The toxicity of cadmium, zinc and Cd/Zn mixtures to the transmission of Echinoparyphium recurvatum (Digenea: Echinostomatidae) cercariae into the snail second intermediate hosts was investigated at concentrations ranging from 100 μg l-1 to 10 000 μg l-1 in both soft and hard water. A differential response in the infectivity of metal-exposed cercariae into Lymnaea peregra and Physa fontinalis was demonstrated which was dependent on the snail species being infected. Exposure of L. peregra, P. fontinalis, and L. stagnalis to heavy metals caused a differing susceptibility to E. recurvatum cercariae depending on the snail species being exposed. The mechanism and effects of metal toxicity, together with the importance of the parasite/host strain on cercarial transmission are discussed.

A description is given of three contrasting adhesive attitudes exhibited by three species of capsalid monogeneans from the gills of three different species of teleost fish from Heron Island, Queensland, Australia. The proximal end of the primary lamella of the coral trout, Plectropomus maculatus has a wide inner border, free from secondary lamellae, on each flat face. The haptor of Trochopus plectropomi is small enough to attach to this flat surface without folding. Benedenia sp. 1 attaches itself to the gills of stripey, Lutjanus carponatatus, by folding the haptor longitudinally around the inner edge of the primary lamella. Most specimens of T. plectropomi and all specimens of Benedenia sp. 1 were orientated with the anterior end projecting towards the tip of the primary lamella. Benedenia sp. 2 generally prefers relatively flat surfaces in the gill chamber but is more versatile in its choice of attachment sites on its host, the blacktip cod, Epinephelus fasciatus; two specimens were attached to the gill arch, one to a gill raker and one to the dorsal pharyngeal tooth pad.

The rate of uptake of H3 tyrosine by unisexual females in vitro was accelerated by 22% when male worm extract was added to the culture medium. Pairing of unisexual females with mature male worms in vitro resulted in a similar acceleration of H3 tyrosine uptake. As tyrosine is avidly taken up by the vitelline gland for the formation of egg shell protein the change in the rate of H3 tyrosine uptake can be employed as a sensitive quantitative criterion for assessing its development following stimulation.

Trichuris trichiura and Trichuris suis parasitize (at the adult stage) the caeca of humans and pigs, respectively, causing trichuriasis. Despite these parasites being of human and animal health significance, causing considerable socio-economic losses globally, little is known of the molecular characteristics of T. trichiura and T. suis from China. In the present study, the entire first and second internal transcribed spacer (ITS-1 and ITS-2) regions of nuclear ribosomal DNA (rDNA) of T. trichiura and T. suis from China were amplified by polymerase chain reaction (PCR), the representative amplicons were cloned and sequenced, and sequence variation in the ITS rDNA was examined. The ITS rDNA sequences for the T. trichiura and T. suis samples were 1222–1267 bp and 1339–1353 bp in length, respectively. Sequence analysis revealed that the ITS-1, 5.8S and ITS-2 rDNAs of both whipworms were 600–627 bp and 655–661 bp, 154 bp, and 468–486 bp and 530–538 bp in size, respectively. Sequence variation in ITS rDNA within and among T. trichiura and T. suis was examined. Excluding nucleotide variations in the simple sequence repeats, the intra-species sequence variation in the ITS-1 was 0.2–1.7% within T. trichiura, and 0–1.5% within T. suis. For ITS-2 rDNA, the intra-species sequence variation was 0–1.3% within T. trichiura and 0.2–1.7% within T. suis. The inter-species sequence differences between the two whipworms were 60.7–65.3% for ITS-1 and 59.3–61.5% for ITS-2. These results demonstrated that the ITS rDNA sequences provide additional genetic markers for the characterization and differentiation of the two whipworms. These data should be useful for studying the epidemiology and population genetics of T. trichiura and T. suis, as well as for the diagnosis of trichuriasis in humans and pigs.

An extensive survey of helminth parasites in fish and shellfish species from Santa Gilla, a brackish water lagoon in southern Sardinia (western Mediterranean), resulted in the identification of 69 helminth parasite taxa and/or species from 13 fish species (n= 515) and seven bivalve species (n= 2322) examined between September 2001 and July 2011. The list summarizes information on the helminth parasites harboured by fish and molluscs contained in the available literature. Digenea species (37), both adults and larvae, dominated the parasite fauna, whereas Cestoda were the least represented class (three species). Monogenea, Nematoda and Acanthocephala were present with 17, 6 and 6 species, respectively, which were mainly adults. The most widespread parasite species was the generalist Contracaecum rudolphii A (Nematoda). Other species, such as the Haploporidae and Ascocotyle (Phagicola) spp. 1 and 2 (Digenea), showed a high family specificity in Mugilidae. Importantly, the study recorded the occurrence of potential zoonotic agents, such as Heterophyes heterophyes, Ascocotyle (Phagicola) spp. and C. rudolphii A, the latter two reaching the highest indices of infection in the highly marketed fish grey mullet and sea bass, respectively. The highest parasite richness was detected in Dicentrarchus labrax, which harboured 17 helminth species, whereas the lowest value was observed in Atherina boyeri, infected by only three species. The list includes the first geographical record in Italian coastal waters of Robinia aurata and Stictodora sawakinensis, and 30 reports of new host–parasite complexes, including the larval stages of Ascocotyle (Ascocotyle) sp. and Southwellina hispida in D. labrax.

