Arborocystis nov.nom. is proposed to replace Dendrocystis Rees, 1962, a junior homonym of Dendrocystis Bather, 1889.

The authors wish to thank Dr David L. Pawson, Division of Marine Invertebrates, Smithsonian Institution, Washington, D.C., for furnishing data from Barrande (1887).

The cloning and characterization of Ts-p41, an EF-hand calcium-binding protein of the protozoan parasite Tritrichomonas suis is describedNucleotide sequence data reported in this paper are available in the GenBankTM, EMBL and DDBJ databases under the accession numbers TSU011991 and TSU011992.. A T. suis cDNA library was screened with monospecific antibodies affinity purified on an immunoreactive 41kDa antigen in a Triton X-114 membrane-protein fraction. The resulting cDNA fragments turned out to be derived from 2 different genes encoding closely related Ts-p41 variants. The deduced amino acid sequences contained 6 EF-hand domains perfectly matching the canonical consensus motif and a putative C-terminal prenylation site. Northern and Southern hybridizations revealed that Ts-p41 was highly expressed and encoded by a gene-family. A cDNA encoding Ts-p41 was expressed as recombinant protein in Escherichia coli. By overlay with 45Ca it was demonstrated that the native and recombinant Ts-p41 proteins bind Ca2+. In immunofluorescence, epitopes recognized by anti-Ts-p41 antibodies were distributed as well on the anterior flagella as on the recurrent flagellum of the parasite. Our findings with the parabasalid T. suis suggest that multiple EF-hand bearing calcium-binding proteins might be a common phenomenon associated with flagellar motility.

Wildlife translocations, which involve the introduction of naive hosts into new environments with novel pathogens, invariably pose an increased risk of disease. The meningeal worm Parelaphostrongylus tenuis is a nematode parasite of the white-tailed deer (Odocoileus virginianus), which serves as its primary host and rarely suffers adverse effects from infection. Attempts to restore elk (Cervus canadensis) to the eastern US have been hampered by disease caused by this parasite. Using DNA sequence data from mitochondrial and nuclear genes, we examined the hypothesis that elk translocated within the eastern US could be exposed to novel genetic variants of P. tenuis by detailing the genetic structure among P. tenuis taken from white-tailed deer and elk at a source (Kentucky) and a release site (Missouri). We found high levels of diversity at both mitochondrial and nuclear DNA in Missouri and Kentucky and a high level of differentiation between states. Our results highlight the importance of considering the potential for increased disease risk from exposure to novel strains of parasites in the decision-making process of a reintroduction or restoration.

Acetylcholine (ACh) is one of an array of neurotransmitters used by invertebrates and, analogous to vertebrate nervous systems, acetylcholinesterase (AChE) regulates synaptic levels of this transmitter. Similar to other invertebrates, nematodes possess several AChE genes. This is in contrast to vertebrates, which have a single AChE gene, transcripts of which are alternatively spliced to produce different types of the enzyme which vary at their C-termini. Parasitic nematodes have a repertoire of AChE genes which include those encoding neuromuscular AChEs and those genes which code for secreted AChEs. The latter proteins exist as soluble monomers released by the parasite during infection and these AChE are distinct from those enzymes which the nematodes use for synaptic transmission in their neuromuscular system. Thus far, Dictyocaulus viviparus is the only animal-parasitic nematode for which distinct genes that encode both neuromuscular and secreted AChEs have been defined. Here, we describe the isolation and characterization of a cDNA encoding a putative neuromuscular AChE from D. viviparus which contains a tryptophan amphiphilic tetramerization (WAT) domain at its C-terminus analogous to the common ‘tailed’ AChE form found in the neuromuscular systems of vertebrates and in the ACE-1 AChE from Caenorhabditis elegans. This enzyme differs from the previously isolated, D. viviparus neuromuscular AChE (Dv-ACE-2), which is a glycosylphosphatidylinositol-anchored variant analogous to vertebrate ‘hydrophobic’ AChE.

