The global threat of neglected tropical diseases (NTDs) constitutes a public health issue in underdeveloped countries. Zoonotic helminthiases are the most common human NTD agents in developing countries in sub-Saharan Africa, Asia, and the Americas, causing a global burden of disease that exceeds that of more recognized infectious diseases such as malaria and tuberculosis. Wild canids are well-known mammals that act as natural reservoirs of zoonotic-relevant helminthiasis worldwide, thus playing a pivotal role in their epidemiology and transmission to humans. Here we evaluate the occurrence of zoonotic gastrointestinal helminths in two Neotropical wild canid species from the Amazonian and Andean regions of Colombia, i.e., the bush dog (Speothos venaticus) and the crab-eating fox (Cerdocyon thous). We recovered tapeworm proglottids from bush dog fecal samples and identified them molecularly as the canine-specific lineage of Dipylidium caninum by using cytochrome c oxidase subunit I (cox1) gene sequences. Moreover, examination of a crab-eating fox during necropsy revealed the presence of non-embryonated eggs of the neglected nematode Lagochilascaris cf. minor, in addition to eggs and gravid proglottids of the cestode Spirometra mansoni. These findings represent the first report of zoonotic-relevant cestodes, i.e., D. caninum ("canine genotype"), S. mansoni, and the nematode L. cf. minor, in bush dogs and crab-eating foxes as final hosts. The occurrence of these zoonotic helminthiases in wild canid species calls for regular monitoring programs to better understand the epidemiology and transmission routes of neglected dipylidiasis, lagochilascariosis, and sparganosis in South America.
- Publikační typ
- časopisecké články MeSH
Introduction: We developed a new simple method to assess the composition of proteinaceous components in the saliva of Ornithodoros moubata, the main vehicle for pathogen transmission and a likely source of bioactive molecules acting at the tick-vertebrate host interface. To collect naturally expectorated saliva from the ticks we employed an artificial membrane feeding technique using a simple, chemically defined diet containing phagostimulants and submitted native saliva samples collected in this way for liquid chromatography-mass spectrometry (LC-MS) analysis. These experiments were conducted with groups of uninfected ticks as well as with O. moubata infected with B. duttonii. The ticks exhibited a fair feeding response to the tested diet with engorgement rates reaching as high as 60-100% of ticks per feeding chamber. The LC-MS analysis identified a total of 17 and 15 proteins in saliva samples from the uninfected and infected O. moubata nymphs, respectively. Importantly, the analysis was sensitive enough to detect up to 9 different proteins in the samples of saliva containing diet upon which as few as 6 nymphal ticks fed during the experiments. Some of the proteins recognized in the analysis are well known for their immunomodulatory activity in a vertebrate host, whereas others are primarily thought of as structural or "housekeeping" proteins and their finding in the naturally expectorated tick saliva confirms that they can be secreted and might serve some functions at the tick-host interface. Most notably, some of the proteins that have long been suspected for their importance in the vector-pathogen interactions of Borrelia spirochetes were detected only in the samples from infected ticks, suggesting that their expression was altered by the persistent colonization of the tick's salivary glands by spirochetes. The simple method described herein is an important addition to the toolbox available to study the vector-host-pathogen interactions in the rapidly feeding soft ticks.
- MeSH
- Argasidae * MeSH
- Borrelia * fyziologie MeSH
- Ornithodoros * MeSH
- sliny MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The immune system is a complex and sophisticated biological system, spanning multiple levels of complexity, from the molecular level to that of tissue. Our current understanding of its function and complexity, of the heterogeneity of leukocytes, is a result of decades of concentrated efforts to delineate cellular markers using conventional methods of antibody screening and antigen identification. In mammalian models, this led to in-depth understanding of individual leukocyte subsets, their phenotypes, and their roles in health and disease. The field was further propelled forward by the development of single-cell (sc) RNA-seq technologies, offering an even broader and more integrated view of how cells work together to generate a particular response. Consequently, the adoption of scRNA-seq revealed the unexpected plasticity and heterogeneity of leukocyte populations and shifted several long-standing paradigms of immunology. This review article highlights the unprecedented opportunities offered by scRNA-seq technology to unveil the individual contributions of leukocyte subsets and their crosstalk in generating the overall immune responses in bony fishes. Single-cell transcriptomics allow identifying unseen relationships, and formulating novel hypotheses tailored for teleost species, without the need to rely on the limited number of fish-specific antibodies and pre-selected markers. Several recent studies on single-cell transcriptomes of fish have already identified previously unnoticed expression signatures and provided astonishing insights into the diversity of teleost leukocytes and the evolution of vertebrate immunity. Without a doubt, scRNA-seq in tandem with bioinformatics tools and state-of-the-art methods, will facilitate studying the teleost immune system by not only defining key markers, but also teaching us about lymphoid tissue organization, development/differentiation, cell-cell interactions, antigen receptor repertoires, states of health and disease, all across time and space in fishes. These advances will invite more researchers to develop the tools necessary to explore the immunology of fishes, which remain non-conventional animal models from which we have much to learn.
