A retrospective study on different Lymnaea glabra samples collected from central France between 1993 and 2010 was carried out to determine the prevalence of natural co-infections with Calicophoron daubneyi and Fasciola hepatica, and to specify the composition of redial burdens. Experimental infections of L. glabra performed during the same period of time were also analysed to study metacercarial production of each digenean in co-infected snails. Controls were naturally or experimentally co-infected Galba truncatula. In natural co-infections, prevalence was 0.7% in L. glabra (186/25,128) and 0.4% in G. truncatula (137/31,345). Low redial burdens were found in these snails, with F. hepatica rediae significantly more numerous in L. glabra than in G. truncatula (7.5 per snail instead of 5.2). In contrast, the total numbers of C. daubneyi rediae in both lymnaeids were close to each other (4.3 and 3.0 rediae, respectively). In experimentally co-infected groups, prevalence was greater in G. truncatula than in the other lymnaeid (6.3% instead of 3.0%). Significantly shorter patent periods and lower metacercarial production for each digenean were noted in L. glabra than in G. truncatula. However, in both lymnaeids, the two types of cercariae were released during the same shedding waves and several peaks during the patent period were synchronous. In spite of a greater shell height for L. glabra, metacercarial production of both digeneans in co-infected snails was lower than that in G. truncatula, thus indicating a still incomplete adaptation between these French L. glabra and both parasites.

A new species, Belondira bagongshanensis n. sp., extracted from soil under grass in Bagongshan Forest Park, Anhui Province, China, is described and illustrated. The new species is mainly characterized by a body length 1.6–2.1 mm; cephalic framework moderately sclerotized; odontostyle robust with a distinct lumen; anterior part of pharynx with a distinct fusiform swelling, bearing distinct sclerotized valve plates and basal expansion occupying about three-fifths of the total neck length; female genital system mono-opisthodelphic and anterior branch 0.8–1.6 times the corresponding body diameter; tail short and hemispheroid; male spicules 36–49 μm long and two widely spaced ventromedian supplements. The new species is close to B. wajahati, B. golden and B. eugeniae in possessing a short tail, a robust odontostyle with a distinct aperture and a moderately sclerotized cephalic framework. New sequences of 18S rDNA and the D2–D3 region of 28S rDNA of the new species were also identified.

Hookworm infection stands out for its worldwide distribution and for its veterinary and public health relevance. Based on copromicroscopic examinations and polymerase chain reaction (PCR) amplification of the ITS1–5.8S–ITS2 region, we assessed, respectively, the prevalence of intestinal parasites and the identification of canine hookworm species in faeces recovered from 278 dogs living in households of an inland municipality of São Paulo State, Brazil. Intestinal parasites were found in 67.3% of dogs and hookworm infection was found at the highest prevalence rate (56.6%), followed by Toxocara canis (11.9%), Isospora spp. (11.9%), Giardia spp. (5.8%), Sarcocystis spp. (4.0%), ‘Hammondia-like’ (1.4%), Dipylidium caninum (1.1%) and Trichuris vulpis (0.7%). Of 158 samples positive for hookworm eggs, 106 (67.1%) were amplified by PCR and, of those, 88 (55.7%) were successfully sequenced for species identification. Single infections with Ancylostoma caninum and Ancylostoma braziliense were recorded in 61.4% and 12.5%, respectively, and mixed infections were found in 26.1%. The nucleotide sequences of both species showed high identity rates (98–100%) when compared with reference sequences. Although A. caninum was the most prevalent hookworm in the dogs assessed, the occurrence of both A. caninum and A. braziliense in single and/or mixed infections poses a potential risk for the local population in a low-income area, especially children, to acquire cutaneous larva migrans (CLM).

A new species of entomopathogenic nematode, Steinernema pwaniensis n. sp., belonging to the glaseri group, is described from Tanzania. The infective juveniles of S. pwaniensis n. sp. are characterized by a body length of 978 μm (808–1131), distance from anterior end to excretory pore of 86 μm (80–95) and a tail length of 87 μm (75–95). The ratios a, c and E% of S. pwaniensis n. sp. are substantially lower than those of all other African ‘glaseri’ group members. The first-generation males of S. pwaniensis n. sp. can be distinguished by a large spicule length of 92 μm (80–97) and by the absence of the caudal mucron, while second-generation males possess a short spine-like mucron. First-generation females have a peg-like tail tip bearing three spine-like projections. Second-generation females can be recognized by a slightly protruding vulva and well-developed post-anal swelling. The new species is further characterized by sequences of the internal transcribed spacer (ITS) and partial 28S regions of the ribosomal DNA. Phylogenetic analyses show that S. pwaniensis n. sp. forms a strongly supported monophyletic clade with two other East African species, S. ethiopiense and S. karii.

