• Ocean and Polar Research
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• v.37 no.1
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• pp.49-59
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• 2015

Spatial variation in the reproductive effort of Manila clam Ruditapes philippinarum is often closely associated with variation in the seawater temperature and food availability, which determines gonad maturity and the quantity of gamates produced during spawning. Previous studies also have reported that severe infection by the protozoan parasite Perkinsus olseni exerts a negative impact on clam reproduction, retarding gonad maturation or decreasing the reproductive effort. In the present study, we investigated impacts of P. olseni infection on the reproductive condition of Manila clam during a spawning season. Histology revealed that 54% of female clams in Wando off the south coast were in spawning, while only 10% of the female from Gomso and 0% of the female from Seonjaedo in Gyeonggi bay off the west coast were engaged in spawning at the end of May in 2004. Ray's fluid thioglycollate media (RFTM) assay was applied to assess P. olseni infection and indicated that the infection intensity in Wando ($3,608,000{\pm}258,000cells/g$ wet tissue) was significantly higher than the levels in Gomso ($1,305,000{\pm}106,000cells/g$ wet tissue) and Seonjaedo ($1,083,000{\pm}137,000cells/g$ wet tissue, p < 0.001). The size of the ripe female follicle determined from histology was significantly smaller in Wando ($0.032mm^2$) compared to the sizes in Gomso ($0.059mm^2$) and Seonjaedo ($0.052mm^2$, p < 0.05). Accordingly, the number of ripe eggs in the follicle was significantly fewer among clams in Wando (14) compared to the numbers determined in Gomso (23) and Seonjaedo (22). The absolute quantity of egg in ripe clams from Wando (31.01 mg) was also significantly smaller than Seonjaedo (61.79 mg) and Gomso (133.3 mg). Quantity of total protein, carbohydrate, and lipid in the tissue in the Wando samples was significantly smaller than the quantities determined in Gomso and Seonjaedo (p < 0.001). The observed poor reproductive condition and proximate tissue composition of the females in Wando were, in part, explained by the extremely high level of the parasites, sapping the ability to store energy in the host tissues, which is used in tissue growth and the egg production.

• Parasites, Hosts and Diseases
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• v.33 no.4
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• pp.357-364
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• 1995

The protozoan parasite, Entcmoeba histoIWticc, is one of major causative agents of intestinal disease all over the world. In acute experimental infection, the early host response to 5. histoIHtica is characterized by an infiltration of neutrophils. However, the chemotactic signal for this response is not well known. Based on the (jading that human epithelial cells produce the potent neutrophil chemoattractant and activator, interleukin-8 (IL-8), IL-8 gene expression was examined thoroughly in human colon epithelial cells exposed to 5. histolvtica trophozoites. Cellular RNAs were extracted from HT-29 or Caco-2 human colon epithelial cells exposed to 5. histoLvtica trophozoites for 30 minutes, 1 and 3 hours. IL-8 mRNA transcripts were measured by reverse transcriptional polprnerase chain reaction (RT-PCR) using synthetic standard RNA. The number of IL-8 mRNA molecules increased from 30 minutes to 3 hours of exposure period, reaching 3.1 H 107 molecules/ug of total RNA. Expression pattern of IL-8 mRNA transcripts was parallel to the amounts of IL-8 protein measured by enzyme-linked immunosorbent assay (ELISA) . Lysates of 5. histoIVtica also induced expression of mRNA for IL-8 in colon epithelial cells. These results sugf:esc that acute inflammatory reaction by 5. histoIVticc may be initially triggered by proinflammatory cytokines such as IL-8 secreted from epithelial cells of the colon.

• Parasites, Hosts and Diseases
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• v.54 no.1
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• pp.39-46
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• 2016

Theileria annulata is a tick-borne intracellular protozoan parasite that causes tropical theileriosis, a fatal bovine lymphoproliferative disease. The parasite predominantly invades bovine B lymphocytes and macrophages and induces host cell transformation by a mechanism that is not fully comprehended. Analysis of signaling pathways by quantitative real-time PCR (qPCR) could be a highly efficient means to understand this transformation mechanism. However, accurate analysis of qPCR data relies on selection of appropriate reference genes for normalization, yet few papers on T. annulata contain evidence of reference gene validation. We therefore used the geNorm and NormFinder programs to evaluate the stability of 5 candidate reference genes; 18S rRNA, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), ACTB (${\beta}-actin$), PRKG1 (protein kinase cGMP-dependent, type I) and TATA box binding protein (TBP). The results showed that 18S rRNA was the reference gene most stably expressed in bovine PBMCs transformed and non-transformed with T. annulata, followed by GAPDH and TBP. While 18S rRNA and GAPDH were the best combination, these 2 genes were chosen as references to study signaling pathways involved in the transformation mechanism of T. annulata.

• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.1-13
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• 2007

The use of aquatic species in ecotoxicity research is well established in developed countries. However, there are limitations of using the species that are not native to Korea, and the toxicity data produced by domestic test species are significantly needed to reflect the domestic situation. The purpose of this study was to investigate the domestic species that can be applicable for the aquatic toxicity assessment in Korea. Aquatic toxicity data were collected in the framework of the project 'Development of integrated methodology for evaluation of water environment' to obtain a range of test species used for aquatic toxicity assessment internationally. The test species collected were evaluated in terms of domestic distribution based on the reliable references and the advices of experts. We figured out the 71 test species native to Korea. They included 7 fish, 26 invertebrates (2 annelids, 2 bryozoa, 13 crustaceans, 3 insects, 4 mollusc, 1 platyhelminth, and 1 protozoan), 26 plants (9 diatoms, 14 green algae, 3 macrophytes), and 12 others (2 amphibians, 3 bacteria, 6 blue-green algae, and 1 fungus). The result of this study should be a very useful information for ecotoxicity assessment in aquatic ecosystem, especially in choosing the test species applicable for the ecotoxicity in Korea hereafter.

• Journal of fish pathology
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• v.3 no.2
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• pp.51-60
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• 1990

Parasites of freshwater fishes in Cheju-do were studied from May 1989 to April 1990, and incidence of infection in 16 fish species was reported. Protozoan parasites (Trichodina sp., Chilodonella sp., Ichthyophthirius sp., Vorticella sp., Myxidium sp., Myxobolus sp., Henneguya sp:, Ichthyobodo sp., and Trychophrya sp.), water mold (Saproregnia sp.), two monogenes (Dactylogyrus sp. and Gyrodactylogyrus sp.), Trematods, Cestods, Nematods, Acanthocephalas, parasitic copepods(Lernaea sp. and Pseudergasilus sp.) and a Hirudinea were recognized as freshwater fish parasites in Cheju-do. Trichodina sp. showed the highest infection rate (18.3%). Fifty seven individual fishes out of 311 were infected by this parasite. Nematods showed the second highest infection rate (13.5%). Dactylogyrus sp., Acanthocephalas, and Trematods showed the third (4.8%), fourth (4.2%), and fifth (2.6%) infection rate respectively. Of the 16 fish species Cryptocentrus filifer (Gobiidae) showed the highest infection rate. Nineteen fish out of 28 have Trichodina sp., and 14 fish out of 28 have Nematods. Those infection rates were 67.9% and 50.0% respectively. No parasites were collected from the fishes of Gwangryung vally, Dosoon-chun, Gangjeong-chun, and Hyodon-chun.

• Parasites, Hosts and Diseases
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• v.56 no.5
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• pp.419-427
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• 2018

This study aimed to develop a new multiplex real-time PCR detection method for 3 species of waterborne protozoan parasites (Cryptosporidium parvum, Giardia lamblia, and Cyclospora cayetanensis) identified as major causes of traveler's diarrhea. Three target genes were specifically and simultaneously detected by the TaqMan probe method for multiple parasitic infection cases, including Cryptosporidium oocyst wall protein for C. parvum, glutamate dehydrogenase for G. lamblia, and internal transcribed spacer 1 for C. cayetanensis. Gene product 21 for bacteriophage T4 was used as an internal control DNA target for monitoring human stool DNA amplification. TaqMan probes were prepared using 4 fluorescent dyes, $FAM^{TM}$, $HEX^{TM}$, $Cy5^{TM}$, and CAL Fluor $Red^{(R)}$ 610 on C. parvum, G. lamblia, C. cayetanensis, and bacteriophage T4, respectively. We developed a novel primer-probe set for each parasite, a primer-probe cocktail (a mixture of primers and probes for the parasites and the internal control) for multiplex real-time PCR analysis, and a protocol for this detection method. Multiplex real-time PCR with the primer-probe cocktail successfully and specifically detected the target genes of C. parvum, G. lamblia, and C. cayetanensis in the mixed spiked human stool sample. The limit of detection for our assay was $2{\times}10$ copies for C. parvum and for C. cayetanensis, while it was $2{\times}10^3$ copies for G. lamblia. We propose that the multiplex real-time PCR detection method developed here is a useful method for simultaneously diagnosing the most common causative protozoa in traveler's diarrhea.

• Parasites, Hosts and Diseases
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• v.55 no.2
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• pp.213-218
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• 2017

Most men infected with Trichomonas vaginalis are asymptomatic and can remain undiagnosed and untreated. This has been hypothesized to result in chronic persistent prostatic infection. Adhesion of the protozoan organisms to mucosal cells is considered a first and prerequisite step for T. vaginalis infection. Adhesion of T. vaginalis to prostate epithelial cells has not yet been observed; however, there are several reports about inflammation of prostate epithelial cells induced by T. vaginalis. The aim of this study was to investigate whether adhesion and cytotoxicity of T. vaginalis are involved in inflammation of prostate epithelial cells. When RWPE-1 cells were infected with T. vaginalis (1:0.4 or 1:4), adhesion of T. vaginalis continuously increased for 24 hr or 3 hr, respectively. The cytotoxicity of prostate epithelial cells infected with T. vaginalis (RWPE-1: T. vaginalis=1:0.4) increased at 9 hr; at an infection ratio of 1:4, cytotoxicity increased after 3 hr. When the RWPE-1 to T. vaginalis ratio was 1:0.4 or 1:4, production of IL-$1{\beta}$, IL-6, CCL2, and CXCL8 also increased. Epithelial-mesenchymal transition (EMT) was verified by measuring decreased E-cadherin and increased vimentin expression at 24 hr and 48 hr. Taken together, the results indicate that T. vaginalis adhered to prostate epithelial cells, causing cytotoxicity, pro-inflammatory cytokine production, and EMT. Our findings suggest for the first time that T. vaginalis may induce inflammation via adhesion to normal prostate epithelial cells.

