Setaria cervi, a bovine filarial parasite contains significant acid phosphatase (AcP) activity in its various life stages. Two forms of AcP were separated from somatic extract of adult female parasite using cation exchange, gel filtration and concavalin affinity chromatography. One form having a molecular mass of 79 kDa was characterized as dual specific protein tyrosine phosphatase (ScDSP) based on substrate specificity and inhibition studies. With various substrates tested, it showed significant activity in the order of phospho-L-tyrosine>pNPP>ADP>phospho-L-serine. Inhibition by orthovanadate, fluoride, molybdate, and zinc ions further confirms protein tyrosine phosphatase nature of the enzyme. Km and Vmax determined with various substrates were found to be 16·66 mM, 25·0 μM/ml/min with pNPP; 20·0 mM, 40·0 μM/ml/min with phospho-L-tyrosine and 27·0 mM, 25·0 μM/ml/min with phospho-L-serine. KI with pNPP and sodium orthovanadate (IC50 33·0 μM) was calculated to be 50·0 mM. Inhibition with pHMB, silver nitrate, DEPC and EDAC suggested the presence of cysteine, histidine and carboxylate residues at its active site. Cross-reactivity with W. bancrofti-infected sera was demonstrated by Western blotting. ScDSP showed elevated levels of IgE in chronic filarial sera using ELISA. Under in vitro conditions, ScDSP resulted in increased effector function of human eosinophils when stimulated by IgG, which showed a further decrease with increasing enzyme concentration. Results presented here suggest that S. cervi DSP should be further studied to determine its role in pathogenesis and the persistence of filarial parasite.

The distribution of Paragonimus kellicotti metacercariae in a mixed population of crayfish from a small central Ohio stream was studied for two seasons. The distribution of worms in crayfish approximates the negative binomial distribution. Prevalence and intensity of infection increased with crayfish body weight. Although no difference in intensity of infection was noted between male and female crayfish, the prevalence of infection was higher in males. The data demonstrate a seasonal recruitment of metacercariae into the crayfish only during late summer and autumn. Metacercariae can live for over 1 year but some die and become mineralized. There is no apparent detrimental effect of P. kellicotti infection on the crayfish. The seasonal timing of life-cycle events is postulated.

An activity cell apparatus to facilitate quantitative measurements of motility of small nematodes in saline is described. The effects of salines with a pO2 either greater than 120 mmHg or less than 12 mmHg upon the motility of adult N. brasiliensis females was studied. The worms were found to require an oxygen tension greater than 12 mmHg to be able to maintain their motility.

I am grateful to Professors J. Brough and D. Bellamy for providing the facilities during the course of this study. I should also like to thank Dr R. A.Hammond for his supervision, help and criticism throughout the project, and Mr C. Welsby for his technical assistance in the construction of the activity cell.

This work was carried out during the tenure of a Scientific Research Council Studentship.

Autophagy process in Toxoplasma gondii plays a vital role in regulating parasite survival or death. Thus, once having an understanding of certain effects of autophagy on the transformation of tachyzoite to bradyzoite this will allow us to elucidate the function of autophagy during parasite development. Herein, we used three TgAtg proteins involved in Atg8 conjugation system, TgAtg3, TgAtg7 and TgAtg8 to evaluate the autophagy level in tachyzoite and bradyzoite of Toxoplasma in vitro based on Pru TgAtg7-HA transgenic strains. We showed that both TgAtg3 and TgAtg8 were expressed at a significantly lower level in bradyzoites than in tachyzoites. Importantly, the number of parasites containing fluorescence-labelled TgAtg8 puncta was significantly reduced in bradyzoites than in tachyzoites, suggesting that autophagy is downregulated in Toxoplasma bradyzoite in vitro. Moreover, after treatment with drugs, bradyzoite-specific gene BAG1 levels decreased significantly in rapamycin-treated bradyzoites and increased significantly in 3-MA-treated bradyzoites in comparison with control bradyzoites, indicating that Toxoplasma autophagy is involved in the transformation of tachyzoite to bradyzoite in vitro. Together, it is suggested that autophagy may serve as a potential strategy to regulate the transformation.

