Over the past few years, symptoms akin to late blight disease have been reported on a variety of crop plants in South America. Despite the economic importance of these crops, the causal agents of the diseases belonging to the genus Phytophthora have not been completely characterized. In this study, a new Phytophthora species was described in Colombia from tree tomato (Solanum betaceum), a semi-domesticated fruit grown in northern South America. Comprehensive phylogenetic, morphological, population genetic analyses, and infection assays to characterize this new species, were conducted. All data support the description of the new species, Phytophthora betacei sp. nov. Phylogenetic analyses suggest that this new species belongs to clade 1c of the genus Phytophthora and is a close relative of the potato late blight pathogen, P. infestans. Furthermore, it appeared as the sister group of the P. andina strains collected from wild Solanaceae (clonal lineage EC-2). Analyses of morphological and physiological characters as well as host specificity showed high support for the differentiation of these species. Based on these results, a complete description of the new species is provided and the species boundaries within Phytophthora clade 1c in northern South America are discussed.

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RESUMENLos ectoparásitos afectan de manera importante el estado sanitario de los animales debido a que sus efectos exfoliatrices, tóxicos y alérgicos causan un detrimento en su bienestar y, adicionalmente, pueden tener un efecto negativo en los índices de conversión alimenticia en animales de producción. Las ectoparasitosis pueden afectar animales de todas las especies y edades; sin embargo, los jóvenes son los más susceptibles. La importancia de un adecuado diagnóstico de estos problemas sanitarios está dada no solo por la incomodidad que generan en sus hospederos, sino por la posibilidad que tienen de transmitir otros agentes patógenos. El objetivo del presente trabajo fue presentar imágenes donde se describen algunas características morfológicas de determinados ectoparásitos de interés en Medicina Veterinaria, especialmente bajo las condiciones de Colombia.Palabras clave: diagnóstico, parásitos externos, microscopía óptica, microscopía electrónica de barrido ABSTRACTThe ectoparasites significantly affect the health status of the animals due to their toxic and allergic effects that cause a detriment in their welfare and additionally may have a negative effect on feed conversion rates in farm animals. Ectoparasites can affect animals of all species and ages, being the young animals the most susceptible. The importance of a proper diagnosis of these health problems is given not only by the

An in vitro model for the formation of an Enterococcus faecalis endodontic biofilm under nutritional restriction was established, simulating clinical conditions for the evaluation of antimicrobial substances. Biofilm formation in dentin was standardized using root quarters incubated with E. faecalis ATCC 29212 at 37°C without nutritional changes. Biofilms were evaluated at 7, 14, and 30 days, counting bacterial colony-forming units using conventional culture and verified scanning electron microscopy. Bacterial viability and biovolume were determined with confocal laser microscopy. Colonization of E. faecalis and biofilm formation on the dentinal surface was confirmed after 7 and 14 days, respectively. Microorganism colonization was homogeneous over the entire root surface at each time point, without significant differences in the viability percentage and biovolume. On the contrary, a decrease in viability and an increase in biovolume were observed when the time was increased. Compared with other incubation times, 14 days was found to be the best time for the establishment of the biofilm in terms of biovolume and bacterial viability. This in vitro model for the formation of endodontic biofilm will allow future evaluation of the efficacy of antimicrobial substances with a more adequate clinical approach.