In order to study egg release by Aspiculuris tetraptera total faecal collections from infected mice were made every 1½ h throughout successive 24 h periods. This was done with the aid of a histokinette machine. The cage containing the mice was suspended from one of the arms of the machine and every 1½ h the cage was moved on by the machine to the next adjacent collecting dish. The faecal pellets passed were counted and then used for flotation egg counts.

It was found that eggs were not released steadily and continuously and, in the case of the worms in an isolated mouse, egg output was clearly intermittent. Egg production did not appear to vary with the faecal production of the host in a consistent way but with two groups of 8 mice it was highest when faecal production was at its peak shortly before dawn. For the groups of 8 mice the concentration of eggs per faecal pellet was also highest at this time. In two experiments with an individual mouse, however, the egg counts fell to zero at dawn before the level of faecal production became reduced.

It is suggested therefore that egg output by female A. tetraptera may be stimulated by the altered physiological state of the host associated with feeding or general activity.

An examination of a considerable number of specimens of larval Ascarids from the peritoneal tissues of marine fishes has led me to the conclusion that the great majority of these young nematodes are referable to a single species, Ascaris capsularia Rud. The older descriptions of this form are inadequate and superficial, and even by the more recent writers it appears to have been assumed that, as a larval form, it was impossible, or not worth while, to define it more precisely. I believe, however, that by paying attention to the internal structure it is possible, even at this early stage, to discover characters of specific importance. The imperfect recognition of these characters has led, it appears, to considerable confusion, and to the inclusion in the species of some forms which should be regarded as specifically distinct. A full synonymy and bibliography has been given by Stossich (1896, pp. 55–57) and it is unnecessary here to review the literature in detail. It is desirable to point out, however, that some even of the comparatively recent descriptions intended to refer to A. capsularia seem, in reality, to belong to some other form. Thus É. Blanchard (1849) describes and figures under the name of A. salaris a small form, 20–35 mm. in length, having three lips already visible, a lateral caecum at the base of the oesophagus and female genital organs already developed.

In a former paper (Baylis, 1944) an account was given of some observations on the life-history of Mermis nigrescens, and of its occurrence, naturally and experimentally, in earwigs (Forficula auricularia). As stated in that paper, the material then available did not seem to warrant an attempt to describe the larval development. Further material has now been obtained and studied, and it seems desirable to place on record some of the observations made, although many points still remain obscure.

In haemolymph of Lymnaea stagnalis, parasitized with the digenetic trematode parasite Trichobilharzia ocellata, a neuropeptide (schistosomin) occurs which antagonizes female gonadotropic hormones, e.g. calfluxin (CaFl). By means of an ultracytochemical hormone-assay, the CaFl assay, it was demonstrated that the occurrence of schistosomin is a general phenomenon in schistosome-infected freshwater snails. Haemolymph of the schistosomiasis-transmitting snail species Biomphalaria glabrata and B. pfeifferi, parasitized with Schistosoma mansoni, also appeared to contain an antagonizing factor, i.e. schistosomin. In contrast, in haemolymph of L. stagnalis parasitized with Diplostomum spathaceum (Diplostomatidae) no schistosomin could be found. This suggests that schistosomin may only occur in snails infected with parasites belonging to the Schistosomatidae. The effect of schistosomin is rather specific. Haemolymph of B. glabrata parasitized with S. mansoni had not the capacity to inhibit the response to CaFl in the target organs for CaFl, the albumen glands of L. stagnalis and Bulinus truncatus. The same holds true for haemolymph of infected L. stagnalis: it did not inhibit the CaFl response in glands of B. glabrata and B. truncatus and even not in those of a related species (L. ovata). Schistosomins in haemolymph of infected B. glabrata and B. pfeifferi, on the other hand, seem more related. Both appeared to inhibit the hormone response in glands of the two Biomphalaria species studied. The results indicate that schistosomin in haemolymph of schistosome-infected pulmonate snails, although functionally related, may differ structurally.