• Journal of Food Hygiene and Safety
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• v.32 no.3
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• pp.199-205
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• 2017

Although many PCR-based assays have been developed, the majority of rapid detection of Toxoplasma gondii in animal and their meat product has been dependent on immunogenic assays. Thus, there is still a need for more reliable PCR based detection method for T. gondii in retail meats. Recently, a 529-bp repeat element that exists in 200-300 copies per genome of T. gondii genome had been spotlighted for its usefulness as potential detection targers. In this study, the 529-bp repeat element was selected for real-time PCR to detect three types of T. gondii (type I, II and III). A primer pair targeting 82-bp of the 529-bp element detected all three types of T. gondii and showed high level of specificity against 14 different food-borne pathogens as well as 3 protozoan parasites such as Giardia lamblia, Cryptosporidium parvum and Entamoeba histolytica. Application of the new real-time PCR assay in meat samples showed improved detection sensitivity compared to the B1-gene targeted method suggesting potential new target for Toxoplasma gondii screening in retail meats.

• Korean Journal of Veterinary Research
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• v.43 no.1
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• pp.157-163
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• 2003

The present study was performed to elucidate the effect of canine electroacupuncture anesthesia on vital signs and blood gas values. Groups were divided into experimental (electroacupuncture: EA) and control (ketamine) groups. The vital signs (body temperature, respiration rate and pulse) and blood gas values (pH, $pCO_2$ and $pO_2$) of venous and arterial blood were determined. Body temperatures of EA group were significant higher than than of ketamine group at 15 min., 30 min., 45min. and 60 min. (p<0.05) after anesthesia, respectively. The respiration rates of EA group were higher than those of ketamine group, however, significant differences were not observed between both groups. The pulses of EA group were significant higher than those of ketamine group at 5 min. (p<0.05), 10 min. (p<0.01), 15 min. and 30 min. (p<0.05) after anesthesia, respectively. The arterial and venous blood pHs of ketamine group were slightly higher than those of EA group, respectively, however, no significant differences were found between both groups. Significant differences were not observed between both groups in the arterial and venous blood $pCO_2$, respectively. The arterial blood $pO_2$ of EA group was significant higher than those of ketamine group at 5 min. (p<0.05) after anesthesia. No significant differences were observed between both groups in the venous blood $pO_2$. These results suggest that the changes of vital signs and blood gas values of EA group are similar to those of ketamine group with the exception of changes in the body temperature, pulse and arterial blood $pO_2$.

• Journal of agricultural medicine and community health
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• v.7 no.1
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• pp.50-56
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• 1982

This study was undertaken to evaluate the present status of parasitic infection and swine pen human latrine system in Cheju Do, from July to September 1982. The 663 stool specimens (male 323 and female 340) and 579 scotch tape anal swabs collected from 161 households of 2 areas in Cheju Do were examined. The methods employed were formalin-ether technique for the prevalence rate of various helminthic and protozoan infection, and scotch tape anal swab technique for the prevalence rates of Enterobius vermicularis. In addition to these, questionaire was used to evaluate the present status of swine pen human latrine system and prevalence rates of taeniasis in these areas. The results are as follows ; 1) Prevalence rates of parasitic infections of any kind was 33.9%. It was 35.7% in Cheju City in contrast to 32.1% in North Cheju Gun. The infection rates of Trichuris trichiura was 10.0% and it was the highest prevalence rate in this survey. The prevalence rates of the other parasites were as follows ; Ascaris lumbricoides 2,3%, Hookworm 0.2%, Clonorchis sinensis 0.5%, Hymenolepis nana 1.5%, Entamoeba coli 3.2%, and Giardia lamblia 0.5%. 2) The infection rates of Enterobius vermicularis in 579 peoples (male 285, female 294) by applying scotch tape anal swab technique was 13.1% through the survey. It was 16.9 in Cheju City and 8.5% in North Cheju Gun. 3) The Infection rate of Taenia species by applying the stool examination and making up a question was 19.2%(21.4% in Cheju City and 16.7% in North Cheju Gun). 4) Sexual distribution of the parasitic infections showed slightly higher rate in female than that of male. 5) The positive rates of parasitic infection by the stool examination and questionaire positive cases of taeniasis were higher in 0-9 and over 60 year old than any other age group. 7) The swine pen human latrine systems were used in 46 households (28.6%). 7) Relationship between swine pen human latrine system and taeniasis was not noted.