A rare cardiopulmonary parasite of the European badger, Meles meles: first description of the larvae, ultrastructure, pathological changes and molecular identification of Angiostrongylus daskalovi Janchev & Genov 1988.

BACKGROUND: Angiostrongylus daskalovi is a rare cardiopulmonary nematode infecting badgers. The parasite was described in 1988 and, since then, found only once in mustelids in Europe. The present study aims to report new cases of patent A. daskalovi infection in badgers from northern Romania and to provide new information on its ultrastructure, molecular diagnosis, and pathology. METHODS: Eight road-killed or hunted badgers originating from Maramureș and Alba counties in Romania were collected and necropsied. Adults and larvae of cardio-pulmonary nematodes were collected and examined by light and scanning electron microscopy (SEM). Genomic DNA was extracted from adults and first-stage larvae (L1). PCR amplification of the internal transcribed spacer 2 (ITS2, ∼500 bp) of the rRNA gene was performed. Amplicons were purified, sequenced, and compared to those available in the GenBank database. Histopathological examination of the lungs was performed and lesions described. RESULTS: The necropsy revealed the presence of nematodes in the pulmonary arteries of three animals. All parasites were mature adults and the coproscopic examination showed the presence of eggs and L1 larvae in all three positive animals. Light microscopy examination confirmed the morphological and morphometric similarity of parasites to Angiostrongylus daskalovi. SEM highlighted the typical angiostrongylid structure of the rays of the copulatory bursa and the anterior extremity, with the presence of six sensory papillae surrounding the mouth opening in which a triangular tooth was visible. The first-stage larva (L1) of A. daskalovi is described here for the first time. Histopathological examination of the lungs showed chronic interstitial verminous pneumonia due to the presence of adult parasites. Molecular analysis showed 100 % nucleotide similarity to an Angiostrongylus sp. isolate originating from a badger from Spain, tentatively identified as A. daskalovi. CONCLUSIONS: Our study unequivocally demonstrates the presence of A. daskalovi in European badgers from Romania, provides the first description of the larvae and reveals new data about the ultrastructure of adult parasites and their pathological impact, contributing to the understanding of the phylogenetic relationships with other congeneric species.

Fatal Parastrongylus dujardini infection in captive callitrichids.

Intravascular nematodes were considered the cause of death of 14 captive callitrichids. All animals were captive born at zoos in France and died with little or no premonitory signs of disease. No consistent gross lesions were observed at necropsy, although in certain cases intracardiac adult parasites were noted. The most significant histologic findings were verminous pneumonia and pulmonary endarteritis. In all cases except one, intravascular adult nematodes were observed with eggs and larvae in the lungs. Adult nematodes were obtained from 8 animals and in all cases were identified as Parastrongylus dujardini. To the authors' knowledge, this is the first report of intravascular angiostrongylosis with primary cardiopulmonary location in callitrichids in France.

Morphological aspects of Angiostrongylus costaricensis by light and scanning electron microscopy.

Angiostrongylus costaricensis is a parasitic nematode that can cause severe gastrointestinal disease, known as abdominal angiostrongiliasis, in humans. This paper presents the characterization of first- and third-stage larvae and male and female adult worms of A. costaricensis by scanning electron and light microscopy. Several novel anatomical structures were identified by scanning electron microscopy, including details of the cuticular striations of the spicules in male worms and a protective flap of the cuticle covering the vulvar aperture in female worms. Other taxonomic features revealed by light microscopy include the gubernaculum and the esophageal-intestinal valve. The use of two microscopy techniques allowed a detailed characterization of the morphology of this nematode. A number of previously identified taxonomic features, such as the striated nature of the spicules and the lateral alae were confirmed; however, the use of scanning electron microscopy resulted in a reassessment of the correct number of papillae distributed around the oral opening and behind the cloacal opening. These observations, in combination with light microscopy-based characterization of the gubernaculum and esophageal valves, have allowed a more detailed description of this nematode taxonomy.

A new metastrongyloidean species (Nematoda) parasitizing pulmonary arteries of Puma (Herpailurus) yagouaroundi (É. Geoffroy, 1803) (Carnivora: Felidae) from Brazil.

Angiostrongylus felineus n. sp. (Nematoda, Metastrongyloidea), parasitic in Puma (Herpailurus) yagouaroundi (É. Geoffroy, 1803) (Carnivora, Felidae) from the municipality of Juiz de Fora, Minas Gerais state, Brazil, is described and illustrated herein. Angiostrongylus felineus n. sp. differs from all congeneric species by having the anterior extremity with accentuated cuticular expansion and by smaller size of spicules. This study describes for the first time a species of Angiostrongylus in a wild Felidae in Brazil.

A new angiostrongylid (Nematoda) species from the pulmonary arteries of Akodon azarae (Rodentia: Cricetidae) in Argentina.

Angiostrongylus morerai n. sp. (Nematoda: Angiostrongylidae) is described from the pulmonary arteries of Azara's grass mouse Akodon azarae (Rodentia: Cricetidae) in Argentina. It is distinguished from its congeners principally by the morphology of the dorsal ray, which is as long, or longer, than the externodorsals and has 2 long branches; the spicule lengths are also greater (400-465 microm). This is the first record of a metastrongyloid from sigmodontine rodents in Argentina.

The first record of Aelurostrongylus abstrusus (Angistrongylidae: Nematoda) in Eurasian lynx (Lynx lynx L.) from Poland based on fecal analysis.

