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In Vitro Activity of the Triazinyl Diazepine Compound FTSD2 Against Drug-Resistant Mycobacterium tuberculosis Strains
(Multidisciplinary Digital Publishing Institute (MDPI), 2025-03-02) Aranaga, Carlos; Varela, Ruben; Falco, Aura; Villa, Janny; Moreno, Leydi M.; Causse, Manuel; Martínez Martínez, Luis
Background/Objectives: Compounds derived from pyrimido-diazepine have shown selective inhibition of the susceptible Mycobacterium tuberculosis strain H37Rv. However, there is a need for studies that evaluate the activity of these compounds against multidrug-resistant strains and clinical isolates. This study aims to evaluate the antitubercular potential of FTSD2 against drug-resistant strains of M. tuberculosis.
Methods: The compound 4-(2,4-diamino-8-(4-methoxyphenyl)-8,9-dihydro-7H-pyrimido[4,5-b][1,4]diazepin-6-yl)-N-(2-(4-(dimethylamino)-6-(4-fluorophenyl)amino-1,3,5-triazin-2-yl)amino)ethyl)benzenesulfonamide (FTSD2) was tested against drug-resistant M. tuberculosis strains at minimal inhibitory and bactericidal concentrations (MIC and MBC). Kill curve assays were performed to assess bactericidal activity, and cytotoxicity was evaluated in human monocyte-derived macrophages and the RAW 264.7 murine macrophage cell line. Intracellular death assays, specifically macrophage infection assays, were also conducted to evaluate the effect of FTSD2 on intracellular M. tuberculosis growth.
Results: FTSD2 inhibited the growth of drug-resistant M. tuberculosis at MIC and MBC values between 0.5 and 1 mg/L. Kill curve assays demonstrated concentration-dependent bactericidal activity. No cytotoxicity was observed in macrophages at concentrations below 64 mg/L. Additionally, FTSD2 significantly suppressed intracellular M. tuberculosis growth after 192 h. FTSD2 did not inhibit the growth of nontuberculous mycobacteria, including M. avium, M. abscessus, M. fortuitum, M. chelonae, and M. smegmatis at 50 mg/L.
Conclusions: FTSD2 exhibits strong potential as a leading compound for the development of new antitubercular drugs, with selective activity against M. tuberculosis and minimal cytotoxic effects on macrophages. Further studies are needed to explore its mechanisms of action and therapeutic potential.
Tropical lakes as a novel source of oleaginous yeasts with lipid profiles for biodiesel, oleochemical, and nutraceutical applications
(Springer Science and Business Media B.V., 2025-03-13) Ramirez Castrillon, Mauricio; Benavides León, Tatiana Andrea; Arcos Velasco, Lizeth Vanessa; Pantoja Pulido, Kriss Dayana; Lopez Parra, Lizbeth Lorena; Bolaños Rojas, Ana Cristina; Osorio Cadavid, Esteban
Oleaginous yeasts have emerged as promising microbial cell factories for lipid production, offering sustainable alternatives to traditional sources of biodiesel and nutraceuticals. In this study, the lipid accumulation potential of yeast strains isolated from two freshwater aquatic ecosystems in Cali, Colombia, was evaluated to identify novel candidates for biotechnological applications. A total of 56 strains were tested for their oleaginous nature using a gravimetric lipid assay with glucose as a carbon source. Of the assessed strains, 46.15% exceeded 20% lipid yields relative to the dry biomass. Seven strains were selected using glycerol as a carbon source, but only five yeasts were further characterized for their lipid profiles. Molecular identification revealed diverse species, including Aureobasidium sp., Papiliotrema rajashtanensis, Rhodotorula spp., and Clavispora lusitaniae. The selected strains demonstrated unique lipid profiles, with high proportions of monounsaturated and polyunsaturated fatty acids, such as oleic acid (C18:1) and linoleic acid (C18:2). In particular, Aureobasidium sp. accumulated uncommon fatty acids such as petroselinic acid under conditions induced by glycerol. This fatty acid, which has a double bond in position 6,7 and a melting point of 33 °C, highlights its potential as an alternative to margarine production, as well as a precursor to sophorolipids, estolide esters, soaps, and plastics. Rhodotorula sp. exhibited very long-chain fatty acids such as docosadienoic and docosatrienoic acids in its lipid profile. These findings underscore the biotechnological value of yeasts from lentic aquatic systems as sustainable lipid producers, paving the way for innovations in biofuels, nutraceuticals, and oleochemicals.
