METHODS: Infective larvae were obtained after incubating and hatching fertile eggs of A. suum in order to extract their cuticle and excretory/secretory antigens. The ability of both extracts to bind and activate plasminogen, as well as promote plasmin generation were assayed by ELISA and western blot. The location of plasminogen binding on the larval surface was revealed by immunofluorescence. The plasminogen-binding proteins from both antigenic extracts were revealed by two-dimensional electrophoresis and plasminogen-ligand blotting, and identified by mass spectrometry.
RESULTS: Cuticle and excretory/secretory antigens from infective larvae of A. suum were able to bind plasminogen and promote plasmin generation in the presence of plasminogen activators. Plasminogen binding was located on the larval surface. Twelve plasminogen-binding proteins were identified in both antigenic extracts.
CONCLUSIONS: To the best of our knowledge, the present results showed for the first time, the pro-fibrinolytic potential of infective larvae of Ascaris spp., which suggests a novel parasite survival mechanism by facilitating the migration through host tissues.
METHODS: A total of 432 collections were performed in this study (24 samplings at each of 18 fixed-streams at monthly intervals) from February 2012 to January 2014. Larvae and pupae attached on aquatic substrates such as grasses, leaves and stems, twigs, plant roots and rocks were collected by hand using fine forceps. Stream depth (m), width (m), velocity (m/s), water temperature (°C), acidity (pH), conductivity (mS/cm) and dissolved oxygen (mg/L) were measured at the time of each collection.
RESULTS: A total of 35 black fly species were recorded in the present study. The most frequently collected species were Simulium tani (31.7%) and S. whartoni (21.5%), while the relatively common species were Simulium sp. (nr. feuerborni) (16.2%), S. decuplum (15.5%), S. angulistylum (14.8%), S. bishopi (13.2%) and S. izuae (11.8%). Total estimated species richness ranged between 39.8 and 41.3, which yielded more than 80% of sampling efficiency. Six simuliid species were distributed below 500 m, whereas eight species were distributed above 1400 m. Simulium sp. (nr. feuerborni) and S. asakoae were found from middle to high altitudes (711-1813 m). Simulium whartoni, S. brevipar and S. bishopi were distributed widely from low to high altitudes (159-1813 m). Regression analysis between species richness and PCs revealed that the species richness was significantly associated with wider, deeper and faster streams at low altitude, normal water temperature (23-25 °C), low conductivity, higher discharge, more canopy cover and riparian vegetation and with larger streambed particles (F = 20.8, df = 1, 422, P