The effect of six available and commercial disinfectants on the embryonation and larval development of Toxascaris leonina eggs was studied. Dettol® and Virkon® both induced a 100% reduction in larval development (P ≤ 0.05). Dettol® resulted in deformed eggshells and a halt in embryonal development at 1 week post exposure. All Virkon®-treated eggs showed an early embryonic lysis 24 h post exposure. TH4+ and 70% ethanol both significantly (P ≤ 0.05) affected larval development, with 58.8 and 85.8% reduction, respectively. Neither sodium hypochlorite nor phenol significantly affected larval development (2.8 and 21.0%, respectively). Sodium hypochlorite treatment caused a visible decortication of the eggshell; however, phenol-treated embryonated Toxascaris eggs appeared more or less morphologically normal. In conclusion, the disinfectants tested induced variable degrees of decortication and suppression of larval development. Virkon®S was the most effective disinfectant against Toxascaris eggs, suggesting that it is the most advisable one to use. To the best of our knowledge, this is the first report of the use of Virkon®S as an ovicide and/or larvicide of helminths, particularly Toxascaris leonina.

Schistosomiasis – caused by trematodes from the genus Schistosoma – affects more than 200 million people worldwide. Growing resistance to therapy with praziquantel (PZQ) has encouraged the search for novel treatments against this neglected disease. The compound 7-epiclusianone (7-epi) – isolated from ‘bacupari’ (the fruit of the Gracinia brasiliensis tree) – has promising activity against Schistosoma mansoni in vitro, damaging the parasite's tegument. However, the target and mechanism of action of 7-epi have not been identified. Here, we examined the possibility that 7-epi harms the tegument by inhibiting parasite superoxide dismutase (SOD), which protects the tegument from damage by reactive oxygen species produced by host immune cells. Molecular docking analysis in silico suggested strong interactions between 7-epi and S. mansoni cytosolic superoxide dismutase (SmCtSOD) at allosteric cavities. Schistosoma mansoni couples were cultivated ex vivo with 12.44–198.96 μm 7-epi for 24 h, and then parasite extracts were tested for lipid peroxidation (as a surrogate for oxidative stress), and SOD activity and expression. Lipid peroxidation levels increased after incubation with concentrations ≥99.48 μm 7-epi, and this compound reduced SOD activity at concentrations ≥24.87 μm. However, contact with 7-epi did not alter SOD expression, by quantitative real-time polymerase chain reaction (qRT-PCR). Our results show that the inhibition of SmCtSOD is partly responsible for the tegument detachment observed after incubation with 7-epi, but is not the only cause of the antiparasitic action of this compound in vitro.

The overall goal of this study was to use the Rattus spp./Hymenolepis diminuta model to assess environmental lead pollution in different landscape units of an urban ecosystem. Rats of the genus Rattus were collected from three shanty towns and three residential neighbourhoods of the city of Buenos Aires. Concentrations of lead in the livers of wild rats and in their parasite H. diminuta were measured using inductively coupled plasma mass spectrometry (ICP-MS). The landscape unit and tissue type had a significant effect on lead concentration, being higher in residential neighbourhoods as well as in H. diminuta tissue. Nevertheless, no significant differences were found for the mean lead concentration in livers between uninfected and infected rats. Since the available information describing heavy-metal pollution within the city of Buenos Aires is scarce, the results of this study allow us to update data about the extent of biologically available lead contamination. Considering that rats and H. diminuta are distributed worldwide, this monitoring system for lead pollution might be applied successfully in other urban ecosystems.

The aim of this survey was to study two Hymenolepididae species in urban rodents, Rattus rattus and Rattus norvegicus, and to analyse factors that favour their presence in the environment and pose a sanitary risk. Hymenolepis diminuta and Rodentolepis nana were found in R. rattus and R. norvegicus in different proportions. Values of prevalence, mean abundance and mean intensity were recorded, and new morphometric characters were described, adding to previously known information. No significant differences were found. However, the results revealed that there is a tendency for these parasites to develop in areas with deficient socio-structural conditions and in water bodies. This study thereby shows that certain areas on the periphery of the Gran La Plata favour the existence of rodents, which act as sentinels of zoonotic diseases, and stresses the need to take action to minimize them in order to avoid putting human and animal health at risk.

