Redescription and first molecular characterization of the little known feline neurotropic nematode Gurltia paralysans (Nematoda: Metastrongyloidea).

Gurltia paralysans is a poorly documented metastrongyloid nematode of cats, which mainly parasitizes the veins in the spinal cord subarachnoid space and parenchyma. Parasitic paraparesis caused by G. paralysans is a lesser-known spinal cord disease affecting domestic and wild felids of South America. Regions where feline gurltiosis is endemic include the southern parts of Chile and Argentina. Intra vitam diagnosis of feline gurltiosis remains challenging and is based primarily on neurological signs and the exclusion of other ethiologies for feline myelopathies. In view of the lack of information in the literature for this neglected feline neurological parasitosis, we have undertaken a detailed redescription and molecular characterization to expand on the previously available details in the original descriptions by Wolffhügel in 1993. The specimens used in this study were collected from spinal cord lesions of gurltiosis-affected domestic cats. Female and male specimens were morphologically and morphometrically examined using light and scanning electron microscopy. Molecular characterization was performed by sequencing a partial region of the nuclear ribosomal DNA and cytochrome oxidase gene of this parasite, and phylogenetic trees were constructed from the 28S D2-D3 and ITS2 regions using the Maximum Likelihood method. Sequence matching and phylogenetic analysis with these new sequences were consistent with the morphological classification of G. paralysans being within the Metastrongyloidea superfamily, but no consistent relation to a specific metastrongyloid family. The newly developed G. paralysans-specific PCR described here not only provides a useful diagnostic tool for feline gurltiosis in domestic cats living in endemic areas, but could also be used in large-scale epidemiological surveys on the intermediate mollusk host and the final host. By combining the morphology, molecular, and phylogenetic data we have reliably identified G. paralysans and confirmed its taxonomic status within the Metastrongyloidea.

Lungworm Heterostrongylus heterostrongylus Travassos, 1925 from the black-eared opossum in South America: Morphologic, histopathological and phylogenetic aspects.

Nematode parasites of the cardiopulmonary system of livestock and pet animals have been receiving attention due to the pathogenic effects they produce in the course of the infection. However, parasitism in wild animals by metastrongilid nematodes has been neglected, resulting in potential risk to wildlife. Heterostrongylus heterostrongylus is the etiological agent of bronchial pneumonia in the black-eared opossum, Didelphis aurita, a widely distributed marsupial frequently reported to inhabit areas from wild environments to peri-urban spaces. In this study, we reassessed the taxonomy of H. heterostrongylus, describing and comparing morphology of L1 and L3 larvae and adult worms with closely related angiostrongilids, and inferring phylogenetic affinities within the family Angiostrongylidae; we also detailed histopathological reactions under natural infection. Ultrastructural morphology and light microscopy confirmed cephalic structures with well-developed trilobed lips, patterns of caudal bursa rays, spicules shape, terminal anal aperture and presence of the ventral protuberance in L3 larvae, characteristics present for the family Angiostrongylidae. Our molecular phylogenetic analyses, based on the partial small subunit (SSU) 18S rRNA gene, suggested that H. heterostrongylus and Didelphostrongylus hayesi are closely related. Pathological analyses agreed with previous findings, showing that cardiopulmonary parasitism provokes verminous pneumonia and mucous bronchiolitis with hypertrophy of the smooth bronchiolar muscle. These data confirmed that H. heterostrongylus represents a pulmonary pathogen in D. aurita, produces severe pathological effects, and may represent risk to domestic and wild animals.

Human Pulmonary Infection by the Zoonotic Metastrongylus salmi Nematode. The First Reported Case in the Americas.

Pulmonary metastrongylosis, a zoonotic disease found primarily in pigs, is caused by eight different species of the cosmopolitan nematode Metastrongylus genus. To date, only four human cases have been reported, all from Europe. Herein, a severe case of pulmonary infection caused by Metastrongylus salmi in an Ecuadorian man, with successful treatment with ivermectin, is described.

