Unembryonated Eggs Research Articles

New data on the life cycle of Nippostrongylus brasiliensis (Travassos, 1914) (Nematoda: Heligmosomidae): development of eggs and larval stages in the intestine of naturally infected Rattus norvegicus (Berkenhout, 1769)

Nippostrongylus brasiliensis is an intestinal parasite of rodents with a worldwide distribution. Due to the similarities between its life cycle and that of the human hookworms Ancylostoma duodenale and Necator americanus, N. brasiliensis has been widely used as a model in experimental research. We provide new data on the embryonation and hatching processes of N. brasiliensis eggs, not in the soil, but in the large intestine of naturally infected Rattus norvegicus. The parasite was investigated in 109 rats trapped in urban and periurban areas of Valencia, Spain. Rats were preserved at − 20 °C. After thawing, all the rat organs were examined. The contents of the large intestine were analysed by the Midi-Parasep® technique. N. brasiliensis (adult prevalence 69.72%) was identified by morphological and molecular techniques. Parasite eggs were found in 88.16% of the sediments. In addition to unembryonated eggs, eggs in different stages of embryonation were encountered in 67 of the 76 contents (88.16%). Free larval stages (L1 and more developed larvae) were also found in 47 of the 76 (61.84%) sediments studied. Filariform larval stages of N. brasiliensis were also sporadically detected in the lungs of the infected rats. According to our results, the development of eggs and larvae in the intestine of naturally infected rats opens up the possibility of autoinfection in the natural life cycle of N. brasiliensis, which could explain the high burdens of adult stages frequently found in the small intestine of infected rats.

First report of Paracapillaria philippinensis infection in flowerhorn cichlid in India.

The flowerhorn cichlid is a popular ornamental fish in many Asian countries. The present study reports the occurrence of Paracapillaria philippinensis (Chitwood et al., 1968), a parasitic nematode in flowerhorn cichlid (Cichlasoma sp.) from south India. The infected fish demonstrated clinical symptoms viz. dark coloration, poor appetite, lethargy, erratic swimming, and white stringy faeces. Microscopic observation of the intestinal content and faeces revealed the presence of adult worms, larvae, and unembryonated eggs. PCR amplification of eukaryotic 18S rRNA, P. philippinensis-specific SSU rRNA gene, and the subsequent sequence analysis confirmed the species identity as P. philippinensis. The generated sequences were submitted in the GenBank, NCBI, under the accession numbers, MK895507.1, MK895446.1, MW144993.1, and OR685675.1. This is the first scientific report of P. philippinensis in fish from India, and it confirms that the flowerhorn cichlid can act as a definitive host for P. philippinensis. This report alerts fish handlers and enthusiasts to undertake suitable precautionary measures while handling live flowerhorn cichlids to prevent possible transmission of P. Philippinensis, which has the potential to infect humans causing intestinal capillariasis.

Ocular Toxocariasis in The Anterior Chamber of The Eye

Introduction : Ocular toxocariasis (OT) is a zoonotic infection caused by Toxocara canis and Toxocara cati. Dogs and cats, the definitive hosts of the roundworm, pass unembryonated eggs via their feces into the environment (often into the soil). Transmission to humans occurs through ingestion of soil or contaminated food, or the fecal– oral route.
 Case Illustration : A 14 years old male presented with pain and redness in the right eye 2 months prior to the visit. Complaints are redness, itching, and pain especially in the night on the right eye. The patient had habits of eating raw meat and walking around in dirt without any footwear. Ophthalmologic examination showed a toxocara sp. larvae in the anterior chamber of the right eye. This patient treated with surgical removal of the worm, given antihelminth and topical corticosteroid.
 Discussion : Toxocariasis results from infection with Toxocara cati (an intestinal parasite of cats) or Toxocara canis (an intestinal parasite of dogs). Children acquire the disease by close association with pets and by eating dirt (pica) contaminated with Toxocara ova. The ingested ova form larvae that penetrate the intestinal mucosa and gain access to the systemic circulation and finally to the eye. Systemic or local corticosteroids should be given when there is evidence of significant intraocular inflammation.
 Conclusion : This case described a patient who was diagnosed with a living worm as foreign bodies in the right eye.

