Parmi les parasites, les échinocoques revêtent une importance majeure en santé publique de par leur distribution mondiale et les maladies potentiellement très graves, qu’ils occasionnent. En Europe, les espèces présentes sont E. multilocularis, qui a un cycle sylvatique et E. granulosus spp., dont les hôtes sont essentiellement domestiques.En France, peu de données étaient disponibles quant à la distribution de ces espèces parasitaires lors de la création du LNR Echinococccus spp. en 2006. Une forte réduction supposée des zones et du niveau d’enzootie pour E. granulosus laissait envisager un risque zoonotique moindre voire désormais absent. S’agissant d’E. multilocularis, l’expansion constatée en Europe était également suspectée en France. La modification des techniques de parasitologie classique ainsi que le développement d’outils moléculaires par le LNR ont contribué à l’actualisation et à une meilleure connaissance de la distribution des espèces parasitaires en France.Une large étude de surveillance menée chez le renard avec la méthode SSCT validée par le LNR a révélé une expansion de la zone d’enzootie d’E. multilocularis jusqu’en Ille-et-Vilaine. L’analyse par microsatellite EmsB a permis d’estimer à plusieurs décennies la dispersion du parasite vers l’ouest et le nord à partir du foyer historique de l’est. Cette expansion a été confirmée à l’ouest chez des rongeurs aquatiques et rétrospectivement au sud chez le renard.Des études de surveillance d’E. granulosus en abattoir ont confirmé sa présence dans le sud de la France et en Corse. Les caractérisations moléculaires ont permis d’identifier E. granulosus sensu stricto dans le sud et E. canadensis G6-7 en Corse. Un plan de surveillance national en abattoir a ensuite montré la présence d’E. granulosus s.s. à travers l’ensemble du territoire continental. Les niveaux de prévalence d’infestation par E. granulosus s.s. estimés chez les ovins à 15,3 et chez les bovins à 8,3 cas pour 1 million de têtes abattues sont très inférieurs à ceux décrits il y a vingt ans. Deux foyers majeurs constitués par les Alpes pour E. granulosus s.s. et la Corse pour E. canadensis G6-7 demeurent, alors que l’identification d’E. ortleppi confirme le maintien de cette espèce zoonotique pourtant désormais rare en Europe.Les niveaux de prévalence d’infestation par E. multilocularis chez le chien et le chat en France confirment leurs importances mineures dans le maintien du cycle parasitaire. Le rôle zoonotique du chat semble négligeable d’après les observations d’infestations naturelles, corroborées par les données obtenues lors d’infestations expérimentales. La vermifugation régulière et adaptée des chiens, en particulier des chiens de chasse, apparait nécessaire. Cette recommandation de vermifugation canine s’applique également pour E. canadensis G6-7 en Corse, où l’accès aux viscères des porcs et des sangliers implique un volet sylvatique dans le cycle.La reconnaissance de l’expertise du LNR a permis d’initier des collaborations internationales qui ont en retour enrichi la diversité des situations épidémiologiques étudiées. Ainsi, l’étude de la diversité génétique d’E. multilocularis (microsatellite EmsB) a contribué à une meilleure compréhension de la dynamique d’expansion du parasite en Europe (Pologne, Suède, Danemark). L’étude des foyers d’hyper enzootie d’E. granulosus (Moldavie, Maroc, Algérie) et la caractérisation des espèces présentes et de leurs niveaux d’infestation chez les hôtes intermédiaires a permis d’envisager des actions de lutte adaptées. Le LNR a participé à l’expérimentation de méthodes de lutte contre E. multilocularis, démontrant la complexité des conditions requises pour leur efficacité tant par la vermifugation des renards que par la régulation de leur population. Au bilan, les nouvelles données épidémiologiques obtenues au cours des dix années de travaux ont permis d’aboutir à une meilleure appréhension