It was found that Lucilia porphyrina Walker lays eggs on living toads (Bufo melanostictus). Larvae hatched out of the eggs in about two days and attacked the region of the upper eye-lids of the toads, where a lesion was produced. The parotoid gland was sometimes attacked. The larvae also infested the sites of injuries on the toads.

The toads thus attacked soon died and the larvae fed on their dead tissues. Mature larvae came out of the carcass within a few days and entered the soil, where they pupated. The adult fly emerged after about 20 days.

In this study, we have analysed enzyme polymorphism among a group of protozoan parasites of the genus Endotrypanum (Kinetoplastida: Trypanosomatidae). Seventeen stocks of Endotrypanum spp. isolated from sloths (Choloepus didactylus and C. juruanus) in the Amazon Region of Brazil were analysed by enzyme electrophoresis, and their electromorphic profiles were compared with reference strains reported previously. The 16 enzymic loci were analysed, and the strains were classified into zymodemes, each representing parasites with unique enzyme profiles. Each zymodeme was considered as an elementary taxon, and using numerical analyses (cladistic, agglomerative hierarchical and ordination techniques) the genus was shown to be monophyletic and the 12 zymodemes characterized could be divided into 3 groups (A, B, C). The heterogeneous population (which may represent a complex of parasite species or strains variants) showed, however, no correlation with the origin (i.e. host species involved or geographic area of isolation) of Endotrypanum stocks. Eight isolates of Endotrypanum sp. from Rondonia State (Brazil) and a parasite strain from Panama were clustered together into a zymodeme, which was phenetically closely related to the E. monterogeii from Costa Rica. The data indicate that E. schaudinni is a species complex.

Many workers have described abnormal forms and structures in ticks. Neuman (1899) was the first who recorded some abnormal Ixodidae. Brumpt (1934) reviewed the literature and recorded some new interesting abnormalities. The posterior region of the body of one of the specimens described by Brumpt had two ani and four stigmata. Brumpt considered that only the Ixodidae display abnormal forms, but since then Robinson (1943–4) described abnormalities in laboratory-bred Ornithodorus moubata. He also noticed a ‘partially twinned’ tick which mated, and laid eggs which developed into normal ticks.

Following incubation with sporozoites of the protozoan parasite Theileria annulata, dendritic cells (DC), extracted from bovine afferent lymph, became infected and transformed into large, rounded, continuously proliferating cell lines. Phenotypic analysis of the transformed cells by immunostaining and flow cytometry revealed that they expressed MHC class I and II antigens, the myeloid marker MyD1 (SIRPα) and the bovine WC6 (workshop cluster 6) molecule. Transformed DC cell lines differed from those produced from infection of macrophages and B cells in that some lines expressed CD21 and a proportion of cells continued to express the antigen stained by the mAb CC81, a marker which defines a subpopulation of DC in afferent lymph. Both of the main populations of DC that have been identified in bovine afferent lymph appeared to be equally permissive for infection and transformation with T. annulata. These findings raise the possibility that the transformed proliferating cells characteristic of in vivo infections could be derived from DC as well as macrophages. This could have consequences for understanding the pathogenesis of the disease and for developing methods to manipulate immune responses to eliminate the parasite.

The ability to monitor the expression levels of thousands of genes in a single microarray experiment is a huge progression from conventional Northern blot analysis or PCR-based techniques. Microarrays can play a pivotal role in the mass screening of genes in a wide range of fields including parasitology. The relatively few parasites that can be readily cultured or isolated from a host, as compared with cell lines or tissue sources, makes microarray technology ideal for maximizing experimental results from a limiting source of starting material. Khan et al. (1999a) commented in an early review of microarray technology “With this system in place, one can anticipate a time when data from thousands of gene expression experiments will be available for meta-analysis…..… leading to more robust results and subtle conclusions”. Now in 2005, microarrays represent a very powerful resource that can play an important role in the characterization and annotation of the transcriptomes of many parasites of medical and veterinary importance.

