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.

A new monogenean fluke, collected from the urinary bladder of a megophryid frog, Xenophrys glandulosa Fei, Ye & Huang, 1991 from Mokokchung and Tuensang districts of Nagaland, north-eastern India is described. Of the six genera under the subfamily Polystomatinae (Polystomatidae) known so far, the present form comes closer to Eupolystoma Kaw, 1950; Pseudopolystoma Yamaguti, 1963 and Riojatrema Lamothe-Argumedo, 1964, in all of which the opisthaptor lacks large hooks. However, a combination of characters, namely, shape of the body, rounded or bulbous pharynx, intestinal caeca not joining posteriorly in the opisthaptoral region, ovary located in the anterior third of the body and presence of vaginal apertures, sets the present form apart from all these genera, and also from the known species of Riojatrema. These differences warrant the establishment of a new species and a new genus to accommodate the present form. The validity of this new monogenean, named as Neoriojatrema mokokchungensis after the type locality of the fluke, is discussed.

This study was carried out 10 years after a wildfire in the Spanish Serra Calderona Natural Park, following a previous analysis comprising the first 5 years after the fire. Its primary aim was to elucidate the impact of this perturbation on the population biology of the wood mouse Apodemus sylvaticus, and the repercussions on its helminth community in this regenerating Mediterranean ecosystem. Second, confirmation of the ability of the parasites to tolerate environmental stressors and the effects on their transmission strategies was sought. Five hundred and sixty-four individuals of A. sylvaticus were studied in a 9-year period, from the second to the tenth post-fire year: 408 mice from the burned area and 156 from the control – non-burned – area. The helminth community for both areas and the effect of intrinsic (host age and sex) and extrinsic (site, period and year of capture) factors on helminth prevalence, abundance and diversity, and species richness were analysed. Our findings show that, after an environmental disaster, the behaviour of helminth species might be related to their pre-catastrophe presence, their biological cycles, the host's immunological condition, the change of host dynamics, the direct effects of the perturbation, and the processes related to the re-establishment of the ecological balance of a devastated ecosystem.

Fasciola gigantica fatty acid binding protein (FABP) was evaluated for evoking an immune response in mice, by delivering the gene coding for this protein with mannosylated-polyethylenimine (PEI) to peritoneal cells. Mice were immunized with 50 μg recombinant plasmid DNA (Group I) or DNA-PEI-mannose (a 22 kDa linear cationic polymer with mannose ligand) (Group II) via the intraperitoneal route. Antibody studies showed no significant humoral immune response evoked to this DNA immunization with either PEI-mannose-delivered or naked DNA. However, on protein boosting of these DNA-primed mice there was a significant enhancement of antibody titre. Flow cytometric bead array was used to measure quantitites of interleukin (IL)-2, IL-4, IL-5, interferon-γ (IFN-γ) and tumour necrosis factor (TNF) cytokines. Overexpression of T-helper 1 (Th1) cytokines such as IFN-γ and TNF, with a lower but significant expression of the T-helper 2 (Th2) cytokine IL-5 was detected. Gene delivery using polyethylenimine-mannose ligand showed significant expression of IFN-γ and TNF (P < 0.05), but no significant difference in IL-2, IL-4 and IL-5 (P>0.05) cytokine expression was observed between naked-DNA- and mannosylated PEI-DNA-delivered mice. Naked- or PEI-delivered-DNA immunization produced insignificant levels of IL-2 and IL-4 (P>0.05) cytokines in both groups of mice.

A new nematode species, Philometra floridensis sp. n. (Philometridae), is described from male and female specimens found in the ovary of red drum, Sciaenops ocellatus (Linnaeus) (Sciaenidae, Perciformes), from the Gulf of Mexico off Treasure Island, Florida, USA. Based on light and scanning electron microscopy examination, the new species differs from most other gonad-infecting Philometra spp. in having a smooth gubernaculum with a distinct dorsal tooth on the distal tip. The new species is most similar to P. carolinensis Moravec, de Buron & Roumillat, 2006, but differs in length and shape of spicules. It can be distinguished from P. carolinensis and other species with unknown males, by the markedly greater body length of gravid females (up to about 100 cm). Philometra floridensis is the third valid gonad-infecting species of Philometra reported from sciaenids.