The Pantanal is a large ecosystem located in South America. This preserved area is seasonally flooded due to abundant rainfall during the summer and the subsequent overflow of the Paraguai River. In this paper, we examine the helminth community structure in the wild rodent Thrichomys pachyurus during the wet and dry seasons in two locations of the preserved and cattle ranching areas in the Southern Pantanal. We identified 12 species of helminth, and, although we did not find any differences in species richness between locations within the Pantanal, we found that richness was higher during the wet season. Helminth species were largely aggregated in both farm locations and during seasons. The most common helminth species were more abundant during the dry season than during the wet season, which may have been due to the increased habitat availability and rodent population increase. The intensity of the infection also followed the same pattern for most helminths. The trichostrongylids (Heligmostrongylus crucifer, H. almeidai and Pudica cercomysi) were dominant at both farm locations. The land use of each area was not correlated with helminth diversity. However, species composition of the helminth community of T. pachyurus differed between locations and may be correlated with environmental differences between the habitats. The seasonality of the Pantanal was highly correlated with helminth parasitism in T. pachyurus.

Fourteen species of Monogenea (Dactylogyridae) are reported from fish from the Eilat and Suez gulf littoral. The parasites were collected from fish of 12 species (10 families) and include 9 species of the genus Halioirema (Johnston and Tiegs, 1922) (including four new species), two species of Ancyrocephalus Creplin, 1839 and one species of each of the genera: Atherinicus Bychowski and Nagibina, 1969, Diversohamulus Bychowski and Nagibina, 1969 and Placodiscus n.gen.

The karyotypes of two hermaphroditic trematodes, Megalodiscus temperatus and Philophthalmus gralli, were described and compared as to chromosomal morphology and constitutive heterochromatin constitution. The haploid number of chromosomes for both species is 10 and both karyotypes are composed mainly of acrocentric chromosomes. Constant heteromorphism of the No. 10 chromosomes was found in M. temperatus. The heteromorphic chromosomes differ is size and heterochromatin constitution. The possible mechanisms of chromosomal dimorphism in M. temperatus and its significance in the evolution of sexchromosome differentiation in trematodes are discussed.

During a survey in agricultural fields of the sub-humid region of Meerut district, India, two strains of entomopathogenic nematodes, labelled CS31 and CS32, were isolated using the Galleria baiting technique. Based on morphological and morphometric studies, and molecular data, the nematodes were identified as Steinernema pakistanense, making this finding the first report of this species from India. For the first time, we performed a molecular and biochemical characterization of the bacterial symbiont of S. pakistanense. Furthermore, a co-phylogenetic analysis of the bacteria from the monophyletic clade containing a symbiont of S. pakistanense, together with their nematode hosts, was conducted, to test the degree of nematode–bacteria co-speciation. Both isolates were also tested in a laboratory assay for pathogenicity against two major pests, Helicoverpa armigera and Spodoptera litura. The morphology of the Indian isolates corresponds mainly to the original description, with the only difference being the absence of a mucron in first-generation females and missing epiptygmata in the second generation. The sequences of bacterial recA and gyrB genes have shown that the symbiont of S. pakistanense is closely related to Xenorhabdus indica, which is associated with some other nematodes from the ‘bicornutum’ group. Co-phylogenetic analysis has shown a remarkable congruence between the nematode and bacterial phylogenies, suggesting that, in some lineages within the Steinernema / Xenorhabdus complex, the nematodes and bacteria have undergone co-speciation. In the virulence assay, both strains caused a 100% mortality of both tested insects after 48 h, even at the lowest doses of 25 infective juveniles per insect, suggesting that S. pakistanense could be considered for use in the biocontrol of these organisms in India.

The pathogenesis of H. contortus infection in lambs under 6 months of age challenged orally with 10,000 third stage infective larvae is described. The development of the parasite and its relationship to haematological and pathological changes are discussed, with particular reference to specific cellular mobilizations, and detailed descriptions are given of the haematology and parasitology, gross pathology and histopathology at 4, 7, 12, 18, 22 and 35 days after infection. Dramatic changes had developed by day 12.