Trypanosoma brucei is the etiological agent of devastating parasitic disease in humans and livestock in sub-saharan Africa. The pathogenicity and growth of the parasite are intimately linked to its shape and form. This is in turn derived from a highly ordered microtubule cytoskeleton that forms a tightly arrayed cage directly beneath the pellicular membrane and numerous other cytoskeletal structures such as the flagellum. The parasite undergoes extreme changes in cellular morphology during its life cycle and cell cycles which require a high level of integration and coordination of cytoskeletal processes. In this review we will discuss the role that proteomics techniques have had in advancing our understanding of the molecular composition of the cytoskeleton and its functions. We then consider future opportunities for the application of these techniques in terms of addressing some of the unanswered questions of trypanosome cytoskeletal cell biology with particular focus on the differences in the composition and organisation of the cytoskeleton through the trypanosome life-cycle.

Sirtuin proteins form a family of NAD+-dependent protein deacetylases that are considered potential drug targets against parasites. Here, we present the first characterization of a sirtuin orthologue from Leishmania amazonensis, an aetiological agent of American tegumentary leishmaniasis that has been the subject of many studies focused in the development of therapeutic approaches. The protein has high sequence identity with other Kinetoplastid Silent information regulator 2 Related Protein 1 (Sir2RP1) and was named LaSir2RP1. The gene exists as a single copy, encoding a monomeric protein (LaSir2RP1) of approximately 41 kDa that has NAD+-dependent deacetylase activity. LaSir2RP1 was immunodetected in total protein extracts, in cytoplasmic granules, and in the secreted material of both promastigotes and lesion-derived amastigotes. Analysis of both lectin‑affinity purified promastigote and amastigote extracts revealed the presence of a major enriched protein of approximately 66 kDa that was recognized by an anti-LaSir2RP1 serum, suggesting that a parasite sirtuin could be glycosylated in vivo.

In 1916, the writer (Van Cleave, 1916) called attention to the fact that lack of published records should not be taken as an indication of scarcity of Acanthocephalans in the Chinese fauna. A single species of Centrorhynchus has been described from a magpie, and Faust (1921 a) has recorded the species common in the hog. As yet, apart from these two specific identifications, the acanthocephalan fauna of China has remained unknown.

Corridor disease is an acute, fatal disease of cattle caused by buffalo-adapted Theileria parva. This is a nationally controlled disease in South Africa and strict control measures apply for the movement of buffalo, which includes mandatory testing for the presence of T. parva and other controlled diseases. Accurate diagnosis of the T. parva carrier state in buffalo using the official real-time hybridization PCR assay (Sibeko et al. 2008), has been shown to be affected by concurrent infection with T. sp. (buffalo)-like parasites. We describe the Hybrid II assay, a real-time hybridization PCR method, which compares well with the official hybridization assay in terms of specificity and sensitivity. It is, however, not influenced by mixed infections of T. sp. (buffalo)-like parasites and is as such a significant improvement on the current hybridization assay.

A few specimens very badly preserved and pigmented: coating them was a deposit which entirely obscured the internal anatomy and could not be removed. The internal anatomy therefore could not be removed. The internal anatomy therefore could not be elucidated. Length 10*, greatest breadh 0·47. Scolex 0·54 dia. As the only species without a rostellum recorded from this host is A. vaginatus the specimens are listed under that name.

1. Egg masses of Limnaea truncatula collected in March 1925 were isolated and hatched in the Laboratory. The average number of ova per mass (for 20) proved to be 9·75.

2. The hatching period lasted 12 to 26 days, with an average of 20–21 days (for the Spring generation).

3. On hatching, young snails were isolated, reared, and again oviposited during the first week of July. Ova from these snails again hatched during the first week of August.

4. It is thus shown that L. truncatula is self fertile; that oviposition can commence at a shell altitude of 4 to 4·5 mm.

5. Further data on growth-rates were obtained, showing that two (and probably three) generations occur between March and October.