Aelurostrongylus abstrusus and Troglostrongylus sp. (Nematoda: Metastrongyloidea) infections in cats inhabiting Ibiza, Spain.

Multiple species of metastrongylid lungworm (Nematoda: Metastrongyloidea) have been reported to infect members of the Felidae. This study describes two metastrongylid species infecting cats in Ibiza, Spain, including clinical features of infection and diagnosis via morphological and molecular characterisation of larval stages. Cats (n=7) presented with suspect lungworm infection, exhibiting coughing and other respiratory signs of infection. Faecal samples were collected from each cat and were subjected to the Baermann method for the detection of first stage larvae. In four cats, two different species of larvae were observed on the basis of morphology and were further molecularly characterised by PCR and sequencing of the 18S rRNA gene. Sequence data confirmed the presence of Aelurostrongylus abstrusus and an unknown species of Troglostrongylus. Molecular characterisation of Oslerus rostratus is also reported for the first time. Given the diversity of metastrongylid species capable of infecting cats, and morphological similarity of larval stages, an emphasis should be placed on the use of molecular characterisation for accurate diagnosis of infection.

A new species of Skrjabingylus Petrov, 1927 (Nematoda: Metastrongyloidea) from the frontal sinuses of the hooded skunk, Mephitis macroura (Mustelidae).

Skrjabingylus santaceciliae n. sp. is described based on specimens from the frontal sinuses of a hooded skunk, Mephitis macroura, collected from the Area de Conservación Guanacaste, Costa Rica. Skrjabingylus santaceciliae n. sp. differs from the other 5 species in the genus in having pointed spicule tips that lack a rounded or lobed formation and by lacking a prominent distal projection at the tail tip. Morphometric comparisons show that S. santaceciliae n. sp. is much smaller than the only other valid species from Mephitis, Skrjabingylus chitwoodorum Hill, 1939. Likewise, morphometric comparisons also distinguish S. santaceciliae n. sp. from other described Skrjabingylus species.

Caudal polymorphism and cephalic morphology among first-stage larvae of Parelaphostrongylus odocoilei (Protostrongylidae: Elaphostrongylinae) in Dall's sheep from the Mackenzie Mountains, Canada.

We demonstrate polymorphism in the structure of the tail among first-stage larvae of Parelaphostrongylus odocoilei (Protostrongylidae). Two distinct larvae, both with a characteristic dorsal spine, include (1) a morphotype with a kinked conical tail marked by 3 distinct transverse folds or joints and a symmetrical terminal tail spike and (2) a morphotype with a digitate terminal region lacking folds or joints and with an asymmetrical, subterminal tail spike. These divergent larval forms had been postulated as perhaps representing distinct species of elaphostrongyline nematodes. Application of a multilocus approach using ITS-2 sequences from the nuclear genome and COX-II sequences from the mitochondrial genome confirmed the identity of these larvae as P. odocoilei. Additionally, based on scanning electron microscopy (low-temperature field emission), the cephalic region of these larvae consisted of a cuticular triradiate stoma surrounded by 6 single circumoral papillae of the inner circle, 10 papillae of the outer circle (4 paired and 2 single), and 2 lateral amphids. Our's is the first demonstration of structural polymorphism among larval conspecifics in the Metastrongyloidea and Strongylida. The basis for this polymorphism remains undetermined, but such phenomena, if discovered to be more widespread, may contribute to continued confusion in discriminating among first-stage larvae for species, genera, and subfamilies within Protostrongylidae.

Carmine-propionic acid stain for elucidation of fine cellular structure in nematodes.

Carmine-propionic acid staining was found to enhance the elucidation of cellular membranes in the esophagus and genital tract and the structure of sperm in strongylate nematodes. This regressive staining technique may also have general utility for differentiation of cellular membranes and nuclear structure in other taxa of parasitic helminths.

Evidence of alae in Aelurostrongylus abstrusus larvae examined by scanning electron microscope (SEM).

