• 대한수의학회지
• /
• 제35권1호
• /
• pp.107-113
• /
• 1995

Four Holstein calves 7-day-old were infected with C parvum oocysts for parasitological and pathological investigations of bovine cryptosporidiosis. Of those calf 1 was orally administered with $7{\times}10^6$ oocysts of C parvum isolated from a Korean mouse (VRI-CN91), and calf 2 with same number of C parvum oocysts provided by Washington State University(WSU). The rest (calf 3 and 4) were orally administered with $1{\times}10^8$ oocysts of VRI-CN91 strain. Calf 1 commenced to discharge oocysts in feces at days 6 post inoculation(PI), and it reached a peak $1.4{\times}10^7$ oocysts per gram of feces(OPG) on day 8 PI. Calf 2 commenced to discharge oocysts in feces at day 4 PI, and it reached a peak $3.75{\times}10^6$ OPG on day 7 PI. Calf 3 and 4 commenced to discharge oocysts in feces at day 3 and day 4 PI, and it reached a peak on day 7 PI (calf 3, $7.8{\times}10^6$ OPG; calf 4, $1.7{\times}10^6$ OPG). Clinically, the calves began to show mucoid-watery diarrhea at day 3 to 5 PI, and the sign lasted 5 to 7 days. Calf 2 died on day 9 PI with a severe dehydration. On necropsy the intestine was found to be congested and hemorrhagic. Protozoan oocysts were observed mainly in the ileum and occasionally in jejunum. The results in the present study indicate that the Korean isolate was pathogenic in calves.

• Parasites, Hosts and Diseases
• /
• 제58권1호
• /
• pp.7-14
• /
• 2020

Toxoplasma gondii is an intracellular protozoan parasite that infects approximately one third of the human population worldwide. Considering the toxicity and side effects of anti-toxoplasma medications, it is important to develop effective drug alternatives with fewer and less severe off-target effects. In this study, we found that 4-hydroxybenzaldehyde (4-HBA) induced autophagy and the expression of NAD-dependent protein deacetylase sirtuin-1 (SIRT1) in primary murine bone marrow-derived macrophages (BMDMs). Interestingly, treatment of BMDMs with 4-HBA significantly reduced the number of macrophages infected with T. gondii and the proliferation of T. gondii in infected cells. This effect was impaired by pretreating the macrophages with 3-methyladenine or wortmannin (selective autophagy inhibitors) or with sirtinol or EX527 (SIRT1 inhibitors). Moreover, we found that pharmacological inhibition of SIRT1 prevented 4-HBA-mediated expression of LC3-phosphatidylethanolamine conjugate (LC3-II) and the colocalization of T. gondii parasitophorous vacuoles with autophagosomes in BMDMs. These data suggest that 4-HBA promotes antiparasitic host responses by activating SIRT1-mediated autophagy, and 4-HBA might be a promising therapeutic alternative for the treatment of toxoplasmosis.

• Fisheries and Aquatic Sciences
• /
• 제13권1호
• /
• pp.79-83
• /
• 2010

Since 1998, a new viral disease with high mortality has been consistently recorded in Korea in cultured carp, Cyprinus carpio. In this study, we investigated an epizootic of the disease that caused high mortality rates in carp obtained from 11 farms in Korea between 1999 and 2007. Assessment of koi herpesvirus (KHV) levels in diseased carp was carried out to determine if this virus was the etiologic agent of disease in this instance. High mortality rates in carp were recorded mainly in the spring and autumn at water temperatures between $19^{\circ}C$ and $24^{\circ}C$. Diseased fish typically showed surface discoloration, with a thick opaque mucus covering the body and gills. Protozoan parasites and bacteria were recovered from 7/29 (24%) and 2/26 (8%) of fish, respectively. Evidence of viral infection was marked; cytopathic effects (CPEs), characterized by cell rounding and an extended cytoplasm in fathead minnow (FHM) cells, were detected in 40/41 fish (98%). A high mortality rate (80%) resulted when supernatants of cell cultures showing CPEs were applied to previously healthy fish. KHV was detected by polymerase chain reaction in 6/41 fish (15%), but was not detected in supernatants obtained from cell cultures showing CPEs. These results suggest that KHV may not be the etiologic agent of the high mortality occurring among cultured carp in Korea; therefore, some other-as yet unidentified-infective agent must be responsible.

