• Parasites, Hosts and Diseases
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• v.42 no.2
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• pp.61-66
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• 2004

The plasmepsins are the aspartic proteases of malaria parasites. Treatment of aspartic protease inhibitor inhibits hemoglobin hydrolysis and blocks the parasite development in vitro suggesting that these proteases might be exploited their potentials as antimalarial drug targets. In this study, we determined the genetic variations of the aspartic proteases of Plasmodium vivax (PvPMs) of wild isolates. Two plasmepsins (PvPM4 and PvPM5) were cloned and sequenced from 20 P. vivax Korean isolates and two imported isolates. The sequences of the enzymes were highly conserved except a small number of amino acid substitutions did not modify key residues for the function or the structure of the enzymes. The high sequence conservations between the plasmepsins from the isolates support the notion that the enzymes could be reliable targets for new antimalarial chemotherapeutics.

• Parasites, Hosts and Diseases
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• v.42 no.2
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• pp.85-89
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• 2004

Cryptosporidium parvum oocysts were isolated from a child suffering from acute gastroenteritis and successfully passaged in a calf and mice (designated hereafter SNU-H1) in the Republic of Korea; its molecular genotype has been analyzed. The GAG microsatellite region was amplified by a polymerase chain reaction (PCR), with a 238 base pair product, which is commonly displayed in C. parvum. The isolate was shown to be a mixture of the genotypes 1 (anthroponotic) and 2 (zoonotic). To study its infectivity in animals, 2 calves and 3 strains of mice were infected with the SNU-H1; in these animals, the propagation of both genotypes was successful. In immunosup-pressed (ImSP) BALB/c and C57BU6 mice the number of oocysts decreased after day 10 post-infection (PI); but in ImSP ICR mice, they remained constant until day 27 PI. The results show that both the C. parvum genotypes 1 and 2 can be propagated in calves and ImSP mice.

• Parasites, Hosts and Diseases
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• v.46 no.1
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• pp.49-53
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• 2008

The metacercariae of Centrocestus formosanus, a minute intestinal trematode of mammals and birds, were detected in the freshwater fish, Puntius brevis, from Vientiane Municipality, Lao PDR. The metacercariae were experimentally fed to mice, and adult flukes were recovered in their small intestines 7 days later. The adult flukes were morphologically characterized by having 32 (rarely 34) circumoral spines arranged in 2 alternative rows, a large bipartite seminal vesicle, an oval-shaped ovary, and an X-shaped excretory bladder. Based on these characters, the adults were identified as Centrocestus formosanus (Nishigori, 1924). The taxonomic significance of C. formosanus, in relation to a closely related species, C. caninus (Leiper, 1913), is briefly discussed. It has been first verified by adult worm recovery that C. formosanus is prevalent in Vientiane areas of Lao PDR, taking the freshwater fish, P. brevis, as a second intermediate host.

• Parasites, Hosts and Diseases
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• v.45 no.3
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• pp.219-223
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• 2007

A case of Diphyllobothrium latum infection in a 49-year old man is described, and diphyllobothriasis latum in the Republic of Korea is briefly reviewed. An incomplete strobila of a tapeworm, 95 cm in length, without scolex and neck, was spontaneously discharged in the feces of a patient. On the basis of morphologic characteristics of the worm and eggs, the worm was identified as D. latum. The patient was successfully treated with a single dose (15 mg/kg) of praziquantel. The most probable source of infection was salmon flesh according to the past history of the patient. The first case of D. latum infection was documented in 1971, and this is the 43rd recorded case in the Republic of Korea. The 43 cases were briefly reviewed. The patients' main complaints were gastrointestinal troubles, such as mild abdominal pain, indigestion, and diarrhea, and discharge of tapeworm segments in the feces. The suspected infection sources included raw or improperly cooked flesh of fresh or brackish water fish, including the perch, mullet, salmon, and trout.

