Surveillance for diseases, pathogens, and toxicants of muskrat (Ondatra zibethicus) in Pennsylvania and surrounding regions.

Using diagnostic data and contemporary sampling efforts, we conducted surveillance for a diversity of pathogens, toxicants, and diseases of muskrats (Ondatra zibethicus). Between 1977 and 2019, 26 diagnostic cases were examined from Kansas and throughout the Southeast and Mid-Atlantic, USA. We identified multiple causes of mortality in muskrats, but trauma (8/26), Tyzzer's disease (5/6), and cysticercosis (5/26) were the most common. We also conducted necropsies, during November 2018-January 2019 Pennsylvania muskrat trapping season, on 380 trapper-harvested muskrat carcasses after the pelt was removed. Tissue samples and exudate were tested for presence of or exposure to a suite of pathogens and contaminants. Gastrointestinal tracts were examined for helminths. Intestinal helminths were present in 39.2% of necropsied muskrats, with Hymenolepis spp. (62%) and echinostome spp. (44%) being the most common Molecular testing identified a low prevalence of infection with Clostridium piliforme in the feces and Sarcocystis spp. in the heart. We detected a low seroprevalence to Toxoplasma gondii (1/380). No muskrats were positive for Francisella tularensis or Babesia spp. Cysticercosis was detected in 20% (5/26) of diagnostic cases and 15% (57/380) of our trapper-harvested muskrats. Toxic concentrations of arsenic, cadmium, lead, or mercury were not detected in tested liver samples. Copper, molybdenum, and zinc concentrations were detected at acceptable levels comparative to previous studies. Parasite intensity and abundance were typical of historic reports; however, younger muskrats had higher intensity of infection than older muskrats which is contradictory to what has been previously reported. A diversity of pathogens and contaminants have been reported from muskrats, but the associated disease impacts are poorly understood. Our data are consistent with historic reports and highlight the wide range of parasites, pathogens and contaminants harbored by muskrats in Pennsylvania. The data collected are a critical component in assessing overall muskrat health and serve as a basis for understanding the impacts of disease on recent muskrat population declines.

Intestinal fluke Metagonimus yokogawai infection increases probiotic Lactobacillus in mouse cecum.

Helminth infection can alleviate immune-mediated disorders such as allergies and autoimmune diseases, by altering the gut microbiome. However, changes in gut microbiome due to intestinal trematodes remain unelucidated. Here, we evaluated the changes in the gut microbiome of ICR mice infected with Metagonimus yokogawai, a hypo-virulent intestinal trematode. Four weeks after infection, mouse cecal content was analyzed by 16S rRNA amplicon analysis. Although there was no apparent difference in species richness and diversity, the microbiome composition was different in the infected and control groups. Furthermore, several Lactobacillus species with known immunomodulatory role in immune-mediated diseases were increased in the infected group.

Trematode Aspidogastrea found in the freshwater mussels in the Yangtze River basin / Trematodos Aspidogastrea encontrados en los mejillones de agua dulce en la cuenca del río Yangtze

Objective: To investigate the prevalence of trematode Aspidogastrea in the freshwater mussels in the Yangtze River basin within Anhui province, China. Methods: We initially harvested the freshwater mussels living in the Yangtze River running through Anhui area, and labeled them with corresponding number. Then the samples were dissected for isolating the flukes, which were identified by conventional staining. Results: Infection rate of trematode Aspidogastrea in freshwater mussels in the Yangtze River basin within the territory of Anhui province was 30.38% (103/339) in general, and a total of 912 flukes of Aspidogastrea were detected in the 103 mussels, with average infection rate of 8.85 for each mussel. Conclusion: Trematode Aspidogastrea is prevalent in the freshwater bivalves living in the Yangtze River basin running through Anhui area, and the treamatode was identified as Aspidogaster sp. belong to Aspidogaste under Aspidogastridae of Aspidogastrea (AU)