• 한국환경보건학회지
• /
• 제39권1호
• /
• pp.32-42
• /
• 2013

Objectives: Cryptosporidium, a protozoan parasite, has been recognized as a frequent cause of waterborne disease due to its extremely strong resistance against chlorine disinfection. Although there has as yet been no report of a Cryptosporidium outbreak through drinking water in Korea, it is important to estimate the health risk of Cryptosporidium in water supply systems because of the various infection cases in human and domestic animals and frequent detection reports on their oocysts in water environments. Methods: This study evaluated the annual infection risk of Cryptosporidium in tap water using the quantitative microbial risk assessment technique. Exposure assessment was performed upon the results of a national survey on Cryptosporidium on the water sources of 97 large-scale water purification plants in Korea, water treatment efficacy, and daily unboiled tap water consumption. The estimates of the US Environmental Protection Agency on the mean likelihood of infection from ingesting one oocyst were applied for effect assessment. Results: Using probabilistic methods, mean annual infection risk of Cryptosporidiosis by the intake of tap water was estimated to fall within the range of $2.3{\times}10^{-4}$ to $1.0{\times}10^{-3}$ (median $5.7{\times}10^{-4}$). The risk in using river sources was predicted to be four times higher than with lake sources. With 0.5-log higher removal efficacy, the risk was estimated to be $1.8{\times}10^{-4}$, and could then be lowered by one-third. Conclusions: These estimations can be compared with acceptable risk and then used to determine the adequacy and priority of various drinking water quality strategies such as the establishment of new treatment technology.

• 대한수의학회지
• /
• 제35권3호
• /
• pp.583-593
• /
• 1995

The present study was conducted to develop a toxoplasma latex agglutination test antigen(Test-MT) and evaluate the toxoplasma latex agglutination(LA) test using a newly-made "Test-MT kit" by comparing with the Toxo-MT kit(Eiken chemical co, Tokyo). Also, the specifity and sensitivity test were made by comparing with IFA test and IgG-ELISA. Tachyzoite suspensions of Toxoplasma gondii(RH strain) were ultracentrifuged for 30min at $60,000{\times}g(4^{\circ}C)$ and the supernatant was used as a water-lysate antigen. Polystyrene latex particles of $1.0{\mu}m$ in diameter(Polyscience co) were used for the preparation of sensitized latex-antigen supension(Test-MT). The frequency distribution of LA titers in Test-MT showed two peaks at <1:32 and 1:128. The borderline titer for positive test in Test-MT was determined to be 1:64. But the frequency distribution of LA tites in Toxo-MT showed two peaks at <1:16 and 1:64. The positive borderline was determined to be 1:32. Agreement of reactions between Test-MT and Toxo-MT kit by LA test was shown 92.5% in bovine sera and 97.0% in swine sera, respectively. From the results obtained here it was determined that the sensitized latex-antigen, Test-MT kit, for the microtiter agglutination test prepared as same as by the procedure described in the previous paper(Suh and Lee, 1993) was useful as a highly specific, sensitive and stable immunotiteration reagent for serodiagnosis of toxoplasma infection in animal sera.

• 대한수의학회지
• /
• 제51권2호
• /
• pp.107-115
• /
• 2011

Theileria (T.) buffeli (formerly T. sergenti/T. orientalis) is the major hemo-protozoan distributed in the Far East Asian countries such as Korea, China and Japan. It is responsible for the clinical symptoms of anorexia, ateliosis, anemia, fever and icterus. It also causes abortion and sudden death under severe cases, resulting in economic losses for many livestock farms. The objective of this study was to analyze the genetic diversity of the major surface protein (Msp) gene in T. buffeli in Holstein in Korea, and we characterized the association of the diversification of the Msp gene and its relationship with the pathogenicity of Theileria. For this, complete blood counts and Theileria PCR sequence analysis were performed from 57 Holstein in Jeju Island. A total of 26 PCR positive Holstein (16 anemic and 10 non-anemic) were then randomly selected based on 18s rRNA sequence typing of the Theileria Msp gene. The DNA sequence of the T. buffeli Msp gene in Holstein showed 99.0%, 99.2%, 99.9%, 99.5%, 98.7%, 98.4% and 98.4% homology with T. sergenti, Theileria spp., T. sergenti, Theileria spp., Theileria spp., Theileria spp. and Theileria spp., respectively. The result showed a genetic variation of 57.7% (type I), 3.8% (type II), 15.4% (type III), 7.7% (type IV), 13.5% (type V) and 1.9% (type VI). Type I is the most frequent type in both anemic and non-anemic Holstein while type II was found in only non-anemic Holstein. This results of our study help confirm the diversity of Msp gene types and demonstrate that the gene type distribution of Msp genes varies among Theileria-infected Holstein in Jeju Island.

