Angiostrongylus cantonensis (A. cantonensis) infection causes eosinophilic meningitis in humans. Eosinophilia and a Th2-type immune response are the crucial immune mechanisms for eosinophilic meningitis. CD4+CD25+ regulatory T cells (Treg) are involved in the pathogenesis of A. cantonensis. Diammonium glycyrrhizinate (DG) is a compound related to glycyrrhizin (GL), a triterpene glycoside extracted from liquorice root. We investigated the curative effects and probable mechanisms of therapy involving a combination of albendazole and DG in BALB/c mice infected with A. cantonensis, and compared these with therapy involving albendazole and dexamethasone. We analysed survival time, body weight, signs, eosinophil numbers, immunoglobulin E (IgE), interleukin-5 (IL-5), and eotaxin concentrations, numbers and Foxp3 expression of CD4+CD25+ Treg, worm recovery and histopathology. The present results demonstrated that the combination of albendazole and DG could increase survival time more efficiently and relieve neurological dysfunction; decrease weight loss, eosinophil numbers, concentrations of IgE, IL-5 and eotaxin, the number and expression of Foxp3 of CD4+CD25+ Treg; and improve worm recovery and histopathology changes in treated animals, compared with the combination of albendazole and dexamethasone. The observations presented here suggest that the albendazole and dexamethasone combination could be replaced by the combination of albendazole and DG.

Cerebral involvement in parasitoses is an important clinical manifestation of most of the human parasitoses. Parasites that have been described to affect the central nervous system (CNS), either as the dominant or as a collateral feature, include cestodes (Taenia solium (neurocysticerciasis), Echinococcus granulosus (cerebral cystic echinococcosis), E. multilocularis (cerebral alveolar echinococcosis), Spirometra mansoni (neurosparganosis)), nematodes (Toxocara canis and T. cati (neurotoxocariasis), Trichinella spiralis (neurotrichinelliasis), Angiostrongylus cantonensis and A. costaricensis (neuroangiostrongyliasis), Gnathostoma spinigerum (gnathostomiasis)), trematodes (Schistosoma mansoni (cerebral bilharziosis), Paragonimus westermani (neuroparagonimiasis)), or protozoa (Toxoplasma gondii (neurotoxoplasmosis), Acanthamoeba spp. or Balamuthia mandrillaris (granulomatous amoebic encephalitis), Naegleria (primary amoebic meningo-encephalitis), Entamoeba histolytica (brain abscess), Plasmodium falciparum (cerebral malaria), Trypanosoma brucei gambiense/rhodesiense (sleeping sickness) or Trypanosoma cruzi (cerebral Chagas disease)). Adults or larvae of helminths or protozoa enter the CNS and cause meningitis, encephalitis, ventriculitis, myelitis, ischaemic stroke, bleeding, venous thrombosis or cerebral abscess, clinically manifesting as headache, epilepsy, weakness, cognitive decline, impaired consciousness, confusion, coma or focal neurological deficits. Diagnosis of cerebral parasitoses is dependent on the causative agent. Available diagnostic tools include clinical presentation, blood tests (eosinophilia, plasmodia in blood smear, antibodies against the parasite), cerebrospinal fluid (CSF) investigations, imaging findings and occasionally cerebral biopsy. Treatment relies on drugs and sometimes surgery. Outcome of cerebral parasitoses is highly variable, depending on the effect of drugs, whether they are self-limiting (e.g. Angiostrongylus costaricensis) or whether they remain undetected or asymptomatic, like 25% of neurocysticerciasis cases.

Cystic echinococcosis is endemic in Iran, particularly in Ardabil Province, where it causes health and economic problems. The genetic pattern of Echinococcus granulosus has been determined in most parts of Iran, except in this area. In the present investigation, 55 larval isolates were collected from humans (11), sheep (19), goats (4) and cattle (21). For analysis of the genetic characteristics of E. granulosus isolates, DNA sequencing of mitochondrial cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) genes was applied. Fifty isolates were successfully analysed, with 92% (46) and 8% (4) identified as G1 and G3 genotypes, respectively. The sequence analyses of the isolates displayed nine characteristic profiles in cox1 sequences and eight characteristic profiles in nad1 sequences. Based on these results, the sheep strain (G1 genotype) was the most prevalent in humans, sheep, goats and cattle. The buffalo strain (G3 genotype) was not only demonstrated in sheep (1 isolate) and cattle (1 isolate), but also for the first time in two human isolates. These findings will provide information for local control of echinococcosis.

