Recognizing that enteric tuft cells can signal the presence of nematode parasites, we investigated whether tuft cells are required for the expulsion of the cestode, Hymenolepis diminuta, from the non-permissive mouse host, and in concomitant anti-helminthic responses. BALB/c and C57BL/6 mice infected with H. diminuta expelled the worms by 11 days post-infection (dpi) and displayed DCLK1+ (doublecortin-like kinase 1) tuft cell hyperplasia in the small intestine (not the colon) at 11 dpi. This tuft cell hyperplasia was dependent on IL-4Rα signalling and adaptive immunity, but not the microbiota. Expulsion of H. diminuta was slowed until at least 14 dpi, but not negated, in tuft cell-deficient Pou2f3-/- mice and was accompanied by delayed goblet cell hyperplasia and slowed small bowel transit. Worm antigen and mitogen evoked production of IL-4 and IL-10 by splenocytes from wild-type and Pou2f3-/- mice was not appreciably different, suggesting similar systemic immune reactivity to infection with H. diminuta. Wild-type and Pou2f3-/- mice infected with H. diminuta displayed partial protection against subsequent infection with the nematode Heligmosomoides bakeri. We speculate that, with respect to H. diminuta, enteric tuft cells are important for local immune events driving the rapidity of H. diminuta expulsion but are not critical in initiating or sustaining systemic Th2 responses that provide concomitant immunity against secondary infection with H. bakeri.

Hymenolepis diminuta is a common parasite of rats and mice, but is very rare in humans with cases reported from various parts of the world. Here, we reported a case of Hymenolepis diminuta infection involving both the respiratory and digestive tracts in a 49-year-old male patient whose initial imaging and symptoms were strikingly similar to pneumonia. Since no disease-causing pathogens were found during routine examinations, we considered respiratory infection by specific pathogens before metagenomic next-generation sequencing of broncho-alveolar lavage fluid confirmed the diagnosis of Hymenolepis diminuta. After confirming the diagnosis, we retested the patient\'s stool repeatedly and found Hymenolepis diminuta eggs finally. To help doctors better understand this condition and avoid misdiagnosis, this article provided a summary of the clinical characteristics, diagnostic techniques, and therapeutic options for infection by Hymenolepis diminuta.
缩小膜壳绦虫，是鼠类常见的寄生虫，偶然寄生于人体。在全世界有广泛的病例报告。缩小膜壳绦虫通常通过消化道寄生于人体。本文报道1例同时寄生在人体呼吸道及消化道的缩小膜壳绦虫感染，通过对该病例的诊断及治疗的详细介绍，以提高临床医生对本病的认知水平。.

The leaves of Phlogacanthus thyrsiflorus are used as an anthelmintic remedy by the tribal communities of upper Assam in India. The present study was carried out to validate the anthelmintic credentials of this plant. Mature and larval Hymenolepis diminuta worms were exposed to varying concentration of methanolic leaf extract of plant and parasites were observed for paralysis and mortality. At the end of the experiment, worms were collected and processed for scanning electron microscopy (SEM) study to observe the effect of extract on tegument of parasite. The in vivo study was carried out in H. diminuta-rat model with 200, 400 and 800 mg/kg concentrations of extract. The in vivo anthelmintic efficacy was assessed by reductions in egg per gram (EPG) and worm counts after necropsy of animals. In vitro studies revealed the earliest mortality of larval worms in 1.05 ± 0.04 h by 30 mg/ml concentration and of adult worms in 2.05 ± 0.08 h. SEM study revealed extensive damage to the suckers, body tegument and microtriches of worms treated with 30 mg/ml concentration of extract. In in-vivo studies, 800 mg/kg dose of extract showed highest efficacy, with 59% and 54.25% reduction in EPG counts and worm count against juvenile worms, and 63.16% and 66.75% reduction in EPG counts and worm counts, respectively against adult worms. Although the effects were comparatively less than the reference drug, nevertheless this study reveals that P. thyrsiflorus possess anthelmintic efficacy and justify its use in traditional medicine against intestinal-worm infections.