We surveyed the nematode assemblages associated with populations of the parthenogenetic whiptail lizard Ameivula nativo from six coastal restinga areas in eastern Brazil: Setiba, Comboios and Guriri (State of Espirito Santo) and Guaratiba, Prado and Maraú (State of Bahia). A total of five nematode species (Physaloptera retusa, Physalopteroides venancioi, Skrjabinelazia intermedia, Subulura lacertilia and Parapharyngodon sp.) were recorded from the six different populations of A. nativo. There was considerable variation in overall prevalence of infection (1–42%) among study sites, but geographical distance among areas did not influence similarity in the composition of nematode assemblages. Overall intensity of infection was not affected by lizard body size and did not seem to affect host body condition, based on pooled data of all populations. The studied populations of the unisexual A. nativo had relatively low prevalences and intensities of infection compared to some bisexual congeners and to sympatric lizards from other families for which such data are available. We believe that the low richness of the nematode fauna associated with A. nativo, both locally and regionally, may reflect its narrow geographic distribution and the low diversity of habitats it occupies.

In March 2011, a predator killed 33 hooded grebes, Podiceps gallardoi Rumboll (Podicipedidae), a critically endangered species, in a nesting colony at El Cervecero Lake, Santa Cruz Province, Argentina. The viscera of ten birds were examined for helminths. Two new species of Trematoda were recovered from the intestines. The plagiorchid Plagiorchis patagonensis n. sp. is mainly characterized by the larger size of the oral sucker relative to the ventral sucker, and by the distribution of the vitellarium in two lateral fields, confluent between the caecal bifurcation and the ventral sucker. The echinostomatid Euparyphium tobianum n. sp. is mainly characterized by possessing a head collar with 37–39 spines (4 angle spines on each ventral lappet, 4 lateral spines in a single row on each side, and 21–23 dorsal spines in a double row). An unidentified cestode, a tetramerid nematode and a notocotylid trematode were also recovered from the birds. This is the first record of helminths parasitizing the hooded grebe.

Members of the genus Drepanocephalus are endoparasites of fish-eating birds of the families Phalacrocoracidae and Sulidae distributed across the Americas. Currently, Drepanocephalus contains three species, i.e. D. spathans (type species), D. olivaceus and D. auritus. Two additional species, D. parvicephalus and D. mexicanus were transferred to the genus Petasiger. In the current study, available DNA sequences of D. spathans, D. auritus and Drepanocephalus sp., were aligned with newly generated sequences of D. spathans and Petasiger mexicanus. Phylogenetic analyses inferred with three nuclear (LSU, SSU and ITS1, 5.8S, ITS2) and two mitochondrial (cox1, nad1) molecular markers showed that the sequences of D. spathans and D. auritus are nested together in a single clade with very low genetic divergence, with Petasiger mexicanus as its sister species. Additionally, P. mexicanus was not a close relative of other members of the genus Petasiger, showing that P. mexicanus actually belongs to the genus Drepanocephalus, suggesting the need to re-allocate Petasiger mexicanus back into the genus Drepanocephalus, as D. mexicanus. Morphological observations of the newly sampled individuals of D. spathans showed that the position of the testes is variable and testes might be contiguous or widely separated, which is one of the main diagnostic traits for D. auritus. Our results suggest that D. auritus might be considered a synonym of D. spathans and, as a result, the latter represents a species with a wide geographic range across the Americas, parasitizing both the Neotropical and the double-crested cormorant in Argentina, Brazil, Paraguay, Venezuela, Colombia, Mexico, USA and Canada.

Timoniella spp. are cryptogonimid flukes (Digenea: Cryptogonimidae) that parasitize the guts of fish in brackish waters. Timoniella imbutiforme, a species from the Mediterranean Sea, is recorded in the Black Sea, while T. balthica has been described from the Baltic Sea. In this paper, we clarify the taxonomic status of Timoniella populations in the Baltic and Black seas. Adults and metacercariae of Timoniella spp. were sampled from localities in the Mediterranean Sea (France), Black Sea (Ukraine) and Baltic Sea (Germany) and subjected to molecular and morphological analysis, including Bayesian phylogenetic reconstruction based on concatenated sequences of ITS1–ITS2–28S. This allowed us to construct a new key to species of the genus Timoniella. Our results suggest that T. balthica forms part of the Boreal–Atlantic relict fauna of the Black Sea and should now be considered a junior synonym of T. imbutiforme.

