Suppression of the growth and metastasis of mouse melanoma by Taenia crassiceps and Mesocestoides corti tapeworms.

Cancer is still one of the leading causes of death, with an estimated 19.3 million new cases every year. Our paper presents the tumor-suppressing effect of Taenia crassiceps and Mesocestoides corti on B16F10 melanoma, the intraperitoneal application of which followed the experimental infection with these tapeworms, resulting in varying degrees of effectiveness in two strains of mice. In the case of M. corti-infected ICR mice, a strong tumor growth suppression occurred, which was accompanied by a significant reduction in the formation of distant metastases in the liver and lung. Tapeworm-infected C57BL/6J mice also showed a suppression of tumor growth and, in addition, the overall survival of infected C57BL/6J mice was significantly improved. Experiments with potential cross-reaction of melanoma and tapeworm antigens with respective specific antibodies, restimulation of spleen T cells, or the direct effect of tapeworm excretory-secretory products on melanoma cells in vitro could not explain the phenomenon. However, infections with T. crassiceps and M. corti increased the number of leukocytes possibly involved in anti-tumor immunity in the peritoneal cavity of both ICR and C57BL/6J mice. This study unveils the complex interplay between tapeworm infections, immune responses, and melanoma progression, emphasizing the need for further exploration of the mechanisms driving observed tumor-suppressive effects.

Evaluation of brain injury in goats naturally infected with Coenurus cerebralis; brain specific biomarkers, acute inflammation, and DNA oxidation.

This investigate goals are to establish the utility of brain-specific biomarkers (GFAP and S100B) in vivo and to assess the brain damage in C. cerebralis-infected goats using histopathological and immunopathological methods. The animal material of the study consisted of 10 healthy and 20 Coenurus cerebralis infected female hair goats. Serum GFAP and S100B concentrations were measured to determine brain damage. Serum S100B (p < 0.037), GFAP (p < 0.012), urea (p < 0.045), GGT (p < 0.001) and ALT (p < 0.001) concentrations in the C.cerebralis group were significantly higher than the control group. There was no significant difference between the C.cerebralis group and the control group for hsTnI (p > 0.078), creatinine (p > 0.099) and CK-MB (p > 0.725). In the histopathological examination, pressure atrophy and related inflammatory changes were observed due to mechanical damage of the parasite. Immunohistochemical examinations revealed that the parasite stimulated inflammation with the expression of TNF-α and caused DNA damage with the expression of 8-OHdG. As a result, when the data collected for this study are assessed as a whole, it is thought that the use of brainspecific GFAP and S100B biomarkers may be beneficial in determining brain damage in naturally infected hair goats with C.cerebralis. Changes in the levels of brain-specific biomarkers contribute significantly to determining the prognosis of the disease in vivo. Measurement of GFAP and S100B concentrations from serum offers an important alternative to the CSF method.

Morphological updates, host-specificity, molecular data and phylogenetic analysis of Acanthobothrium coronatum (Cestoda: Onchoproteocephalidea), a neglected parasite of the nursehound Scyliorhinus stellaris.

Acanthobothrium is the most speciose genus of onchoproteocephalidean cestodes, whose adults parasitize the intestine of elasmobranch fishes. Acanthobothrium coronatum, the type species of the genus described from Mediterranean elasmobranchs, remains a little known parasite, with the most recent reports dating back to the fifties. We hereby investigate host-specificity and redescribe A. coronatum from the same locality of its original description by using light and scanning electron microscopy approaches. Moreover, molecular and phylogenetic data inferred from the analysis of the 28S rDNA gene are reported for the first time. Out of the nine elasmobranch species examined from Gulf of Naples, we only detected A. coronatum in the intestine of Scyliorhinus stellaris, with infection patterns that supports evident host-specificity for this shark species. The genetic characterization of 28S rDNA showed 99.8-100% similarity with larvae previously found in Octopus vulgaris from the same area investigated here. Conspecificity between the present material and the larvae found in the octopus was also confirmed by the tree topology. The host-parasite phylogeny is discussed, even if additional molecular data are needed to clarify potential host-parasite patterns. Notwithstanding this limitation, this is the first molecular study revealing conspecificity between an adult Acanthobothrium species from a shark and the larvae found in an intermediate/paratenic host, shedding light on the transmission pathway of A. coronatum in S. stellaris. Finally, the taxonomic, molecular, and phylogenetic data presented here allow a better characterization of a neglected parasite.

