• Parasites, Hosts and Diseases
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• v.61 no.3
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• pp.240-250
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• 2023

The genus Anisakis is among the most significant parasites to public health, as it causes anisakiasis, a parasitic infection in humans resulting from consuming raw or undercooked seafood. Although the infection status of Anisakis in second intermediate hosts, such as marine fishes and cephalopods, and humans have been severally reported in Korea, no information about the definitive host in Korean waters is available. In 2014, 2 adult gastric nematodes were collected from a common minke whale (Balaenoptera acutorostrata) found in the East Sea, Korea. These worms were identified as A. simplex sensu stricto (s.s.) by comparing the mitochondrial COX2 marker with previously deposited sequences. Phylogenetic and phylogeographic analyses of A. simplex (s.s.) worldwide revealed 2 distinct populations: the Pacific population and the European waters population. This is the first report on adult Anisakis and its definitive host species in Korea. Further studies on Anisakis infection in other cetacean species and marine mammals in Korean seas are warranted.

• Journal of Veterinary Clinics
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• v.40 no.4
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• pp.314-320
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• 2023

An acanthocephalan parasite, Corynosoma strumosum, was found in the intestine of harbor seal, Phoca largha, living in the East Sea, Korea. The probosci's hook and trunk spine patterns typical of the collected worms indicated it to be C. strumosum. The body lengths measured are 4.2-5.8 (4.9) mm in males and 5.3-6.8 (5.7) mm in females. The proboscis is bent ventrally, armed with 18 longitudinal rows of 9-13 hooks in males and 20 longitudinal rows of 11-13 hooks in females. The proboscis receptacle is double-walled with the robust trapezoidal neck being unarmed. The hind-trunk is pipe-shaped with posterior parallel sides. The characteristic hind trunk spines cover the anterior third of the ventral surface. The lemnisci are equal and slightly shorter than the double-walled proboscis receptacle, which is longer than the proboscis. This species is an acanthocephalan parasite reported for the first time in Korea.

• Parasites, Hosts and Diseases
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• v.61 no.2
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• pp.194-197
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• 2023

Ascaris lumbricoides causes one of the most common soil-transmitted helminthiases globally. The worms mostly infect the human small intestine and elicit negligible or nonspecific symptoms, but there are reports of extraintestinal ectopic ascariasis. We describe a rare case of biliary ascariasis mistaken for biliary stent in a 72-year-old female patient with a history of liver resection. She visited our outpatient clinic complaining of right upper quadrant pain and fever for the past week. She had previously undergone left lateral sectionectomy for recurrent biliary and intrahepatic duct stones 2 years ago. Besides mildly elevated gamma-glutamyl transferase levels, her liver function tests were normal. Magnetic resonance cholangiopancreatography revealed a linear filling defect closely resembling an internal stent from the common bile duct to the right intrahepatic bile duct. A live female A. lumbricoides adult worm was removed by endoscopic retrograde cholangiopancreatography (ERCP). Despite a significant decrease of the ascariasis prevalence in Korea, cases of biliary ascariasis are still occasionally reported. In this study, a additional case of biliary ascariasis, which was radiologically misdiagnosed as the biliary stent, was described in a hepatic resection patient by the worm recovery with ERCP in Korea.

• Parasites, Hosts and Diseases
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• v.27 no.4
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• pp.231-248
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• 1989