Metazoan parasites of the sand smelt Atherina boyeri Risso, 1810 in Lake Iznik were studied. A total of 271 specimens of A. boyeri, 208 female and 63 male, mean ( ± SD) total length 8.4 ± 2.2 cm (range 3.1–12.2 cm) and mean total weight 4.7 ± 3.5 g (range 0.1–11.7 g) were examined between June 2008 and May 2009 at monthly intervals. In 33 fish no parasites were found. In the other fish, four parasite species were recorded: Diplostomum sp. (prevalence 39.13%, mean intensity 3.50 ± 3.03); Tylodelphys clavata (prevalence 74.16%, mean intensity 10.41 ± 14.89); Bothriocephalus cf. acheilognathi (prevalence 40.59%, mean intensity 31.83 ± 57.74); and Eustrongylides excisus (prevalence 6.64%, mean intensity 1.16 ± 0.39). The mean abundance of Diplostomum sp., T. clavata and E. excisus was higher during the winter and early spring months. In contrast, the mean abundance of B. cf. acheilognathi was higher in the summer and autumn months. This distribution of the parasites was related to a change in the environment of A. boyeri from the pelagic zone to deeper water at the end of autumn and a change in food supply.

Ninety-five specimens from 13 species of lizard collected during a herpetofaunal monitoring programme of the Faxinal II power plant, municipality of Aripuanã, state of Mato Grosso, Brazil (southern Amazon region) were examined for helminths. A total of 21 helminth species (16 Nematoda, 1 Cestoda and 4 Trematoda) were recovered, with an overall prevalence of 67.37%. Seventeen new host records and seven new locality records are reported. A low number of specialists and core helminth species were found. Lizard body size was positively correlated with both the total number of helminth species and individuals. Active foragers exhibited higher helminth diversity. However, sit-and-wait foragers, especially Plica plica, had similar diversity values as active foragers and harboured more helminth species. The degree of similarity in helminth fauna was higher among closely related host species.

Specimens (n= 41) of the amphisbaenid Amphisbaena wuchereri taken from a population in Minas Gerais state, south-eastern Brazil, were examined for gastrointestinal parasites. A single nematode species was found, Paradollfusnema amphisbaenia. This was a new host record for this nematode species. This parasite was encountered in the large intestine (prevalence of 100%), in the stomach (prevalence of 2%) and in the small intestine (prevalence of 7.3%). The intensity of infection ranged from 1 to 457 individual parasites per host and was positively correlated with body size of both male and female amphisbaenians. The discrepancy index (D) indicated that P. amphisbaenia tended to an even distribution in this host population. The nematode, which did not affect fat body mass, induced inflammatory infiltrations in the small intestine, indicating that the parasites might injure the host's organs.

The contamination, distribution and pathogenicity of Toxocara canis and T. cati eggs in sandpits in the Tokyo metropolitan area, Japan, are described. A total of 34 sandpits were examined, 14 of which were contaminated with T. cati eggs, as assessed by the floatation method and polymerase chain reaction (PCR) analysis. Two naturally contaminated sandpits were investigated to determine the vertical and horizontal distribution of eggs, and an inverse relationship between the sand depth and number of eggs was observed. To examine the pathogenicity of the eggs, three ICR mice were inoculated with 300 eggs, which were recovered from sandpits. The mice exhibited eosinophilia in the peripheral blood and IgG antibody production in the sera after 3 weeks of infection. Most migrating larvae were recovered from carcasses, although three were found in the brains of two infected mice. These three larvae were determined to be T. canis by PCR, revealing that not only T. cati, but also T. canis eggs could be found in sandpits and, further, that eggs recovered from sandpits have the ability to invade a paratenic host.