Detailed characterisation of the Co-Smad protein in liver fluke Fasciola gigantica.

Fasciolosis, caused by the liver flukes Fasciola hepatica and Fasciola gigantica, is a zoonotic parasitic disease associated with substantial economic losses in livestock. The transforming growth factor-beta signalling pathway is implicated in developmental processes and biological functions throughout the animal kingdom, including the Fasciola spp. It may also mediate host-helminth interactions during infection. In this work, we present an exploration of FgSmad4, the sole member of the Co-Smad protein family in F. gigantica. The isolated FgSmad4 cDNA was 4,014 bp in length encoding for a protein comprising 771 amino acids. FgSmad4 exhibited typical Co-Smad protein features, including Mad Homology 1 (MH1) and Mad Homology 2 (MH2) domains, a Nuclear Localisation Signal, a DNA-Binding Motif, and a Nuclear Export Signal. Sequence and phylogenetic analyses of FgSmad4 revealed that its MH1 and MH2 sequences are most similar to those of other trematode species. The MH1 domain, in particular, closely resembles the Co-Smad protein in mammalian hosts more than those in cestodes and nematodes. The expression patterns of FgSmad4 during the liver fluke's developmental stages showed significant variation. Transcript levels were highest at the newly excysted juvenile stage, followed by unembryonated egg, redia, and metacercaria, with the lowest expression in the adult fluke, embryonated egg, and cercaria stages. Our results underscore the conservation and suggest the potential role of FgSmad4, a key transforming growth factor-beta signalling molecule within the liver fluke F. gigantica. As Co-Smad is typically involved in several biological pathways, the precise functions and mechanisms of this identified FgSmad4 necessitate further exploration.

Alaria alata (Digenea: Diplostomidae) from Korean Raccoon Dog, Nyctereutes procyonoides koreensis, in Korea.

We report a species of diplostomid fluke recovered from 3 carcasses of wild Korean raccoon dog, Nyctereutes procyonoides koreensis, in Korea. A total of 107 diplostomid flukes were recovered from the small intestines of Korean raccoon dogs, which were obtained from the Gangwon Wildlife Medical Rescue Center. Worms fixed with 10% neutral formalin were subjected to microscopic observation and those fixed in 70% ethanol were used for molecular genomic analysis. The worm was divided into 2 separate parts, forebody and hindbody, with a total length of 3,020-4,090 (3,855) µm and a width of 1,210-1,770 (1,562) µm. The boat-shaped forebody has a pair of characteristic tentacular appendage, 2 suckers, holdfast organ, and vitelline follicles. The oval to cylindrical hindbody has reproductive organs. The ovary was round or elliptical and located in the anterior of the testes. Two large testes were slightly segmented and tandemly arranged, occupying almost half of hindbody. The short uterus contained a relatively small number of unembryonated eggs sized 130-140×85-96 µm. The partial sequence of 18S rRNA of this fluke was consistent with Alaria alata. Based on the morphological and molecular characteristics, the diplostomid flukes recovered from the small intestine of Korean raccoon dogs were identified as A. alata (Digenea: Diplostomidae).

Indirect immunofluorescence assay using embryonated eggs of Toxocara in human toxocariasis diagnosis is unreliable due to autofluorescence nature

Toxocariasis is caused by infection with the nematode species Toxocara canis and Toxocara cati. Serological methods using eggs, larvae and adult worms of Toxocara spp. as antigen have been used for the diagnosis of human toxocariasis. The current study aimed to evaluate indirect immunofluorescence assay (IFA) using embryonated eggs of Toxocara for diagnosis of human toxocariasis. A total of 58 sera including twenty sera from patients with toxocariasis, 20 from healthy persons and 18 from patients with other parasitic infections were collected and used for the study. The embryonated eggs of Toxocara were prepared as antigen. Indirect immunofluorescence assay was performed using the frozen section of uterus containing embryonated T. canis eggs and unembryonated T. cati eggs. All serum samples had a positive reaction using IFA. The eggs of Toxocara as antigen exposed to the serum samples of toxocariasis, other parasitic infections and healthy persons, followed by IFA gave a bright greenish-yellow fluorescence. A number of samples such as eggs of Toxocara, Toxascaris, Trichuris and strongyloides larvae, and adult worm of Ancylostoma exhibited the bright greenish-yellow autofluorescence under fluorescent microscope. IFA using cryocut of embryonated eggs of Toxocara cannot be used for the diagnosis of human toxocariasis due to the existence of autofluorescence of the unembryonated and embryonated eggs, the second stage larva and adult worms of Toxocara spp.