Molecular phylogenetic identification and morphological characteristics of Raillietina echinobothrida (Cestoda: Cyclophyllidea: Davaineidae) in commercial chickens in North China.

Raillietina echinobothrida (R. echinobothrida) is one of the most pathogenic and prevalent tapeworms threat to the commercial chickens in China. However, there is a lack of research on their molecular identification and morphological characteristics. This study explored the molecular identification markers for R. echinobothrida in North China based on 18s ribosomal RNA (18s rRNA) gene and the ribosomal DNA second internal transcribed spacer (ITS-2) gene. The BLAST results of 18s rRNA (1643 bp) and ITS-2 (564 bp) gene sequences showed that the isolated intestinal tapeworms were R. echinobothrida. Phylogenetic trees obtained by maximum likelihood (ML) or neighbor-joining (NJ) method revealed that the R. echinobothrida in North China had the closest evolutionary relationship with the species found on the Qinghai-Tibet plateau, China. Morphological observations by hematoxylin staining and scanning electron microscope showed four round suckers and a retractable rostellum on the spherical scolex of R. echinobothrida. Two rows of alternately arranged hooks distributed around the rostellum. There were 30-40 testes in each mature segment. A well-developed cirrus pouch lied outside the excretory duct of mature segment. The gravid segment contained 200-400 eggs and there was a well-developed oncosphere in each egg. In addition, abundant ultrastructural features in mature proglottid of R. echinobothrida in North China were identified by transmission electron microscopy. In conclusion, the present study established ways of molecular phylogenetic identification for R. echinobothrida based on 18s rRNA and ITS-2 gene, and identified the morphological and ultrastructural characteristics of R. echinobothrida in North China.

Suppression of inflammatory genes expression in the injured host intestinal wall during Mesocestoides vogae tetrathyridium larvae migration.

Mesocestoides vogae is a cestode parasite of the family Mesocestoididae (order Cyclophyllidea). Its larvae, tetrathyridium, are approximately 1 mm long and 300 µm wide and infect a wide range of host species including humans. Tetrathyridium migrate through the intestinal wall to invade the peritoneal cavity. Despite intestinal penetration by such a large-sized parasite, symptomatic intestinal disorders are not common during the migration period. In this study, the dynamics of tetrathyridia migration and their pathogenicity towards intestinal tissues were examined in mice infected orally with these parasites. Most tetrathyridia were found to migrate through the intestinal wall, moving into the peritoneal cavity or liver 24 to 48 hours after the oral infections. Next, the pathogenicity of tetrathyridium in the intestinal wall was histopathologically evaluated, and tissue injury from tetrathyridium migration was confirmed. Inflammatory foci were observed as tetrathyridium migration tracks from 48 hours after oral infection; however, the number of inflammatory foci had decreased by half more than 48 hours later. Therefore, we examined the gene expression levels of the macrophage driving cytokine, IL-1ß, and the eosinophil recruiting chemokine, CCL11, by quantitative reverse-transcriptase PCR. The expression levels of these genes in the infected group were significantly lower than those of the non-infected group at 48 hours post-infection. Although the immunomodulating ability of the excretory-secretory products released from tetrathyridium has been previously shown by in vitro assays, the significance of this ability in their lifecycle has remained unclear. In this study, we discovered that tetrathyridium causes temporal inflammation in the intestinal wall during penetration and large-scale migration in this organ, but tetrathyridium simultaneously suppresses the host's inflammatory gene expression, might to be a strategy that reduces inflammatory responses and increases survival of the parasite.

A Rare Case of Non-cerebral Coenurus Cyst on the Heart of a Ewe

During the routine postmortem inspection from carcasses and offal of slaughtered ewes in an abattoir in Isfahan (Iran), an ovine heart was discovered with a firm nodule in the myocard on palpation. In closer examination, a liquid containing cyst (1x1 cm) was recognized on left part of the heart. The cyst had thick fibrotic capsule in outer surface and a thin inner layer containing few white clusters of scolices. White clusters contained scolices that adhered to the inner transparent layer, like white beads. Based on the gross and microscopical characteristics, the cyst was diagnosed as non-cerebral coenurus cyst. This is a rare report of heart coenurosis in a sheep.