Schistosomiasis is the second major parasitic disease in the world after malaria. It affects 201.5 million cases in Africa alone. The aim of this research was to explore alternative vaccination strategies against experimental schistosomiasis mansoni. We assessed the effect of cercarial transformation fluid (CTF) singly and in combination with crude cercarial antigen (CCA) using alum as an adjuvant. The combined antigens gave the best results, as evidenced by a significant reduction in the worm load (62.07%), tissue egg count (78.16%, 86.46%) in liver and intestine respectively, and hepatic granuloma size (29.96%). Scanning electron microscopy revealed changes in the tegument, in the form of roughness and appearance of vesicles and furrows between the tegumental tubercles. Also, resorption of the ventral sucker and dimples replacing its spines were observed. The female tegument was irregular and its posterior end showed loss of spines and sensory bulbs. Moreover, there was a significant decrease in liver enzymes (alanine transaminase (ALT) and aspartate transaminase (AST)) compared to infected control mice. A significant elevation in CD4+T-lymphocytes, denoting amelioration of the immune status, in mice that received combined antigens was also observed. It can be concluded that combined antigens demonstrate potential as a vaccine against Schistosoma mansoni.

Human lymphatic filariasis is a neglected tropical disease, causing permanent and long-term disability with severe immunopathology. Abundant larval transcript (ALT) plays a crucial role in parasite establishment in the host, due to its multi-faceted ability in host immune regulation. Although ALT protein is a key filarial target, its exact function is yet to be explored. Here, we report epitope mapping and a structural model of Brugia malayi ALT-2, leading to development of a multi-epitope vaccine. Structural analysis revealed that ALT represents unique parasitic defence proteins belonging to a toxin family that carries a ‘knottin’ fold. ALT-2 has been a favourite vaccine antigen and was protective in filarial models. Due to the immunological significance of ALT-2, we mapped B-cell epitopes systematically and identified two epitope clusters, 1–30 and 89–128. To explore the prophylactic potential of epitope clusters, a recombinant multi-epitopic gene comprising the epitopic domains was engineered and the protective efficacy of recombinant ALT epitope protein (AEP) was tested in the permissive model, Mastomys coucha. AEP elicited potent antibody responses with predominant IgG1 isotype and conferred significantly high protection (74.59%) compared to ALT-2 (61.95%). This proved that these epitopic domains are responsible for the protective efficacy of ALT-2 and engineering protective epitopes as a multi-epitope protein may be a novel vaccine strategy for complex parasitic infections.

An in vivo study in the laboratory rat model has been carried out to monitor changes to the spermatogenic cells in the testis tubules of adult Fasciola hepatica following treatment with the artemisinins, artemether and artesunate. Rats infected with the triclabendazole (TCBZ)-resistant Sligo isolate were dosed orally with artemether at a concentration of 200 mg/kg and flukes recovered at 24, 48 and 72 h post treatment (pt). Rats infected with the TCBZ-resistant Oberon isolate were dosed orally with artesunate at a concentration of 200 mg/kg and flukes recovered 24, 48, 72 and 96 h pt. The flukes were processed for histological and transmission electron microscope (TEM) examination. Changes to the spermatogenic cells were evident at 24 h pt with artemether. The spermatogonial and spermatocyte cells contained abnormal mitochondria, there were fewer spermatids and spermatozoa in the tubules than normal, and a number of cells showed signs of apoptosis. There was a further decline in cell numbers at 48 h pt and the organization of the spermatocyte and spermatid rosettes was atypical. Sperm formation had become abnormal and those spermatozoa present possessed only a single axoneme. By 72 h pt, the testis tubules were vacuolated and filled with abnormal cells and cell debris. Only spermatogonial cells could be identified and there was widespread evidence of apoptosis in the cells. Distinct cellular changes following artesunate treatment did not become apparent until 48 h pt. The changes seen were similar to those described for artemether, but were generally less severe at matching time-periods. The fine structural changes occurring in the spermatogenic cells were compared to those observed in other cell types and fluke tissues and the overall information was collated to identify the cellular targets for artemisinin action and to establish the time-line for drug action.

