• Parasites, Hosts and Diseases
• /
• v.28 no.3
• /
• pp.161-174
• /
• 1990

The complete life cycle of Spirometra erinacei has been experimentally maintained in the laboratory. The cyclops were reared as the first intermediate host, and the tadpoles of Rana nigromaculata as the second intermediate host. ICR mice were used as another second host. The experimental definitive hosts were dogs and cats. Maturation and hatching of the eggs took 8 to 14 days by incubation at 29℃. The coracidium measured 43.8×36.9㎛. Mesocyclops leuckarti and Eucyclops serrulatus were susceptible to the coracidial infection. The procercoids older than 5 days in the cyclops had minute spines at the anterior end, calcium corpuscles in the body parenchyme and the cercomer at the posterior end. Procercoids 10 to 20 days old were infective to tadpoles, and 15 or 21 day old worms could infect the mice. The plerocercoids from the tadpoles at 15 days after experimental infection were pear-shaped and shorter than 1 mm in the length and were infective to mice. Fifteen to 18 days after experiMental inoculation of plerocercoids to dogs or cats, the adult worms began to produce eggs. One life cycle from egg to egg needed 48 to 67 days in the laboratory. The morphology of larval or adult worms was compatible with the description of Spirometra erinacei.

• Parasites, Hosts and Diseases
• /
• v.38 no.3
• /
• pp.195-199
• /
• 2000

The 27 kDa cathepsin L-like cysteine protease of Spirometra erinocei plerocercoid is known to play an important function in tissue penetration, nutrient uptake and immune modulation in human sparganosis. In the present study, the expression of this enzyme was examined at different developmental stages of S. erinacei including immature egg, coracidium, plerocercoid in tadpole and rat, and adult Proteolytic activity against carboxybenzoyl-phenylalanyl-arginyl-7-amino-4-rnethylcournarin was do tooted in the extracts of coracidia and plerocercoid while no activity was observed in those of immature egg and adult. The specific activity in coraridial extracts was lower than that in the plerocercoid. Reverse transcription-polymerase chain reaction and Northern biol analysis demonstrated that the gene was expressed in the coracidium and plerocercoid but not in immature egg and adult. These results suggest that the 27 kDa cysteine protease is only expressed in the stages involving active migration of the parasite in the host tissue.

• Biomedical Science Letters
• /
• v.11 no.2
• /
• pp.153-163
• /
• 2005

To clarify the species validity of the genus Spirometra, the biological characteristics of Spirometra erinacei and S. mansonoides by developmental stages were compared. Their experimental life cycles were maintained under the same laboratory conditions, and the biological characteristics were experimentally observed in vivo and in vitro conditions. Eggs of S. erinacei and S. mansonoides were $59.6\pm35.6{\mu}m\;and\;61.4\pm35.8{\mu}m$ in each average size. Both of them became fully matured and hatched in 8 days after incubation at $29^{\circ}C$. The coracidium of S. erinacei was $43.6\times35.8{\mu}m$ in average size, and retained a oncosphere of $39.3\times31.0{\mu}m$. That of S. mansonoides was $43.0\times36.3{\mu}m$ in average size, and retained a oncosphere of $38.3\times30.8{\mu}m$. Procercoids of S. erinacei were somewhat larger than those of S. mansonoides. Both species of procercoids older than 7 days in cyclops had minute spines at the anterior end, calcium corpuscles in the parenchyme and a cercomer at the posterior end. The procercoids older than 4 days in cyclops were infective to tadpoles. The procercoids older than 8 days revealed the infectivity to mice. Plerocercoids of S. erinacei were somewhat lager than those of S. mansonoides when they were compared by age of worms in tadpoles. Both species of plerocercoids older than 5 days were infective to mice. Among 138 plerocercoids of S. erinacei recovered from the experimental mice, $55(39.9\%)$ were detected in the neck portion, $35 (25.4\%)$ in the back portion, $25(18.1\%)$ in the anterior legs, and $23 (16.7\%)$ were found in the abdomen. In case of S. mansonoides plerocercoids, $42.0\%$ were found in the neck portion, $23.8\%$ in the back portion, $14.4\%$ in the abdomen, $13.3\%$ in the anterior legs, and $6.1\%$ were found in the posterior legs. From the above results, it was confirmed that the biological characteristics of S. erinacei and S. mansonoides are almost same when their life cycles are mainteined under the same laboratory condition. Accordingly, these findings suggest that S. erinacei and S. mansonoides may be the same species.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.19 no.2
• /
• pp.155-168
• /
• 1986