Myxozoans are microscopic, metazoan, obligate parasites, belonging to the phylum Cnidaria. In contrast to the free-living lifestyle of most members of this taxon, myxozoans have complex life cycles alternating between vertebrate and invertebrate hosts. Vertebrate hosts are primarily fish, although they are also reported from amphibians, reptiles, trematodes, mollusks, birds and mammals. Invertebrate hosts include annelids and bryozoans. Most myxozoans are not overtly pathogenic to fish hosts, but some are responsible for severe economic losses in fisheries and aquaculture. In both scenarios, the interaction between the parasite and the host immune system is key to explain such different outcomes of this relationship. Innate immune responses contribute to the resistance of certain fish strains and species, and the absence or low levels of some innate and regulatory factors explain the high pathogenicity of some infections. In many cases, immune evasion explains the absence of a host response and allows the parasite to proliferate covertly during the first stages of the infection. In some infections, the lack of an appropriate regulatory response results in an excessive inflammatory response, causing immunopathological consequences that are worse than inflicted by the parasite itself. This review will update the available information about the immune responses against Myxozoa, with special focus on T and B lymphocyte and immunoglobulin responses, how these immune effectors are modulated by different biotic and abiotic factors, and on the mechanisms of immune evasion targeting specific immune effectors. The current and future design of control strategies for myxozoan diseases is based on understanding this myxozoan-fish interaction, and immune-based strategies such as improvement of innate and specific factors through diets and additives, host genetic selection, passive immunization and vaccination, are starting to be considered.
- MeSH
- adaptivní imunita * MeSH
- antiparazitární látky farmakologie MeSH
- B-lymfocyty imunologie metabolismus parazitologie MeSH
- imunitní únik MeSH
- imunoglobuliny imunologie metabolismus MeSH
- interakce hostitele a parazita MeSH
- Myxozoa účinky léků imunologie patogenita MeSH
- nemoci ryb imunologie metabolismus parazitologie prevence a kontrola MeSH
- parazitární nemoci u zvířat imunologie metabolismus parazitologie prevence a kontrola MeSH
- přirozená imunita * MeSH
- ryby imunologie metabolismus parazitologie MeSH
- T-lymfocyty imunologie metabolismus parazitologie MeSH
- vakcíny farmakologie MeSH
- vodní hospodářství MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
Objectives: The potential linkage between Cryptosporidium spp. infection and colorectal human cancer was suggested by limited reports showing higher prevalence of C. parvum and C. hominis in patients with colon cancer. Here we conducted research concerning presence of Cryptosporidium spp. in malignant tissue collected from patients with colorectal cancer. Methods: Cancerous colon tissue samples collected from 145 non-HIV infected patients with colorectal cancer were screened for Cryptosporidium spp. by immunofluorescence antibody test and genus-specific nested polymerase chain reaction followed by sequencing. Results: Screened pathogen was found in cancerous tissue originating from immunocompetent man with colon adenocarcinoma. Genotyping revealed presence of Cryptosporidium meleagridis. The presence of Cryptosporidium life cycle stages (oocysts and endogenous stages) in colon carcinoma tissue was confirmed by genus-specific FITC-labeling. Conclusions: Herein, we report on a C. meleagridis infection of a colon adenocarcinoma in an immunocompetent patient. This is the first report of C. meleagridis infection in the human colon and first evidence of active development of this species in cancer tissue.
Although apicomplexan parasites of the group Piroplasmida represent commonly identified global risks to both animals and humans, detailed knowledge of their life cycles is surprisingly limited. Such a discrepancy results from incomplete literature reports, nomenclature disunity and recently, from large numbers of newly described species. This review intends to collate and summarize current knowledge with respect to piroplasm phylogeny. Moreover, it provides a comprehensive view of developmental events of Babesia, Theileria, and Cytauxzoon representative species, focusing on uniform consensus of three consecutive phases: (i) schizogony and merogony, asexual multiplication in blood cells of the vertebrate host; (ii) gamogony, sexual reproduction inside the tick midgut, later followed by invasion of kinetes into the tick internal tissues; and (iii) sporogony, asexual proliferation in tick salivary glands resulting in the formation of sporozoites. However, many fundamental differences in this general consensus occur and this review identifies variables that should be analyzed prior to further development of specific anti-piroplasm strategies, including the attractive targeting of life cycle stages of Babesia or Theileria tick vectors.
Tick-borne encephalitis virus (TBEV) is divided into three subtypes: European (TBEV-Eu), Siberian (TBEV-Sib), and Far Eastern (TBEV-FE) subtypes. The geographical range of TBEV-Eu dominates in Europe, but this subtype is present focally across the whole non-tropical forested Eurasian belt, through Russia to South Korea. However, the TBEV-Eu strains isolated outside Europe remain poorly characterized. In this study, full-genome sequences of eight TBEV-Eu isolates were determined. These strains were isolated from Ixodes persulcatus ticks, long-tailed ground squirrel (Spermophilus undulatus), and human blood in the natural foci of Western and Eastern Siberia, Russia. A phylogenetic analysis of all available TBEV-Eu genomic sequences revealed that strains from Siberia were closely related to other strains from Europe and South Korea. The closest relation was identified between the Siberian strains and strains from Zmeinogorsk (Western Siberia, Russia) and strain Absettarov (Karelia, Russia), and were most divergent from strains from the Czech Republic and Norway. TBEV-Eu strains isolated in Eastern Siberia were more closely related phylogenetically to strains from South Korea, but strains from Western Siberia grouped together with the strains from Europe, suggesting two genetic TBEV-Eu lineages present in Siberia.
- MeSH
- fylogeneze MeSH
- genom virový * MeSH
- klíště virologie MeSH
- lidé MeSH
- Sciuridae virologie MeSH
- sekvenční analýza RNA MeSH
- viry klíšťové encefalitidy genetika izolace a purifikace MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Sibiř MeSH