Parasitic castration of Buccinanops cochlidium from San José Gulf, Argentina, caused by a lepocreadiid digenean, is reported for the first time. Rediae and ophtalmotrichocercous cercariae probably belonging to Opechona sp. were identified in the gonad and digestive gland. Opechona sp. has been reported previously parasitizing B. monilifer from a northern locality in the Argentine Sea. Overall prevalence of infection was 15.5%; it varied seasonally, rising during the warm months after the host oviposition period. Cercariae were expelled at the same time as the hatching of snail embryos (during the higher water temperature period). Rediae affected male and female snails equally, but prevalence increases along with host size. The parasite causes the complete castration of the host. Parasitized adult snails showed a reduction of penis size in comparison with healthy males. It remains to be confirmed whether the peak of cercariae emission coincides with the presence of jellyfishes and scombrid or other fishes in the area, which could act as second intermediate and definitive hosts, respectively.

Genetic variability of the ovine parasite Haemonchus contortus from the Alpine area was investigated using mitochondrial DNA (nd4 gene), internal transcribed spacers 1 and 2 and microsatellites, in order to assess whether cross-transmission between domestic and wild ruminants occurs. The dataset was composed of 78 individual adult male H. contortus collected from chamois (Rupicapra r. rupicapra), roe deer (Capreolus capreolus), alpine ibex (Capra ibex ibex), domestic goat (Capra hircus) and sheep (Ovis aries) from different alpine areas. The data obtained show low host specificity and high genetic variation within H. contortus populations. The analyses indicate the presence of two mitochondrial haplotype clusters among host species and the absence of cryptic parasite species, confirming H. contortus as a generalist nematode and suggesting that parasite transmission between populations of domestic and wild ruminants normally occurs.

The increasing prevalence of anthelmintic-resistant strains of helminths, drug residues in animal products and high cost of conventional anthelmintics has created an interest in studying medicinal plants as an alternative source of anthelmintic. The potential nematicidal activities of four extracts from the bark of Canthium mannii (Rubiaceae) stem were investigated in vitro. Extracts were diluted in distilled water (DW) to obtain five different concentrations (1.5, 2.0, 2.5, 3.0 and 3.5 mg/ml) and put in contact with eggs and larvae of Heligmosomoides polygyrus. The different stages of the life cycle were also put in contact with the same concentration of mebendazole (MBZ, positive control). One millilitre of each extract at different concentrations and control were added to 1 ml solution containing 30–40 eggs or 10–15 larvae (L1, L2 and L3) and distributed in different Petri dishes. The eggs and larvae were incubated at 24°C and exposure times were: 48 h for un-embryonated eggs, 6 h for embryonated eggs; 2, 4, 6 and 24 h for L1 and L2 larvae, 24–48 h for infective larvae (L3), and 5 days for the larval development test (from L1 to L3). DW and 1% dimethyl sulphoxide (DMSO) were used as placebo and DMSO control, respectively. Significant effects were obtained with three of the four extracts, and differences were observed depending on the parasite stage. Cold water extract (CWE), hot water extract (HWE) and ethanol extract (ETE) inhibited embryonic development (40, 45 and 10%) and hatching of embryonated eggs (40, 85 and 80%), respectively, at 3.5 mg/ml. Only ETE killed L1 (97.18%) and L2 (92.68%) larvae of H. polygyrus after 24 h at 3.5 mg/ml and drastically reduced the production rate (6% at 3.0 and 3.5 mg/ml) of infective larvae (L3) after 5 days of incubation compared to other extracts (P < 0.05). However, the infective larvae of H. polygyrus were resistant to the effect of each of the tested products (extracts and mebendazole). These in vitro results suggested that extracts of C. mannii, used by traditional healers in Dschang, Western Region of Cameroon (Central Africa) to cure intestinal helminthiasis and abdominal pains of their patients, possess nematicidal properties. The active principles responsible for the activity could be secondary metabolites such as alkaloids and saponins present in the extracts. It is suggested that further experiments incorporating in vivo purification of extracts and toxicological investigations should be carried out.

This study was aimed at evaluating the infection levels of Austrodiplostomum compactum metacercariae in 378 specimens of Plagioscion squamosissimus (‘corvina’ or ‘pescada branca’) from the Nova Avanhandava reservoir, low Tietê River, São Paulo State, Brazil. High prevalence, mean intensity of infection and abundance were observed in P. squamosissimus during most of the study, with the exception of March 2004. The relative condition factor (Kn) did not differ between parasitized and non-parasitized fish. A statistically significant positive correlation was observed between host standard length and intensity of infection. The analysis of biotic and abiotic variables showed that no abiotic variable correlated with parasitic infection levels. Moreover, P. squamosissimus status was demonstrated to be unaffected by A. compactum metacercariae infection.