In Korea, lots of Israeli carp (Cyprinus carpio) are cultured by means of net cages in dams and lakes, but many carp have been subjected to heavy infestation of the cestoid, Bothriocephalus opsariichthydis. Nevertheless the parasitic state and life history of the cestoid are not yet reported. This reason led the author to study the parasitic state and life history of B. opsariichthydis parasitized in the carp in order to take effective control measures against its damage. Israeli carp were sampled from two fish farms, in Taech'on and Kyongch'on. After dissection of the specimens, the cestoid were obtained and the parasitic rates were examined. After taking the eggs from adult worms, the development of the eggs were observed. Coracidia were exposed to four kinds of crustaceans in order to investigate the infection rate and development of the larva. Finally, tile development of the larva in the final host was investigated. The fully mature eggs were in the cleavage stage, when they are released, and the size ranged 47.5 to 55.0 $(50.9){\times}30.0$ to 32.5 (31.1) um, in the state of under-developed coracidia and blastomeres. The parasitic rate of the cestoid in Israeli carp from Taechon was $55.5\%$ in 1984 and $21.6\%$ in 1985, that from Kyongchon was $64.7\%$ in 1984, and color carp from Kusan was $14.9\%$ in 1984. The eggs were hatched to coracidia within 48 hours under 26 to $28^{\circ}C$. The cestoid showed a strong affinity to Thermocyclops hyalinus and Paracyclops fimbriatus and the infection rates were $93.5\%$ and $75.5\%$, respectively. At 14 days after the infection to Thermocyclops hyalinus and Paracyclops fimbriatus, the larvae of the cestoid grew into fully developed procercoids; 207 to $226 (214){\times}90$ to 102 (94) um in size. Sixty days after carp have ingested the Thermocyclops hyalinus infected with the fully developed procercoids, the larvae of the cestoid matured into adult worms in the intestines of the carp.

• Applied Microscopy
• /
• v.35 no.1
• /
• pp.41-56
• /
• 2005

Present study was performed to observe the tegumental ultrastructures by the developmental stages which derived from the experimental life cycle of Spirometra erinacei in laboratory conditions. In SEM view, coracidium was spherical in shape with numerous cilia, and its surface was covered with long cilia, tuberclelike projections with millet-like processes, and small holes. The body surface of procercoid was covered with numerous pointed microtriches except that of frontal pit with stout spine-like ones. However that of cercomer was covered with somewhat sparse blunt-tiped microtriches. Plerocercoids of 3 days old resembled the mature procercoid in shape, and their frontal pits were covered with numerous stout spine-like microtriches. However frontal pit and body surface in more than 5 days old ones were covered with conoid microtriches. On the surface of adult scolex, hairly long filamentous and stout short microtriches were mixedly distributed. Filamentous microtriches were more densely distributed in the anterior portion than in the posterior of scolex. The neck and immature proglottid were covered with only stout short conoid microtriches. In TEM view of coracidia, embryophore and oncosphere were obviously distinguished. The embryophore contained numerous glycogen particles, mitochondria and lipid granules. The cilia on the surface of embryophore rooted in the coracidial sheath, and consisted of 9 pairs of microtubules and 2 core complex. The oncosphere was covered with a thin and unarmed tegument, and was multi-nucleated. The protoplasmic layer of procercoid and plerocercoid consisted of disc-shaped bodies, vacuoles and mitochondria. Their tegumental cells commonly retained a nucleus, granular endoplasmic reticulums and secretory granules. The protoplasmic layer of plerocercoid was more compacted than that of procercoid. From the above results, it was confirmed that the tegumental ultrastructures are something different according to the developmental stages of S. erinacei.