POPULATION DYNAMICS OF ENTERIC PARASITES IN THE ENDANGERED VANCOUVER ISLAND MARMOT (MARMOTA VANCOUVERENSIS).

Enteric parasites can have wide-ranging effects throughout an ecosystem, often driving coevolutionary and ecological processes. Parasites have long been overlooked in conservation efforts because of the negative impact inflicted on their hosts; however, parasites make up a significant component of Earth's biodiversity and host conservation efforts need to be parasite inclusive. The Vancouver Island marmot (VIM), Marmota vancouverensis, is an endangered alpine rodent endemic to Vancouver Island, British Columbia, Canada. Captive-bred VIMs are released to augment the wild population, but their susceptibility to parasites is unknown. The objectives of this study were to describe the diversity, prevalence, severity, and temporal variation of VIM enteric parasites. Noninvasive fecal samples were collected from wild and captive marmots and analyzed using a modified McMaster fecal egg floatation technique to indicate parasite prevalence and relative mean abundance. We identified oocysts and ova from 3 parasite taxa including a protozoan coccidium not previously described in the VIM (prevalence 68%), an ascarid nematode Baylisascaris laevis (prevalence 82%), and an anoplocephalid cestode Diandrya vancouverensis (prevalence 8%). Depending on the species, comparisons revealed variation in parasite infection by sex, by colony, and between wild and captive VIMs, but not among age classes or by female reproductive status. Finally, captive VIMs displayed significant monthly variation in parasite prevalence and mean egg abundance, suggesting a seasonal influence on parasite egg shedding. This information is critically important for future research investigating the influences of these trends on the health, ecology, and conservation of VIMs and their parasites.

Absence of blood parasites and other vector-borne pathogens in Alpine marmots (Marmota marmota) in Western Austria.

The importance of vectors and vector-borne diseases (VBDs) is increasing on a global scale. Many vectors and pathogens benefit from global warming and can spread to novel habitats where they were formerly not present, including higher altitudes. Various vector-borne pathogens (VBPs), such as Anaplasma phagocytophilum, have been reported in, for instance, red foxes and wild ungulates in the Western Austrian Alps. However, these animals are known to migrate to lower regions in the winter season, and therefore, it is of interest to investigate if VBPs are also present in mammals faithful to their higher altitude alpine habitat all year round. Blood parasites and other VBPs, namely. Trypanosomatidae, piroplasms, Hepatozoon spp., filarioid helminths, Anaplasmataceae, and Rickettisa spp., were thus analysed with PCR in 148 alpine marmots (Marmota marmota). None of the marmots' blood samples was positive for these VBPs, indicating a low abundance or absence of competent vectors in the alpine region. Alpine marmots seem to be naïve for VBPs (at least in our study area). An overview of VBD agents in other marmot species is given.

Evolutionary selection of biofilm-mediated extended phenotypes in Yersinia pestis in response to a fluctuating environment.

Yersinia pestis is transmitted from fleas to rodents when the bacterium develops an extensive biofilm in the foregut of a flea, starving it into a feeding frenzy, or, alternatively, during a brief period directly after feeding on a bacteremic host. These two transmission modes are in a trade-off regulated by the amount of biofilm produced by the bacterium. Here by investigating 446 global isolated Y. pestis genomes, including 78 newly sequenced isolates sampled over 40 years from a plague focus in China, we provide evidence for strong selection pressures on the RNA polymerase ω-subunit encoding gene rpoZ. We demonstrate that rpoZ variants have an increased rate of biofilm production in vitro, and that they evolve in the ecosystem during colder and drier periods. Our results support the notion that the bacterium is constantly adapting-through extended phenotype changes in the fleas-in response to climate-driven changes in the niche.

Higher risk of gastrointestinal parasite infection at lower elevation suggests possible constraints in the distributional niche of Alpine marmots.

Alpine marmots Marmota marmota occupy a narrow altitudinal niche within high elevation alpine environments. For animals living at such high elevations where resources are limited, parasitism represents a potential major cost in life history. Using occupancy models, we tested if marmots living at higher elevation have a reduced risk of being infected with gastro-intestinal helminths, possibly compensating the lower availability of resources (shorter feeding season, longer snow cover and lower temperature) than marmots inhabiting lower elevations. Detection probability of eggs and oncospheres of two gastro-intestinal helminthic parasites, Ascaris laevis and Ctenotaenia marmotae, sampled in marmot feces, was used as a proxy of parasite abundance. As predicted, the models showed a negative relationship between elevation and parasite detectability (i.e. abundance) for both species, while there appeared to be a negative effect of solar radiance only for C. marmotae. Site-occupancy models are used here for the first time to model the constrains of gastrointestinal parasitism on a wild species and the relationship existing between endoparasites and environmental factors in a population of free-living animals. The results of this study suggest the future use of site-occupancy models as a viable tool to account for parasite imperfect detection in eco-parasitological studies, and give useful insights to further investigate the hypothesis of the contribution of parasite infection in constraining the altitudinal niche of Alpine marmots.