Glutathione S-transferase from an Indian isolate of Fasciola gigantica of buffalo origin was isolated and characterized. Total RNA was transcribed to cDNA by reverse transcription and an amplicon of 657 bp glutathione S-transferase gene was obtained by polymerase chain reaction (PCR). The present isolate showed 99.1% sequence homology with the published sequence of the F. giganticaGST gene of cattle origin, with six nucleotide changes causing an overall change of four amino acids. Glutathione S-transferase protein was expressed in Escherichia coli using a prokaryotic expression vector pPROEXHTb. The recombinant protein was purified under non-denaturing and denaturing conditions by nickel nitrilotriacetic acid (Ni-NTA) affinity chromatography. Recombinant GST protein detected F. gigantica infection in naturally infected buffaloes by dot-ELISA.

A study to determine the seroprevalence of Dirofilaria immitis was carried out in feral cats in Grenada. Of the 137 feral cats tested for circulating antibodies (IgG; lateral-flow immunoassay) and circulating antigens (Ag; enzyme-linked immunosorbent assay), 8% (95% confidence interval (CI) 3.5–12.5%) were antibody positive and 5.1% (95% CI 1.4–8.8%) were antigen positive. No significant difference between cats aged>1 to 4 years and cats less than 1 year of age was found (P>0.05, χ2). There was also no significant difference (P>0.05, χ2) between male and female cats. Dirofilaria immitis prevalence is relatively high in the feral cat population of Grenada. Evidence of D. immitis infection in feral cats coupled with the endemic nature of heartworm disease in dogs in Grenada leads us to suggest the introduction of heartworm prophylaxis in cats. To the authors' knowledge, this serological evidence of heartworm infection in feral cats in Grenada is the first report from the Caribbean region.

Various strains of Atlantic salmon exhibit different levels of susceptibility to infections with the ectoparasitic monogenean Gyrodactylus salaris. The basic mechanisms involved in this differential ability to respond to this monogenean were elucidated using controlled and duplicated challenge experiments. Highly susceptible East Atlantic salmon allowed parasite populations to reach up to 3000 parasites per host within 6 weeks, whereas less susceptible Baltic salmon never reached larger parasite burdens than 122 parasites per host during the same period. The present study, comprising immunohistochemistry and gene expression analyses, showed that highly susceptible salmon erected a response mainly associated with an increased expression of interleukin-1β (IL-1β), interferon-γ (IFN-γ), IL-10 and infiltration of CD3-positive cells in the epidermis of infected fins. Less susceptible salmon showed no initial response in fins but 3–6 weeks post-infection a number of other genes (encoding the immune-regulating cytokine IL-10, cell marker MHC II and the pathogen-binding protein serum amyloid A) were found to be up-regulated. No proliferation of epithelial cells was seen in the skin of less susceptible salmon, and IL-10 may play a role in this regard. It can be hypothesized that resistant salmon regulate the parasite population by restricting nutrients (sloughed epithelial cells and associated material) and thereby starve the parasites. In association with this ‘scorched-earth strategy’, the production of pathogen-binding effector molecules such as serum amyloid A (SAA) (or others still not detected) may contribute to the resistance status of the fish during the later infection phases.

Rhabdias filicaudalis n. sp. (Nematoda: Rhabdiasidae) from the lung of Spilotes pullatus (Serpentes: Colubridae) is described. The host snake was captured in the municipality of Avaré, São Paulo State, Brazil. Rhabdias filicaudalis n. sp. differs from all other species by the combination of the following characters: straight body, truncated anterior end, six weakly developed lips arranged in two opposite groups of three, pre-equatorial vulva, oesophagus length/body length ratio (%) 4.9–7.5 (5.8 ± 0.6), nerve ring distance from anterior end/oesophagus length ratio (%) 36.9–61.1 (49.8 ± 6.4), tail length/body length ratio (%) 3.0–5.5 (4.0 ± 0.5), vulva distance from anterior end/body length ratio (%) 39.9–51.7 (45.9 ± 3.5), and a cuticular filiform tail tip.