Lysis of Tritrichomonas foetus with a solution of the non-ionic detergent Triton X-114 at 0 °C, followed by low-speed centrifugation, resulted in a detergent-insoluble pellet and a detergent-soluble supernatant. The supernatant was further fractionated by phase separation at 30 °C into a detergent-rich phase and an aqueous phase. Neuraminidase activity was mostly located in the detergent-insoluble pellet. When the parasites were incubated with bacterial phosphatidylinositol phospholipase C (PI–PLC) prior to detergent solubilization and phase separation neuraminidase activity was predominantly recovered in aqueous phase, rather than in the pellet and detergent phase. The molecular mass determined by gel permeation in high performance liquid chromatography (HPLC) and SDS–PAGE was 80000 Da. Indirect immunofluorescence microscopy using polyclonal antibodies raised in rabbits against the purified neuraminidase, indicated that the enzyme is exposed on the cell surface. Previous treatment of the cells with PI–PLC significantly reduced antibody binding. Incubation of cryo-sections with the antibodies followed by detection using gold-labelled anti-rabbit IgG confirmed the presence of neuraminidase in the plasma membrane enclosing the cell body and flagella and in the membrane of vesicles preferentially located at the peripheral region of the protozoan.

High throughput technologies continue to develop in response to the challenges set by the genome projects. This article discusses how the techniques of both high throughput screening (HTS) and synthesis can influence research in parasitology. Examples of the use of targeted and phenotype-based HTS using unbiased compound collections are provided. The important issue of identifying the protein target(s) of bioactive compounds is discussed from the synthetic chemist's perspective. This article concludes by reviewing recent examples of successful target identification studies in parasitology.

The biodiversity of Trypanosoma cruzi is one of the main factors complicating the understanding of its molecular epidemiology. As an alternative to classical genetic methods, investigators have used DNA-mediated transformation techniques to study this diversity. Recently, transient expression data were shown to correlate with the genetic data. This led investigators to speculate on a potential speciation within clonal populations of Trypanosoma cruzi. To further test the phylogenetic significance of transient expression analysis in Trypanosoma cruzi, multiple plasmids were used to drive the expression of a reporter gene in different parasite populations. In our study, population specific expression of the reporter gene was observed but the variability revealed by these transient expression assays was very large and did not follow the grouping of Trypanosoma cruzi populations in 2 lineages. In this report, we discuss some of the limitations of transient assays on such a diverse parasite.

Apical membrane antigen-1 (AMA-1) has been described as a potential vaccine candidate in apicomplexan parasites. Here we characterize the ama-1 gene. The full-length ama-1 gene of Babesia sp. BQ1 (Lintan) (BLTAMA-1) is 1785 bp, which contains an open reading frame (ORF) encoding a 65-kDa protein of 594 amino acid residues; by definition, the 5′ UTR precedes the first methionine of the ORF. Phylogenetic analysis based on AMA-1 amino acid sequences clearly separated Piroplasmida from other Apicomplexa parasites. The Babesia sp. BQ1 (Lintan) AMA-1 sequence is most closely associated with that of B. ovata and B. bigemina, with high bootstrap value. A recombinant protein encoding a conserved region and containing ectodomains I and II of BLTAMA-1 was constructed. BLTrAMA-1-DI/DII proteins were tested for reactivity with sera from sheep infected by Babesia sp. BQ1 (Lintan). In Western-blot analysis, native Babesia sp. BQ1 (Lintan) AMA-1 proteins were recognized by antibodies raised in rabbits against BLTrAMA-1 in vitro. The results of this study are discussed in terms of gene characterization, taxonomy and antigenicity.