du risque zoonotique actuel lié aux échinocoques en France / Among parasites, Echinococcus species are of major public health importance due to their worldwide distribution and the potential severity of the diseases they cause. In Europe, the endemic species are E. multilocularis, which has a sylvatic lifestyle, and E. granulosus spp., which the hosts are mainly domestic species. When the Echinococcus spp. NRL was created in France in 2006, few data were available on the distribution of these parasitic species. The implementation of health measures made it possible to consider a marked reduction of the endemic level and geographical distribution of E. granulosus and consequently a reduced or inexistent zoonotic risk. With regard to E. multilocularis, the parasite spread already observed in Europe was also suspected in France. The development of classical parasitology and molecular techniques for diagnosis and epidemiology has helped improve understanding of the distribution of these parasitic species in France.A large-scale surveillance study in foxes, using the SSCT method validated by the NRL, led to the description of significant westward and northward expansion from E. multilocularis’s historical endemic focus, which was estimated, using a spatio-temporal scenario deduced by EmsB microsatellite analysis, to have begun several decades ago. Molecular analyses of various types of animal samples confirmed its westward expansion in aquatic rodents. Its extension southward was confirmed thanks to fecal samples of foxes.Surveillance studies of E. granulosus at the slaughterhouse confirmed its presence in southern France and in Corsica. The first molecular characterization of this parasite in France resulted in the identification of E. granulosus sensu stricto in southern France and E. canadensis G6-7 in Corsica. The presence of E. granulosus s.s. throughout continental France was then observed on the basis of a national surveillance study at the slaughterhouse. The prevalence level of infection by E. granulosus s.s. estimated per million was 15.3 cases in sheep and 8.3 cases in cattle which was much lower than that described 20 years ago. The two main endemic foci – the Alps for E. granulosus s.s. and Corsica for E. canadensis G6-7 – still exist, while the identification of E. ortleppi confirmed maintenance of this species despite its current rarity in Europe.In France, the low prevalence of E. multilocularis infection in dogs and cats was ascertained, confirming the minor contribution of these hosts to the lifecycle. The zoonotic role of the cat appears to be negligible based on observations of natural infection cases and on data obtained from experimental infection. The regular and adapted deworming of dogs, especially hunting dogs, appears to be necessary. This deworming recommendation is also relevant against E. canadensis G6-7 in Corsica where access to viscera of pigs and wild boar adds a sylvatic component at this lifecycle.An acknowledgment of the NRL’s expertise led to several international collaborations which in turn contributed to the diversity of the epidemiological situations studied. Thus, the study of the genetic diversity of E. multilocularis by EmsB microsatellite led to a better understanding of the parasite’s expansion dynamics throughout Europe. The study of foreign foci of E. granulosus led to characterization of the endemic parasitic species and of their prevalence levels in intermediate hosts, which made it possible to plan appropriate control measures. The NRL participated in the testing of control methods against E. multilocularis, including deworming of foxes and population regulation, which demonstrated the complexity of the conditions required for these methods to be effective.The epidemiological data obtained over ten years of studies has led to a better understanding of the current zoonotic risk associated with the Echinococcus species in France