129/Ola mice resemble WEHI 129J mice in that around 70% of the individuals in any given population resist a primary infection with Schistosoma mansoni. Squashed-organ autoradiographic tracking of [Se]selenomethionine-labelled parasites has shown that the kinetics of worm migration in 129/Ola mice follows the expected pattern, and that all rodents harbour essentially similar numbers of worms on day 14 post-infection. Combined lung and liver worm recovery techniques have revealed, however, that segregation of mice into ‘permissive’ and ‘non-permissive’ individuals can first be detected on day 20. ‘Non-permissive’ mice are characterized by the absence of schistosome eggs at all times in the liver parenchyma and, in consequence, lack the attendant manifestations of pathology; they do, however, harbour a few stunted worms in the liver and significant numbers of adult schistosomes in the pulmonary vasculature. Histological analysis of sectioned lung tissue from such animals indicates that some lung-located schistosomes feed, pair and lay eggs. Nevertheless, eosinophil-enriched inflammatory reactions develop around such worms and the parasites themselves exhibit various manifestations of trauma, ranging from minor vacuolation to gut herniation and extrusion. The phenomenon of ‘non-permissiveness’ thus involves retardation of worm development in the liver and, in consequence, relocation of the parasites to the lungs, where they become subject to host effector responses.

Quantitative chromatographic analysis of the free amino acids of the head–foot muscle of uninfected and infected Littorina littorea indicates that there is specific variation in the physiological effects of parasitism. The total concentration of free amino acids in the host head–foot muscle showed an increase of 10·9% with infections of Cryptocotyle lingua rediae, a decrease of 12·7% with infections of Himasthla leptosoma rediae and a decrease of 57·5% with infections of Cercaria emasculans sporocysts. These effects probably depend on three main factors namely, the nature, size and mobility of the larvae of the three species concerned and the influence of these factors in determining the extent of any damage to the hepatopancreas of the host.

The larvae of C. lingua are probably less affected by the changes they induce in the free amino acid pool of the host than the larvae of H. leptosoma and Cercaria emasculans which induce changes equivalent to starvation.

This work was conducted during the tenure of a Science Research Council Studentship. I would like to thank Professor B. John and Mr A. R. Hockley for their helpful advice and criticism.

We have observed that when cercariae penetrate the skin of mice, there is influx into their tissues of Lucifer Yellow and certain labelled molecules of up to 20 kDa molecular weight. This observation was made using a variety of fluorescent membrane-impermeant compounds injected into the skin before the application of cercariae. This unexpected phenomenon was investigated further by transforming cercariae in vitro in the presence of the membrane-impermeant compounds and examining the distribution by microscopy. In schistosomula derived from this procedure, the nephridiopore and surface membrane were labelled while the pre- and post-acetabular glands were not labelled. The region associated with the oesophagus within the pharyngeal muscle clearly contained the fluorescent molecules, as did the region adjacent to the excretory tubules and the germinal mass. We used cercariae stained with carmine to aid identification of regions labelled with Lucifer Yellow. Although the mechanism of this influx is unclear, the observation is significant. From it, we can suggest an hypothesis that, during skin penetration, exposure of internal tissues of the parasite to external macromolecules represents a novel host-parasite interface.

Effective control of gastrointestinal parasites is necessary in sheep production. The development of anthelmintics resistance is causing the available chemically based anthelmintics to become less effective. Biological control strategies present an alternative to this problem. In the current study, we tested the larvicidal effects of Bacillus thuringiensis var. israelensis Cry11Aa toxin against Haemonchus contortus larvae. Bacterial suspensions [2 × 108 colony-forming units (CFU) g−1 of the feces] of B. thuringiensis var. israelensis and recombinant Escherichia coli expressing Cry11Aa toxin were added to naturally H. contortus egg-contaminated feces. The larvae were quantified, and significant reductions of 62 and 81% (P < 0·001) were, respectively observed, compared with the control group. A 30 mL bacterial suspension (1 × 108 CFU mL−1) of B. thuringiensis var. israelensis and recombinant E. coli expressing Cry11Aa toxin were then orally administered to lambs naturally infected with H. contortus. Twelve hours after administration, feces were collected and submitted to coprocultures. Significant larvae reductions (P < 0·001) of 79 and 90% were observed respectively compared with the control group. The results suggest that the Cry11Aa toxin of B. thuringiensis var. israelensis is a promising new class of biological anthelmintics for treating sheep against H. contortus.