MATERIAL: Thirty eight fecal samples of Eurasian Lynx (Lynx lynx L.) collected in Bialowieza Primeval Forest (E Poland) in years 2001-2004 were analysed. RESULTS: The presence of Aelurostrongylus abstrusus (L1) larvae was evidenced by use of decantation and flotation methods. The general prevalence of the infection recorded during the study was 21.1%, whereas mean intensity was 11,5 (1-33 larvae per sample). To our knowledge, this is the first case of Aelurostrongylus abstrusus recorded in Euroasian lynx from Poland.

In vitro cultivation of Angiostrongylus costaricensis eggs to first stage larvae in chemically defined medium.

Angiostrongylus costaricensis eggs were successfully cultured to first stage larvae in a chemically defined medium. The most suitable medium for development was Ham's F-12 among 7 chemically defined media and 10 serum supplemented media examined. The addition of serum to Ham's F-12 did not provide any further benefits for egg development. When the eggs were cultured in this medium under 8% CO2 in air, they developed and formed larvae inside the eggs 5 days later. Thereafter, the eggs began to hatch to first stage larvae. Ten days after cultivation, 34% of the eggs had developed to first stage larvae. When these first stage larvae were infected to the snail intermediate host, Biomphalaria glabrata, they developed to third stage larvae.

Scanning electron microscopic observations of first- and third-stage larvae and adults of Angiostrongylus costaricensis.

The surfaces of larval and adult Angiostrongylus costaricensis, causative agent of human abdominal granuloma, were studied by the use of scanning electron microscopy. Cuticular annulations were clearly demonstrated on the surface of larvae and adults. Differences in the appearance of alae in larval stages and in the shape of the tail at different stages of development are described and illustrated. Several aspects of morphology previously unreported for this parasite are also described.

Migratory effects on the body surface of Angiostrongylus cantonensis from subarachnoid space to pulmonary artery in rats.

Juvenile worms of Angiostrongylus cantonensis recovered from subarachnoid spaces and pulmonary arteries of rats, respectively, at 28 days post-infection have been compared with respect to their surface composition, antigenicity of surface proteins and morphological appearance. Quantitative and qualitative differences were shown between surface proteins of these two stages of worms. One major and 6 minor proteins appeared on brain stage worm's surface as assessed by surface-labelling and SDS-PAGE techniques. The same, but more predominant banding pattern, with one additional major protein of Mr 80,000 kDa presented on the lung stage worm's surface. Surface components from both stages were antigenic in permissive rat hosts but refractory in nonpermissive human hosts. The surface antigens are common to both stages within the rat. Observed by scanning electron microscopy, the surface appearance of brain stage worms is thickened, rough and irregular. Besides, particle clusters adhere randomly, without cluster adherence but transverse and longitudinal clefts were shown on the surface, before the outer layer was shed. The possible mechanisms of evasion from the host's immune attack with the surface-shedding phenomenon remain to be elucidated.

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

Scanning electron microscopic observations on the structure of the body surface of various larval stages and young adults of Angiostrongylus cantonensis were made. The mouth opening of the first and second stage larvae closes in "Y" form until well developed young adult stage. There are two rows of 6 sensory papillae each around the mouth. With development of the worm, the papillae of the outer row gradually degenerated and could hardly be seen in adult worms. A pair of amphidial pores was present on the external side of lateral papillae of the inner row, being conspicuous in the fourth-stage larvae. There was one excretory pore on the ventral side of the anterior end. The copulatory bursa of the male worms began to develop in the third stage larvae and became well developed in the 25-day young adults. The processes of the development of copulatory bursa were described. The gonopore could be seen in the female worm as early as in the first-stage larvae but the anal pore appeared only in the fourth-stage larvae, both of them did not develop completely until the young adult stage of 11 day old (Figs. 1-18).

[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.

[Angiostrongylus vasorum (Nematoda) and its migration in the small intestine (duodenum) of a dog]. / Angiostrongylus vasorum (Nematoda) bei seiner Wanderung im Intestinum tenue (Duodenum) eines Hundes.

Larvae of Angiostrongylus vasorum in the third stage of its migration through the wall of the duodenum are demonstrated histologically. Greatly dilated lymph capillaries are found here, particularly in the inner circular muscle layer.

Ultrastructural evidence for eosinophil-mediated destruction of Angiostrongylus cantonensis transferred into the pulmonary artery of non-permissive hosts.

Ultrastructural and cytochemical analyses were carried out on cellular reactions to the young adult worms of Angiostrongylus cantonensis surgically transferred into the pulmonary arteries of permissive (rat) and non-permissive (rabbit and guinea-pig) hosts. In permissive hosts, no appreciable cellular reactions could be found around worms throughout the course of the observations. By contrast, the infiltration of neutrophils along with eosinophils was observed around worms in non-permissive hosts even at early stages (days 2 to 4). At day 7 and later, the prominent degranulation (solubilization of the whole granule or the matrix alone with preserved crystalloid, tubulovesicular structure formation, and vacuole formation containing lysosomal contents, etc.) of eosinophils, and subsequent release of the lysosomal contents on to the worm surface were noted. Discharge of large amounts of peroxidase on to the worm surface was also demonstrated. The worms were thus damaged and their cuticular fragments were frequently found removed. In addition to this, degenerative changes, such as lipid-droplet and vacuole formations, were detectable in the hypodermis, somatic musculature and intestine of the parasites transferred into the non-permissive hosts, as early as day 4 after transfer. These data suggest that eosinophils would serve as a potential effector cell for killing of pulmonary arterial A. cantonensis in non-permissive hosts.