Objetivo: investigar la prevalencia de trematodos Aspidogastrea en mejillones de agua dulce en la cuenca del río Yangtze en la provincia de Anhui, China. Métodos: se recogieron mejillones de agua dulce en el río Yangtze a su paso por la provincia de Anhui y se etiquetaron con su número correspondiente. Posteriormente se disecaron para aislar los trematodos por medio de tinción convencional. Resultados: la tasa de infección de trematodos en mejillones de agua dulce en la cuenca del río Yangtze, en el territorio de la provincia de Anhui fue 30,38% (103/339), en general, y un total de 912 trematodos fueron detectados en 103 mejillones, con tasa promedio de infección de 8,85 por cada mejillón. Conclusión: el trematodo Aspidogastrea es frecuente en los bivalvos de agua dulce que viven en la cuenca del río Yangtze, en la región de Anhui, y el trematodo fue identifi cado como Aspidogaster sp. pertenecen a la familia Aspidogaste bajo el género Aspidogastridae de Aspidogastrea (AU)

Investigation on the zoonotic trematode species and their natural infection status in Huainan areas of China / Investigación sobre las especies de trematodos zoonóticos y su estado natural de infección en las zonas de Huainan en China

Background: To investigate the species of zoonotic trematodes and the endemic infection status in the domestic animals in Huainan areas, north Anhui province of China, we intent to provide evidences for prevention of the parasitic zoonoses. Methods: The livestock and poultry (definitive hosts) were purchased from the farmers living in the water areas, including South Luohe, Yaohe, Jiaogang and Gaotang Lakes, and dissected the viscera of these collected hosts to obtain the parasitic samples. Then the specimens were microscopically identified, with reference to the descriptions in previous literatures for counting the zoonotic species found in these areas. Results: A total of 41 species were detected in the domestic samples, in which 23 were zoonotic trematodes, and 18 were internal trematodes of animals. Of the 41 species, 38 were novel records in Huainan areas, and 12 were newly detected in Anhui province, including Metorchis anatinus, Echinostoma hortense, E. cinetorchis, E. angustitestis, E. lindoensis, E. nordiana, E. ilocanum, Metagonimus yokogawai, Prosthogonimus gracilis, P. skrjabini, P. anatinus and Trichobilharzia sp. which generally occurred in definitive hosts of chicken, ducks, geese, dogs, cattle, buffaloes, sheep, goats and pigs, respectively. Conclusion: A large quantity of livestock and poultry are fed by the local farmers living along the river banks in Huainan area, suggesting that the population in that area are at higher risks of natural focus of zoonotic infections, since these animals are favorable definitive hosts to the zoonotic trematodes (AU)

Introducción: para investigar las especies de trematodos zoonóticos y el estado de infección endémica en los animales domésticos en áreas de Huainan, al norte de la provincia de Anhui, China, tenemos la intención de proporcionar evidencias para la prevención de enfermedades zoonóticas. Métodos: el ganado y las aves (hospedadores definitivos) fueron adquiridos a los campesinos que viven en las zonas con agua, incluyendo el sur de Luohe, Yaohe, Jiaogang y Gaotang Lagos, y se diseccionaron las vísceras de estos anfitriones recogidos para obtener las muestras parasitarias. Las muestras fueron identificadas microscópicamente, con referencia a las descripciones de la literatura revisada para contar las especies zoonóticas que se encuentran en estas áreas. Resultados: se detectaron un total de 41 especies en las muestras nacionales, de las que 23 eran trematodos zoonóticos y 18 eran trematodos internos de los animales. Estas especies representaron 22 géneros en 12 familias de 4 órdenes. De las 41 especies, 38 fueron registros nuevos en las áreas de Huainan y 12 fueron detectadas recientemente en la provincia de Anhui, incluyendo Metorchis anatinus, Echinostoma hortense, E. cinetorchis, E. angustitestis, E. lindoensis, E. nordiana, Euparyphium ilocanum, Metagonimus yokogawai, Prosthogonimus gracilis, P. skrjabini, P. anatinus y Trichobilharzia sp., generalmente producidos en huéspedes definitivos de pollo, patos, gansos, perros, vacas, búfalos, ovejas, cabras y cerdos, respectivamente. Conclusión: los agricultores locales que viven a lo largo de las orillas del río se alimentan de gran cantidad de ganado y aves de corral de la zona de Huainan, lo que sugiere que la población en esa área tiene mayor riesgo ante el foco natural de las infecciones zoonóticas, ya que estos animales son huéspedes definitivos favorables a los trematodos zoonóticos (AU)