The life cycle of Proctotrema bartolii Carballo, Laurenti & Cremonte 2011 (Digenea: Monorchiidae) at Fracasso Beach (the type locality) (42°25′S, 64°07′W), Península Valdés, Argentina, was investigated. This digenean uses the clam Darina solenoides (Mactridae) as both the first and second intermediate hosts in the natural environment. The metacercariae were located mainly at the tip of the incurrent siphon, with an infection prevalence of 100%. Experimental infections in other macroinvertebrates, such as the clam Tellina petitiana and the polychaete Glycera americana, were successful, but these and other invertebrates are not naturally infected. Silversides Odontesthes smitti and Odontesthesnigricans (Pisces: Atherinopsidae) and the mullet Eleginops maclovinus (Eleginopidae) act as the definitive hosts of both experimentally and naturally obtained adults. Fish acquire infection by eating either the siphon or the entire clam. Proctotrema bartolii seems to be endemic to the Magellan Region and is distributed where its intermediate clam host is present, from the San José Gulf in Península Valdés to the southern tip of South America.

Species distribution modelling has been a powerful tool to explore the potential distribution of parasites in wildlife, being the basis of studies on biogeography. Vexillata spp. are intestinal nematodes found in several species of mammalian hosts, such as rodents (Geomyoidea) and hares (Leporidae) in the Nearctic and northern Neotropical regions. In the present study, we modelled the potential distribution of Vexillata spp. and their hosts, using exclusively species from the Geomyidae and Heteromyidae families, in order to identify their distributional patterns. Bioclimatic and topographic variables were used to identify and predict suitable habitats for Vexillata and its hosts. Using these models, we identified that temperature seasonality is a significant environmental factor that influences the distribution of the parasite genus and its host. In particular, the geographical distribution is estimated to be larger than that predicted for its hosts. This suggests that the nematode has the potential to extend its geographical range and also its spectrum of host species. Increasing sample size and geographical coverage will contribute to recommendations for conservation of this host–parasite system.

Acanthocephalans can be pathogenic helminths of marine birds. Every year during the breeding season, there is variable mortality among prefledged chicks from the largest known Olrog's gull (Larus atlanticus) colony. Mortality has been associated with infection by the acanthocephalan Profilicollis chasmagnathi. Our aim was to study the role of chicks' size as a risk factor for intensity of infection and severe pathology, and to expand upon previous pathological findings reported in acanthocephalan-infected chicks. Size of the chick was associated with intensity of infection and number of intestinal perforations, which increased by 6.9% and 4.1%, respectively, for each millimetre increment in chick size. Infection was associated with inflammatory enteritis and granulomatous peritonitis. Complete intestinal perforations were observed in 85% and 97.3% of the studied chicks in 2005 and 2006, respectively, and they were observed very early during the post-hatching period. Our results show: (1) the presence of advanced pathology associated with acanthocephalan infections in chicks, beginning very early in the post-hatching period; and (2) significant increases in the intensity of infection and the associated pathology as a function of size of chicks, in dead chicks during this period.

Parasite assemblages of the Western whip snake Hierophis viridiflavus carbonarius were investigated from the Calabria region in southern Italy. A total of 14 parasite taxa including 6 nematodes, 3 acanthocephalans, 2 cestodes, 2 digeneans and a single pentastomid was identified. Within the study area, H. v. carbonarius serves as the final host for seven species of helminths, of which only four (Hexametra quadricornis, Kalicephalus viperae, Paracapillaria sonsinoi and Renifer aniarum) can be considered as snake specialists, while one (Oswaldocruzia filiformis) is shared with other reptiles and amphibians, and two (Paradistomum mutabile and Rhabdias fuscovenosa) with lizards. A large proportion of larval forms of six helminth taxa (about 95% of all helminths collected) was found, for which H. v. carbonarius serves as an intermediate and/or paratenic host; however, adult stages of helminths were prevalent in snakes with snout-to-vent length greater than 70 cm. Our results suggest that ontogenetic and ecological factors should exert a strong influence upon the helminth assemblage of Western whip snakes. We concluded that H. v. carbonarius plays an important role in southern Italy as an intermediate/paratenic host for species of helminths infecting vertebrate groups which may include this snake species within their feeding chain. Eleven taxa, including three potential agents of zoonosis, were added to the poorly known parasite fauna of this host.

