Project description:The Pacific broad tapeworm Adenocephalus pacificus (syn. Diphyllobothrium pacificum) is the causative agent of the third most common fish-borne cestodosis among humans. Although most of the nearly 1,000 cases among humans have been reported in South America (Peru, Chile, and Ecuador), cases recently imported to Europe demonstrate the potential for spread of this tapeworm throughout the world as a result of global trade of fresh or chilled marine fish and travel or migration of humans. We provide a comprehensive survey of human cases of infection with this zoonotic parasite, summarize the history of this re-emerging disease, and identify marine fish species that may serve as a source of human infection when eaten raw or undercooked.
Project description:Six previously unknown triterpene glycosides, pacificusosides L-Q (1-6), and two previously known triterpene glycosides, cucumariosides B1 (7) and A5 (8), were isolated from an alcoholic extract of Pacific sun star, Solaster pacificus. The structures of 1-6 were determined using 1D and 2D NMR, ESIMS, and chemical modifications. Compound 1 is a rare type of triterpene glycoside with non-holostane aglycon, having a linear trisaccharide carbohydrate chain. Pacificusosides M-P (2-5) have new structures containing a Δ8(9)-3,16,18-trihydroxy tetracyclic triterpene moiety. This tetracyclic fragment in sea star or sea cucumber triterpene glycosides was described for the first time. All the compounds under study exhibit low or moderate cytotoxic activity against colorectal carcinoma HCT 116 cells, and breast cancer MDA-MB-231 cells were assessed by MTS assay. Compound 2 effectively suppresses the colony formation of cancer cells at a non-toxic concentration, using the soft-agar assay. A scratch assay has shown a significant anti-invasive potential of compound 2 against HCT 116 cells, but not against MDA-MB-231 cells.
Project description:BackgroundIn Europe, the tapeworm Dibothriocephalus latus (syn. Diphyllobothrium latum) is a well-known etiological agent of human diphyllobothriosis, which spreads by the consumption of raw fish flesh infected by plerocercoids (tapeworm's larval stage). However, the process of parasite establishment in both intermediate and definitive hosts is poorly understood. This study was targeted mainly on the scolex (anterior part) of the plerocercoid of this species, which facilitates penetration of the parasite in intermediate paratenic fish hosts, and subsequently its attachment to the intestine of the definitive host.MethodsPlerocercoids were isolated from the musculature of European perch (Perca fluviatilis) caught in Italian alpine lakes. Parasites were examined using confocal microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Immunofluorescence tagging was held on whole mount larvae.ResultsThe organisation of the central and peripheral nervous system was captured in D. latus plerocercoids, including the ultrastructure of the nerve cells possessing large dense neurosecretory granules. Two types of nerve fibres run from the body surface toward the nerve plexus located in the parenchyma on each side of bothria. One type of these fibres was found to be serotoninergic and possessed large subtegumental nerve cell bodies. A well-developed gland apparatus, found throughout the plerocercoid parenchyma, produced heterogeneous granules with lucent core packed in a dense layer. Three different types of microtriches occurred on the scolex and body surface of plerocercoids of D. latus: (i) uncinate spinitriches; (ii) coniform spinitriches; and (iii) capilliform filitriches. Non-ciliated sensory receptors were observed between the distal cytoplasm of the tegument and the underlying musculature.ConclusionsConfocal laser scanning microscopy and electron microscopy (SEM and TEM) showed the detailed microanatomy of the nervous system in the scolex of plerocercoids, and also several differences in the larval stages compared with adult D. latus. These features, i.e. well-developed glandular system and massive hook-shaped uncinate spinitriches, are thus probably required for plerocercoids inhabiting fish hosts and also for their post-infection attachment in the human intestine.
Project description:Diphyllobothriosis is a reemerging zoonotic disease because of global trade and increased popularity of eating raw fish. We present molecular evidence of host switching of a human-infecting broad fish tapeworm, Dibothriocephalus latus, and use of salmonids as intermediate or paratenic hosts and thus a source of human infection in South America.