An epidemiological study of gastrointestinal helminths of dogs (Canis familiaris) in two veterinary clinics in Ibadan, Nigeria, was conducted between January 2001 and December 2002. Faecal samples collected from 959 dogs were processed by modified Kato–Katz technique and then examined for helminth eggs. The results of the study showed that 237 (24.7%) of the dogs examined were infected with different types of helminths. The prevalences for the various helminth eggs observed were: Toxocara canis 9.0%, Ancylostoma spp. 17.9%, Toxascaris leonina 0.6%, Trichuris vulpis 0.5%, Uncinaria stenocephala 0.4% and Dipylidium caninum 0.2%. The faecal egg intensities, determined as mean egg count/gram of faeces ( ± SEM), were: T. canis 462.0 ± 100.5, Ancylostoma spp. 54.1 ± 8.6, T. leonina 0.8 ± 0.4, T. vulpis 0.1 ± 0.0, U. stenocephala 1.0 ± 0.7 and D. caninum 0.2 ± 0.1. Host age was found to be a significant factor with respect to the prevalence and intensity of T. canis and Ancylostoma spp. There was no significant difference in the prevalence of intestinal helminth parasites between male (27.0%) and female (22.5%) dogs (P>0.05). The prevalence of helminth parasites was significantly higher (P < 0.05) in the local breed (African shepherd) (41.2%) than in Alsatian dogs (16.2%) or in other exotic breeds (21.0%). Single parasite infections (85.7%) were more common than mixed infections (3.5%).

Vietnam is recognized to be endemic for fasciolosis. However, most of the available publications have not been published in international journals. This review is based on national and international Vietnamese publications and highlights the current status of fasciolosis in Vietnam. It also provides some information available for neighbouring countries. Updated data on responsible species, distribution, transmission and control aspects are summarized. The central region of Vietnam is reported as being highly endemic for fasciolosis, with a high number of human patients (more than 20,000 in 2011). Fasciola gigantica is reported to be the main species in Vietnam. However, hybrids between F. gigantica and F. hepatica were identified. Both humans and animals are infected by the ingestion of raw vegetables and possibly contaminated drinking water. Three lymnaeid snail species (Austropeplea viridis, Radix auricularia and Radix rubiginosa) may act as intermediate hosts of Fasciola spp. However, due to the likely misidentification of snail species and cercariae during the past decade the critical analysis of published data is difficult. A better understanding of transmission aspects of fasciolosis would allow the implementation of preventive measures of this important neglected zoonotic disease.

A series of experiments examined the effects of various media, serum supplements, gas phases and the incorporation of mammalian cell feeder layers on the survival on Onchocerca gutturosa adult worms in vitro. The survival of male worms was poor in all media tested that were not supplemented with inactivated foetal calf serum (IFCS), with improved but variable survival in media supplemented with 10–30% IFCS. Using a cell-free system in an atmosphere of 5% CO2in air, good results were obtained in medium NCTC 135 + 10% IFCS (median survival time 39 days, range 25–41). Marginally better survival was obtained with the same medium in an atmosphere of 95% N2/5% CO2 (medium 45 days, range 25–56)and with a 1:1 mixture of media NCTC 135 and IMDM+10% IFCS(medium 38 days, range 38–51). Survival was enhanced in culture systems which incorporated bovine kindney (MDBK) cells, bovine trachea (EBTR) cells and monkey kidney (LLCMK2) cells. Exceptionally long survival was obtained using medium MEM+10% IFCS+LLCMK2 cells under a gas phase of 5% CO2in air, in which male worms survived from approximately 6 to over 7 months. Under similar conditions, female worms were also maintained for periods of up to 6 months and 5 out of 18 specimens released microfilariae into the culture system. The long-term culture described in this study will be useful for basic biochemical, chemotherapeutic and immunological studies in vitro.

Praziquantel was shown to have adverse effects on protoscoleces of Echinococcus granulosus in vitro. Exposure to one dose of praziquantel at a concentration of 10μg/ml caused protoscoleces to die within 12 to 15 days. Protoscolecidal effects were more marked when cultures were exposed to the drug continuously by the addition of multiple doses. On the basis of these observations, there is a need to reappraise the metacestocidal potential of praziquantel, particularly with regard to the development of new drug regimes employing multiple dose or sustained release schedules. Possible reasons for the reduced susceptibility of protoscoleces and juvenile worms to praziquantel observed in this study are discussed.

Analysis of the major biochemical components of Taenia hydatigena cysticerci collected from goats and pigs showed marked differences, particularly in glycogen, protein, lipid and DNA levels. Differences were also detected in the levels of cholesterol, triglycerides, free fatty acids and phospholipids. Furthermore, the profile of phospholipid fractions revealed quantitative differences between the two species. It is concluded that the cysticerci of goat and pig origin probably represent two different strains and possibly follow the same pattern of speciation as reported in the related taeniid, Echinococcus granulosus.