The growth and development of the metacercariae of F. seoulensis cultivated in vitro or on the chick chorioallantois were assessed by comparison with the optimum process of maturation in albino rats and new born chickens. The process of maturation was divided for convenience into six stages: Stage 1 ; cell multiplication, Stage 2; body shaping, Stage 3; separation of genital anlagen, Stage :1 organogeny, Stage 5; gametogony, and Stage 6: oviposition. In Hank's and Tyrode's .solutions, the metacercariae were alive up to 200 days or more at $4^{\circ}C$ without any development. The in vivo maturation process in rats or chicks was as follows: stage 1 from 6 hours; stage 2 from 24 hours; stage 3 from 48 to 72 hours; stage 4 from 3 to 4 days; stage 5 from 4 to 5 days; and stage 6 from 5 to 8 days. Despite unsuccessful infection of the metacercariae to 12 day old chicks, fully mature worms of stage 5 or 6 were recovered from new born chicks (1 to 2 days old), The metacercariae of F. seoulensis grown in vitro were up to stage 3 and no further maturation was observed. Of various media employed, the medium NCTC 109 (Gibco) or NCTC 135(Gibco) supplemented with 20% egg yolk or 20% whole egg macerate or 0.5% yeast was basically required for the earlier development of the fluke. It took 16.1 days(in average) to reach the stage 3 after cultivation. The metacercariae cultivated on the chorioallantoic membranes of 6∼13 day old chick embryo at 37∼38℃ showed their full development up to stage 5 or 6. However, the worms were in general remarkably retarded, compared with those grown in rats or chickens. In the experiments of worm transplant, although the transfer was failed from in vitro culture to in vivo of rats(Per os), the transplants from in vitro culture to the chorioallantois and from the choriollantois to in vivo of rat host were successful with or without development of the transferred worms. In the present study, it was observed that the metacercariae of F, seoulensis can be maintained in vitro media with poor development as well as fully matured in 1 to 2 day-old chicks or on the chorioallantois at a very low rate.

• Parasites, Hosts and Diseases
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• v.21 no.1
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• pp.83-86
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• 1983

A survey on the infection status of Sparganum and Gnathossoma in frogs was carried out in 11 areas in Gyeongsangnam-do and Cheonlanam-do province, a southern part of Korea. 1. Among 626 frogs examined, 4% were infected with Sparganum, but none with Gnathostoma. The infection rates of Sparganum were variable according to the areas. Those from Kimhae, Sunchon, Jinhae, Sachun, Kosung, Keoje, and Hadong were 16%, 9.1%, 9.1%, 4.1%, 2%, 2%, and 1.5% respectively, but frogs from Hapchun, Kwangju, Namwon and Sanchung were not found infected. 2. Rana nigromaculata was the only species infected with Sparganum. Rana rugesa and Bombing orientalis were not infected. 3. Sparganum was mainly found in the legs and the trunk of frog. About 92.5% of worms were detected in the femoral intermuscular connective tissue. 4. Number per infected frog was in range of one to five, and 2.8% of frogs were inacted by only one worm. 5. The heavier the frog weight, the higher the infection rate of Sparganum. In frogs of 51~60grams, 28.6% were infected.

• The Journal of the Korea Contents Association
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• v.9 no.4
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• pp.131-141
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• 2009

An increasing variety of malware, such as worms, spyware and adware, threatens both personal and business computing. Remotely controlled bot networks of compromised systems are growing quickly. This paper proposes an intrusion detection system based outflow traffic analysis. Many research efforts and commercial products have focused on preventing intrusion by filtering known exploits or unknown ones exploiting known vulnerabilities. Complementary to these solutions, the proposed IDS can detect intrusion of unknown new mal ware before their signatures are widely distributed. The proposed IDS is consists of a outflow detector, user monitor, process monitor and network monitor. To infer user intent, the proposed IDS correlates outbound connections with user-driven input at the process level under the assumption that user intent is implied by user-driven input. As a complement to existing prevention system, proposed IDS decreases the danger of information leak and protects computers and networks from more severe damage.

• Parasites, Hosts and Diseases
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• v.54 no.1
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• pp.109-112
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• 2016

We performed a molecular genetic study on the sequences of 18S ribosomal RNA (ITS1 region) gene in 4-day-old adult worms of Macroorchis spinulosus recovered in mice experimentally infected with metacercariae from crayfish in Jeollanam-do Province, Korea. The metacercariae were round, $180{\mu}m$ in average diameter, encysted with 2 layers of thick walls, but the stylet on the oral sucker was not clearly seen. The adult flukes were oval shape, and $760-820{\mu}m$ long and $320-450{\mu}m$ wide, with anterolateral location of 2 large testes. The phylogenetic tree based on ITS1 sequences of 6 M. spinulosus samples showed their distinguished position from other trematode species in GenBank. The most closely resembled group was Paragonimus spp. which also take crayfish or crabs as the second intermediate host. The present study is the first molecular characterization of M. spinulosus and provided a basis for further phylogenetic studies to compare with other trematode fauna in Korea.