Os estudos de reatividade dos antígenos de líquido hidático de Echinococcus granulosus (Ag LH-Eg) e de líquido vesicular de Taenia crassiceps (Ag LV-Tcra) foram feitos com anticorpos monoclonais (AcMos) anti-E. granulosus e anti-T. crassiceps e amostras humanas por eletroforese em gel de poliacrilamida contendo dodecil sulfato de sódio (SDS-PAGE), Enzyme-Linked Immunosorbent Assay (ELISA) e immunoblot. O SDS-PAGE mostrou um padrão complexo de proteínas entre 97- e 8-kDa do LH-Eg e 97- e 14-kDa do LV-Tcra. A caracterização dos antígenos com os AcMos por ELISA mostrou que todos os AcMoss anti-E . granulosus reagiram com o antígeno LH-Eg e um deles cruzada mente com o antígeno LV-Tcra. Um dos dois AcMo anti-T . crassiceps reagiu também com o LH-¬Eg. A reatividade do LH-Eg com amostras humanas apresentaram melhores resultados com o cut off média mais dois devios-padrão (M+2DP) e na diluição 1:250. As amostras de hidatidose (Hi) mostraram reatividade máxima (100%) nessa diluição. As amostras neurocisticercose (NC) ensaiadas por ELlSA-LH-Eg, apresentaram reatividade cruzada de 66,5%, teníase (T) 46%, controle negativo (CN) 4% e outras parasitoses (OP) 84,5%. O ELlSA-LV-Tcra mostrou 100% de reatividade com as amostras NC na diluição 1 :50 pelo cut off TgRoc. Com as amostras hidatidose, teníase, outras parasitoses e controle negativo a reatividade foi de 73,5; 61,5; 69 e 2%, respectivamente. Todos os AcMos anti-LH-Eg reconheceram as frações 79-,67- e 8-kDa do Ag LH-Eg e as de 24- e 16-kDa pelo AcMo anti¬-antígeno rAgB. No immunoblot, as amostras humanas reconheceram as frações 79-, 67-, 57-, 43-, 38-kDa e também as específicas (24-, 16-e 8-kDa) para o diagnóstico da hidatidose. As frações responsáveis pela reatividade cruzada foram 79-, 67-e 57¬kDa. Nossos estudos mostraram que é necessária uma melhor abordagem incluindo em estudos futuros a obtenção de antígenos recombinantes, específicos de cada um dos parasitos. / Studies to evaluate the reactivity of the hydatic liquid antigens of Echinococcus granulosus (Ag LH-Eg) and of the vesicular liquid antigens of Taenia crassiceps (Ag LV-Tcra) were conducted using anti-E. granulosus and anti-T . crassiceps monoclonal antibodies (MoAbs), and human sample, through SDS-PAGE, ELISA and immunoblot tests. The SDS-PAGE showed a complex standard of proteins from 97¬to 8-kDa of the LH-Eg and from 97-to 14-kDa of the LV-Tcra. The characterization of antigens with the MoAbs through ELISA showed that ali the anti-E . granulosus MoAbs reacted with the LH-Eg antigen and one of them cross-reacted with the LV¬-Tcra antigen. One of the two anti-T. crassiceps MoAb also reacted with the LH-Eg antigen. The reactivity of the LH-Eg with human samples presented better results with the cut off value representing the mean value plus two standard deviations (M+2DP) and with a dilution of 1:250. The hydatidosis samples (Hi) showed maximum reactivity (100%) with this dilution. When evaluated by the ELlSA-LH-Eg, the neurocysticercosis samples (NC) showed cross-reactivity of 66,5%, the taeniasis (T) showed 46%, the negative control (CN) of 4% and 84,5% for other parasitoses (OP). The NC samples, diluted at 1:50, showed 100% of reactivity in ELlSA-LV-Tcra test with the TgRoc cut off value. Concerning the samples of hydatidosis, taeniasis, other parasitoses and the negative control, reactivity was 73,5; 61,5; 69 and 2%, respectively. Ali the anti-LH-Eg MoAbs recognized the fractions 79- and 67-kDa of the Ag LH-Eg and the 24-and 16-kDa through the rAgB anti-antigen MoAb. By immunoblot, the human samples recognized the fractions 79-, 67-, 57-, 43-, 38-kDa and also the specific ones (24-, 16-and 8-kDa) for diagnosing hydatidosis. The fractions, responsible for the cross-reactivity, were 79-, 67-and 57-kDa. Our study showed that further approaches are needed and should include the obtaining of recombinant antigens, specific for each parasite.

