First Report of Trichinella nativa in Red Foxes（Vulpes vulpes schrencki) from Otaru City,Hokkaido,Japan

北海道小樽市で捕獲された43頭のキタキツネと9頭のタヌキについて、筋肉中のトリヒナ線虫の寄生状況を調べた。そのうち5頭のキツネからトリヒナ線虫の一種Trichinella nativaの幼虫が検出された。この発見は、北海道でキタキツネが、トリヒナ線虫の野外型の生活環維持の重要な宿主であることを示唆している。北海道におけるキタキツネからT.nativaの寄生報告は、最初のものである

Medical Treatment of Echinococcus multilocularis and New Horizons for Drug Discovery: Characterization of Mitochondrial Complex II as a Potential Drug Target

As an efficient drug for alveolar echinococcosis (AE) is still not available, new chemotherapy targets are necessary. The mitochondrial respiratory chain may be a good drug candidate because parasite respiratory chains are quite different from those of mammalian hosts. For example, Ascaris suum possesses an NADH‐fumarate reductase system (fumarate respiration) that is highly adapted to anaerobic environments such as the small intestine. It is composed of mitochondrial complex I (NADH‐ubiquinone reductase), complex II (succinate‐ubiquinone reductase), and rhodoquinone. We previously demonstrated that fumarate respiration is also essential in E. multilocularis. Quinazoline, a complex I inhibitor, inhibited growth of E. multilocularis larvae in vitro. These results indicate that fumarate respiration could be a target for E. multilocularis therapy. In the current chapter, we focused on complex II, which is another component of this system, because quinazoline exhibited strong toxicity to mammalian mitochondria. We evaluated the molecular and biochemical characterization of E. multilocularis complex II as a potential drug target. In addition, we found that ascofuranone, a trypanosome cyanide‐insensitive alternative oxidase inhibitor, inhibited E. multilocularis complex II at the nanomolar order. Our findings demonstrate the potential development of targeted therapy against Echinococcus complex II

A Pilot Study on Developing Mucosal Vaccine against Alveolar Echinococcosis (AE) Using Recombinant Tetraspanin 3: Vaccine Efficacy and Immunology

Humans and rodents become infected with E. multilocularis by oral ingesting of the eggs, which then develop into cysts in the liver and progress an endless proliferation. Untreated AE has a fatality rate of >90% in humans. Tetraspanins have been identified in Schistosoma and showed potential as the prospective vaccine candidates. In our recent study, we first identified seven tetraspanins in E. multilocularis and evaluated their protective efficacies as vaccines against AE when subcutaneously administered to BALB/c mice. Mucosal immunization of protective proteins is able to induce strong local and systemic immune responses, which might play a crucial role in protecting humans against E. multilocularis infection via the intestine, blood and liver. We focused on Em-TSP3, which achieved significant vaccine efficacy via both s.c. and i.n. routes. The adjuvanticity of nontoxic CpG OND as i.n. vaccine adjuvant was evaluated. The widespread expression of Em-TSP3 in all the developmental stages of E. multilocularis, and the strong local and systemic immune responses evoked by i.n. administration of rEm-TSP3 with CpG OND adjuvant suggest that this study might open the way for developing efficient, nontoxic human mucosal vaccines against AE

LONGEVITY AND FECUNDITY OF TRICHINELLA SPIRALIS IN MAST CELL-DEFICIENT Sl/Sl^d MICE

Response to Trichinella spiralis infection in genetically mast cell-deficient Sl/Sl^d mice was studied. Very few or no subepithelial mast cells (SMC) and globule leucocytes (GL) were observed in WCB6F_1-Sl/Sl^d mice in the primary and tertiary infections with T. spiralis. While marked increases of these two cell types were seen in the primary and tertiary infections in their normal littermates. In both primary and tertiary infections delayed expulsion of adult worms from the intestine was seen in Sl/Sl^d mice as compared with that in the normal littermates. In Sl/Sl^d mice the expulsion of worms occurred only slightly faster in the tertirary infection than in the primary infection, whereas in the normal littermates, the expulsion was remarkably faster in the former than in the latter. No difference was noted in the number of muscle larvae recovered from Sl/Sl^d mice and their littermates after intravenous injection of newborn larvae, but greater number of muscle larvae was recovered from Sl/Sl^d mice after oral inoculation of infective muscle larvae. Adult worms obtained from Sl/Sl^d mice showed greater fecundity in vitro than those from the normal litteremates. In both Sl/Sl^d mice and their normal littermates, no significant difference was noted in the production of specific antibodies, as shown by the indirect hemagglutination serum titers and the IgE titers measured by passive cutaneous anaphylaxis reaction. These results suggest a certain positive participation of SMC and GL in the resistance to intestinal phase of T. spiralis infection