Among about 50 nominal Paragonimus species, Paragonimus proliferus is rather a rare species, found only in Yunnan province, China, until our recent discovery of this species in Lai Chau province, northern Vietnam close to Yunnan, China. Here we add Quang Binh province, central Vietnam as a new endemic area of P. proliferus. Large excysted metacercariae found in mountainous crabs, Potamiscus tannanti, were morphologically identified as P. proliferus, which was confirmed further by molecular analyses. Second internal transcribed spacer (ITS2) sequences of the P. proliferus population in Quang Binh province were completely (100%) identical with those of P. proliferus populations in Lai Chau province, northern Vietnam and Yunnan province, China. However, cytochrome oxidase subunit 1 (CO1) gene sequences of Quang Binh population were significantly different (5.6%) from that of previously reported northern Vietnam and Yunnan, China populations. A phylogenetic tree revealed that all CO1 sequences of P. proliferus Quang Binh population formed a distinct group, which was clustered with northern Vietnam and Yunnan, China populations with the bootstrap value of 75%. This is the first record of the genetically variant population of P. proliferus, distribution of which is geographically remote from the previously reported endemic areas in the border between northern Vietnam and Yunnan, China, suggesting that P. proliferus may be much more widely distributed in the Indochina peninsula (or South-East Asia) than expected.

The main goals of this study were to compare the richness of parasitic trematodes in amphibians with diverse habits (terrestrial, fossorial, semi-aquatic and arboreal), and to evaluate whether the composition of the trematode community is determined by ecological relationships. Specimens were collected between April 2001 and December 2006 from a common area (30 ha) in Corrientes Province, Argentina. Trematodes of amphibians in this area comprised a total of 19 species, and were dominated by common species. Larval trematodes presented highest species richness, with the metacercaria of Bursotrema tetracotyloides being dominant in the majority (7/9, 78%) of the parasite communities. Adults of the trematode Catadiscus inopinatus were dominant in the majority (6/9, 67%) of amphibians. The amphibians Leptodactylus latinasus, Leptodactylus bufonius and Scinax nasicus presented a high diversity of trematodes, whereas Leptodactylus chaquensis had the lowest diversity even though it presented with the highest species richness. The patterns of similarity among amphibian species showed groups linking with their habitats. Leptodactilid amphibians, with a generalist diet and an active foraging strategy showed highest infection rates with adult trematodes. The mean richness of trematode species related to host's habitat preferences was higher in semi-aquatic amphibians. Results suggest that semi-aquatic amphibians, present in both aquatic and terrestrial environments, present a greater diversity of parasites as they have a higher rate of exposure to a wider range of prey species and, hence, to diverse infective states. The trematode composition is related to the diets and mobility of the host, and habitat.

Co-expression of Trichinella spiralis macrophage migration inhibitory factor (TsMIF) with T. spiralis cystatin-like domain protein (TsMCD-1) in a DNA vaccine induces a Th1 immune response and partial protection against T. spiralis infection. The present study evaluated whether co-expression of mouse ubiquitin (Ub) with TsMIF and TsMCD-1 might improve the immune response against T. spiralis infection. Groups of BALB/c mice were immunized twice at 2-week intervals with 100 μg of plasmid DNA encoding either a TsMIF–TsMCD-1 fusion protein (pVAX1-Tsmif-Tsmcd-1) or an Ub-co-expressing triple fusion protein Ub–TsMIF–TsMCD-1 (pVAX1-Ub-Tsmif-Tsmcd-1). Control animals were immunized with pVAX1-Ub or blank vector plasmid. Specific antibody levels (IgG, IgG1, IgG2a, IgG2b, IgM, IgA, IgE) against the recombinant protein TsMIF–TsMCD-1, serum cytokines (interferon (IFN)-γ, interleukin (IL)-4, IL-5, transforming growth factor (TGF)-β1 and IL-17), CD4+/CD8+ T cells and cytotoxic T lymphocyte (CTL) responses were monitored. Challenge infection was performed 2 weeks after the second immunization and worm burden was assayed at 35 days post-challenge. Antibody responses induced by pVAX1-Ub-Tsmif-Tsmcd-1 were significantly lower than for TsMIF-TsMCD-1, but the vaccine induced increased levels of Th1 cytokine (IFN-γ) and increased T-cell cytotoxicity. The reduction of worm burden (37.95%) following immunization with pVAX1-Ub-Tsmif-Tsmcd-1 was significantly greater than that induced by the pVAX1-Tsmif-Tsmcd-1 vaccine (23.17%; P< 0.05).