Anoplocephala perfoliata Infection in Horses in Iceland: Investigation of Associations Between Intensity of Infection and Lesions.

In Iceland, there is at least 1 horse for every 5 human inhabitants, mostly kept on uncultivated rangelands. Although the Icelandic horse is considered robust compared with other breeds, it is nevertheless susceptible to disease. Few studies have investigated the prevalence of intestinal parasites in horses in Iceland. The purpose of this study was to determine the prevalence of the tapeworm, Anoplocephala perfoliata, in horses in Iceland and to explore associations between intensity of infection and the severity of macroscopic pathological lesions in this population. In addition, the relationship between infection and geographical location in Iceland, horse age, and gender were investigated. The utility of a modified McMaster flotation method for identifying infected horses from fecal samples was also studied. The study sample consisted of 104 horses (aged 1-30 yr) slaughtered in 3 abattoirs in North and South Iceland during June and July 2016. The prevalence of A. perfoliata in the horses was 64.4%, with between 1-131 worms found in infected horses. The pathological changes in the horses associated with infection varied from mild (hyperemia in small areas) to severe (large ulcers and necrotic lesions coated with fibrin), and intensity of infection correlated with the size and type of pathological lesions in the intestines. No statistically significant associations between infection with A. perfoliata and geographical location, horse age, or horse gender were detected. The McMaster egg counting method used here was of very low sensitivity (7.4%) and was concluded to be inadequate for detection of A. perfoliata infection in horses. The prevalence of A. perfoliata in horses in Iceland in this study was found to be relatively high compared with results from many studies performed elsewhere in Europe. This may reflect the lack of treatment of horses in Iceland for this parasite, the environmental suitability for the intermediate mite host, and grazing management practices in Iceland. The high prevalence and association with pathology suggest that diagnosis of infection using a sensitive method, along with appropriate treatment, should be considered for horses in Iceland.

First Human Case of Metacestode Infection Caused by Versteria sp. in a Kidney Transplant Recipient.

Cestodes are emerging agents of severe opportunistic infections among immunocompromised patients. We describe the first case of human infection, with the recently-proposed genus Versteria causing an invasive, tumor-like hepatic infection with regional and distant extension in a 53-year-old female kidney transplant recipient from Atlantic Canada.

Dipylidium caninum Infection in Children: Clinical Presentation and Therapeutic Challenges.

Dipilidium caninum infection is a relatively uncommon parasitic infection in children. We present 10 cases treated in our tertiary care hospital during the last 2 years. This parasitosis has a relatively benign course but should be considered in children with gastrointestinal symptoms and eosinophilia. Treatment can be challenging, especially in infancy. Preventative measures are necessary to avoid the spread of the disease.

Experimental murine model of neurocysticercosis: first report of cerebellum as a location for Mesocestoides corti tetrathyridia.

Neurocysticercosis is a parasitic disease caused by encysted larvae of Taenia solium in the human central nervous system. Cysts mainly affect the cerebral hemispheres, although they can also be found in ventricles, basal cisterns, and subarachnoid spaces, and rarely in the cerebellum. Given the impossibility of studying the disease in human patients, Cardona et al. (1999) developed a mouse model of neurocysticercosis, using Mesocestoides corti, a closely related cestode. This allows us to study the parasite-host relationship and the mechanisms involved in the disease, in order to improve the therapy. In this murine model of neurocysticercosis, the location of tetrathyridia in parenchyma, ventricles and meninges has already been reported. The aim of this work is to report the cerebellum as a new location for M. corti tetrathyridia in the murine model of neurocysticercosis. A murine model that reproduces the human pathology is essential to evaluate the symptomatology and response to drug treatment in experimentally infected mice.

Is cestode infection intensity associated with decreased body condition in the Eurasian woodcock Scolopax rusticola?