[Sympatric Speciation of the Plague Microbe Yersinia pestis: Monohostal Specialization in the Host-Parasite Marmot-Flea (Marmota sibirica-Oropsylla silantiewi) System].

An ecological scenario of the origin of the plague microbe that is interpreted in the light of modern Darwinism (synthetic theory of evolution) is presented. It is shown that the plague microbe emerged from a clone of the psychrophilic saprozoonotic pseudotuberculosis microbe Yersinia pseudotuberculosis O:1b in the mountain steppe landscapes of Central Asia in the Sartan time, 22000-15000 years ago, in the monohostal Mongolian marmot (Marmota sibirica)-flea (Oropsylla silantiewi) host-parasite system. It was noted that the evolutionary process described corresponds to the sympatric form of speciation by transition ofthe clone of migrant founders to a new, already-existing ecological niche. It was established that monohostal specialization of the plague microbe was made possible due to heterothermia (5-37 degrees C) of marmots in the hibernation period. The factors of the speciation process--isolation, the struggle for existence, and natural selection--were analyzed.

The effect of anthelmintic treatment on coccidia oocyst shedding in a wild mammal host with intermittent cestode infection.

While hosts are routinely exploited by a community of parasite species, the principles governing host responses towards parasites are unclear. Identifying the health outcomes of coinfections involving helminth macroparasites and microparasites is one area of importance for public and domestic animal health. For instance, it is controversial how deworming programmes affect incidence and severity of such important microparasite diseases as malaria. One problem is that most study systems involve domestic and laboratory animals with conditions hardly comparable to those of free-living animals. Here, we study the effect of anthelmintic treatment on coccidia infection intensity in wild Alpine marmots, M. marmota. Our results lend support to the hypothesis that helminth infection has a positive effect on concurrent microparasite infection. However, our work also points to the fact that within-host interactions between helminths and microparasites are context-dependent and can turn to negative ones once helminth burdens increase. Our study suggests that coccidia benefit from intermittent helminth infection in marmots due to the protective effects of helminth infection only during the early phase of the host's active season. Also, the marmot's response towards coccidia infection appears optimal only under no helminth infection when the host immune response towards coccidia would not be compromised, thereby pointing to the importance of regular intestinal helminth elimination by marmots just before hibernation.

The effect of herbivore faeces on the edaphic mite community: implications for tapeworm transmission.

Oribatid mites may be of epidemiological and medical importance because several species have been shown to serve as intermediate hosts for anoplocephalid tapeworms of wild and domestic animals. Despite their economic and conservation significance, relatively few studies examined factors influencing the effective number of oribatid mites that can serve as intermediate hosts. We examined variation in the structure of the edaphic arthropod community in functionally different territory parts of the Alpine marmot (Marmota marmota latirostris), a known definitive host of a prevalent anoplocephalid tapeworm, Ctenotaenia marmotae. We used a field experiment to test whether the abundance of oribatid mites in marmot pastures is affected by the presence of fresh herbivore faeces. We found that the abundance of soil and litter dwelling oribatid mites in marmot pastures did not change shortly after faeces addition. In contrast, numbers of other predominant soil-litter and phoretic microarthropods increased after faeces addition. The abundance of the two predominant phoretic mites colonizing the faeces was inversely related to the abundance of oribatid mites. In contrast, the abundance of a ubiquitous soil-litter mesostigmatid mite was a positive function of oribatid numbers. Although absolute numbers of oribatid mites did not change after faeces addition, our study suggests that, depending on soil quality or type, the probability of tapeworm egg ingestion by oribatid mites can be reduced due to increased interspecific prey-predatory and trophic interactions. Latrine site selection in Alpine marmots is consistent with a reduced probability of tapeworm transmission by oribatids.

Prevalence of antibodies to Toxoplasma gondii in woodchucks across an urban-rural gradient.