Model parasite species, whose entire life cycle can be completed in the laboratory and maintained for multiple generations, have played a fundamental role in our understanding of host–parasite interactions. Yet, keeping parasites in laboratory conditions may expose them to unnatural evolutionary pressures, and using laboratory cultures for research is therefore not without limitations. Using 2 widely-used model helminth species, the cestode Hymenolepis diminuta and the nematode Heligmosomoides polygyrus, I illustrate the caution needed when interpreting experimental results on model species. I first review more than 1200 experimental studies published on these species in the past 4 decades, to determine which research areas they have contributed to. This is followed by an examination of the institutional laboratory cultures that have provided the parasites used in these studies. Some of these have persisted for decades and accounted for a substantial proportion of published studies, whereas others have been short-lived. Using information provided by the curators of active cultures, I summarize data on their origins and maintenance conditions. Finally, I discuss how laboratory cultures may have been subject to the influence of evolutionary genetic processes, such as founder effects, genetic drift and inbreeding. I also address the possibility that serial passage through laboratory hosts across multiple generations has exerted artificial selection on several parasite traits, resulting in genetic and phenotypic divergence among laboratory cultures, and between these cultures and natural parasite populations. I conclude with recommendations for the continued usage of laboratory helminth cultures aimed at maximizing their important contribution to parasitological research.

The rat tapeworm Hymenolepis diminuta is a parasite that usually uses rats as a definitive host. It also infects humans and non-human primates. Human infections have been reported in 80 countries worldwide, including China. Nevertheless, nearly all the literature on human infections in China by the rat tapeworm is in Chinese journals, which are very difficult to access by readers outside China. The main aim of the current manuscript was to systematically review human infections by the rat tapeworm in China for readers inside and outside the country. Chinese characters for H. diminuta were used to search several databases, including Google Scholar. In total, 511 infections were reported in 24 Chinese provinces/autonomous regions, which surpassed 320 in Costa Rica as the country with the highest number of infections. Furthermore, three nationwide surveys on parasitic infections in the past 3 decades revealed detailed prevalence of this parasite along with that of roundworm, whipworm, hookworm and pinworm in Chinese populations. These data contribute to better understanding of this greatly neglected zoonosis in the world\'s most populated country.

Tapeworm infections cause insidious and irreversible effects in the infected individuals and some of them have already shown resistance to available drugs. A search for alternative treatment is urgently required. Phenolic compounds are amongst the most researched natural substances for their medicinal use. The present study aims to determine anthelmintic efficacy of two polyphenols Gallic acid and Catechin against the zoonotic rat tapeworm Hymenolepis diminuta. Both compounds are potent anti-oxidants and play major roles in combating pathogens, while their anthelmintic property according to our knowledge is yet to be explored. The parasite model H. diminuta was procured from intestine of infected rats raised in our laboratory. Two sets of parasites were treated in vitro with 5, 10, 20 and 40 mg/ml concentrations of each Gallic Acid and Catechin separately, another set of parasites were treated with standard dose of Praziquantel in RPMI 1640, while still another set of worms were kept in RPMI 1640 at 37 ± 10C with 1% Dimethyl sulfoxide as control. Motility and structural alterations were the parameters assessed for anthelmintic efficacy of the compounds. After paralysis the worms were processed for morphological, histological, and ultrastructural study and observed under light and electron microscope. Dose-dependent efficacy was observed in both compounds. Shrinkage of suckers, deformed proglottids and architectural alteration of the tegument were observed throughout the body of treated parasites compared to control. Although in terms of time taken for paralysis and mortality Gallic acid was more effective than Catechin, the degree of morphological aberrations caused were almost similar, except histological alteration was more in Catechin treated worms than in Gallic acid. Nevertheless, both Gallic acid and Catechin are suggested to possess anthelmintic efficacy besides other health benefits but extended studies are required to compare their efficacy.