Project description:Neurocysticercosis (NCC) is a parasitic infection of the central nervous system caused by Taenia solium larval cysts. Its epidemiology in cysticercosis-nonendemic regions is poorly understood, and the role of public health institutions is unclear. To determine the incidence of NCC and to pilot screening of household contacts for tapeworms, we conducted population-based active surveillance in Oregon. We screened for T. solium infection by examining hospital billing codes and medical charts for NCC diagnosed during January 1, 2006-December 31, 2009 and collecting fecal and blood samples from household contacts of recent case-patients. We identified 87 case-patients, for an annual incidence of 0.5 cases per 100,000 general population and 5.8 cases per 100,000 Hispanics. In 22 households, we confirmed 2 additional NCC case-patients but no current adult intestinal tapeworm infections. NCC is of clinical and public health concern in Oregon, particularly among Hispanics. Public health intervention should focus on family members because household investigations can identify additional case-patients.
Project description:Sleep is a complex and conserved biological process that affects several body functions and behaviors. Evidence suggests that there is a reciprocal interaction between sleep and immunity. For instance, fragmented sleep can increase the probability of parasitic infections and reduce the ability to fight infections. Moreover, viral and bacterial infections alter the sleep patterns of infected individuals. However, the effects of macro-parasitic infections on sleep remain largely unknown. In this study, we investigated whether macro-parasite infections could alter the sleep of their hosts. We experimentally infected three-spined sticklebacks (Gasterosteus aculeatus) with the tapeworm Schistocephalus solidus and used a hidden Markov model to characterize sleep behavior in sticklebacks. One to four days after parasite exposure, infected fish showed no difference in sleep compared with non-exposed fish, whereas fish that were exposed-but-not-infected slept less during daytime. 29-32 days after exposure, infected fish slept more than uninfected fish, while exposed-but-not-infected fish slept less than non-exposed fish. Using brain transcriptomics, we identified immune- and sleep-associated genes that potentially underlie the observed behavioral changes. These results provide insights into the complex association between macro-parasite infection, immunity, and sleep in fish and may thus contribute to a better understanding of reciprocal interactions between sleep and immunity.
Project description:We report a sheep infected with Echinococcus canadensis G8 tapeworm in China in 2018. This pathogen was previously detected in moose, elk, muskox, and mule deer in Europe and North America; our findings suggest a wider host range and geographic distribution. Surveillance for the G8 tapeworm should be conducted in China.
Project description:Taenia saginata is the most common human tapeworm worldwide but has been unknown in Myanmar. In 2017, fecal examination in Yangon, Myanmar, revealed eggs of Taenia species in 2 children from a monastic school. Several proglottids expelled after medication with praziquantel were morphologically and molecularly confirmed to be T. saginata tapeworms.
Project description:BackgroundA total number of 14 valid species of Diphyllobothrium tapeworms have been described in literature to be capable of causing diphyllobothriosis, with D. latum being the major causative agent of all human infections. However, recent data indicate that some of these infections, especially when diagnosed solely on the basis of morphology, have been identified with this causative agent incorrectly, confusing other Diphyllobothrium species with D. latum. Another widely distributed species, D. dendriticum, has never been considered as a frequent parasite of man, even though it is found commonly throughout arctic and subarctic regions parasitizing piscivorous birds and mammals. Recent cases of Europeans infected with this cestode called into question the actual geographic distribution of this tapeworm, largely ignored by medical parasitologists.Methodology and resultsOn the basis of revision of more than 900 available references and a description and revision of recent European human cases using morphological and molecular (cox1) data supplemented by newly characterized D. dendriticum sequences, we updated the current knowledge of the life-cycle, geographic distribution, epidemiological status, and molecular diagnostics of this emerging causal agent of zoonotic disease of man.ConclusionsThe tapeworm D. dendriticum represents an example of a previously neglected, probably underdiagnosed parasite of man with a potential to spread globally. Recent cases of diphyllobothriosis caused by D. dendriticum in Europe (Netherlands, Switzerland and Czech Republic), where the parasite has not been reported previously, point out that causative agents of diphyllobothriosis and other zoonoses can be imported throughout the world. Molecular tools should be used for specific and reliable parasite diagnostics, and also rare or non-native species should be considered. This will considerably help improve our knowledge of the distribution and epidemiology of these human parasites.