2. Universidad Cardenal Herrera-CEU

In recent decades, worldwide fish consumption has increased notably worldwide. Despite the health benefits of fish consumption, it also can suppose a risk because of fishborne diseases, including parasitic infections. Global changes are leading to the emergence of parasites in new locations and to the appearance of new sources of transmission. That is the case of the zoonotic protozoa Cryptosporidium spp., Giardia duodenalis, and Toxoplasma gondii; all of them reach aquatic environments and have been found in shellfish. Similarly, these protozoa can be present in other aquatic animals, such as fish. The present review gives an overview on these three zoonotic protozoa in order to understand their potential presence in fish and to comprehensively revise all the evidences of fish as a new potential source of Cryptosporidium spp., Giardia duodenalis, and Toxoplasma gondii transmission. All of them have been found in both marine and freshwater fishes. Until now, it has not been possible to demonstrate that fish are natural hosts for these protozoa; otherwise, they would merely act as mechanical transporters. Nevertheless, even if fish only accumulate and transport these protozoa, they could be a “new” source of infection for people.

The current therapies of leishmaniasis, the second most widespread neglected tropical disease, have limited e ectiveness and toxic side e ects. In this regard, natural products play an important role in overcoming the current need for new leishmanicidal agents. The present study reports a bioassay-guided fractionation of the ethanolic extract of leaves of Piper pseudoarboreum against four species of Leishmania spp. promastigote forms, which a orded six known alkamides (1–6). Their structures were established on the basis of spectroscopic and spectrometric analysis. Compounds 2 and 3 were identified as the most promising ones, displaying higher potency against Leishmania spp. promastigotes (IC50 values ranging from 1.6 to 3.8 M) and amastigotes of L. amazonensis (IC50 values ranging from 8.2 to 9.1 M) than the reference drug, miltefosine. The e cacy of (E)-piplartine (3) against L. amazonensis infection in an in vivo model for cutaneous leishmaniasis was evidenced by a significant reduction of the lesion size footpad and spleen parasite burden, similar to those of glucantime used as the reference drug. This study reinforces the therapeutic potential of (E)-piplartine as a promising lead compound against neglected infectious diseases caused by Leishmania parasites.

Background: Giardia duodenalis is one of the most common enteric parasites in domestic animals including dogs. Young animals are more prone to the infection, with clinical manifestations ranging from asymptomatic to acute or chronic diarrhoea. Dogs are primarily infected by canine-specific (C-D) assemblages of G. duodenalis. However, zoonotic assemblages A and B have been increasingly documented in canine isolates, raising the question of whether and to which extent dogs can act as natural reservoirs of human giardiosis. Methods: In this cross-sectional epidemiological survey we assessed the molecular diversity of G. duodenalis in dogs in the province of Castellón, Eastern Spain. A total of 348 individual faecal samples from sheltered (n = 218), breeding (n = 24), hunting (n = 68), shepherd (n = 24), and pet (n = 14) dogs were collected between 2014 and 2016. Detection of G. duodenalis cysts in faecal material was carried out by direct fluorescence microscopy as a screening test, whereas a qPCR targeting the small subunit ribosomal RNA gene of the parasite was subsequently used as a confirmatory method. Results: Giardia duodenalis was detected in 36.5% (95% CI: 31.6–41.7%) of dogs. No significant differences in prevalence rates could be demonstrated among dogs according to their sex and geographical origin, but breeding (45.8%; 95% CI: 27.9–64.9%) and sheltered (40.4%; 95% CI: 34.1–47.0%) dogs harboured significantly higher proportions of G. duodenalis. Multi-locus sequence-based genotyping of the glutamate dehydrogenase and β-giardin genes of G. duodenalis allowed the characterization of 35 canine isolates that were unambiguously assigned to assemblages A (14.3%), B (22.9%), C (5.7%), and D (37.1%). A number of inter-assemblage mixed infections including A + B (11.4%), A + D (2.9%), and A + B + D (5.7%) were also identified. Conclusions: Data presented here are strongly indicative of high infection pressures in kennelled animals. Zoonotic sub-assemblages AII, BIII, and BIV were responsible for a considerable proportion of the G. duodenalis infections detected, but very few of the genotypes identified have been previously documented in Spanish human populations. Although possible, zoonotic transmission between dogs and humans seems an infrequent event in this Spanish region.