Antibodies directed against diagnostic Mr 31 000 polypeptide(s) of adult Schistosoma mansoni were already formed in mice during prepatency. In contrast, repeated immunization of mice with homogenates of adult schistosomes failed to elicit antibodies detectable in immunoblots in the Mr 31 000 region. Therefore, spleen cells of infected mice were used to produce hybridoma lines. The “miniblot technique” was developed in order to detect in hybridoma supernatants antibodies against schistosome Mr 31 000 components. Electrophoretically separated total S. mansoni proteins were transferred onto nitrocellulose, and the position of the Mr 31 000 components was determined with polyclonal antisera and immunoblotting. Pieces of about 3 square mm of nitrocellulose bearing the diagnostic proteins were incubated with about 100 μ1 of hybridoma supernatant in microtitre plates and subsequently probed with peroxidase-conjugated antibody to mouse IgG. This screening technique identified hybridomas secreting antibody to the relevant S. mansoni antigens. It is applicable to other defined parasit antigens, which are, however, not available in biochemically purified form. The monoclonal antibodies produced against the proteins with diagnostic potential reacted with antigens localized in the schistosome gut.

Stomach intubation is the most common method used in the experimental infection of animals with Angiostrongylus cantonensis. In order to compare the effectiveness of other possible transmission methods, groups of BALB/c mice were given infective third-stage larvae of A. cantonensis by different routes including intraperitoneal or subcutaneous injections, and penetration of anal mucosa, vaginal mucosa, conjunctival mucosa, lacerated skin, unabraded skin, foot pad and tail skin, while stomach intubation was used as control. Recovery of fifth-stage larvae was higher in mice inoculated with third-stage larvae subcutaneously. Successful infections were established through all experimental transmission routes except tail skin penetration. This study suggests that oral infection may not be the only route for the transmission of human angiostrongyliasis, and subcutaneous infection may be a better method for experimental infection.

A molecular phylogeographic study of Paragonimus mexicanus collected from Guatemala and Ecuador was performed. Genomic DNA was extracted from individual metacercariae, and two gene regions (partial mitochondrial cytochrome c oxidase subunit 1 (CO1) and the second internal transcribed spacer of the nuclear ribosomal gene repeat (ITS2)) were amplified by the polymerase chain reaction (PCR). Sequences segregated in a phylogenetic tree according to their geographic origins. ITS2 sequences from Ecuador and Guatemala differed at only one site. Pairwise distances among CO1 sequences within a country were always lower than between countries. Nevertheless, genetic distances between countries were less than between geographical forms of P. westermani that have been suggested to be distinct species. This result suggests that populations from Guatemala and Ecuador are genetically differentiated perhaps at the level of subspecies.

In Great Britain free-living common pheasants Phasianus colchicus are often managed at high densities owing to their popularity as a quarry species. They are prone to infection by a range of parasite species including Heterakis gallinarum, Capillaria spp. and Syngamus trachea. In 1995 the efficacy of an indirect anthelmintic technique for controlling parasitic worm burdens of pheasants was determined in a pilot study on a shooting estate in the south of England. Between 2000 and 2003 a large-scale field experiment was conducted on nine estates in eastern England to determine the effect of the technique on parasite burden and pheasant breeding success. In the absence of anthelmintic treatment worm burdens increased rapidly through March and April, whereas birds given anthelmintic-treated grain had lower worm burdens during the same period. The breeding success of pheasants was significantly higher on plots provided with anthelmintic treatment, although no long-term increases in population densities were observed. The burdens of the most common parasite H. gallinarum were significantly lower in pheasants from treatment plots six weeks after the anthelmintic treatment had ceased, but spring treatment did not influence parasite burden in the following winter.

Anisakis infection parameters were studied in horse mackerel (Trachurus trachurus) taken from two areas of northern Morocco (Tetouan and Tangier), which showed a mean prevalence of 54.9%. Identification of the ITS1–5.8S–ITS2 fragment by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) showed A. pegreffii to be the dominant species; no A. simplex s.s. were detected. The presence of A. pegreffii in horse mackerel was not influenced by the sex (P= 0.46) or catch area (Atlantic versus Mediterranean, P= 0.52) of the fish, but was significantly related to their length, weight, liver weight and gonad weight, and to the season of their capture (P< 0.05). A low prevalence (8.6%) and mean intensity (1.0) was detected in the muscle, probably related to the reduced ability of A. pegreffii to penetrate muscle. The risk of the presence of A. pegreffii in the muscle was fivefold higher in fish caught during the summer than during any other season. Susceptible members of the human population can minimize the risk of infection by avoiding the consumption of larger horse mackerel specimens during the summer.