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Echinococcus multilocularis and E. granulosus s.l. are the causative agents of alveolar and cystic echinococcosis, respectively. Drug treatment options for these severe and neglected diseases are limited to benzimidazoles, which are not always efficacious, and adverse side effects are reported. Thus, novel and improved treatments are needed. In this study, the previously established platform for E. multilocularis in vitro drug assessment was adapted to E. granulosus s.s. In a first step, in vitro culture protocols for E. granulosus s.s. were established. This resulted in the generation of large amounts of E. granulosus s.s. metacestode vesicles as well as germinal layer (GL) cells. In vitro culture of these cells formed metacestode vesicles displaying structural characteristics of metacestode cysts generated in vivo. Next, drug susceptibilities of E. multilocularis and E. granulosus s.s. protoscoleces, metacestode vesicles and GL cells were comparatively assessed employing established assays including (i) metacestode vesicle damage marker release assay, (ii) metacestode vesicle viability assay, (iii) GL cell viability assay, and (iv) protoscolex motility assay. The standard drugs albendazole, buparvaquone, mefloquine, MMV665807, monepantel, niclosamide and nitazoxanide were included. MMV665807, niclosamide and nitazoxanide were active against the parasite in all four assays against both species. MMV665807 and monepantel were significantly more active against E. multilocularis metacestode vesicles, while albendazole and nitazoxanide were significantly more active against E. multilocularis GL cells. Albendazole displayed activity against E. multilocularis GL cells, but no effects were seen in albendazole-treated E. granulosus s.s. GL cells within five days. Treatment of protoscoleces with albendazole and monepantel had no impact on motility. Similar results were observed for both species with praziquantel and its enantiomers against protoscoleces. In conclusion, in vitro culture techniques and drug screening methods previously established for E. multilocularis were successfully implemented for E. granulosus s.s., allowing comparisons of drug efficacy between the two species. This study provides in vitro culture techniques for the reliable generation of E. granulosus s.s. metacestode vesicles and GL cell cultures and describes the validation of standardized in vitro drug screening methods for E. granulosus s.s. Author summary: Tapeworms of the genus Echinococcus cause severe zoonotic diseases in humans and livestock, which goes along with substantial burden on human and veterinary health and big economic losses. Most relevant to human health are the species E. multilocularis and E. granulosus s.l., which are two closely related parasites that cause alveolar and cystic echinococcosis, respectively. Both diseases have limited treatment options, which is why there is a strong need for new drugs against these neglected tropical diseases. Efficacy of new drugs against E. multilocularis can be assessed via various standardized in vitro assays. For E. granulosus, activity of drugs is currently mainly assessed via optical readout methods, which are time consuming and are not easily carried out in a blinded manner. We here describe the application of several standardized in vitro drug screening assays targeting different parasite stages and isolated germinal layer cells of E. granulosus s.s. We have performed these assays in a comparative manner including E. multilocularis and tested various standard drugs with known activity in these assays. All assays could be applied to E. granulosus s.s. and this will allow for standardized, higher throughput testing against this parasite in the future. [ABSTRACT FROM AUTHOR]

Cystic echinococcosis (CE) is endemic in Sardinia and constitutes a serious public health concern due to high prevalence in livestock and humans. Despite sustained efforts, control of the disease had been unsuccessful in the region. Problematic carcass disposal due to soaring incineration costs and free access of dogs to infected carrion are dominant factors, fueling endemicity among other. As sole obligate scavenger, griffon vultures (Gyps fulvus) are uniquely specialized to eliminate carcasses swiftly and efficiently, saving on unnecessary environmental and economic costs for carrion disposal. However, following drastic population declines across Europe, griffon vultures practically went extinct in Italy. A conservation expansion program in Sardinia successfully reinforced the last remaining Italian vulture population by mitigating the main threats to its survival; food shortage. Through the establishment of supplementary feeding stations, permanent supply of livestock cadavers was provided. In this research, the management and conservation implications on the controlled disposal of carcass disposal through vulture feeding stations on the control of CE in Sardinia were assessed. During the course of the project, vultures scavenged a total of 81,361 kg of biomass, saving €90,041 in incineration costs and € 1,054 in CO2 emission. Through extrapolation of these results, a total of 5,304 kg of suspected CE infected sheep carcasses (65.3%) was calculated to have been disposed by griffons, considerably reducing the CE risk and burden in Sardinia. A quantification of the amount of biomass that could be eliminated by griffon in a succeeding conservation project was also made. These calculations implied that 162,722 kg of biomass, including 10,608 kg of infected biomass from sheep, would be consumed over a period of 5 years, further lowering the CE burden in Sardinia. Our results, driven under one health approach, emphasize the crucial and direct role of griffons in breaking the lifecycle of CE as well as their indirect role in rendering multiple ecosystem and economic services through the elimination of carcasses. Author summary: Cystic echinococcosis (CE), is a major parasitic disease of animal and public health significance due to high morbidity and mortality. The infection is caused by the larval stage of the dog tapeworm Echinococcus granulosus, frequently reported in rural pastoral regions. In Sardinia, CE is very abundant in livestock, especially in sheep (65.3%). Several control strategies were attempted to limit the spread of CE, however, it turns out that the elimination of disease requires long lasting efforts. High prevalence of CE in Sardinia is due to multiple factors, but the cost of carcass incineration and free access of dogs to unattended carcasses are major points in the persistency of the infection. Griffon vultures as sole obligate scavengers, are highly specialized in removing the animal carcasses swiftly and efficiently, but have suffered severe population declines in the last decade. A wildlife conservation project in Sardinia envisioned to expand the griffon population by utilizing animal carcasses of animals as feed for vultures. We aimed to investigate these natural scavenging habits of vultures and the use of such "vulture restaurants" in relation to the control of CE. Our results show that the vultures remove a significant quantity of infected biomass, simultaneously saving high cost for incineration and carbon emission. The study is one of the pioneer investigations in the biological control of CE along with its estimation of ecosystem and economic services provided by the griffons. [ABSTRACT FROM AUTHOR]