• Parasites, Hosts and Diseases
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• v.54 no.1
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• pp.47-53
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• 2016

Echinostomes are intestinal trematodes that infect a wide range of vertebrate hosts, including humans, in their adult stage and also parasitize numerous invertebrate and cold-blooded vertebrate hosts in their larval stages. The purpose of this study was to compare Echinostoma malayanum parasite growth, including worm recovery, body size of adult worms, eggs per worm, eggs per gram of feces, and pathological changes in the small intestine of experimental animals. In this study, 6-8-week-old male hamsters, rats, mice, and gerbils were infected with echinostome metacercariae and then sacrificed at day 60 post-infection. The small intestine and feces of each infected animal were collected and then processed for analysis. The results showed that worm recovery, eggs per worm, and eggs per gram of feces from all infected hamsters were higher compared with infected rats and mice. However, in infected gerbils, no parasites were observed in the small intestine, and there were no parasite eggs in the feces. The volume of eggs per gram of feces and eggs per worm were related to parasite size. The results of histopathological changes in the small intestine of infected groups showed abnormal villi and goblet cells, as evidenced by short villi and an increase in the number and size of goblet cells compared with the normal control group.

• Parasites, Hosts and Diseases
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• v.54 no.1
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• pp.55-60
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• 2016

The aim of the present study is to determine the characteristics of genotype and phenotype of Echinococcus granulosus derived from wild sheep and to compare them with the strains of E. granulosus sensu stricto (sheep-dog) and E. granulosus camel strain (camel-dog) in Iran. In Khojir National Park, near Tehran, Iran, a fertile hydatid cyst was recently found in the liver of a dead wild sheep (Ovis orientalis). The number of protoscolices (n=6,000) proved enough for an experimental infection in a dog. The characteristics of large and small hooks of metacestode were statistically determined as the sensu stricto strain but not the camel strain (P=0.5). To determine E. granulosus genotype, 20 adult worms of this type were collected from the infected dog. The second internal transcribed spacer (ITS2) of the nuclear ribosomal DNA (rDNA) and cytochrome c oxidase 1 subunit (COX1) of the mitochondrial DNA were amplified from individual adult worm by PCR. Subsequently, the PCR product was sequenced by Sanger method. The lengths of ITS2 and COX1 sequences were 378 and 857 bp, respectively, for all the sequenced samples. The amplified DNA sequences from both ribosomal and mitochondrial genes were highly similar (99% and 98%, respectively) to that of the ovine strain in the GenBank database. The results of the present study indicate that the morpho-molecular features and characteristics of E. granulosus in the Iranian wild sheep are the same as those of the sheep-dog E. granulosus sensu stricto strain.

• Parasites, Hosts and Diseases
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• v.55 no.4
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• pp.421-424
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• 2017

Sparganosis is a parasitic infection caused by the sparganum, the plercercoid of the genus Spirometra. The preoperative diagnosis of breast sparganosis is difficult in most cases because it is a rare parasitic infection less than 2% of all cases. We report a 62-year-old woman case of breast sparganosis that were confirmed by surgical removal of worms from the right breast. The radiologic images of the patient also revealed characteristic features of breast sparganosis. The patient described the migrating palpable breast mass, which strongly suggested the possibility of breast sparganosis. The treatment of choice and confirmative diagnosis for sparganosis are complete surgical extraction of the sparganum irrespective of infected site. Inspection of the mass site with detailed medical history and radiological examinations are important for preoperative diagnosis of sparganosis patients.