Dactylogyrus intermedius parasitism enhances Flavobacterium columnare invasion and alters immune-related gene expression in Carassius auratus.

The monogenean Dactylogyrus intermedius and the bacterium Flavobacterium columnare are 2 common pathogens in aquaculture. The objective of the present study was to examine the effect of prior parasitism by D. intermedius on the susceptibility of goldfish to F. columnare and to explore the potential immune mechanisms related to the parasite infection. A F. columnare challenge trial was conducted between D. intermedius-parasitized and non-parasitized goldfish. The F. columnare load in gill, kidney, spleen and liver were compared. The expression of immune-related genes (IL-1ß2, TNF-α1, TGF-ß, iNOS-a, C3 and Lyz) in gill and kidney of D. intermedius-only infected and uninfected control fish were evaluated. D. intermedius-parasitized goldfish exhibited higher mortality and significantly higher loads (3051 to 537,379 genome equivalents [GEs] mg(-1)) of F. columnare, which were 1.13 to 50.82-fold higher than non-parasitized fish (389 to 17,829 GEs mg(-1)). Furthermore, the immune genes IL-1ß2, TNF-α1, iNOS-a and Lyz were up-regulated while the TGF-ß and C3 were down-regulated in the gill and kidney of parasite-infected fish compared to the non-parasitized controls. The down-regulation TGF-ß and C3 was especially noteworthy, as this might indicate the suppression of the host immune functions due to the parasitism by D. intermedius. Taken together, these data demonstrate that parasite infection can enhance bacterial invasion and presents a hypothesis, based on gene expression data, that modulation of host immune response could play a role.

Helminth.net: expansions to Nematode.net and an introduction to Trematode.net.

Helminth.net (http://www.helminth.net) is the new moniker for a collection of databases: Nematode.net and Trematode.net. Within this collection we provide services and resources for parasitic roundworms (nematodes) and flatworms (trematodes), collectively known as helminths. For over a decade we have provided resources for studying nematodes via our veteran site Nematode.net (http://nematode.net). In this article, (i) we provide an update on the expansions of Nematode.net that hosts omics data from 84 species and provides advanced search tools to the broad scientific community so that data can be mined in a useful and user-friendly manner and (ii) we introduce Trematode.net, a site dedicated to the dissemination of data from flukes, flatworm parasites of the class Trematoda, phylum Platyhelminthes. Trematode.net is an independent component of Helminth.net and currently hosts data from 16 species, with information ranging from genomic, functional genomic data, enzymatic pathway utilization to microbiome changes associated with helminth infections. The databases' interface, with a sophisticated query engine as a backbone, is intended to allow users to search for multi-factorial combinations of species' omics properties. This report describes updates to Nematode.net since its last description in NAR, 2012, and also introduces and presents its new sibling site, Trematode.net.

Individual and combined effects of multiple pathogens on Pacific treefrogs.