The 14.5 kDa fatty acid binding protein (FABP) was isolated from the crude extract of adult Fasciola gigantica worms. Polyclonal anti-FABP IgG was generated in rabbits immunized with prepared FABP antigen. Sandwich enzyme-linked immunosorbent assay (ELISA) was applied to detect coproantigen in stools and circulating Fasciola antigen (CA) in sera of 126 water buffaloes by using purified and horseradish peroxidase (HRP)-conjugated anti-FABP IgG. Sandwich ELISA sensitivity was 96.97% and 94.95%; while specificity was 94.12% and 82.35% for coproantigen and CA detection, respectively. However, sensitivity and specificity of the Kato–Katz technique was 73.74% and 100%, respectively. The diagnostic efficacy of sandwich ELISA was 96.55% and 93.1% for coproantigen and CA detection, respectively. In contrast, the diagnostic efficacy of the Kato–Katz technique was 77.59%. In conclusion, these results demonstrate that the purified 14.5 kDa FABP provides a more suitable antigen for immunodiagnosis of early and current bubaline fascioliasis by using sandwich ELISA.

Gastrointestinal parasites of livestock cause diseases of important socio-economic concern worldwide. The present study investigated the prevalence of gastrointestinal parasites in sheep and goats in lowland and highland regions of Papua New Guinea (PNG). Faecal samples were collected from a total of 165 small ruminants (110 sheep and 55 goats) from February to April 2011. Analysis by a modified McMaster technique revealed that 128 animals (72% of sheep and 89% of goats) were infected with one or more species of gastrointestinal parasites. The gastrointestinal parasites found and their prevalences in sheep (S) and in goats (G) were as follows: strongyle 67.3% (S), 85.5% (G); Eimeria 17.3% (S), 16.4% (G); Strongyloides, 8.2% (S), 23.6% (G); Fasciola, 5.5% (S), 18.2% (G); Trichuris, 1.8% (S), 3.6% (G); and Nematodirus, 1.8% (S), 3.6% (G). Two additional genera were found in goats: Moniezia (9.1%) and Dictocaulus (3.6%). This is the first study to quantitatively examine the prevalence of gastrointestinal parasites in goats in PNG. The high rates of parasitism observed in the present study are likely to be associated with poor farming management practices, including lack of pasture recovery time, lack of parasite control measures and poor-quality feed.