Increasing urbanization has important consequences for wildlife, including the potential for higher prevalence of diseases within "urban adapter" species exposed to spillover from domestic animals. We investigated whether prevalence of antibodies to Toxoplasma gondii in woodchucks (Marmota monax) was related to urbanization in a Midwestern landscape. We collected serum samples from adult woodchucks captured across an urban-rural gradient in Illinois, USA in May-November 2007. We used an indirect fluorescent antibody test (IFAT) on the serum samples to detect T. gondii antibodies. Five of 35 (14.3%) sera from woodchucks had detectable T. gondii antibodies. Prevalence was related positively to urbanization. All positive samples were from individuals inhabiting areas in which urban land cover exceeded 70%. Urban woodchucks are likely exposed to high levels of T. gondii oocysts in the environment due to habitat overlap with the definitive hosts for the parasite, domestic and feral cats, which reach high densities in urban areas.

Toxoplasmosis in a woodchuck (Marmota monax) and two American red squirrels (Tamiasciurus hudsonicus).

Toxoplasmosis was diagnosed in a woodchuck (Marmota monax) and 2 American red squirrels (Tamiasciurus hudsonicus). The woodchuck was euthanized by a wildlife rescue organization in New York after progressive clinical signs of head tilt, circling, and rapid weight loss. Necropsy examination revealed acute subdural hemorrhage over the right cerebral hemisphere. Histologic lesions included meningoencephalitis, myocarditis, and hepatitis. Protozoal cysts were present in affected and unaffected neuroparenchyma. The squirrels were found dead, emaciated, and moderately infested with fleas near a park in northern Indiana. In both squirrels, the lungs were consolidated with numerous nodules up to 2 mm in diameter. Histologically, pneumonia and encephalitis were associated with intracellular and free protozoa. Additional histologic lesions included multifocal lymphoplasmacytic encephalitis with intralesional protozoa in both squirrels. The protozoa were positive with Toxoplasma gondii-specific immunohistochemistry and had ultrastructural features consistent with T. gondii in both squirrels. A real-time polymerase chain reaction test using T. gondii-specific probes demonstrated protozoal DNA in the lung, brain, and kidney of the squirrels and in the brain and heart of the woodchuck. To the authors' knowledge, this is the first report of toxoplasmosis in woodchucks or American red squirrels. Because rodents are common near urban settlements, this finding underscores their role as important intermediate hosts for T. gondii.

Cerebral cysticercosis in a woodchuck (Marmota monax).

A juvenile woodchuck (Marmota monax) with vestibular signs was found in Woodbridge, Ontario (Canada) and later euthanized. At necropsy there was marked distortion of the right side of the skull, where a large, fluctuant, subcutaneous mass extended under the zygomatic arch and caudally from the right eye towards the right ear. The mass was multiloculated and contained a large number of tapeworm cysticerci, each about 1 to 2 mm in diameter. The third and lateral ventricles of the brain were dilated and contained large numbers of similar cysticerci. Based on the exogenous budding of cysts and the morphology of the scolex in each cyst, they were identified as cysticerci of Taenia crassiceps. This is the first report of cerebral cysticercosis in a woodchuck.

[Two cases of hepatic helminthiasis in Marmota monax with hepatitis virus(WHV) infection]. / A propos de deux observations d'helminthoses hépatiques sur des marmottes, Marmota monax, infectées par le virus de l'hépatite virale (WHV).

Autopsy of two Woodchuck Hepatitis Virus (WHV) infected Woodchucks, Marmota monax, revealed the presence of two parasites in an hepatic localization, Taenia mustelae (Larvae) and Calodium hepaticum. The authors present the identification of the two parasites, based on the observation of cysticerci of Taenia mustelae, or on the observation of the eggs of C. hepaticum. They discuss the probable interaction between hepatic parasites and WHV infection.

Toxoplasma gondii antibodies in woodchucks (Marmota monax) from Pennsylvania.

Serum samples from 545 woodchucks Marmota monax from 22 counties in Pennsylvania were examined for antibodies to Toxoplasma gondii by the modified direct agglutination test. Fifty-one woodchucks (9.4%) had antibodies to T. gondii, with 10% at dilutions of 1:25, 2% at dilutions of 1:50, and 4% at dilutions of 1:500. This is the first report of T. gondii antibodies in woodchucks.

Trichinosis in a dog.

Trichinella spiralis infection was identified by direct fecal examination as the cause of gastrointestinal disease in a dog. The source of infection was believed to be a woodchuck. Management included supportive care and benzimidazole treatment. Vomiting, diarrhea, anorexia, and myalgia are the main signs of trichinosis, but routine fecal examination seldom reveals T spiralis in natural infections. Mebendazole is the recommended anthelmintic and should be used to eliminate intestinal larvae and prevent muscle invasion. Although the prevalence of trichinosis is decreasing in swine, wild mammals may still be a potential source for dogs and cats. Nevertheless, because of the nonspecific clinical signs of trichinosis, many cases probably go undiagnosed.