• Journal of agricultural medicine and community health
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• v.15 no.2
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• pp.107-111
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• 1990

A survey was undertaken to evaluate the present status of intestinal infection in army soldiers. Stool specimen of 417 soldiers fixed by SAF solution were collected from a camp located in area of Nakdong river during the period from August to October of 1990. And these stool samples were examined by formalin-ether sedimentation technique once for helminths and protozoan cysts stained with Lugol's iodine solution. The results obtained in this survey were summarized as follows : l) The overall positive rate of intestinal parasite was 18.0%. 2) The egg positive rate of intestinal helminth was 15.1%, : and 11.5% for Clonorchis sinensis. 5.0% for Metagonimus vokogawai, 1.2% for Ascaris lumbricoides 1.7% for Trichiuris trichiura. 0.2% for Taenia sp. 3) The cyst positive rate of intestinal protozoa was 4.1% ; and 1.4% for Entamoeba coli, 1.9% for Giardia lamblia 0.7% for Entamoeba histolytica, 0.5% for Endolimax nana. 4) Most of samples were positive(85.3%) by single species. 10.7% by two species, 2.7% by three species and 1.3% by four species. 5) Infection rate of intestinal parasites among army soldiers decreased distinctly compared with previous data but it is revealed that the infection rate of Clonorchis sinensis among army soldiers in area of Nakdong river is still high in comparison with ever-reported data. 6) SAF fixatives used in this field survey during summertime was useful to conserve protozoan cyst and helminths ova. Also we could examine stool samples directly by formalin-ether sedimentation technique.

• Parasites, Hosts and Diseases
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• v.53 no.6
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• pp.699-703
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• 2015

Cystic echinococcosis (CE) is one of the most widespread zoonotic helminthiases, which can last an asymptomatic infection for several years. The purpose of this study was to demonstrate serum antibody prevalence of CE among asymptomatic people in Uzbekistan using ELISA. A total of 2,547 serum samples were collected, 66 from confirmed CE patients and 2,481 of patients with other diseases than CE at a hospital in Tashkent, Uzbekistan. The serum samples were screened for CE specific IgG antibodies by ELISA using cystic fluid antigen obtained from sheep. The serum antibody positive rate was 89.4% (59/66) in CE and 3.6% (89/2,481) in other disease patients. The present ELISA recognized 89.4% sensitivity and 96.4% specificity. The ELISA absorbance of positive samples was distributed 0.271-0.971 for CE and 0.273-0.887 for other disease patients. The other disease patients with high absorbance over 0.3 were 50 (2.0%) who were presumed to be active CE patients. The patients in their 40s showed the highest positive rate of 5.2% (P=0.181), and women were 4.4% while men were 3.1% positive (P=0.136). The data confirmed that there are many asymptomatic patients of CE in Tashkent. It is indicated that CE is an endemic disease of public health importance in Uzbekistan.

• Journal of agricultural medicine and community health
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• v.16 no.1
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• pp.70-78
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• 1991

Antibody changes in experimental anisakiasis were observed by ELlSA and SDS-PAGE/EITB using various antigens : whole worm extract antigen(WWE), somatic antigen(SOM), excretory-secretory antign(ES), and hemoglobin antigen(HB) of Anisakis Type 1. The results obtained were as follows. l) Serum levels of IgG antibody by ELISA increased from 1st week of infection and reached their maximum titer at 5th week after infection, and decreased gradually thereafter. 2) The best result expressed as positive/negative ratio could be obtained when ES antigen was used. 3) Silver stained SDS-PAGE of each antigen showed at least 20 protein bands : In WWE, 286, 278, 262, 38, 18 Kd bands ; In SOM, 38 Kd band : In ES, 286, 65, 13 Kd bands ; In Hb, 61, 55, 38, 28, 26, 22, 20, 16, 15 Kd bands iepntibied as were major bands. 4) By EITB using WWE, Serum antibody recognized major protein with molecular weight of 86 Kd and 16 Kd. Using ES, 69, 59, 16 Kd bands were observed and using Hb, 28 Kd band was observed as specific band. In conclusion, excretory-secretory antigen(ES) of Anisakis larvae was most usable for ELISA.