The rise of antimicrobial resistance, coupled with a lack of industrial focus on antimicrobial discovery over preceding decades, has brought the world to a crisis point. With both human and animal health set to decline due to increased disease burdens caused by near untreatable microbial pathogens, there is an urgent need to identify new antimicrobials. Central to this is the elucidation of new, robustly validated, drug targets. Informed by industrial practice and concerns, the use of both biological and chemical tools in validation is key. In parallel, repurposing approved drugs for use as antimicrobials may provide both new treatments and identify new targets, whilst improved understanding of pharmacology will help develop and progress good ‘hits’ with the required rapidity. In recognition of the need to increase research efforts in these areas, in 14–16 September 2017, the British Society for Parasitology (BSP) Autumn Symposium was hosted at Durham University with the title: Microbial Protein Targets: towards understanding and intervention. Staged in collaboration with the Royal Society of Chemistry (RSC) Chemistry Biology Interface Division (CBID), the core aim was to bring together leading researchers working across disciplines to imagine novel approaches towards combating infection and antimicrobial resistance. Sessions were held on: ‘Anti-infective discovery, an overview’; ‘Omic approaches to target validation’; ‘Genetic approaches to target validation’; ‘Drug target structure and drug discovery’; ‘Fragment-based approaches to drug discovery’; and ‘Chemical approaches to target validation’. Here, we introduce a series of review and primary research articles from selected contributors to the Symposium, giving an overview of progress in understanding antimicrobial targets and developing new drugs. The Symposium was organized by Paul Denny (Durham) for the BSP and Patrick Steel (Durham) for RSC CBID.

The material for this investigation was obtained from the intestines of cormorants shot on the coast of Cardigan Bay between Aberystwyth and Borth. Of 23 birds examined, 5, or 23 per cent., were infected with this species. Anything from 1–10 individuals were obtained from each intestine.

Simultaneous hermaphrodites maximize their fitness by optimizing their investment into male or female functions. Allocation of resources to male function (tissues, traits, and/or behaviours increasing paternity) is predicted to increase as density, and the associated level of sperm competition, increases. We tested whether the simultaneous hermaphroditic cestode Schistocephalus solidus uses cues of potential partner densities in its fish intermediate host to improve its male reproductive success in the final host. We had two worms, one originating from a multiple infection in the fish intermediate host and one from a single infection, sequentially compete to fertilize the eggs of a third worm. The fertilization rates of the two competitors nearly always differed from the 50–50 null expectation, sometimes considerably, implying there was a ‘winner’ in each experimental competition. However, we did not find a significant effect of density in the fish host (single vs multiple) or mating order on paternity. Additional work will be needed to identify the traits and environmental conditions that explain the high variance in male reproductive success observed in this experiment.

Angiostrongylus cantonensis causes severe neurological disorders in a wide range of warm-blooded animals, including several avian species. A laboratory isolate of A. cantonensis originating from French Polynesia, genotyped as clade 2, was used to assess the effect of experimental infection in chicken and Japanese quail. Low dose groups of birds were infected orally by 100 L3 larvae, high dose groups by 1500 L3 larvae and the birds in the third group were fed three infected snails, mimicking a natural infection. Clinical signs during the first week after infection, haematology, biochemistry, gross lesions and histology findings were used to assess the pathology of the infection. Some of the infected birds showed peripheral eosinophilia, while mild neurological signs were seen in others. No larvae were observed in serial sections of the central nervous system of infected birds 1 week after infection and no major gross lesions were observed during necropsy; histopathology did not reveal lesions directly attributable to A. cantonensis infection. Our results suggest that galliform birds are not highly susceptible to A. cantonensis infection and open a question of the importance of Galliformes in endemic areas as natural pest control, lowering the number of hosts carrying the infective larvae.

1. The distribution of the larvae of Simulium spp. in the River Tees area is discussed.

2. The dominant species of

(a) the upper Tees are S. monticola and S. variegatum;

(b) the lower Tees are S. equinum and S. reptansvar. galeratum;

(c) the Skerne is S. ornatum.

3. The causes of these differences are unknown, but it is suggested that geological structure, the distribution of water plants and the hardness of the water are important factors.