Aelurostrongylus abstrusus larvae lateral alae, previously noticed in cat lung sections, are described by SEM in larvae found in the faeces of an infected cat.

Between goat-farm biological variability of the nematode Muellerius capillaris first-stage larvea. Influence of anthelmintic treatment.

Seven dairy-goat farms from the centerwest of france were investigated for morphology and ecology of first-stage larvae (L1) of Muellerius capillaris before and after treatment of goats with febantel, a probenzimidazole anthelmintic. The lengths, survivals at 20 and -20 degrees C, and infectivity of L1 to intermediate host Helix aspersa, were different between farms. The between farms differences in survivals were reduced after treatment of goats with febantel. The observed between farm differences in L1 did not seem to be related to farm characteristics (intensity of treatments, susceptibility to febantel, and intermediate host species).

Use of fenbendazole for treatment of Crenosoma vulpis infection in a dog.

An 8-month-old Labrador Retriever was examined because of a 1-month history of productive coughing unresponsive to ampicillin treatment. Larvae of Crenosoma vulpis were found in fecal samples examined by zinc sulfate centrifugation and Baermann technique. Physical examination abnormalities or larvae in fecal samples were not detected 6 weeks after treatment with prednisone (1 mg/kg, PO, q 24 h, for 7 days, then 0.5 mg/kg, PO, q 48 h, for 8 days) and fenbendazole granules (50 mg/kg, PO, q 24 h, for 3 days). This report suggests that fenbendazole may be effective for treating Crenosoma vulpis infection in dogs.

Lungworm infection in a sheep flock in Maryland.

First-stage larvae of Protostrongylus rufescens were detected in the feces of a ram with diarrhea, anorexia, weight loss, and mucopurulent nasal discharge. Subsequently, a survey was initiated in the experimental sheep flocks maintained at the Agricultural Research Service's Helminthic Diseases Laboratory in Beltsville, Md to determine the extent and effect of infection with the parasite. Five of 31 ewes and 4 of 16 rams were found to be infected with the lungworm. Clinical signs of infection, which ranged from mild to severe, included diarrhea, weight loss, and respiratory distress. Natural transmission of the parasite to parasite-naive lambs grazing on pasture occurred during the course of this study. Three lambs born to infected ewes during this study were not infected, suggesting that there is no vertical transmission. Additionally, cattle grazing the same pastures as infected sheep were not infected with the parasite. Results of this study indicated that Protostrongylus rufescens can cause serious disease in domestic sheep in the United States and should be considered as a differential diagnosis in sheep with nonspecific respiratory tract signs.

[Scanning electron microscopic observations on adults of Angiostrongylus cantonensis].

Scanning electron microscopic observations were made on adult Angiostrongylus cantonensis, The apex of the head has a round mouth with two rows of 6 sensory papillae each around it. The papillae of the outer row are more rudimentary and inconspicuous. A pair of amphidial pores are visible on the external side of lateral papillae of the inner row. The surface of the body is covered with a circular striated cuticle and short longitudinal ridges lying between two circular cuticles. The two copulatory spicules at the posterior end of male worms are obviously different in morphology. According to their morphological characteristics, we named them "tube-like" copulatory spicule and "grooves-like" copulatory spicule. The former, when enclosed in the latter, appeared as a single one. The copulatory bursa of the males and the structures of the tail part of the female are also described.

The spermatogenesis of Dictyocaulus filaria (Nematoda, Trichostrongyloidea).

A cytological study was carried out, using male Dictyocaulus filaria, that revealed the diploid number of chromosomes was 2n = 11 and the sex determining mechanism was XO. The behaviour of the chromosomes in the different stages of meiosis was also investigated. Cross, open ring and rod bivalents were observed in diakinesis. The chromosomes appeared to be acrocentric since they acquired a radial disposition in Metaphase-II. The chiasma frequency was 1 and the nucleolus-organizing region was located at the ends of the chromosomes.