia. After standardizing the method, we tested the CRISPR/Cas system with Silvio X10/4 laboratory strain of T. cruzi and scaled up to blood samples of naturally infected Didelphis marsupialis. As a result, we observed the DNA cleavage employing the CRISPR/Cas system with Cytb guide with a sensitivity of up to 0.0475 ng/uL of provided DNA. Sequencing of the Cytb gene showed no mutations in the cleavage site. However, point mutations and indels were found in SR18S and H2A, avoiding the formation of the CRISPR/LbCas12 complex. Furthermore, we introduce the design of a fluorescent detection prototype with CRISPR/LbCas12a called "Tropical Diseases Detector" (TropD-Detector). This device operates with an excitation wavelength of 480 nm emitted by an LED and a high-pass light filter with a cutoff wavelength of 500 nm. We detected positive samples using any photographic camera system. The TropD-Detector provides a visual, viable, and sensitive method for detecting T. cruzi in both vectors and reservoirs from endemic areas.

molecular biology↗

bioRxiv2024

Differentiation smelling footprints of the Chagas disease vector using an electronic nose based on artificial intelligence algorithms

The present study aims to present the design of an electronic nose capable of learning and differentiating semiochemical signals emitted by insects usable to identify species that transmit Chagas disease. The proposed device used different non-specific resistor gas sensors integrated into a system of artificial intelligence models. To validate the nose, we used eight insect species of the Triatominae subfamily and one population that was a natural carrier of the parasite Trypanosoma cruzi. Also, the discriminatory capacity of distant species was tested with other insects like Aedes aegypti (arbovirus vector) and Sitophilus oryzae (stored grains plague). As a result, the electronic nose was able to differentiate up to gender level with an accuracy of 89.64% and to differentiate Rhodnius pallensces naturally infected with T. cruzi with less than 1% of error in classification. These results show that our designed device can detect particular smelling footprints, and one electronic nose like that could be a tool to discriminate against insects in the future.

animal behavior and cognition↗

bioRxiv2024

Sand flies around Tona, an artificial water reservoir in Bucaramanga (Santander, Colombia): diversity, spatiotemporal frequency, and efficacy of four sampling methods

Characterizing the sand fly diversity is crucial for an effective design of control strategies for Leishmaniasis. We aimed to characterize the sand fly biodiversity around the Tona Reservoir (Santander, Colombia) and to compare the performance of four sampling methods. A sampling of insects was performed in 2017 in the most preserved and least preserved areas close to the Tona Reservoir, using Torre Vigia-UIS and HomeTrap-UIS, two sticky traps previously designed by our working group, CDC, and Bg-Sentinel traps. We collected 268 Phlebotominae specimens, most with CDC (47.8%) and Torre Vigia-UIS (30.2%) traps. Some specimens (47%) could not be determined because of their preservation status; these samples came mostly from the sticky traps. We found 16 sand fly morphospecies, of which 12 were determined to species level. Here, we report two new records for Santander: Pintomyia youngi (Feliciangeli and Murillo, 1987) and Lutzomyia ceferinoi (Ortiz and Alvarez, 1963). We also collected some confirmed vectors of Leishmania: Pi. youngi, Lutzomyia gomezi (Nitzulescu, 1931), and Lu. longipalpis (Lutz and Neiva, 1912). The highest diversity was collected in the most disturbed area (15 spp.), and in the rainy season (April, 12 spp.). Pintomyia youngi distribution was broad through the Tona Reservoir in all the sampled periods, and we suggest tracking it to infer leishmaniasis risk in the Tona Reservoir. Torre Vigia-UIS seems a valuable tool for vector control, but we do not recommend it for biodiversity studies.

ecology↗

bioRxiv2020

Effect of Altitude on Wing Metric Variation of Aedes aegypti (Diptera: Culicidae) in a Region of the Colombian Central Andes

In mosquitoes of medical importance, wing shape and size can vary with altitude, an aspect that can influence dispersion and, consequently, their vector capacity. Using geometric morphometry analysis, Aedes aegypti wing size and shape variation of males and females was studied in four altitudes in the second-smallest department in Colombia: 1.200 m (Tebaida), 1.400 m (Armenia), 1.500 m (Calarca), and 1.700 m (Filandia). Wing shape in males (P < 0.001) and females (P < 0.001) was significantly different through the altitudinal gradient; in turn, wing size in males followed the altitudinal gradient (Males R2 = 0.04946, P = 0.0002), Females (R2 = 0.0011, P = 0.46). Wing allometry for males (P < 0.001) and females (P < 0.001) was significant. Likewise, the shape and size of the wings of males (P < 0.001) and females (P < 0.001) had significant fluctuating asymmetry. It is concluded that, in a small scale with an altitudinal variation of 500 meters, it is detected that the size and shape of the wings varied in A. aegypti, principal vector of dengue, chikungunya, and Zika. The fluctuating asymmetry is present in the individuals studied and could be associated with environmental effects caused by vector control campaigns present in some sampling locations.

evolutionary biology↗