A monitoring programme aimed at the diagnosis of subcutaneous dirofilariasis and heartworm disease in working (police and military) dogs in Slovakia has been performed during the period of September 2007 to February 2008. In co-operation with the Ministry of the Interior and the Ministry of Defence, in total, 710 dogs (591 police dogs and 119 military dogs) were investigated for the presence of microfilariae in blood. All police and military dogs in active service held on the territory of Slovakia were included. Microfilariae were detected in 118 (20.0%) police dogs and 10 (8.4%) military dogs. The most infected individuals originated from southern parts of Slovakia (Trnava region 53.6% and Nitra region 39.6%); the prevalence was low in northern regions (Žilina 3.1% and Prešov 6.6%). In several districts of southern Slovakia, the prevalence of subcutaneous dirofilariasis in working dogs exceeded 40%. In all infected animals, the autochthonous origin of the disease was confirmed; however, due to the frequent movement of working dogs, it was not possible to identify the exact locality of infection. At present, a dog living in Nemšová village in Trenčín district (north-western part of the country) is regarded as the northernmost localized autochthonous case of subcutaneous dirofilariasis in Slovakia. In three dogs, co-infection of Dirofilaria repens and Dirofilaria immitis was detected. High prevalence rates in working dogs and the zoonotic characteristic of the disease represent an undoubtedly important veterinary and medical problem that requires the urgent introduction of prophylactic and control measures.

The metacestode stage of Echinococcus granulosus is of zoonotic importance. In general, the 14-3-3 protein is involved in multiplication and survival of eukaryotes. Therefore, this communication presents succinct information on relative expression of the 14-3-3 protein in six different morphotypes of cysts of E. granulosus. All isolated E. granulosus belonged to the common sheep strain (G1). Relative expression of the 14-3-3 protein was higher in fertile cysts when compared to sterile cysts. The predicted amino acid sequence of the 14-3-3 protein was closely clustered with zeta-type isoforms 1 and 2 of the 14-3-3 protein. In addition, the present study demonstrates the presence of the 14-3-3 protein which until now had not been detected in the germinal layer. Our findings indicate that the expression of this biomolecule in the germinal layer of sterile organisms may contribute to the development and survival of the parasite in the host. The uniform expression of actin II conclusively proves the survivability of the harvested organisms.

Diplostomum species are economically important worldwide due to their metacercariae which parasitize the eyes of fish, in both natural and aquaculture systems. However, their striking morphological similarity, especially at the metacercarial stage, makes species separation difficult. Three closely related diplostomid metacercariae, namely Diplostomum mashonense (type 3), Tylodelphys sp. 1 and 2 (type 1 and 2, respectively), coexist in the cranial cavity of the catfish, Clarias gariepinus from Mindu dam, Lake Victoria, Msimbazi, Ruvu and Kilombero rivers. The morphometrics of these three species were analysed by discriminant function analysis to investigate the degree of variation among the populations from the five localities sampled. The first canonical functions for all visual examination plots accounted for over 50% of the between-group variability. The observed differences were mainly from measurements associated with length, indicating that these measurements are important in the description of population characteristics. Visual examination of the samples along the canonical functions showed a clear between-population differentiation. The overall random assignment of individuals into their original groups was high (97%). These extensive morphometric variations introduce doubt about the reliability of measurements in the determination of species in these trematodes, as they may lead to misidentifications.

Parasitological investigations on ruminal paramphistomosis were carried out in 2033 cattle over a 14-month period in three Algerian slaughterhouses to determine the prevalence and intensity of this disease. The prevalence of infection varied from different slaughterhouses (1.2% at El Khroub, 7.5% at Ferdjioua and 12.1% at Jijel). The worm burden was significantly higher in cattle from El Khroub than for those slaughtered in the other two sites (a mean of 984.1 parasites compared with 87.5 and 140.7 at Jijel and Ferdjioua, respectively). No significant correlation between prevalence, intensity of infection and age of cattle was noted. Overall, females were significantly more infected than males, whereas the sex of animals was independent of worm burdens recovered in slaughtered cattle. The climatic conditions of provinces in which the slaughterhouses were located (a more temperate climate for Jijel and semiarid conditions for the other two provinces) may partly explain variations noted in prevalence and intensity of infection. The present results will contribute to our understanding of the epidemiology of Paramphistomum daubneyi infections in north-eastern Algeria.