Parasites of the laboratory woodchuck (Marmota monax).

The parasite burden of captive and colony-born woodchucks maintained in laboratory animal facilities was determined and compared to woodchucks recently trapped. Microfilariae of Ackertia marmotae in blood or dermis were most commonly observed in trapped woodchucks. There was a linear decrease in woodchucks positive for microfilariae after introduction in the laboratory colony, but even after 39 months, 53% were positive. Microfilaremia or microfilariderma were never observed in colony born woodchucks. Eggs or oocysts of Obeliscoides cuniculi, Citellina triradiata and Eimeria sp. were found by fecal flotation. The O. cuniculi population declined exponentially in captive woodchucks following colony entry, and this nematode was never found in colony-born woodchucks. However, low rates of infection with Citellina and Eimeria sp. were found in the colony-born group. Ixodes cookei, Oropsylla sp., and Androlaelaps sp. ectoparasites were observed commonly in recently trapped woodchucks, but were not present in any woodchucks maintained in the colony. Clinical disease associated with parasitic infection was not observed.

Parasitic encephalitis due to Baylisascaris sp. in wild and captive woodchucks (Marmota monax).

Twelve of 102 woodchucks submitted for necropsy to the New York State College of Veterinary Medicine had clinical histories of central nervous system disorder. All had multifocal eosinophilic encephalitis with formation of granulomas. Nematode larvae, identified as Baylisascaris sp. were found in six of the 12 and were assumed to be the etiologic agent in all affected woodchucks. Both wild and captive (wild-trapped) woodchucks were affected, and all occurrences were between mid-June and early September.

Cerebrospinal Nematodiasis in a woodchuck suspected of having rabies.

A young woodchuck (Marmota monax) with a history of CNS dysfunction and abnormal behavior was submitted frozen to the Animal Disease Diagnostic Laboratory, Purdue University, as a rabies suspect. The woodchuck was negative for rabies by the fluorescent antibody test. Histologically, multifocal areas of necrosis, malacia, and inflammation were seen in sections of cerebrum, midbrain, and cerebellum, accompanied by marked perivascular cuffing with eosinophils and lymphocytes. Sections of lung contained parasitic granulomas, one of which contained a large ascarid larva identified as Baylisascaris sp. The CNS lesions were typical of parasite migration, and resembled those commonly associated with infection with Baylisascaris larvae of raccoon or skunk origin. Cerebrospinal nematodiasis was diagnosed as the cause of the nervous disorder.

Ticks of small mammals from the Hindu Kush (Afghanistan).

During the First Czechoslovak expedition to the East Hindu Kush in June-September 1965 a total of 193 hosts belonging to 12 species was examined on the presence of ticks. Specimens of the genera Ixodes, Haemaphysalis, Dermacentor and Rhipicephalus were found. Data and comments are given for the species collected.

[Oribatids (Oribatei, Acari) as intermediate hosts of Ctenotaenia marmotae (Frölich, 1802), a tapeworm parasitic in marmots (author's transl)]. / Oribatiden (Oribatei, Acari) als Zwischenwirte des Murmeltier-Banwurmes Ctenotaenia marmotae (Frölich, 1802

Out of 30 species of Oribatids (from 23 genera), which were provided with eggs of Ctenotaenia marmotae in the laboratory, 24 proved to be potential intermediate hosts. The course of development of the parasite in the intermediate host could be followed up as far as to the cysticercoid (Figs. 2-8). It largely corresponds to the development of other Anoplocephalidae. After 113 days p.i. (test temperature 18-20 degrees C) the cysticercoid stage was reached. In the Pölla valley (Carinthia), at sea level of 2,200 m, the droppings of marmots scattered on the grass andmingled with proglottids of C. marmotae were marked. 9 months later 24 grass samples were taken and examined as to infected Oribatids. Out of a total of 12,100 specimens 49 turned out to be infected with cysticercoids; these specimens, however, belong to the species of Trichoribates incisellus (Kramer) and Trichoribates trimaculatus (C.L. Koch). They were taken from 16 samples with a total of 8,400 Oribatids. This is the first evidence under natural conditions of Oribatids acting as intermediate hosts to C. marmotae. It is presumed that 2 seasonal invasion peaks occur in the final host Marmota marmota (L.).