• Parasites, Hosts and Diseases
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• v.42 no.1
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• pp.27-34
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• 2004

We investigated the optimal culture conditions for Cryptosporidium muris in a human stomach adenocarcinoma (AGS) cell line by determining the effects of medium pH and of selected supplements on the development of C. muris. The optimum pH of the culture medium required for the development of C. muris was determined to be 6.6. The number of parasites significantly increased during cultivation for 72 hr (p < 0.05) at this level. On the other hand, numbers decreased linearly after 24 hr of incubation at pH 7.5. When cultured in different concentrations of serum, C. muris in media containing 5% FBS induced 4-7 times more parasites than in 1% or 10% serum. Of the six medium supplements examined, only 1 mM pyruvate enhanced the number of C. muris in vitro. Transmission electron microscopic observation showed the developmental stages of C. muris in the cytoplasm of the cells, not in an extracytoplasmic location. The growth of C. muris in AGS cells provides a means of investigating its biological characteristics and of testing its response to therapeutic agents. However, a more optimized culture system is needed for the recovery of oocysts on a large scale in vitro.

• Korean Journal of Veterinary Research
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• v.46 no.1
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• pp.27-34
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• 2006

This paper describes the slaughter check results of breeding pigs from the Korean Swine Testing Station for the control of endemic diseases. Gross lesions monitored in the present study included those conditions commonly associated with economically significant subclinical herd infections: enzootic pneumonia, pleuropneumonia, pleuritis, atrophic rhinitis, liver white spots, papular dermatitis and ileitis. A total of 128 slaughter pigs were investigated at 4 subsequent tests according to the slaughter check procedures established. The prevalence of enzootic pneumonia, pleuropneumonia and pleuritis in the initial test was 67.9%, 28.6% and 17.9%, respectively. However, these were decreased to 46.7%, 6.7% and 6.7%, respectively, in the last test after implementation of counter measures including clean-up protocols and medication programs (p > 0.05). The mean pneumonic score also significantly decreased from 6.8 in the initial test to 2.8 in the last test. The prevalence of atrophic rhinitis (${\geq}score\;2$) was 32.2% and mean atrophic rhinitis score of 1.1 were recorded. However, no significant improvement of conditions was achieved with the counter measures indicating that atrophic rhinitis was originated from the source herds and lesions developed early in the life. In the initial test, prevalence of liver white spots and papular dermatitis lesions was 21.4% and 25.0%, respectively. These conditions were cleaned by the implementation of parasite control measures with all-in all-out, strict clean-up protocols and proper medications adopted in the present study (liver white spots, p = 0.0124; papular dermatitis lesions, p = 0.0055). The prevalence of ileitis lesions in slaughter pigs from the initial test was 28.6%, it could be gradually reduced by the use of repeated treatments and control measures but the effect was not so significant (p > 0.05). In conclusion, slaughter check procedures were successfully established and applied for the control of endemic diseases in the Korean Swine Testing Station.

• Journal of agricultural medicine and community health
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• v.6 no.1
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• pp.68-72
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• 1981

This study was undertaken to evaluate the status of intestinal protozoan infections in the children of specific groups. A total number of 441(male 250; female 191) consisting of 224 children of national feeble minded children institute, 59 Han-Bit blindness students, 158 children of local mental retardation children institute(Kang-Dong Ku) of specific groups were examined. The method employed was formalin-ether sedimentation technique with Lugol's iodine stain. The results were as follows: 1) The positive rates for any kinds of protozoan cysts were 13.8%(72 positives out of 441 samples) with sexual difference of 14.0% in male and 12.6% in female. 2) In the institute differences of positive rates of protozoan cysts were 15.2% in national feeble minded children institute, 16.9% in Han-Bit blindness school, and local mental retardation children institute(Kang-Dong Ku). 3) Cysts of Entamoeba coli were recovered in 8.6% and cysts of pathogenic amoeba, Entamoeba histolytica were found in 1.4%. Cysts of Endolimax nana (3.4%). Giardia lamblia (2.9%) were found in this study. 4) The degree of multiple infections of protozoan cysts were; single infection 81.4%, double infection 16.9% and quadriple infection 1.7% respectively.