Schistosomiasis is a significant cause of human morbidity and mortality. We performed a genome-wide transcriptional survey of liver biopsies obtained from Chinese patients with chronic schistosomiasis only, or chronic schistosomiasis with a current or past history of viral hepatitis B. Both disease groups were compared with patients with no prior history or indicators of any liver disease. Analysis showed in the main, downregulation in gene expression, particularly those involved in signal transduction via EIF2 signalling and mTOR signalling, as were genes associated with cellular remodelling. Focusing on immune associated pathways, genes were generally downregulated. However, a set of three genes associated with granulocytes, MMP7, CLDN7, CXCL6 were upregulated. Differential gene profiles unique to schistosomiasis included the gene Granulin which was decreased despite being generally considered a marker for liver disease, and IGBP2 which is associated with increased liver size, and was the most upregulated gene in schistosomiasis only patients, all of which presented with hepatomegaly. The unique features of gene expression, in conjunction with previous reports in the murine model of the cellular composition of granulomas, granuloma formation and recovery, provide an increased understanding of the molecular immunopathology and general physiological processes underlying hepatic schistosomiasis.

This work contains the description of two new Coccidia parasitic in the South American lizard Cnemidophorus lemniscatus lemniscatus. One is identified as Eimeria flaviviridis americana subsp.nov., which is described and discussed in relation to the other species recorded from sauria. The other is Hoarella garnhami gen.nov., sp.nov., whose position in the family Eimeriidae necessitated a revision of the classification of the Coccidia Eimeriidae.

I wish to acknowledge the help and encouragement I received from Professor P. C. C. Garnham, in whose department this work was carried out. My thanks are also due to Dr Cecil Hoare for his private communications and assistance in the interpretation of histological specimens. The author is grateful for co-operation of the School's Photograph Staff and to members of the staff of the Department of Parasitology, especially to Mr P. E. Nesbitt for his valuable sections. Finally, the author is indebted to the Consejo de Desarrollo Cientifico y Humanístico de la Universidad Central, Caracas, for their assistance in the form of a scholarship during the tenure of which this work was produced.

The longevity of filarial nematodes is dependent on secreted immunomodulatory products. Previous investigation of one such product, ES-62, has suggested a critical role for post-translationally attached phosphorylcholine (PC) moieties. In order to further investigate this, ES-62 lacking PC was produced, using the Pichia pastoris recombinant gene expression system. Unlike parasite-derived ES-62, which is tetrameric the recombinant material was found to consist of a mixture of apparently stable tetramers, dimers and monomers. Nevertheless, the recombinant protein was considered to be an adequate PC-free ES-62 as it was recognized by existing antisera against the parasite-derived protein. However, subsequent to this, recognition of parasite-derived ES-62 by antibodies produced against the recombinant protein was found to be absent. In an attempt to explain this, recombinant ES-62 was subjected to structural analysis and was found to (i) contain 3 changes in amino acid composition; (ii) demonstrate significant alterations in glycosylation; (iii) show major differences in protein secondary structure. The effects of these alterations in relation to the observed change in immunogenicity were investigated and are discussed. The data presented clearly show that recognition by existing antibodies is insufficient proof that recombinant proteins can be used to mimic parasite-derived material in studies on nematode immunology and vaccination.

The aspidogastrid trematodes form a well-defined group of at most eight genera with a wide distribution. They are known from five continents and they occur in various cold-blooded hosts from both marine and fresh-water habitats, notably, Gasteropod and Lamellibranch molluscs, the larger Crustacea, some Fishes, and Chelonians. The recording of a new genus in a fresh locality is thus of some zoological importance.

Anthomyia pluvialis Linn. (1761) is a very common and beautiful fly, widely distributed in the old world, and easily recognisable by having characteristic black spots on the thorax and abdomen.

Clinical trichostrongylosis, caused by T. tenuis in the caeca, previously known in epizootic form among gallinaceous birds in Great Britain, is here reported for the first time in this country, in native domestic geese in the District of Columbia and in imported pheasants in Michigan.