The Eurasian woodcock Scolopax rusticola is a widespread woodland specialist and a widely harvested quarry species throughout its European wintering areas, including Britain. Woodcock are prone to cestodiasis, but prevalence levels and possible effects on body condition remain under-studied. We studied the prevalence, abundance and intensity of cestodiasis in 161 woodcock harvested in four British regions in December and January during two consecutive winters (2013/14 and 2014/15). Cestodiasis prevalence was 90%, and there was no difference in prevalence between birds harvested in Cornwall, Wessex, East Anglia and Scotland. High prevalence levels were explained by the fact that earthworms (Lumbricidae) are intermediate hosts for some cestode species and also the most important dietary component of woodcock. The distribution of cestodiasis in woodcock was aggregated, such that when using the total length of cestodes per sample to measure abundance, 65% of the birds had less than 80 cm. Cestodiasis abundance varied between sexes across regions but the intensity was not affected by region, sex, age or their interactions. The intensity of cestodiasis was positively correlated with fresh weight and pectoral mass, while no significant correlation was found with the abdominal fat pad. Our results suggest that, despite high prevalence levels and intensity of cestodiasis in woodcock, host body condition is not significantly affected and hence it is unlikely that cestodiasis has a major effect on woodcock population dynamics.

The Asian fish tapeworm Schyzocotyle acheilognathi is widespread in baitfish retail stores in Michigan, USA.

BACKGROUND: The Asian fish tapeworm Schyzocotyle acheilognathi (Yamaguti, 1934) is an important fish pathogen because of its wide range of intermediate and definitive hosts and its pathological consequences. This study was designed to determine if baitfish are a likely vector contributing to the expansion of the invasive Asian fish tapeworm. RESULTS: We collected live baitfish for examination from 78 retail stores in Michigan between September 2015 and June 2016. A total of 5400 baitfish (90 lots, 60 fish/lot) were examined, including 42 emerald shiners [Notropis atherinoides (Rafinesque, 1818)] lots, 30 fathead minnow [Pimephales promelas (Rafinesque, 1820)] lots, 11 golden shiners [Notemigonus crysoleucas (Mitchill, 1814)] lots, 3 sand shiners [Notropis stramineus (Cope, 1865)] lots, 1 lot each of spottail shiners [Notropis hudsonius (Clinton, 1824)], Northern redbelly dace [Phoxinus eos (Cope, 1861)], and blacknose dace [Rhinichthys atratulus (Hermann, 1804)] and 1 lot of mixed two species: weed shiners [Notropis texanus (Girard, 1856)] and sand shiners. CONCLUSIONS: Based on its scolex and strobilar morphology combined with gene sequence analysis, S. acheilognathi was only found in emerald shiners, golden shiners and sand shiners. The mean within lot prevalence and abundance of infection was highest in emerald shiners (20.3 ± 14.0 and 1.15 ± 1.34), followed by golden shiners (8.3 ± 10.7 and 0.89 ± 1.27) and sand shiners (1.3 ± 2.6 and 0.02 ± 0.05). However, the mean intensity of S. acheilognathi in emerald shiners was lower (4.3 ± 2.6) than that of golden shiners (6.6 ± 6.7). S. acheilognathi-infected fish exhibited enlargement of the abdomen, distension of the intestinal wall, and intestinal occlusion and hemorrhage. This finding suggests that live baitfish are a likely vector by which the invasive Asian tapeworm's range is expanding.

A Human Case of Zoonotic Dog Tapeworm, Dipylidium caninum (Eucestoda: Dilepidiidae), in China.

We described a human case of zoonotic dog tapeworm, Dipylidium caninum (Eucestoda: Dilepidiidae), rarely occurring in China. The mother of a 17 month-old boy noted the appearance of small white and active worms over a month period in her son's feces, but the boy was asymptomatic except mild diarrhea. We observed 3 tapeworm proglottids resembling cucumber seeds in his stool sample. Microscopically, each proglottid had 2 genital pores, 1 on each lateral edge, and numerous egg capsules in the uterus. The patient was successfully treated with a single oral dose of praziquantel. Adult worms were recovered in the diarrheic stool after praziquantel treatment and purgation. His family had household pet dogs for several years, and he might have acquired the infection by ingestion of infected fleas of his pet dogs. A history of dog or cat pets and flea bites may be important clues to diagnosis of D. caninum infection. The infected pets should also be treated.

Clinical evolution of cerebral coenurosis from invasive to chronic infection in sheep and a goat.

