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URI permanente para esta colecciónhttp://10.0.96.45:4000/handle/11056/20509

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Antimicrobial activity of diverse chemotypes of Lippia graveolens against Aeromonas hydrophila isolated from tilapia
(Cold Spring Harbor Laboratory (Estados Unidos), 2023-07-25) García-Pérez, Josué; Perez-Sabino, Juan Francisco; Mendoza, Susana; Ribeiro da Silva, Antonio Jorge; Ulloa Rojas, Juan B.
Objetive: This study aimed to evaluate the antimicrobial efficacy of essential oil (EO) from diverse chemotypes of Lippia graveolens against oxytetracycline-resistant Aeromonas hydrophila, which primarily affects the tilapia aquaculture (Oreochromis sp) in Guatemala. Methodology: L. graveolens were collected in three departments in Guatemala, the EO was obtained by hydrodistillation and characterized by gas chromatography and mass spectrometry (GC/MS). Subsequently, an antimicrobial assay was conducted by screening the disk and dilution susceptibility tests, and evaluation of synergistic interactions among the chemotypes, each test being carried out in triplicate. Results: The analysis revealed the presence of twenty-seven compounds in the EO obtained from the chemotypes, the main class being monoterpene. The major constituents identified were cis-Dihydro-β-terpineol (8.84%) in chemotype I, carvacrol (51.82%) in chemotype II, and thymol (79.62%) in chemotype III. All EO chemotypes of L. graveolens demonstrated the ability to inhibit the A. hydrophila growth. Thymol chemotype exhibited the strongest inhibitory effect against bacterial growth, with a minimum inhibitory concentration (MIC) of 92.4 µg/mL and a minimum bactericidal concentration (MBC) of 184.8 µg/mL. Furthermore, the results suggest that there is no synergistic or additive effect when combining different chemotypes of L. graveolens. Conclusions: This the first report of L. graveolens chemotypes exhibiting antimicrobial activity against oxytetracycline-resistant A. hydrophila. The findings suggest the chemotype thymol could be a potential treatment for infections in the tilapia aquaculture in Guatemala.
The opossum and other didelphids in the cultures of Costa Rican society and indigenous peoples: an approach to ecology and conservation
(Cold Spring Harbor Laboratory (Estados Unidos), 2024) Azofeifa Romero, Yara; Durán Alvarado, Francisco
The opossum Didelphis marsupialis, commonly referred to as the zorro pelón in Costa Rica, is a marsupial that holds significant representation in both Costa Rican and indigenous cultures, such as the Talamanca natives. This species, along with the other ten opossums found in Costa Rica, constitute one of the groups of mammals with the least representation in scientific literature. This study aims to (1) document the knowledge, uses, perceptions, and human-zorro pelón interactions through surveys conducted with individuals in three types of zones: rural, semi-urban, and urban; and (2) explore the presence of opossums in the 19th-century worldview of farmers and in the cosmovision of indigenous peoples. We performed an analysis on the text and Likert-scale data collected from 296 surveys conducted across seven provinces in Costa Rica. Nonparametric tests were conducted to assess whether the type of zone influenced the interactions and perceptions of individuals. Valuable information was obtained from key participants and informants regarding the behavior, observation sites, diet, and population trends of the species. The remarkable adaptability of the zorro pelón is evident in rural and semi-urban environments, but not in urban zones. The human-zorro pelón interaction data between the rural and semi-urban zones are similar, but these differ significantly from the urban zone. Although people surveyed generally have a positive perception of the opossum, there has been a notable devaluation over time when compared to the imaginary of indigenous cultures. Parallels were observed in the beliefs and uses of marsupials between pre-Columbian societies and contemporary Costa Rican societies. As part of the educational strategies for the conservation of marsupials, it is important to promote their appreciation and refute negative stereotypes, such as by informing about their ecological role and their ability to resist pathogens and venom. In this context, the rich symbolism of the opossum can be utilized to adapt the message to the various regions of America.
Trophic guild and forest type explain phyllostomid bat abundance variation from human habitat disturbance
(Cold Spring Harbor Laboratory (Estados Unidos), 2020-02-16) Carballo-Morales, Jorge D.; Saldaña-Vázquez, Romeo A.; Villalobos Brenes, Federico
The loss of tropical forest cover caused by land-use change is causing a reduction in functional groups, such as trophic guilds. Phyllostomid bats (family Phyllostomidae) are essential in the Neotropics since they occupy up to six trophic guilds, and are pollinators, seed dispersers, and regulators of vertebrate and invertebrate populations. In this study, a series of meta-analyses were performed in order to analyse their response to habitat disturbance. Data were obtained through a comprehensive literature review whereby we measured the abundance of phyllostomid bats in disturbed habitats and conserved forests. We found that the abundance of phytophagous bats depends on the type of habitat disturbance and the type of forest where it occurs. On the other hand, animal-feeding bats reduce their abundance in any disturbed habitat regardless of disturbance type and forest type. No phylogenetic signal was found in the response of bats to habitat disturbance, nor was the response found to be dependent on the type of crop, the age of the secondary forest, or the distance to a conserved forest. These results demonstrate that feeding and the type of forest where the disturbance occurs are important aspects to understand the reduction of animal populations in the face of habitat destruction processes. This has implications on the conservation of species and their function in ecosystems.

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