The present study examined sequence variability in four mitochondrial genes, namely cytochrome c oxidase subunit (cox1), cytochrome b (cytb) and NADH dehydrogenase subunits 1 and 5 (nad1 and nad5), among Bunostomum trigonocephalum isolates from four different geographic regions in China. Ten B. trigonocephalum samples were collected from each of the four provinces (Heilongjiang, Jilin, Shaanxi and Yunnan), China. A part of the cox1 (pcox1), cytb (pcytb), nad1 and nad5 genes (pnad1 and pnad5) were amplified separately from individual hookworms by polymerase chain reaction (PCR) and were subjected to direct sequencing in order to define sequence variations and their phylogenetic relationships. The intra-specific sequence variations within B. trigonocephalum were 0–1.9% for pcox1, 0–2.0% for pcytb, 0–1.6% for pnad1 and 0–1.7% for pnad5. The A+T contents of the sequences were 69.6–70.4% (pcox1), 71.9–72.7 (pcytb), 70.4–71.1% (pnad1) and 72.0–72.6% (pnad5). However, the inter-specific sequence differences among members of the family Ancylostomatidae were significantly higher, being 12.1–14.2% for pcox1, 13.7–16.0 for cytb, 17.6–19.4 for nad1 and 16.0–21.6 for nad5. Phylogenetic analyses based on the combined partial sequences of cox1, cytb, nad1 and nad5 using three inference methods, namely Bayesian inference (Bayes), maximum likelihood (ML) and maximum parsimony (MP), revealed that all the B. trigonocephalum samples form monophyletic groups, but samples from the same geographical origin did not always cluster together, suggesting that there was no obvious geographical distinction within B. trigonocephalum based on sequences of the four mtDNA genes. These results demonstrated the existence of low-level intra-specific variation in mitochondrial DNA (mtDNA) sequences among B. trigonocephalum isolates from different geographic regions.

Different species of Cassia plant are widely available in India and are commonly used either for their laxative, antimicrobial or antibacterial activity. In the present study the effectiveness in vitro of the crude alcoholic extracts of three species, namely Cassia alata, C. occidentalis and C. angustifolia, in the early paralysis and mortality of the fowl tapeworm Raillietina tetragona at concentrations ranging from 5 to 80 mg/ml was investigated. Time of paralysis and death were monitored frequently. Immediately after paralysis the tapeworms were processed for electron microscopic studies. While the untreated or control parasites survived for 81.93 ± 5.85 h, the parasites treated with C. alata took less time (1.68 ± 0.27 h) to be paralysed, followed by those treated with C. angustifolia (2.95 ± 0.29 h). Although C. occidentalis took more time (4.13 ± 0.31 h) to paralyse, in combination with either C. alata or C. angustifolia the time taken to paralyse became shorter. All the plant-treated parasites showed irrevocable changes in the scolex and proglottids as compared with the control, and these observations are comparable with those obtained with praziquantel. These results indicate that the three plants tested can be claimed to have anthelmintic activity in addition to their known properties, both when used individually and in combination. Further investigations will be required to evaluate their mechanism of action.

This paper reports the adult stage of Prosorhynchoides borealis (Digenea) from Lophius piscatorius in Icelandic waters and infections with the larval stages (sporocysts and cercariae) found for the first time in the bivalve Abra prismatica (Semelidae). The previously known first intermediate host was Abraalba (Semelidae). Ribosomal DNA sequencing studies on all three life stages of the parasite (cercariae, metacercariae, adults) were performed to confirm their identites. Morphometric measurements confirmed that the adult worms belong to the newly described species P. borealis. Prosorhynchoides borealis sporocysts filled with cercariae were found in 16% of A. prismatica bivalves sampled at depths between 34 and 93 m off South Iceland. Prevalence ranged from 0 to 44% between different localities. The parasite was found only in the larger bivalves. Extensive sporocyst infection in the haemocoel of the foot caused mechanical muscle damage with subsequent degeneration and necrosis. Other tissues, including the digestive gland, nephridia, gills and intestine, were less heavily infected. Only focal necrosis was observed in the digestive gland, nephridia and gills, and local atrophy in the intestine. Cercariae were also observed in the lumen of both the stomach and intestine. This is the first report of A. prismatica as an alternative first intermediate host for P. borealis. Ribosomal DNA sequence data reveals 100% homology in the data between cercariae, metacercariae and adult digeneans, supporting the morphological data suggesting that all stages belong to the same species.

Little is known about the actin cytoskeleton architecture in female Strongyloides venezuelensis and thus to investigate the distribution and concentration of actin, female worms were labelled with phalloidin-rhodamine and visualized under confocal microscopy. Our results demonstrate that filamentous actin accumulates in the vulva and the concentration of F-actin at this site suggests its important role, especially during oviposition, in the life cycle of S. venezuelensis.