This survey describes the evolution in vivo of Coenurus cerebralis in small ruminants. At presentation, neurological signs and cerebrospinal fluid (CSF) features were suggestive of multifocal or diffuse inflammatory reaction. Magnetic resonance imaging (MRI) captured the transition between the invasive and quiescent phase of the infection, revealing the concurrent presence of meningitis and small cysts. During the quiescent phase, in all animals, neurological symptoms disappeared, and cerebrospinal fluid was unremarkable while cysts grew progressively. Subsequently, the onset of neurological symptoms coincided with MRI signs of diffuse or localized increase of intracranial pressure, as confirmed by direct intracranial pressure measuring. All the animals had an excellent post-surgical recovery. This is the first report describing the evolution of coenurosis in vivo. Sequential imaging allowed describing interesting such as the death of some coenuri and different parasite growth rate in the same host.

Dynamics and effects of Ligula intestinalis (L.) infection in the native fish Barbus callensis Valenciennes, 1842 in Algeria.

The dynamics of the emergence, duration, and decline phases in epizootic cycles are well known for humans and some crops, but they are poorly understood for host-parasite systems in the wild. Parasites may be particularly insidious as they are often introduced unintentionally, simultaneously with their hosts, and later transferred to species in the new location. Here we investigate the epizootic dynamics of the tapeworm Ligula intestinalis in the Hamiz reservoir, Algeria, and explore its effects on the cyprinid fish Barbus callensis. Regular sampling was conducted from October 2005 to February 2008 with intermittent surveys carried out until 2010. Five percent of the 566 specimens of B. callensis that were caught were infected, with the maximum number of parasites found in spring. There was no obvious difference in weight between uninfected fish and infected ones, and infection did not affect fish condition. However, infected fish were significantly longer than uninfected fish and had inhibited gonad development. The proportion of infected fish caught was significantly higher in year 1 and by the second winter, infection collapsed to zero. The Ligula infection thus appeared to have minimal ecological effects and be of a temporary nature, thus exhibiting an epizootic cycle. Taken together, our data indicates that this infection declined or even failed during our study period. Failure may be due to the specific genetic strain of Ligula, but invasive carp may also have been influential in both the introduction and subsequent decline of this parasite.

Temporal changes in growth, condition and trophic niche in juvenile Cyprinus carpio infected with a non-native parasite.

In host-parasite relationships, parasite prevalence and abundance can vary over time, potentially impacting how hosts are affected by infection. Here, the pathology, growth, condition and diet of a juvenile Cyprinus carpio cohort infected with the non-native cestode Bothriocephalus acheilognathi was measured in October 2012 (end of their first summer of life), April 2013 (end of first winter) and October 2013 (end of second summer). Pathology revealed consistent impacts, including severe compression and architectural modification of the intestine. At the end of the first summer, there was no difference in lengths and condition of the infected and uninfected fish. However, at the end of the winter period, the condition of infected fish was significantly reduced and by the end of their second summer, the infected fish were significantly smaller and remained in significantly reduced condition. Their diets were significantly different over time; infected fish consumed significantly higher proportions of food items <53 µm than uninfected individuals, a likely consequence of impaired functional traits due to infection. Thus, the sub-lethal impacts of this parasite, namely changes in histopathology, growth and trophic niche were dependent on time and/or age of the fish.

Experimental cerebral and non-cerebral coenurosis in goats: A comparative study on the morphological and molecular characteristics of the parasite.

This experimental study was conducted to test whether cerebral and non-cerebral forms of Coenurus cerebralis belong to one origin or they are originated from two different tape worms. In the first step of the study, two groups of dogs were orally infected with the protoscoleces of cerebral and non-cerebral cysts and four months after infection, the adult worms were collected and morphologically characterized. Then the obtained eggs from two groups of adult worms were orally inoculated to two groups of goats to trace the predilection sites and also to compare the morphological and molecular characteristics of the larval stage of the parasites. The results showed that, both cerebral and non-cerebral coenuri, produced morphologically similar worms in the experimentally infected dogs. We observed only non-cerebral coenurus cysts in two groups of experimentally infected goats and the morphological characteristics of the cysts of two different groups were also similar. The molecular findings also showed that the cysts of two groups were 100% identical to each other based on the CO1 and nad1 sequences. In conclusion, our morphological and molecular findings reinforce the evidence that Taenia multiceps is the single origin of both cerebral and non-cerebral form of C. cerebralis but in goats, the cysts show more tendency to non-cerebral organs.