Chemical properties of the coffee grounds and poultry eggshells mixture in terms of soil improver

Spent coffee grounds (SCG) as well as chicken (CES) or duck eggshells (DES) left over from the artificial hatching technology are proposed as potential soil improver and/or organic-mineral fertiliser components. Therefore, it seems interesting and necessary to evaluate the chemical composition of these wastes and their mixtures in terms of their possible use for that purpose. The study was conducted under the incubation experiment conditions using a mixture of SCG and eggshells (10:1 ratio). Macronutrients, i.e. C, N, S, were determined by the catalytic combustion method, while P, K, Mg, Ca, Na by atomic spectrometry. It was found that SCG were rich in C, N, P, and K, while eggshells in Ca, Mg, Na, and S. However, CES compared to DES were richer in deacidifying components (i.e. Ca, Mg, K). At the same time, the content of macronutrients in eggshells decreased gradually along with the embryo development. For this reason, the mixture of SCG and shells of unembryonated chicken eggs (CES I) had the best chemical and usable proprieties. To conclude, the chemical properties of the mixtures of spent coffee grounds and eggshells indicate their possible application in soil bioengineering.

Ultra structural study of the Embryonic Development in the Intrauterine Eggs of Acanthostomum (atrophocaecum) aswaninesis Wannas, 1977 (Digenea, Acanthostomatidae) with evidence of early miracidium development

Intrauterine embryonic development of the eggs of Acanthostomum (atrophocaecum) aswaninesis was investigated by transmission electron microscopy. The study revealed the successive stages of embryonic development of the eggs. The proximal uterus contains unembryonated eggs and eggs with early embryos while the distal regions of the uterus were occupied with eggs containing fully developed embryos, each was composed of a fertilized oocyte and few vitelline cells; which were fused forming the vitelline syncytium that characterized the early embryonated eggs. With egg development, the eggshell progressively thickened with the appearance of the operculum after shell formation at the narrower pole of the eggshell surface. Three types of differentiated blastomeres are formed as a result of the continued cleavage divisions; macromeres, mesomeres and micromeres, with nuclei of different shapes and sizes. They occupy different places within the embryo. As a result of the following cleavage divisions, early degeneration or apoptosis of some micromeres take place. Numerous fully developed cilia are easily visible around the differentiated embryo (miracidium) of the advanced stages. The cilia have a typical 9+2 (nine peripheral and two central) arrangement of microtubules. The germinative cells of miracidia have easily appeared in the medioposterior parts of their ciliated larvae. The results of the present study were compared with those previously reported for other parasitic Platyhelminthes.

Discovery of two highly divergent negative-sense RNA viruses associated with the parasitic nematode, Capillaria hepatica, in wild Mus musculus from New York City.

Recent advances in high-throughput sequencing technology have led to a rapid expansion in the number of viral sequences associated with samples from vertebrates, invertebrates and environmental samples. Accurate host identification can be difficult in assays of complex samples that contain more than one potential host. Using unbiased metagenomic sequencing, we investigated wild house mice (Mus musculus) and brown rats (Rattus norvegicus) from New York City to determine the aetiology of liver disease. Light microscopy was used to characterize liver disease, and fluorescent microscopy with in situ hybridization was employed to identify viral cell tropism. Sequences representing two novel negative-sense RNA viruses were identified in homogenates of wild house mouse liver tissue: Amsterdam virus and Fulton virus. In situ hybridization localized viral RNA to Capillaria hepatica, a parasitic nematode that had infected the mouse liver. RNA from either virus was found within nematode adults and unembryonated eggs. Expanded PCR screening identified brown rats as a second rodent host for C. hepatica as well as both nematode-associated viruses. Our findings indicate that the current diversity of nematode-associated viruses may be underappreciated and that anatomical imaging offers an alternative to computational host assignment approaches.