Os estudos de reatividade dos antígenos de líquido hidático de Echinococcus granulosus (Ag LH-Eg) e de líquido vesicular de Taenia crassiceps (Ag LV-Tcra) foram feitos com anticorpos monoclonais (AcMos) anti-E. granulosus e anti-T. crassiceps e amostras humanas por eletroforese em gel de poliacrilamida contendo dodecil sulfato de sódio (SDS-PAGE), Enzyme-Linked Immunosorbent Assay (ELISA) e immunoblot. O SDS-PAGE mostrou um padrão complexo de proteínas entre 97- e 8-kDa do LH-Eg e 97- e 14-kDa do LV-Tcra. A caracterização dos antígenos com os AcMos por ELISA mostrou que todos os AcMoss anti-E . granulosus reagiram com o antígeno LH-Eg e um deles cruzada mente com o antígeno LV-Tcra. Um dos dois AcMo anti-T . crassiceps reagiu também com o LH-¬Eg. A reatividade do LH-Eg com amostras humanas apresentaram melhores resultados com o cut off média mais dois devios-padrão (M+2DP) e na diluição 1:250. As amostras de hidatidose (Hi) mostraram reatividade máxima (100%) nessa diluição. As amostras neurocisticercose (NC) ensaiadas por ELlSA-LH-Eg, apresentaram reatividade cruzada de 66,5%, teníase (T) 46%, controle negativo (CN) 4% e outras parasitoses (OP) 84,5%. O ELlSA-LV-Tcra mostrou 100% de reatividade com as amostras NC na diluição 1 :50 pelo cut off TgRoc. Com as amostras hidatidose, teníase, outras parasitoses e controle negativo a reatividade foi de 73,5; 61,5; 69 e 2%, respectivamente. Todos os AcMos anti-LH-Eg reconheceram as frações 79-,67- e 8-kDa do Ag LH-Eg e as de 24- e 16-kDa pelo AcMo anti¬-antígeno rAgB. No immunoblot, as amostras humanas reconheceram as frações 79-, 67-, 57-, 43-, 38-kDa e também as específicas (24-, 16-e 8-kDa) para o diagnóstico da hidatidose. As frações responsáveis pela reatividade cruzada foram 79-, 67-e 57¬kDa. Nossos estudos mostraram que é necessária uma melhor abordagem incluindo em estudos futuros a obtenção de antígenos recombinantes, específicos de cada um dos parasitos. / Studies to evaluate the reactivity of the hydatic liquid antigens of Echinococcus granulosus (Ag LH-Eg) and of the vesicular liquid antigens of Taenia crassiceps (Ag LV-Tcra) were conducted using anti-E. granulosus and anti-T . crassiceps monoclonal antibodies (MoAbs), and human sample, through SDS-PAGE, ELISA and immunoblot tests. The SDS-PAGE showed a complex standard of proteins from 97¬to 8-kDa of the LH-Eg and from 97-to 14-kDa of the LV-Tcra. The characterization of antigens with the MoAbs through ELISA showed that ali the anti-E . granulosus MoAbs reacted with the LH-Eg antigen and one of them cross-reacted with the LV¬-Tcra antigen. One of the two anti-T. crassiceps MoAb also reacted with the LH-Eg antigen. The reactivity of the LH-Eg with human samples presented better results with the cut off value representing the mean value plus two standard deviations (M+2DP) and with a dilution of 1:250. The hydatidosis samples (Hi) showed maximum reactivity (100%) with this dilution. When evaluated by the ELlSA-LH-Eg, the neurocysticercosis samples (NC) showed cross-reactivity of 66,5%, the taeniasis (T) showed 46%, the negative control (CN) of 4% and 84,5% for other parasitoses (OP). The NC samples, diluted at 1:50, showed 100% of reactivity in ELlSA-LV-Tcra test with the TgRoc cut off value. Concerning the samples of hydatidosis, taeniasis, other parasitoses and the negative control, reactivity was 73,5; 61,5; 69 and 2%, respectively. Ali the anti-LH-Eg MoAbs recognized the fractions 79- and 67-kDa of the Ag LH-Eg and the 24-and 16-kDa through the rAgB anti-antigen MoAb. By immunoblot, the human samples recognized the fractions 79-, 67-, 57-, 43-, 38-kDa and also the specific ones (24-, 16-and 8-kDa) for diagnosing hydatidosis. The fractions, responsible for the cross-reactivity, were 79-, 67-and 57-kDa. Our study showed that further approaches are needed and should include the obtaining of recombinant antigens, specific for each parasite.

