Póster de Congreso

URI permanente para esta colecciónhttp://10.0.96.45:4000/handle/11056/20323

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Mostrando 1 - 3 de 3

Detección de Candida tropicalis en una vaca Jersey con mastitis de Heredia, Costa Rica
(Universidad Nacional, Costa Rica, 2024-08) Mata Masís, María; Calderón Hernández, Alejandra; BARQUERO-CALVO, ELIAS
La mastitis es un problema frecuente en lecherías especializadas y en la última década, los agentes fúngicos han sido reportados con mayor frecuencia (Segundo et al., 2021). Las levaduras del género Candida, son las que más comúnmente se aíslan en casos de mastitis micótica; no obstante, se consideran subdiagnosticadas (Ortiz et al., 2017). Al igual que con la etiología bacteriana, algunos de los factores que contribuyen con su presentación son el uso de equipos contaminados, deficiencia en higiene del personal, así como el uso irracional de antimicrobianos (Cilvez, 2019; Erbas et al., 2017). Objetivo: Comunicar un caso de mastitis micótica en Costa Rica para concientizar a la población estudiantil y profesionales sobre esta etiología.
P3-01 Manipulating Brucella abortus two-component regulatory system BvrR/BvrS promoter activity through environmental stimuli
(Brucellosis 2022 International Research Conference., 2022-09) Ruiz Villalobos, Nazaret; Altamirano Silvia, Pamela; Molina Mora, José Arturo; Vargas Leitón, Bernardo; Chaves-Olarte, Esteban; Guzman-Verri, Caterina
The two-component regulatory system BvrR/BvrS is required for Brucella abortus transition from an extra- cellular to an intracellular lifestyle. BvrS is a sensor histidine kinase transducing unknown external stimuli to the BvrR transcriptional regulator through phosphorylation. Active BvrR then binds to gene regulatory regions, affecting their transcription. The system is a master regulator controlling the expression of genes related to cell envelope homeostasis, carbon and nitrogen metabolism, the virulence factor VirB and its regulator VjbR. B. abortus bvrR/bvrS mutants are avirulent in mice models. Low concentration of nutrients and pH were recently described as environmental cues affecting the BvrR transcriptional regulator activa- tion through phosphorylation. Here, we describe the environmental cues that affect BvrR/BvrS promoter activity. Using a pbvrR::luxA/luxB transcriptional fusion, the promoter activity was determined during in vitro growth and ex vivo in a cellular infection model. Conditions and chemical compounds simulating the envi- ronment found during intracellular trafficking were evaluated: nutrient restrictions, different pH, presence of metals, carbon, and nitrogen sources, at different concentrations and time. The results obtained for each condition tested, individually or in combination will be presented in this report. Some of the assessed con- ditions affected bvrRp activity and demonstrated a similar effect on BvrR phosphorylation. A combination of conditions tested was found to repress bvrRp activity. Altogether, these results show that conditions that modulate bvrRp activity are not necessarily the same as those sensed by the BvrR/BvrS two-component system but might influence BvrR activation. This work provides a first attempt toin vitro manipulate the bvrRp activity and hence contribute to the understanding of the type of environmental signals need it for regulating bvrR/bvrS transcription.
Positivity of Lawsonia intracellularis in seven regions of Costa Rica diagnosed by porcine fecal samples using Real time PCR
(Anatomical Society, 2019-08) Chaverri Esquivel, Laura; Chacón Ureña, Fernando; Alfaro-Alarcon, Alejandro; Zeledón Donzo, Daniel Francisco ; Esquivel, Milena; Guerrero, Roger
Lawsonia intracellularis is an obligate intracellular, motile, curved, gram-negative bacterium that resides freely within the apical cytoplasm of infected intestinal enterocytes (Pusterla & Gebhart, 2013). Europe, Asia and North America have shown an individual prevalence of 24 to 47%. Herd prevalence for finishing pigs in other EU countries has been estimate to range between 88 and 100% (Pascu et al, 2015). Clinical signs: hypoproteinemia/hypoalbuminemia, thickened small intestinal loops on ultrasonographic evaluation and ruling out other causes of enteropathy and protein losses (Pusterla &Gebhart, 2013). The losses due to enteropathy are estimate by at least US $ 1.53 per affected animal (Moller, 2006). In Costa Rica, we reported two cases by histopathological findings: severe chronic active linfo-histio plasmocitic with eosinophils ileo-tiflitis with peyers patches hyperplasia. Real time qPCR confirmed L. intracellularis. The Cts for the samples were 24 and 20 cycles.

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