RESUMO
An investigation into the potential for transmission of gastrointestinal helminths from wild hogs to livestock and humans was prompted by concerns of recreational wild-hog hunting in the Caribbean region and the recent practice, by livestock farmers in Jamaica, of co-rearing wild and domesticated swine. Thirty-one wild hogs from the Hellshire Hills, a dry limestone forest in southern Jamaica, were necropsied during the period June 2004 to August 2006. Thirteen of the captured animals were male and 18 female. Four species of adult helminths were recovered from the gastrointestinal tracts of the wild hogs: Hyostrongylus rubidus (77%), Globocephalus urosubulatus (48%), Oesophagostomum dentatum (42%) and Macroacanthorhynchus hirudinaceus (77%). Two (6.2%), ten (32.2%) and 18 (58.0%) hogs harboured one, two and three species of helminths, respectively. Mean infection intensities varied from 8.1 for M. hirudinaceus, to 115.5 for O. dentatum. There was no association between any of the recovered helminths and sex of the host; however, a multivariate analysis indicated a positive association between the prevalence of G. urosubulatus and host age (odds ratio (OR) = 6.517). Domesticated hogs co-reared with wild hogs are potentially at risk of infection with all four helminths, while wild-hog hunters and pig farmers may be exposed to M. hirudinaceus.
Assuntos
Gastroenteropatias/parasitologia , Helmintíase Animal/parasitologia , Saúde Pública , Doenças dos Suínos/parasitologia , Animais , Animais Selvagens , Feminino , Gastroenteropatias/epidemiologia , Helmintíase Animal/epidemiologia , Helmintos/classificação , Helmintos/isolamento & purificação , Jamaica/epidemiologia , Larva , Masculino , Suínos , Doenças dos Suínos/epidemiologiaRESUMO
Clustering the tetrameric (alphabetagamma(2)) IgE receptor, FcepsilonRI, on basophils and mast cells activates the Src-family tyrosine kinase, Lyn, which phosphorylates FcepsilonRI beta and gamma subunit tyrosines, creating binding sites for the recruitment and activation of Syk. We reported previously that FcepsilonRI dimers formed by a particular anti-FcepsilonRI alpha mAb (H10) initiate signaling through Lyn activation and FcepsilonRI subunit phosphorylation, but cause only modest activation of Syk and little Ca(2+) mobilization and secretion. Curtailed signaling was linked to the formation of unusual, detergent-resistant complexes between Lyn and phosphorylated receptor subunits. Here, we show that H10-FcepsilonRI multimers, induced by adding F(ab')(2) of goat anti-mouse IgG to H10-treated cells, support strong Ca(2+) mobilization and secretion. Accompanying the recovery of signaling, H10-FcepsilonRI multimers do not form stable complexes with Lyn and do support the phosphorylation of Syk and phospholipase Cgamma2. Immunogold electron microscopy showed that H10-FcepsilonRI dimers colocalize preferentially with Lyn and are rarely within the osmiophilic "signaling domains" that accumulate FcepsilonRI and Syk in Ag-treated cells. In contrast, H10-FcepsilonRI multimers frequently colocalize with Syk within osmiophilic patches. In sucrose gradient centrifugation analyses of detergent-extracted cells, H10-treated cells show a more complete redistribution of FcepsilonRI beta from heavy (detergent-soluble) to light (Lyn-enriched, detergent-resistant) fractions than cells activated with FcepsilonRI multimers. We hypothesize that restraints imposed by the particular orientation of H10-FcepsilonRI dimers traps them in signal-initiating Lyn microdomains, and that converting the dimers to multimers permits receptors to dissociate from Lyn and redistribute to separate membrane domains that support Syk-dependent signal propagation.