Porcine cysticercosis is an emerging zoonosis with public health and economic importance. A cross-sectional study was undertaken to investigate the disease in free-range pigs on 182 smallholder farms in Busia District, Kenya. The survey households were selected using a snowballing technique. Serum samples were obtained from 284 pigs of all ages at farm level and 37 pigs from slaughter slabs in the study area. The samples were analysed for the presence of cysticercus antigen using an antigen enzyme-linked immunosorbent assay (ELISA). A structured questionnaire was administered to determine the risk factors for porcine cysticercosis on the study farms. At pig level, the total number of pigs testing positive were 11, resulting in a seroprevalence of 4% (95% confidence interval (CI): 1.9–6.2%), while the farms with a positive pig were 9% (95% CI: 3.9–14.1%). All pigs examined in the slaughter slab survey were seronegative. The distribution of possible risk factors for porcine cysticercosis that were observed at farm level was as follows: free-range pig keeping (100%), history of human taeniosis infection in a family (51%), slaughtering of pigs at home (20%), lack of meat inspection (15%) and absence of latrines (15%). The only significant (χ2 = 4.4, P = 0.034, odds ratio (OR) = 3.8) risk factor associated with the occurrence of cysticercosis was lack of latrines at household level. The study shows that porcine cysticercosis is prevalent in free-range pigs in Busia District, Kenya and thus control measures need to be instituted.

The anthelmintic effect of Prosopis laevigata (mezquite) n-hexanic extract was evaluated against Haemonchus contortus endoparasitic stages in artificially infected gerbils (Meriones unguiculatus). Prosopis laevigata leaves were collected from the Sierra de Huautla, Ecological Reserve of the Biosphere, in Morelos State, Mexico; dehydrated under shade and macerated with n-hexane for 3 days, followed by distillation for 8 h. This procedure was repeated three times and the final extract was kept at 4°C. The in vivo effect of the plant extract was evaluated in gerbils artificially infected with H. contortus. Plant extract concentration was 40 mg/ml. Three groups of gerbils were as follows: group 1 (n = 7), P. laevigata extract at 100 μl intraperitoneally (IP); group 2 (n = 6), control – Tween 20 in water at a single dose of 100 μ l IP; group 3 (n = 8) also served as a control, receiving water only, to determine the mortality due to causes other than the plant extract. An additional group of seven gerbils (group 4) was administered fenbendazole, as a positive control. Five days later the animals were euthanized and stomach and mucosa removed to quantify the nematodes. Data were analysed using the Student's t-test to compare the mean of nematodes obtained in groups 1, 2 and 3. The parasite population in the plant extract treated group 1 was reduced by 42.5% (P < 0.05) with respect to the control group 2; and when control group 3 was used for comparison the parasitic reduction was estimated as 53.11%. This study shows the in vivo anthelmintic effect of P. laevigatan-hexane extract for the first time, using gerbils as an in vivo model, with potential use in sheep.

The nematode Angiostoma glandicola sp. n. found parasitizing Megaustenia sp. snails (Pulmonata: Helicarionidae) collected in Dong Nai Province, Vietnam, is described and illustrated. The new species is characterized by its unusual host location (the digestive gland) and in having: two circles of cephalic probolae, six lips each bearing two prominent papillae, amphids situated at posterior of lips, the presence of lateral alae, an enlarged stoma, a club-shaped pharynx with cuticularized valves in the bulb, the nerve ring situated on the junction of the corpus and isthmus and the excretory pore opposite the bulb. Oviparous females have a mid-body vulva position, long reflexed ovaries and short divergent uteri, and a conical tail with a slightly triangular tip. Males have long, curved, not distinctly cephalate spicules and a small gubernaculum, nine pairs of pedunculate genital papillae (GP) incorporated into the bursa (three precloacal, six postcloacal in two groups: GP 4–7 closely behind the cloaca and GP 8–9 distanced), of which GP 5 and 8 terminate on dorsal edge of the bursa and GP 8 and 9 are fused at the base, the bursa nearly reaches the tail tip, unpaired precloacal GP and a pair of ventral circumcloacal GP not incorporated into bursa. It clearly differs from other species of the genus by having cephalic probolae vs. no cephalic probolae and the specific number and disposition of male GP. A partial sequence of D2D3 large subunit (LSU) rDNA was obtained and subjected to phylogenetic analyses. Relationships within the Angiostoma genus are discussed.