RESUMO
The oocyst is a sporogonic stage of Plasmodium development that takes place in the mosquito midgut in about 2 weeks. The cyst is protected by a capsule of unknown composition, and little is known about oocyst biology. We carried out a proteomic analysis of oocyst samples isolated at early, mid, and late time points of development. Four biological replicates for each time point were analyzed, and almost 600 oocyst-specific candidates were identified. The analysis revealed that, in young oocysts, there is a strong activity of protein and DNA synthesis, whereas in mature oocysts, proteins involved in oocyst and sporozoite development, gliding motility, and invasion are mostly abundant. Among the proteins identified at early stages, 17 candidates are specific to young oocysts. Thirty-four candidates are common to oocyst and the merosome stages (sporozoite proteins excluded), sharing common features as replication and egress. Western blot and immunofluorescence analyses of selected candidates confirm the expression profile obtained by proteomic analysis.
Assuntos
Anopheles , Plasmodium , Animais , Oocistos/metabolismo , Proteômica , Esporozoítos/metabolismo , Proteínas de Protozoários/metabolismoRESUMO
The antibacterial activity of lime (Citrus x aurantifolia) essential oil (EO) against the foodborne pathogen Listeria monocytogenes in tyndallised apple juice was studied at two temperatures. The EO concentration required to produce a significant increase in the lag phase of bacterial growth was determined. The addition of 200 µL of lime EO per 100 mL of apple juice completely inhibited the growth of L. monocytogenes at 5 ºC and at 37 ºC. This concentration of EO extended the lag time at least 292.7% compared to juice without EO. This is especially important considering that L. monocytogenes was able to grow in the juice at low temperatures in the absence of EOs.
En este trabajo se estudió la actividad antibacteriana del aceite esencial de lima (Citrus x aurantifolia) contra Listeria monocytogenes, patógeno alimentario, cultivado en jugo de manzana tindalizado a dos temperaturas. Se determinó la concentración necesaria del aceite esencial para producir una extensión significativa de la fase de retraso. La adición de 200 µL de aceite esencial de lima por 100 mL de jugo de manzana tindalizado, a 5 ºC produjo la inhibición total del crecimiento de L. monocytogenes, en tanto que con el mismo volumen a 37 ºC la fase de retraso se extendió a 24,7 h (292,7%). Esto es importante debido a que L. monocytogenes fue capaz de crecer en este sustrato a temperaturas bajas en ausencia de aceite esencial.