2,4-Diaminothieno[3,2-d]pyrimidines, a new class of anthelmintic with activity against adult and egg stages of whipworm.

The human whipworm Trichuris trichiura is a parasite that infects around 500 million people globally, with consequences including damage to physical growth and educational performance. Current drugs such as mebendazole have a notable lack of efficacy against whipworm, compared to other soil-transmitted helminths. Mass drug administration programs are therefore unlikely to achieve eradication and new treatments for trichuriasis are desperately needed. All current drug control strategies focus on post-infection eradication, targeting the parasite in vivo. Here we propose developing novel anthelmintics which target the egg stage of the parasite in the soil as an adjunct environmental strategy. As evidence in support of such an approach we describe the actions of a new class of anthelmintic compounds, the 2,4-diaminothieno[3,2-d]pyrimidines (DATPs). This compound class has found broad utility in medicinal chemistry, but has not previously been described as having anthelmintic activity. Importantly, these compounds show efficacy against not only the adult parasite, but also both the embryonated and unembryonated egg stages and thereby may enable a break in the parasite lifecycle.

Hepatic Capillariasis- Drug Targets.

Zoonotic infections are increasingly becoming public health menaces and are usually transmitted to humans due to unsuitable environmental conditions. One of them is hepatic capillariasis, caused by the parasite Capillaria hepatica, primarily a disease of rodents, with hepatic manifestations in humans. Although its prevalence is very low, it can cause significant morbidity and mortality, with cases reported from all over the world. The main infective form for humans is the embryonated egg of the parasite, which hatches in the intestine and ultimately colonize the liver. The larvae mature and reproduce, and eventually form embryonated eggs, which cause chronic focal inflammation and septal hepatic fibrosis. Clinical presentation mainly consists of fever, abdominal pain, hepatomegaly and eosinophilia. Spurious infection with unembryonated eggs cause gastrointestinal symptoms. Diagnostic modalities include liver biopsy, ultrasonography, CT scan, immunological tests like ELISA and IIFT. The infection can be treated mainly with a combination of benzimidazoles like thiabendazole, mebendazole and albendazole; with corticosteroids. The study emphasizes the need for hepatic capillariasis to be considered as a differential diagnosis in cases of suspected hepatitis, leptospirosis, abdominal lymphadenopathy or other hepatic or parasitic infections prevalent in the region concerned; and meticulously assess the cases to facilitate early diagnosis and prompt treatment, thus reducing the distress faced by patients.

Survival of chicken ascarid eggs exposed to different soil types and fungi

Abstract The eggs of intestinal ascarid parasites ( Ascaridia galli and Heterakis spp.) of chickens can survive long-term in soil and this makes contaminated yards and pastures infective to chickens for years. The fungi Pochonia chlamydosporia Biotype 10 and Metarhizium brunneum KVL04-57 can kill ascarid eggs in agar assays but their efficacy against these eggs in soil is unknown. We therefore initially tested the ovicidal effect of the two fungi in laboratory soil assays. Unembryonated eggs were added to sterilised and non-sterilised soil with or without fungi, and egg recovery was examined before and after incubation (22 °C, 30 days). Egg recovery was substantially reduced by P. chlamydosporia and M. brunneum in sterilised soil. However, in non-sterilised soil only M. brunneum slightly reduced egg counts. Notably, egg recovery was reduced markedly in non-sterilised soil though no fungi were applied. To test if this is a general characteristic of natural soil, eggs were incubated in similar assays comprising 7 different soils (sterilised and non-sterilised). After incubation, egg recoveries were reduced substantially in all non-sterilised soils whereas there were only minor reductions in sterilised soils. We next isolated and examined if particular egg-degrading fungi occurred in the non-sterilised soil that had exhibited the most extreme ovicidal activity (99%). The fungal isolates belonged to two genera ( Metarhizium and Acremonium ) with reported egg-degrading properties but when tested in vitro in agar assay, none of the three tested isolates of native fungi degraded >34% eggs, suggesting that these fungi may not individually have caused the reduction in egg survival in the non-sterilised soil. In conclusion, a range of natural soils showed inherent properties related to biotic factors to degrade nematode eggs. The biocontrol efficacy of both P. chlamydosporia Biotype 10 and M. brunneum KVL04-57 was very good in sterilised soil but currently limited in non-sterilised soil, potentially due to competition with natural soil biota in fungal establishment. Further research may determine if efficacy may be increased by changing the formulation.