In cultures made from caecal contents of infected pheasants, eggs hatched in 36–38 hours; the infective larval stage might be reached as early as the sixth day (fourth day after hatching). Moisture being present, migrating larvae, retracted within the cuticular sheath, resisted an average temperature of about −3° C. (range +3° to −20° C.) for 4 months, proving infective for a bird host at the end of that period. The chicken, turkey and guinea-fowl were successfully infected with cultures derived from pheasants; attempts to infect the duck and pigeon with cultures from pheasants, and to infect the duck with cultures from geese, were unsuccessful. Development to adults in bird hosts took place in a minimum of 7 days after infection; the size of adults varied in different birds, being greater in the chicken than in the pheasant, and still greater in the turkey. In early stages of infection diarrhoea from the caeca, with passage of mucus and blood, occurred; later all discharge from the caeca ceased. The pathological picture was that of acute typhlitis, with the trichostrongyles lying in close contact with or penetrating the mucosa. Reinfection being prevented, symptoms were of fairly short duration, and the infestation tended to die out in about 2 months.

In this second contribution to the study of parasitic copepods of fish from Ceylon eight species are described, four of which are new. The male of one species, namely that of Euryphorus nordmanni Milne-Edwards, is described for the first time. Of the three remaining species, Caligodes laciniatus Kröyer has only been recorded once (Heller, 1865) since it was originally described in 1863 and the comparison of Caligus alalongae Kröyer and C. tenax Heller makes it easier to identify the males of these two forms.

A survey in Busoga District, Uganda, where an outbreak of sleeping sickness was detected, has yielded an infection rate with T. brucei subgroup in G. fuscipes of 4.8%. Isolation of the infected flies was by feeding of the flies on mice, followed by trituration and inoculation of a suspension of the triturated flies into mice. The mice were treated with cyclophosphamide to reduce the immune response.The percentage infection as determined by inoculation of triturate was 4.1%, whilst that by feeding on mice was 1–8%.Amongst the 19 strains of T. brucei subgroup isolated, four were identified as T. rhodesiense by the BIIT method.

1. An account is given of the intensity and incidence of infestation of the scorpaenid redfish, Sebastes marinus and S. mentella, by the parasitic copepods Peniculus clavatus, Sphyrion lumpi and Chondracanthopsis nodosus on three fishing grounds in the eastern North Atlantic, namely Iceland, Bear Island and the Barents Sea.

2. Peniculus clavatus was found to be a rare parasite on both species of redfish in the eastern North Atlantic. Adult female parasites were found during the months from September to February only; they were usually attached to the pelvic or dorsal fins of the host causing little damage.

3. Sphyrion lumpi was found to be a comparatively rare parasite on the deep-water Sebastes mentella throughout the eastern North Atlantic but it was found on S. marinus in the vicinity of Bear Island only. It seems justifiable to regard the Bear Island grounds as a centre of abundance of Sphyrion lumpi in the eastern North Atlantic. Adult female S. lumpi tended to infest medium-sized redfish more often than smaller or larger fish.

4. The infestation of Sebastes marinus and S. mentella by Chondracanthopsis nodosus has been examined in some detail and attention directed to the influence on infestation of the host species, geographical distribution, body length, age and sex of the host, and seasonal variations. The distribution of female C. nodosus within the gill chamber of the two species of redfish is described; it appears to be related to the need of the parasite to secure a protected and spatially limited habitat out of the mainstream of the ventilation current through the gill chamber.

5. The ecological relationships between Sebastes marinus and S. mentella and the three species of parasitic copepod are described together with the possibility of using these and other parasites as indicators of the host's mode of life. It is concluded that Chondracanthopsis nodosus and Sphyrion lumpi merit more detailed and extensive study as possible parasitological indicators of different stocks of redfish.

I wish to express my thanks to Messrs Jackson Mills Ltd., Fish Merchants and Curers, Hull, and to the Officer-in-Charge, D.S.I.R., Humber Laboratory, Hull, for their generous assistance in making redfish available for examination. I am also most grateful to Miss E. C. Howard, Librarian, Ministry of Agriculture, Fisheries and Food, Fisheries Laboratory, Lowestoft, for her invaluable assistance in providing certain otherwise unobtainable references in the literature.

Gametocytes of a polychromophilid parasite indistinguishable from those of P. melanipherus are commonly found in the blood of the bent-winged bat Miniopterus schreibersii in New South Wales. There is a seasonal variation in infection rate, this being lowest in April (0%) and highest in August (up to 82·7%), and in density of parasitaemia.

This variation is the reverse to that found in the same species of bat in the northern hemisphere.

The reproductive biology of M. schreibersii in New South Wales is considered in relation to the seasonal variation in infection rate.