• Parasites, Hosts and Diseases
• /
• 제31권4호
• /
• pp.371-374
• /
• 1993

서울 중앙시장에서 1987년 12월 부터 1988년 3월까지 구입한 무게 2-3 kg의 고양이의 장내 기생충 감염 상황을 조사하였다 포르말린-에테르 집란법을 이용한 41마리의 대변검사에서 충란이나 포낭 누적양성수 60. 양성수 31이었다. 고양이회충. 간흡충, 메타고니무스, 고양이주걱흡충(Phqwnosto cordatum), 만손열두조충(Spiromefa erinacei), 고양이조충(Taeniataenioejormis)의 충란과, Isosporaspp. (4)의 oocyst를 발견하였다. 부검한 9마리의 고양이 중 한 마리에서 고래회충(Anisakis simplex) 유충이 발견되어 우리 나라에서 첫 고양이 고래회충 유충에 의한 감염의 기록이다. 메타고니무스는 충체수집 후 요꼬가와홉충으 로 동정하였다. 이 고양이들은 인수공통감염증의 보유숙주로서 역학적인 중요성이 높다고 하겠다.

• Parasites, Hosts and Diseases
• /
• 제44권2호
• /
• pp.101-116
• /
• 2006

Vaginal trichomoniasis, caused by Trichomonas vaginalis, is the most common sexually transmitted disease. More than 170 million people worldwide are annually infected by this protozoan. In the Republic of Korea, 10.4% of women complaining of vaginal symptoms and signs were found to be infected with T. vagina/is. However, despite its high prevalence, the pathogenesis of T. vaginalis infection has not been clearly characterized although neutrophil infiltration is considered to be primarily responsible for the cytologic changes associated with this infection. We hypothesized that trichomonads in the vagina sometime after an acute infection secrete proteins like excretory-secretory product that have a chemotactic effect on neutrophils, and that these neutrophils are further stimulated by T. vaginalis to produce chemokines like IL-8 and $GRO-\alpha$, which further promote neutrophil recruitment and chemotaxis. Thus, neutrophil accumulation is believed to maintain or aggravate inflammation. However, enhanced neutrophil apoptosis induced by live T. vaginalis could contribute to resolution of inflammation. Macrophages may constitute an important component of host defense against T. vaginalis infection. For example, mouse macrophages alone and those activated by lymphokines or nitric oxide are known to be involved in the extracellular killing of T. vaginalis. In the host, T. vaginalis uses a capping phenomenon to cleave host immunoglobulins with proteinases and thus escape from host immune responses. Recently, we developed a highly sensitive and specific diagnostic polymerase chain reaction (PCR) technique using primers based on a repetitive sequence cloned from T. vaginalis (TV-E650), and found that the method enables the detection of T. vaginalis at concentrations as low as 1 cell per PCR mixture.

• Parasites, Hosts and Diseases
• /
• 제53권5호
• /
• pp.597-603
• /
• 2015

Trichomonas vaginalis is a flagellated protozoan parasite that causes vaginitis and cervicitis in women and asymptomatic urethritis and prostatitis in men. Mast cells have been reported to be predominant in vaginal smears and vaginal walls of patients infected with T. vaginalis. Mitogen-activated protein kinase (MAPK), activated by various stimuli, have been shown to regulate the transcriptional activity of various cytokine genes in mast cells. In this study, we investigated whether MAPK is involved in ROS generation and exocytotic degranulation in HMC-1 cells induced by T. vaginalis-derived secretory products (TvSP). We found that TvSP induces the activation of MAPK and NADPH oxidase in HMC-1 cells. Stimulation with TvSP induced phosphorylation of MAPK and $p47^{phox}$ in HMC-1 cells. Stimulation with TvSP also induced up-regulation of CD63, a marker for exocytosis, along the surfaces of human mast cells. Pretreatment with MAPK inhibitors strongly inhibited TvSP-induced ROS generation and exocytotic degranulation. Finally, our results suggest that TvSP induces intracellular ROS generation and exocytotic degranulation in HMC-1 via MAPK signaling.

• Parasites, Hosts and Diseases
• /
• 제46권3호
• /
• pp.153-156
• /
• 2008

One of the most common drugs used against a wide variety of anaerobic protozoan parasites is metronidazole. However, this drug is mutagenic for bacteria and is a potent carcinogen for rodents. Thymus vulgaris is used for cough suppression and relief of dyspepsia. Also it has antibacterial and antifungal properties. The aim of this study was to investigate antiamebic effect of Thymus vulgaris against Entamoeba histolytica in comparison with metronidazole. One hundred gram air-dried T. vulgaris plant was obtained and macerated at $25^{\circ}C$ for 14 days using n-hexane and a mixture of ethanol and water. For essential oil isolation T. vulgaris was subjected to hydrodistillation using a clevenger-type apparatus for 3 hr. E. histolytica, HM-1: IMSS strain was used in all experiments. It was found that the minimal inhibitory concentration (MIC) for T. vulgaris hydroalcoholic, hexanic extracts, and the essential oil after 24 hr was 4 mg/mL, 4 mg/mL, and 0.7 mg/mL, respectively. After 48 hr the MIC for T. vulgaris hydroalcoholic and hexanic extracts was 3 and 3 mg/mL, respectively. Therefore, it can be concluded that the Iranian T. vulgaris is effective against the trophozoites of E. histolytica.