Immune responses and parasitological observations induced during probiotic treatment with medicinal Trichuris suis ova in a healthy volunteer

Ingestion of eggs (ova) of the porcine nematode parasite Trichuris suis (TSO) may reduce the severity of autoimmune disorders, however the development of TSO treatment as a useful therapy for autoimmune diseases is hampered by a lack of knowledge on the development of the parasite and the nature of the local immune responses in humans. Here, we used colonoscopy to investigate the development of T. suis and related mucosal and systemic immune responses during TSO treatment in an intestinally healthy male volunteer. TSO treatment induced T. suis-specific serum antibodies, a transient blood eosinophilia, and increases in IFNγ+ and IL4+ cells within the circulating CD4+ T-cell population. Increased expression of genes encoding cytokines (IL4, IL10, IL17 and TGF-β), and transcription factors (FOXP3, GATA3 and RORC) were apparent in the ascending and transverse colon (the predilection site of the worms), whereas only limited changes in gene expression were observed proximally (ileum) and distally (descending colon) to the infected tissue. We further show that T. suis is able to colonise the human colon, with a number of worms developing to a similar size and morphology observed in the natural pig host, and a small number of unembryonated eggs were passed in the faeces, indicating patent infection. Notably, the volunteer experienced a substantial improvement in psoriasis during the course of TSO treatment. Thus, TSO treatment induced a mixed Th1/Th2/T regulatory response at the local site of infection, which was also reflected to some extent in the peripheral circulation. These results, together with the first definitive observations that T. suis can mature to adult size and reproduce in humans, shed new light on the interaction between the human immune system and probiotic helminth treatment, which should facilitate further development of this novel therapeutic option.

Survival and development of chicken ascarid eggs in temperate pastures.

Eggs of chicken ascarids (Ascaridia galli and Heterakis spp.) are believed to be hardy and survive for long periods. However, this has not been evaluated quantitatively and our study therefore aimed to determine development and recovery of chicken ascarid eggs after burying in pasture soil. Unembryonated eggs were mixed with soil, placed in sealed nylon bags and buried at 7 cm depth in pasture plots April (spring, n = 72) and December 2014 (winter, n = 72). Eight randomly selected bags per season were used to estimate pre-burial egg recovery [0 week post-burial (wpb)]. Eight random bags were removed at 5, 12, 23, 38, 52, 71 wpb per season and additionally at 104 wpb for spring burial. The content of each bag was analysed for numbers and development stages of eggs. Eggs buried in spring were fully embryonated within 12 wpb. In contrast, eggs buried in winter were developing between 23 and 38 wpb, so that all viable eggs seemed to be fully developed by 38 wpb. About 90% eggs disappeared within 23 wpb (spring) and 38 wpb (winter). Small proportions (2-3%) of seemingly viable and infective eggs were still recovered up to 2 years after deposition. In conclusion, most eggs buried in temperate pasture soil seem to experience a heavy mortality within a few months after the deposition, especially during warm periods. However, a small proportion of eggs may survive and remain infective for at least 2 years.

The level of embryonation influences detection of Ostertagia ostertagi eggs by semi-quantitative PCR.