<p>The parasite <i>Echinococcus granulosus</i> causes hydatid disease, a major zoonosis. A fatty-acid-binding protein, EgFABP1, is important for the parasite, as it must acquire almost all its lipids from its environment or the host. The structure of EgFABP1 has been solved and refined to 1.6 Å resolution. The structure reveals that EgFABP1 has the 10-stranded β-barrel fold typical of the family of intracellular lipid-binding proteins. </p><p>Human semicarbazide-sensitive amine oxidase (SSAO; EC 1.4.3.6), also known as vascular adhesion protein-1, is a copper-containing monoamine oxidase that occurs both as a membrane-bound protein and in a soluble form in plasma. SSAO has been implicated in glucose transport in adipocytes, the differentiation of adipose cells and the leukocyte extravasation process. Toxic reaction products have been suggested to cause some of the vascular complications associated with diabetes and SSAO is therefore of pharmaceutical interest.</p><p>The structure of a truncated, soluble form of human SSAO has been determined to 2.5 Å resolution. The structure reveals that a leucine residue located adjacent to the active site could function as a gate controlling its accessibility. An RGD motif is displayed on the surface where it could be involved in integrin binding and possibly play a role in the shedding of SSAO from the membrane. Carbohydrate moieties are observed at five out of six potential N-glycosylation sites. Carbohydrates attached to Asn 232 flank the active site entrance and might influence substrate specificity. The structure also reveals a vicinal disulfide bridge, which we hypothesise could act as a redox switch involved in the protein’s mechanism of action. The structure of a complex of SSAO and the irreversible inhibitor 2-hydrazinopyridine has been solved and refined to 2.9 Å resolution. Both structures together will aid efforts to identify natural substrates, provide valuable information for the design of specific inhibitors and direct further studies. </p>

The parasite Echinococcus granulosus causes hydatid disease, a major zoonosis. A fatty-acid-binding protein, EgFABP1, is important for the parasite, as it must acquire almost all its lipids from its environment or the host. The structure of EgFABP1 has been solved and refined to 1.6 Å resolution. The structure reveals that EgFABP1 has the 10-stranded β-barrel fold typical of the family of intracellular lipid-binding proteins. Human semicarbazide-sensitive amine oxidase (SSAO; EC 1.4.3.6), also known as vascular adhesion protein-1, is a copper-containing monoamine oxidase that occurs both as a membrane-bound protein and in a soluble form in plasma. SSAO has been implicated in glucose transport in adipocytes, the differentiation of adipose cells and the leukocyte extravasation process. Toxic reaction products have been suggested to cause some of the vascular complications associated with diabetes and SSAO is therefore of pharmaceutical interest. The structure of a truncated, soluble form of human SSAO has been determined to 2.5 Å resolution. The structure reveals that a leucine residue located adjacent to the active site could function as a gate controlling its accessibility. An RGD motif is displayed on the surface where it could be involved in integrin binding and possibly play a role in the shedding of SSAO from the membrane. Carbohydrate moieties are observed at five out of six potential N-glycosylation sites. Carbohydrates attached to Asn 232 flank the active site entrance and might influence substrate specificity. The structure also reveals a vicinal disulfide bridge, which we hypothesise could act as a redox switch involved in the protein’s mechanism of action. The structure of a complex of SSAO and the irreversible inhibitor 2-hydrazinopyridine has been solved and refined to 2.9 Å resolution. Both structures together will aid efforts to identify natural substrates, provide valuable information for the design of specific inhibitors and direct further studies.