Synonymous codons are used with different frequencies, a phenomenon known as codon bias, which exists in many genomes and is mainly resolute by mutation and selection. To elucidate the genetic characteristics and evolutionary relationship of Wucheraria bancrofti and Schistosoma haematobium we examined the pattern of synonymous codon usage in nuclear genes of both the species. The mean overall GC contents of W. bancrofti and S. haematobium were 43.41 and 36.37%, respectively, which suggests that genes in both the species were AT rich. The value of the High Effective Number of Codons in both species suggests that codon usage bias was weak. Both species had a wide range of P3 distribution in the neutrality plot, with a significant correlation between P12 and P3. The codons were closer to the axes in correspondence analysis, suggesting that mutation pressure influenced the codon usage pattern in these species. We have identified the more frequently used codons in these species, most codons ending with an A or T. The nucleotides A/T and C/G were not proportionally used at the third position of codons, which reveals that natural selection might influence the codon usage patterns. The regression equation of P12 on P3 suggests that natural selection might have played a major role, while mutational pressure played a minor role in codon usage pattern in both species. These results form the basis of exploring the evolutionary mechanisms and the heterologous expression of medically important proteins of W. bancrofti and S. haematobium.

One new species from Qinghai Province, China, Labronemella major n. sp., is described. The new species is characterized by a body length of 3.03–3.34 mm; lip region wide, offset by a distinct depression, disc-like with six separated inner liplets; amphid fovea funnel-shaped, distinctly bulged on body surface in scanning electron micrographs; odontostyle long (35–39 μm) with distinct lumen, aperture about 39–47% of its length; odontophore rod-like and long; guiding ring double; pharyngeal basal expansion about half of the total neck length; uterus relatively long and tripartite; vulva transverse and sclerotized; spicules 81–90 μm long; ventromedial supplements 19–23; tail short, rounded to conoid. It can be differentiated from all other species of the genus by its relatively longer body, odontostyle and spicules, and wider lip region. Due to the lip region being offset by a deep constriction, and the long (three or more times the body diameter at mid-body) tripartite uterus, the new species is close to Labronemella czernowitzensis (Micoletzky, 1922) Andrássy, 2002 and Labronemella labiata Andrássy, 1985. An improved key to the genus including the new species is provided.

The prevalence of canine Dirofilaria infection in Maio Island (Cape Verde) was analysed by serology, morphological and molecular identification of the parasite species. Blood and sera were collected from 150 dogs and 80 cats aged over 6 months from various localities of the island. DNA was extracted from blood and samples were screened by polymerase chain reaction (PCR) using microfilaria-specific primers. No Dirofilaria immitis was found in dogs while D. repens microfilariae were found in 5.3% of dogs and 6% were positive by PCR. The species identity was confirmed by sequencing of PCR products, which showed almost 100% homology with D. repens European sequences published in GenBank. No difference in Dirofilaria infection was observed between males and females or in dogs with different weights. However, older dogs and those from the western part of Maio Island were more frequently infected. No Dirofilaria was found in cats. This study represents the first evidence of D. repens in Cape Verde (West Africa) and highlights the need for implementing control measures and for a better surveillance of dirofilariosis in Africa.

Studies of amphibian macroparasites are relevant for the investigation of parasite community ecology and disease dynamics. Here, the parasite communities of five anuran species (Hypsiboas raniceps, Phyllomeduza azurea, Pseudis paradoxa, Leptodactylus fuscus and Leptodactylus podicipinus) are described from two habitats with different levels of preservation (pasture versus nature reserve). Specifically, we used mixed-effect models to test whether helminth species richness, prevalence and abundance differ between the two host collection sites. A total of 120 anuran individuals and 25 helminth parasite taxa were collected. Helminth communities differed between collection sites and among host species. In general, helminth species richness, prevalence and abundance were higher in hosts collected in the pond from the nature reserve. In all, these data help fill the gap in parasite biodiversity knowledge in a changing area, within a sensitive group of vertebrate hosts.