BackgroundThe Internal Transcribed Spacer 2 (ITS2) is a candidate diagnostic marker of the pathogenic cattle nematode Ostertagia ostertagi. The aims of this study were: (i) to document and quantify how the development of O. ostertagi eggs affects ITS2 copies under different storage conditions, and (ii) to suggest optimal storage conditions for faecal samples in a diagnostic pipeline that involves detection and semi-quantification by real-time semi-quantitative polymerase chain reaction (qPCR).FindingsEggs of Ostertagia ostertagi were obtained from fresh faeces and stored at 4 °C or 25 °C under aerobic or anaerobic (vacuum packing) conditions. Development was monitored by microscopy for up to 336 h, and the ITS2 copies were determined by qPCR from a fixed number of parasites. Under aerobic conditions at 25 °C, embryonation and a significant increase of ITS2 copies (P < 0.0001) were observed after 12 h. At 4 °C, embryonation occurred after 168 h with a trend towards increased ITS2 copies. Anaerobic conditions inhibited egg development at both temperatures and no significant increase in ITS2 copies was noticed (P = 0.90). ITS2 copies were analysed for each parasite stage: first-stage larvae (L1) exhibited significantly higher copy numbers (20,353 ± 1,950) than unembryonated eggs (568 ± 168; P < 0.0001) with lower coefficient of variation (33 vs 266 %).ConclusionsAerobic storage of O. ostertagi eggs at 25 °C led to a significant increase in ITS2 copies after 12 h due to embryonation and subsequent hatching. In contrast, anaerobic storage (vacuum packing) at 25 °C completely inhibited egg development and any undesirable semi-quantification bias for up to 336 h. Hence, vacuum packing is an optimal storage strategy prior to molecular diagnostic analyses. Alternatively, aerobic storage at 4 °C for up to 72 h can be used. Due to high copy numbers and lower genetic variation, the L1 stage may be considered for diagnostics and further molecular research.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1657-4) contains supplementary material, which is available to authorized users.

Differential expression of β-tubulin isotypes in different life stages of Parascaris spp after exposure to thiabendazole

Anthelmintic resistance (AR) to macrocyclic lactones (ML) has been described in Parascaris of horses world-wide. In contrast, benzimidazoles (BZ) are still effective, although reduced efficacy to this drug class was recently reported. The mode of action of BZ is binding to β-tubulin, which prevents polymerisation of microtubules. In this study, β-tubulin gene expression of isotypes 1 and 2 was investigated at seven time points (0, 6, 24, 72, 96 and 120 h) during embryogenesis and in adult worms. In addition, an in ovo larval developmental test was developed to study β-tubulin gene expression of both isotypes in parasacaris eggs after exposure to different concentrations of thiabendazole (TBZ) for five days at 25 °C. A strong pattern of differential expression of β-tubulin and isotype 1 was observed in all stages, while isotype 2 expression was mainly found at an early phase of the embryogenesis. For isotype 1, a 5-fold increase was observed during the first 48 h, but gene expression gradually decreased after 72, 96 and 120 h. Isotype 2 was only expressed during the first 24h, followed by a 130-fold decrease at (time points) 72, 96 and 120 h. The in ovo larval developmental test, in which we exposed initially unembryonated eggs to increased concentrations of TBZ, did affect isotype 1 gene expression but not isotype 2. This assumes that each isotype has specific functions in different life stages. This is in agreement with the 'multi-tubulin' hypothesis, which states that different tubulin isotypes are required for specialised microtubule functions. Isotype 1 is the most likely drug target for BZs, as isotype 2 was only expressed at very low levels later in development. Increasing concentrations of TBZ altered β-tubulin isotype 1 gene expression after exposure of the eggs for five days, but this was not seen for isotype 2.

Temperature dependent embryonic development of Trichuris suis eggs in a medicinal raw material

The therapeutic potential of infective pig whipworm eggs, Trichuris suis ova (TSO), is currently tested in several clinical trials on immune-mediated diseases. This paper studied the embryonic development of TSO in a medicinal raw product, where the parasite eggs were suspended in sulphuric acid (pH1). Unembryonated T. suis egg batches were stored at 5, 10, 15, 20, 25, 30, and 40°C (±1°C) and examined at 2, 4, 8, and 14 weeks. Subsequently, sub-batches from each temperature were allowed to embryonate for additional 14 weeks at 25°C, and selected samples were tested for infectivity in Göttingen minipigs. Both male and female pigs were used to evaluate eventual gender specific infectivity. Storage at 30°C up to 14 weeks and subsequent embryonation for 14 weeks at 25°C did not significantly reduce the overall larval establishment in minipigs, as compared to storage at 5°C and subsequent embryonation at 25°C. As marked impairment of egg development was observed during storage at 40°C, a second set of unembryonated egg batches were incubated at 30, 32, 34, 36, 38, and 40°C (±1°C) for 1-8 weeks. The development of the eggs was repeatedly examined by manual light microscopy, multispectral analysis (OvaSpec), and an egg hatching assay prior to the final testing in minipigs (Trial 1). These methods showed that the development started earlier at higher temperatures, but the long-term storage at higher temperature affected the egg development. The present study further documents tolerance of the TSO to storage at temperature 5-15°C, at which temperature development of larvae is not initiated.

