Cylicospirura species (Nematoda: Spirocercidae) and stomach nodules in cougars (Puma concolor) and bobcats (Lynx rufus) in Oregon

Department of Microbiology, Oregon State University, 220 Nash Hall, Corvallis, Oregon 97331, USA.
Journal of wildlife diseases (Impact Factor: 1.36). 01/2011; 47(1):140-53. DOI: 10.7589/0090-3558-47.1.140
Source: PubMed


The stomachs and proximal duodena of 160 cougars (Puma concolor) and 17 bobcats (Lynx rufus), obtained throughout Oregon during 7 yr, were examined for Cylicospirura spp. and associated lesions. Prevalence in cougars was 73%, with a range in intensity of 1-562 worms. The mean diameter of nodules was 1.2 cm (SD=0.5), and many extended through the submucosa to the muscularis. About 83% of cougars had nodules; most nodules contained worms, but 14% of the smaller nodules (<0.2 cm) contained porcupine (Erethizon dorsatum) quills. A mean of 12.4 worms/nodule (SD=34.1) was observed, with a maximum of 340 worms/nodule. Prevalence in bobcats was 53%, with an intensity of 1-25 worms. About 65% of bobcats had nodules, which were slightly smaller than those in cougars but appeared to involve similar layers of gastrointestinal tissue. One to 25 Cylicospirura sp. were found in all but two small nodules in bobcats. Cougars killed for livestock damage or safety concerns had a significantly higher median worm intensity than did those that died of other causes. Also, the median worm intensity of older cougars was higher than that of younger lions. There were more males than females killed for livestock damage or safety concerns. The cylicospirurid from cougars was Cylicospirura subaequalis, and that of bobcats was Cylicospirura felineus. These two similar species were separated morphologically by differences in tooth and sex organ morphology. They were also differentiated by DNA sequence analysis of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1). Worm sequences from cougars differed from those from bobcats by 11%, whereas essentially no difference was found among worms from the same host. Phylogenetic analysis showed that within the order Spirurida, both cylicospirurids were most closely related to Spirocerca lupi, based on this gene sequence.

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    • "There is also a report of gastric nodule caused by S. lupi in a domestic cat in Florida, USA (Mense et al. 1992). Another parasite of the same family (Spirocercidae), Cylicospirura spp. was reported to cause similar lesions in wild Felidae (Ferguson et al. 2011). Pence & Stone (1978), on the other hand, found that aortic involvement (scarring and aneurisms) are more frequent in wild carnivores than esophageal nodules. "
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    ABSTRACT: During the necropsy of a red fox Vulpes vulpes that had died from poisoning, we found a nodule of 2 × 3 cm in size in the gastric wall, which was caused by the nematode Spirocerca lupi. The histological features of the parasite include a smooth cuticle, large chords of the hypodermis, muscle cells of the polymyarian/coelomyarian type and large intestine cells with prominent microvillus border. The nodule was infiltrating different layers of the gastric wall and consisted of granulation tissue, with various inflammatory cells and active fibroblasts. This is the first report of S. lupi infection in the red fox in Greece.
    No preview · Article · Sep 2012 · Wildlife Biology
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    • "Given the vast distances, this observation may suggest a very recent global expansion of one mitochondrial DNA haplotype, possibly explaining the observed increase in the incidence of cases. Similar to some macroparasites (Nadler, 1995; Criscione et al., 2010; Ferguson et al., 2011), S. lupi has fairly small infrapopulation sizes – based on counts in du Toit et al. (2008) and van der Merwe et al. (2008) a minimum estimate of the harmonic mean infrapopulation size is N = 6 (the harmonic mean number reflects the effective population size the best; Nadler, 1995; Hedrick, 2000). In such a small population, genetic drift will reduce genetic variation of the population of co-transmitted parasites, while increasing the genetic differences between populations of co-transmitted parasites (Nadler, 1995; Sire et al., 2001; Criscione and Blouin, 2006; Steinauer et al., 2010). "
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    ABSTRACT: The nematode worm Spirocerca lupi has a cosmopolitan distribution and can cause the death of its final canid host, typically dogs. While its life cycle, which involves a coprophagous beetle intermediate host, a number of non-obligatory vertebrate paratenic hosts and a canid final host, is well understood, surprisingly little is known about its transmission dynamics and population genetic structure. Here we sequenced cox1 to quantify genetic variation and the factors that limit gene flow in a 300 km(2) area in South Africa. Three quarters of the genetic variation, was explained by differences between worms from the same host, whereas a quarter of the variation was explained by differences between worms from different hosts. With the help of a newly derived model we conclude that while the offspring from different infrapopulations mixes fairly frequently in new hosts, the level of admixture is not enough to homogenize the parasite populations among dogs. Small infrapopulation sizes along with clumped transmission may also result in members of infrapopulations being closely related.
    Full-text · Article · Dec 2011 · Veterinary Parasitology
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    ABSTRACT: Intramural alimentary nodules in the gastric pylorus and proximal duodenum are a common finding in free-ranging pumas (Puma concolor) in North America, and are often associated with the presence of an indwelling nematode (most commonly Cylicospirura spp.). This study compares the histological, histochemical and immunohistochemical appearance of three proximal gastrointestinal nodules in pumas with four cases of eosinophilic sclerosing fibroplasia in domestic cats. Histologically, the pattern of inflammation and repair was strikingly similar, consisting of lamillated anastomosing trabeculae of dense sclerotic collagen with interspersed inflammatory cells and reactive fibroblasts. The stromal trabeculae were histologically reminiscent of osteoid and were uniformly positive for collagenous protein by Masson's trichrome stain and negative for mineralized osteoid deposits with Von Kossa's stain. Trabecular cells expressed osteonectin, but not osteocalcin immunohistochemically. Collectively, these findings are most consistent with a stroma comprised of dense collagenous trabeculae that resembles, but is distinct, from osteoid. Both the puma and domestic cat lesions demonstrated an eosinophilic inflammatory component; however, eosinophils were present in small numbers in the puma nodules relative to the nodules in domestic cats. These entities likely represent a unique and stereotypic gastrointestinal repair response of felids, given their similar histological, histochemical and immunohistochemical profiles.
    No preview · Article · Aug 2012 · Journal of comparative pathology
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