We describe Isorchis cannoni n. sp. from the rabbitfishes Siganus fuscescens (Houttuyn) and Siganus lineatus (Valenciennes) (Siganidae) collected off Heron Island, southern Great Barrier Reef, Australia and, using molecular data, demonstrate that ‘Cercariae queenslandae II’ of Cannon (1978) from the gastropod Clypeomorus batillariaeformis Habe & Kosuge (Cerithiidae) is the larval form of this new species. The cercariae of I. cannoni n. sp. develop in rediae, encyst in the environment after emergence, and are inferred to then be consumed by grazing rabbitfish. Additionally, we provide a new report of Isorchis currani Andres, Pulis & Overstreet, 2016 from the type host, Selenotoca multifasciata (Richardson) (Scatophagidae) collected in Moreton Bay, south-east Queensland, Australia, greatly expanding the known geographical range of this species. Molecular sequence data (ITS1, ITS2 and 28S rDNA) generated for I. cannoni n. sp. and the new specimens of I. currani, confirm the identification of I. currani and demonstrate a distinct genotype for I. cannoni n. sp. relative to other species of Isorchis Durio & Manter, 1969, for which molecular data are available. Isorchis cannoni n. sp. is morphologically distinct from all other species in the genus, and is further distinguished by utilizing species of Siganidae as definitive hosts, rather than species of Chanidae or Scatophagidae. Because haploporid and atractotrematid cercariae have well-developed reproductive organs, we find cercariae of these closely related families morphologically distinguishable in the same way as adult trematodes: atractotrematids have two symmetrical testes and haploporids have a single testis or, rarely, two tandem or oblique testes.

A new species of cestode of the genus Fuhrmannetta found in the small intestine of Cerradomys goytaca is described herein, named Fuhrmannetta jurubatensis n. sp. Rodents were collected from the sand-plains areas of the northern coast of the State of Rio de Janeiro, Brazil. Morphological analyses were conducted by light and scanning electron microscopy. From the morphological analysis and a comparison with the known species of the genus, F. jurubatensis n. sp. can be identified by a combination of morphological and morphometrical characteristics, including strobila length, number and length of rostellar hooks, position of the genital pore and the number of eggs per uterine capsule.

Pterygodermatites (Paucipectines) zygodontomis, a nematode parasite of the small intestine of the rodent Necromys lasiurus, from Uberlândia, Minas Gerais state, Brazil, was analysed by light and scanning electron microscopy. Additionally, phylogenies were inferred from the mitochondrially encoded cytochrome c oxidase I gene (MT-CO1). Details of the helminth surface, such as the oral aperture, cephalic papillae, papillae in the posterior region of the body and longitudinal cuticular elements represented by spine-like projections and fans are presented, adding new taxonomic details. Molecular phylogenetic analysis, based on the MT-CO1, demonstrated that P. (P.) zygodontomis and Pterygodermatites (Paucipectines) jaegerskioldi form a unique evolutionary unit in accordance with the subgenus Paucipectines and corroborated their occurrence in cricetid and didelphid hosts.

A new species belonging to the genus Belondira is described from natural areas in Iran. Belondira coomansi n. sp. is characterized by its general size, the dimensions and appearance of its lip region, presence of distinct labial and post-labial sclerotization, the length of the odontostyle and its inconspicuous lumen and aperture, the length of the neck and its pharyngeal expansion, the reduction of the female anterior genital branch to a simple uterine sac, a very short posterior uterus, the anterior position of the vulva, the length and shape of the caudal region with distinctly thick cuticle at its tip, the length of the spicules, and the presence of only one pair of ventromedian supplements. The new species is close to Belondira brevibulba, B. sacchari, B. tenuidens and B. thornei, and it is compared to them. Molecular characterization (D2–D3 expansion segments of the rRNA large subunit) of the new species is also provided, representing only the second species of this genus for which any DNA sequence data are available.

A new plant nematode species, Trophurus wuhuensis n. sp., was collected from the soil associated with Cinnamomum camphora in Wuhu, Anhui Province, China. The new species is characterized by having a female with a slender body 660.5–801.5 μm in length, stylet 12–14 μm long, knobs directed laterad, lateral field marked by short and scattered grooves, post-vulval uterine sac shorter than vulval body diameter, post-rectal intestinal sac absent, tail cylindroid, terminus with deep wrinkles; and male with a pointed tail terminus and spicules 16–18 μm long. The internal transcribed spacer sequences of ribosomal DNA (ITS rDNA) and partial 18S ribosomal DNA (18S rDNA) from T. wuhuensis n. sp. were amplified and sequenced. A phylogenetic analysis based on sequences of 18S rDNA fragments is given in this study.

The parasite fauna of cod (Gadus morhus) is well described, but the life cycles of Baltic cod parasites are known only in general terms. Invertebrates commonly found in the stomach of cod are recognized as intermediate hosts in the life cycles of nematodes or acanthocephalans. The aim of this study was to determine the source of infection of Baltic cod with parasites found in situ in invertebrates present in the cod stomach. Our results indicate that Saduria entomon is both a source of infection of Baltic cod with parasites and an intermediate host in the life cycle of Hysterothylacium aduncum in the Baltic Sea.