In nature, individual hosts often encounter multiple pathogens simultaneously, which can lead to additive, antagonistic, or synergistic effects on hosts. Synergistic effects on infection prevalence or severity could greatly affect host populations. However, ecologists and managers often overlook the influence of pathogen combinations on hosts. This is especially true in amphibian conservation, even though multiple pathogens coexist within amphibian populations, and several pathogens have been implicated in amphibian population declines and extinctions. Using an amphibian host, Pseudacris regilla (Pacific treefrog), we experimentally investigated interactive effects among three pathogens: the trematode Ribeiroia sp. (hereafter, Ribeiroia), the fungus Batrachochytrium dendrobatidis (hereafter, BD), and the water mold Achlya flagellata. We detected no effects of A. flagellata, but did find effects of Ribeiroia and BD that varied depending on context. Low doses of Ribeiroia caused relatively few malformations, while higher Ribeiroia doses caused numerous deformities dominated by missing and reduced limbs and limb elements. Exposure to low doses of BD accelerated larval host development, despite there being no detectable BD infections, while exposure to higher BD doses caused infection but did not alter developmental rate. Hosts exposed to both Ribeiroia and BD exhibited the highest mortality, although overall evidence of interactive effects of multiple pathogens was limited. We suggest further research on the influence of multi-pathogen assemblages on amphibians, particularly under a variety of ecological conditions and with a wider diversity of hosts and pathogens.

Immunology and pathology of intestinal trematodes in their definitive hosts.

This review examines the significant literature on the immunology and pathology of intestinal trematodes in their definitive hosts. We emphasize information on selected species in six families for which the literature on these topics is extensive. The families are Brachylaimidae, Diplostomidae, Echinostomatidae, Gymnophallidae, Heterophyidae, and Paramphistomidae. For most of these families, coverage is considered under the following headings: (i) background; (ii) pathology of the infection; (iii) immunology of the infection; (iv) immunodiagnosis; and (v) human infection. Some of these heading have been subdivided further, based on the literature available on a particular topic. Following this coverage, we include a final section on the important topical literature on selected trematodes in families other than the six mentioned above.

Detection of Neorickettsia (Ehrlichia) risticii in tissues of mice experimentally infected with cercariae of trematodes by in situ hybridization.

Neorickettsia (Ehrlichia) risticii was demonstrated to occur in cercariae developing in Juga yrekaensis snails by experimental transmission, genetic detection and histopathology. Cercariae were isolated from the digestive glands of snails collected in a fresh stream water area of Siskiyou County, CA, and inoculated into CF1 mice. Mice developed clinical signs, splenomegaly and histopathologic abnormalities. The agent was maintained by serial passages of whole blood in CF1 mice. A 527-bp product of the 16S rRNA gene of N. risticii was serially detected by nested PCR in blood, feces, salivary gland, suprarenal gland, spleen, intestine and bone marrow of inoculated mice. N. risticii DNA was detected by in situ hybridization with DIG-labeled probe in PCR-positive salivary gland, intestine and spleen tissue sections of experimental mice on day 30 after inoculation. Infection in mice was established when cercariae were inoculated by either IP or SC routes but not established following intraoral route. N. risticii was detected by PCR in spleen, intestine and bone marrow even after 73 days post-inoculation whereas blood from the same animals became negative at 58 days. N. risticii was observed by in situ hybridization in salivary gland, spleen and intestine of mice infected by IP or SC inoculation. This ISH protocol should aid investigations on the host range of the Neorickettsiosis and pathogenesis of neorickettiosis in vector, animal or human.

Cyclocoelum mutabile infection and aortic rupture in an American coot (Fulica americana).

An American coot (Fulica americana) was found dead within the enclosed research compound of the South Central Poultry Research Laboratory at Mississippi State, Mississippi. Gross and microscopic examinations revealed the bird to be in good body condition; however, blood from the beak cavity and external nares was present. Biliary congestion, hemopericardium, blood-filled air sacs, and a ruptured, ascending aorta were also noted. Nineteen trematodes (Cyclocoelum mutabile) were found within the body cavity at necropsy. Bacteriological examination revealed the presence of Escherichia coli in both the heart and liver and Pseudomonas putida in the liver only. No virus was isolated.