The trematode Skrjabinolecithum spasskii Belous, 1954 (Digenea: Haploporidae), a mullet parasite (Mugilidae) from Peter the great bay of the sea of Japan and from Vietnamese waters of the Gulf of Tonkin: Morphology and molecular data

The trematode Skrjabinolecithum spasskii was described by Belous from a redlip mullet, Mugil soiuy (= Liza haematocheila), that was caught in the Razdolnaya (Suifun) River (in the southern Far East of Russia). In the description of the species the author noted that the adult S. spasskii had no pigment eye spots; it had a spherical testis and short caeca; the uterus contained eggs with miracidia devoid of an eye spot. We found adult worms of this species in the intestine of the redlip mullet Liza haematocheila and the striped mullet Mugil cephalus from Peter the Great Bay of the Sea of Japan and in the striped mullet M. cephalus from northern waters of Vietnam in the Gulf of Tonkin. Our study of the morphology of S. spasskii showed that the worms have diffuse eye spots, V-shaped testis, long caeca that reach the level of the middle of the posterior third of the body, as well as a uterus with unembryonated eggs with an operculum on one pole and a knob on the other pole. The miracidium develops on eggs that hatch in water and has an eye spot. An analysis of the nucleotide sequences of the 28S rRNA gene and the ITS1-5.8S-ITS2 fragment revealed the intraspecific differentiation of three genotypes of S. spasskii; two of these were detected in the trematodes from the Primorskii krai and one genotype was found in the trematodes from Vietnam.

Dose-dependent establishment of Trichuris suis larvae in Göttingen minipigs

Embryonated eggs of the pig whipworm Trichuris suis (TSOee) constitute the active pharmaceutical ingredient (API) in a medicinal product explored in human clinical trials against several immune-mediated diseases. The measurement of TSO biological potency (hatchability and infectivity) is a requirement for the assessment of TSO's pharmacological potency in human clinical trials. The present study aims to validate the dose-dependent establishment of T. suis larvae in Göttingen minipigs and eventual clinical implication of a dose range (1000-10,000 TSO). Four groups of 5 minipigs were inoculated with doses of 1000, 2500, 7500, and 10,000 TSOee, respectively, to evaluate a range of concentrations of TSOee in a minipig infectivity model. Unembryonated eggs (TSOue) were added to keep the total egg number in the inoculum constant at 10,000 eggs. Two groups received 2500 and 7500 TSOee per pig without the addition of TSOue as controls. The intestinal larval establishment at 21 days post inoculation (dpi) demonstrated a clear positive linear dose-response relationship between numbers of inoculated TSOee and recovered larvae. There was a low level of variation in larval counts in all study groups. Thus, the infectivity model in minipigs within the tested dose range offers a reliable, sensitive and accurate assay for testing biological potency of TSO.

Investigation into the possibility of vertical transmission of avian bornavirus in free-ranging Canada geese (Branta canadensis)

To investigate the possibility of in ovo infection with avian bornavirus (ABV) in wild Canada geese (Branta canadensis), 53 eggs were opportunistically collected at various stages of embryonic development from 16 free-ranging goose nests at a large urban zoo site where ABV infection is known to be present in this species. ABV RNA was detected in the yolk of one of three unembryonated eggs using real-time reverse transcription polymerase chain reaction. ABV RNA was not identified in the brains from 23 newly hatched goslings or 19 embryos, nor from three early whole embryos. Antibodies against ABV were not detected in the plasma of any of the hatched goslings using an enzyme-linked immunosorbent assay. Possible reasons for the failure to detect ABV RNA in hatchlings or embryos include low sample size, eggs deriving from parents not actively infected with ABV, the testing of only brain tissue, and failure of the virus to replicate in Canada goose embryos. In conclusion, this preliminary investigation demonstrating the presence of ABV RNA in the yolk of a Canada goose egg provides the first evidence for the potential for vertical transmission of ABV in waterfowl.