Diversity analysis, distribution and abundance of mosquito (Diptera: Culicidae) assemblages at urban sector from southwestern Colombia
(Springer Science and Business Media Deutschland GmbH, 2025-01-16) Bedoya Rodríguez, Francisco Javier; Guevara Fletcher, Carlos Eduardo; Pelegrin Ramírez, Jonathan Steven
The Culicidae family (mosquitoes) has great relevance worldwide, due to its involvement in generating several diseases. The Department of Cauca in Colombia is characterized as a region with the influence of several vector-borne diseases. This study aims to analyze the ecological diversity and distribution of mosquitoes with potential transmitters of diseases in a particular urban area of the municipality of Santander de Quilichao. This is one of the first studies of its kind in this municipality. Mosquito collections were carried out during the rainy and dry seasons of 2022, between 17:00 to 19:00. Morphological keys were used for species identification. For the analysis of diversity comparison vs. sampling points, Simpson's index was used, a dendrogram, rarefaction curve, and non-metric multidimensional scaling (nMDS). In the statistical analysis of species-abundances, ANOVA was applied to determine if there were significant differences regarding abundance. A total of 1116 culicid specimens were collected. The 59.4% were mosquitoes of the species Aedes aegypti, 18.5% Culex quinquefasciatus, 18.2% Aedes albopictus, and 3.9% Psorophora ferox, being the rainy season important for their survival. ANOVA analysis showed that the mean abundance of Ae. aegypti was significantly different from the other species. This study is broadly consistent with other studies in the tropical American context where the abundance of Culicidae is more representative in the rainy season. The results suggest a wide presence of Aedes mosquitoes in natural and artificial habitats, showing the importance of establishing controls and permanent epidemiological surveillance in this region.
Application of Bayesian filters to temperature estimation in deep brain stimulation
(Springer Verlag, 2025-02-28) Pereira, Caroline R.; Jardim, Lucas C. S.; Abreu, Luiz A. S.; Knupp, Diego C.; Varon, Leonardo A. B.; Silva Neto, Antônio J.
This work presents an approach for estimating the temperature field and, therefore, improving the accuracy of the internal temperature assessment in a brain containing a deep brain stimulation (DBS) lead. Thus, this research provides a methodology to avoid possible undesirable burns that may occur due to the heating of the tissues around the DBS lead. The classical two-dimensional bioheat equation is considered in the modeling of the heat transfer problem, and the Laplace equation was used to model the electric potential problem. The direct problem is solved with the finite element method (FEM), finite difference method (FDM), and the hybrid numerical–analytical approach generalized integral transform technique (GITT). For the inverse problem, estimates are obtained sequentially by solving a state estimation problem with particle filter methods. Two particle filters are used: the sampling importance resampling (SIR) algorithm and the Liu & West’s algorithm. Some results are presented and critically discussed for synthetic temperature measurements with different noise levels, leading to accurate estimations. The methodology presented in this work may bring a promising sequential approach to reduce the risk of injuries related to the deep brain stimulation technique.
Effects of consecutive dredging on the fish community of a tropical estuary
(Elsevier Ltd, 2025-03) Duque, Guillermo; Gamboa García, Diego Esteban; Molina, Andrés; Cogua, Pilar
Dredging is a human activity that significantly alters aquatic habitats, potentially impacting ecosystem services such as artisanal fishing. This study aimed to evaluate changes in fish density in Buenaventura Bay in response to three dredging events that occurred between 2015 and 2021. Fish monitoring was conducted using artisanal trawl nets before, during, and after each dredging event, with annual sampling in two areas of the bay over the study period. The findings revealed species-specific responses: while species such as the catfish Cathorops multiradiatus and the sole Achirus kluzingeri benefited from dredging, the pygmy pufferfish Sphoeroides trichocephalus was negatively affected. Contrary to common assumptions in the literature, resident estuarine species were not necessarily the most negatively impacted but instead exhibited variable responses to dredging disturbances. The fish assemblage showed a shift towards species more tolerant to these impacts, highlighting a potential loss of ecosystem resilience. These changes could have long-term implications for the productivity of artisanal fisheries and the food security of local fishing communities.