The main vectors of the parasitism are likely to be the nycteribiid flies, Penicillidia oceanica and Nycteribia parilis n.ssp.

The following paper lists the species of cestodes, not hitherto described by the author, obtained from Burmese animals during the years 1923–5. Many of the specimens were collected by Miss I. K. Reynolds while working in the Zoological Department of University College: the writer wishes to acknowledge his indebtedness to her for the use of data, material and slides. He also wishes to express his thanks to the Trustees of the Victoria Memorial Park for permission to collect helminths from animals dying in the gardens.

Adult Ostertagia circumcincta from freshly killed sheep were incubated at 39 °C in a medium containing inorganic salts, antibiotics and D-[U-14C] glucose. The worms appeared healthy even after incubation for as long as 72 h. All the radioactivity was recovered either within the worms or in the incubation vessel in the form of metabolic products or unmetabolized glucose. Incubations were carried out at low oxygen tension except for those in which CO2 was measured. These were either aerobic or anaerobic. In terms of both quantity and radioactivity the main metabolic products of glucose were CO2, propan-1-ol, acetate and propionate. Smaller amounts of ethanol, lactate and succinate were formed. The results are compared with those found for the similar nematode Haemonchus contortus.

The transport of [14C]glucose by Hymenolepis microstoma in vitro following in vivo treatment with cyclosporin A (CsA) was determined over a range of concentrations. For untreated (control) worms glucose uptake showed saturation kinetics with a small diffusion component. Estimates of the maximum velocity of glucose uptake (Vmax) and the affinity of substrate for the glucose transporter (Kt) revealed that untreated 8-day-old worms had a Vmax twice that of 15-day-old worms and that younger worms had a lower Kt. An inverse relationship was demonstrated between log10 worm weight and the rate of uptake of [14C]glucose, reflecting the relatively greater number of glucose transporters due to the larger surface area: volume ratio of smaller worms. Treatment of H. microstoma with CsA in vivo significantly increased the diffusion component of glucose uptake in vitro. Parasites from drug-treated mice had a significantly lower Vmax for glucose uptake than size-matched controls. The affinity of glucose for its transporter in CsA-treated worms (Kt) was not significantly different from size-matched controls. Both juvenile and adult worms underwent transient depletion in total glycogen content after CsA treatment in vivo. The data confirm that CsA treatment in vivo disrupts the functional integrity of the worm tegument, one facet of which is impaired acquisition of glucose.

Parasites have established numerous strategies for evading host immunity. Such tactics promote persistence and chronicity – factors that favour completion of the life cycle and transmission to vectors or the environment. This volume explores many facets of the interaction between host and parasite that will be critical to the development of meaningful vaccines capable of interrupting what has been accomplished over centuries of co-evolution.

A mathematical model that describes the transmission dynamics of Theileria annulata is proposed that consists of 2 host components: the Hyalomma tick population and a compartmental model of T. annulata infection in the cattle population. The model was parameterized using data describing tick infestation and the infection status of cattle in Turkey from 2006 to 2008. The tick attachment rates are highly seasonal and because of the temporal separation of infectious and susceptible ticks virtually all ticks are infected by carrier cattle, so that annual peaks of disease in cattle do not impact on infection in the Hyalomma tick population. The impact of intervention measures that target the tick population both on the host and in the environment and their impact on the transmission of T. annulata were investigated. Interventions that have a limited ‘one-off’ impact and interventions that have a more permanent impact were both considered. The results from the model show the importance of targeting ticks during the period when they have left their first host as nymphs but have yet to feed on their second host.

The morphology of sexual adults is the cornerstone of digenean systematics. In addition, life cycle data have always been significant. The integration of these approaches, supplemented with molecular data, has allowed us to detect a new species that many researchers may have previously seen, but not recognized. Sexual adults from common eiders that we found in northern European seas were extremely similar to other notocotylids, but the discovery of their intermediate host, a marine snail, revealed the true nature of this material. Here we describe sexual adults, rediae and cercariae of Catatropis onobae sp. nov. We discuss how ‘Catatropis verrucosa’ should be regarded, justify designation of the new species C. onobae for our material and explain why it can be considered a cryptic species. The phylogenetic position of C. onobae within Notocotylidae, along with other evidence, highlights the challenges for the taxonomy of the family, for which two major genera appear to be polyphyletic and life cycle data likely undervalued.