Hymenolepis diminuta is a tapeworm commonly found worldwide in small rodents such as rats with occasional reports in other definitive hosts such as primates including chimpanzees and humans. It has not been reported in African green monkey (AGM, Chlorocebus sabaeus), and the parasite\'s molecular phenotype and phylogeny remain primitively sketchy. The aims of the current study were to determine if H. diminuta infected AGMs, to molecularly characterize H. diminuta and to review its infection in non-human primates. Feces of AGMs were examined visually for adult helminths and microscopically for eggs using centrifugation flotation. Total DNA extracted from eggs was amplified by PCR followed by DNA sequencing of targeted sequences of nuclear rRNA + internal transcribed spacers (ITS) and mitochondrial cox1. Phylogenetic analyses were performed. The DNA sequences of both nuclear rRNA + ITS and mitochondrial cox1 showed more than 98% and 99% identity to the known sequences respectively. Hymenolepis diminuta has been reported in various non-human primates with the highest prevalence of 38.5% in the white-headed capuchin monkey. The study presented here confirms that this tapeworm is capable of infecting various species of non-human primates with the first report of infections in AGM. Phylogenetic analyses of rRNA + ITS and mitochondrial cox1 demonstrated three separated clades I, II and III with the newly described AGM1 isolate belonging to the clade I. Whether these differences are at species level remains to be confirmed.

The tapeworm Hymenolepis diminuta is a common parasite of the small intestine in rodents but it can also infect humans. Due to its characteristics and ease of maintenance in the laboratory, H. diminuta is also an important model species in studies of cestodiasis, including the search for new drugs, treatments, diagnostics and biochemical processes, as well as its host-parasite interrelationships. A great deal of attention has been devoted to the immune response caused by H. diminuta in the host, and several studies indicate that infection with H. diminuta can reduce the severity of concomitant disease. Here, we present a critical review of the experimental research conducted with the use of H. diminuta as a model organism for over more than two decades (in the 21st century). The present review evaluates the tapeworm H. diminuta as a model organism for studying the molecular biology, biochemistry and immunology aspects of parasitology, as well as certain clinical applications. It also systematizes the latest research on this species. Its findings may contribute to a better understanding of the biology of tapeworms and their adaptation to parasitism, including complex correlations between H. diminuta and invertebrate and vertebrate hosts. It places particular emphasis on its value for the further development of modern experimental parasitology.

We report a case of Hymenolepis diminuta infection in a two years old boy living in Guilan Province, northern Iran diagnosed in 2019. The patient was complained of anorexia, weight loss, weakness and disturbed sleep. Stool examination revealed numerous eggs of H. diminuta. After treatment with a single dose of oral praziquantel, the patient recovered without evidence of the egg shedding in follow-up stool samples. Moreover, we performed detailed phylogenetic analysis of the H. diminuta comparing with other isolates deposited in GenBank database based on Cox1 gene. Based on BLAST analysis of Cox1 gene our sequence showed 97.4-99.2% similarity with those of H. diminuta available in GenBank. The present study recommends the importance of reporting the infection cases, in order to improve knowledge on epidemiology and control of the neglected disease.

The rat tapeworm Hymenolepis diminuta has been shown to cause alterations in gastrointestinal tissues. Since hymenolepiasis induces a number of reactions in the host, it is reasonable to assume that it may also be involved in the mechanisms of apoptosis in the intestines. Individual research tasks included an examination of the effect of H. diminuta infection on; (i) the cellular localization of the expression of pro-apoptotic protein Bax and anti-apoptotic protein Bcl-2, as well as caspase-3 and caspase-9, and (ii) the effects of the infection on the expression of Bcl-2, Bax, Cas-3 and Cas-9, at the mRNA and protein levels. Molecular tests (including mRNA (qRT PCR) and the protein (Western blot) expression of Bax, Bcl-2, and caspases-3, -9) and immunohistochemical tests were performed during the experiment. They showed that H. diminuta infection activates the intrinsic apoptosis pathway in the small and large intestine of the host. H. diminuta infection triggered the apoptosis via the activation of the caspase cascade, including Cas-3 and Cas-9. Hymenolepiasis enhanced apoptosis in the small and large intestine of the host by increasing the expression of the pro-apoptotic gene and protein Bax and by decreasing the expression of the anti-apoptotic gene and protein Bcl-2.