Hee-Jeong Youn

In vitro antiprotozoal effects of artemisinin on Neospora caninum

Neospora caninum is an intracellular apicomplexan parasite that infects a wide range of mammals and has been associated with abortion in cattle worldwide. Artemisinin is an effective antimalarial compound derived from a traditional Chinese herbal remedy, qinghao or Artemisia annua L. In the study reported, the cultured host cells (vero cells or mouse peritoneal macrophages) infected with N. caninum tachyzoites were incubated with alpha-MEM (minimal essential medium) 10%HS supplemented with various concentration or artemisinin (20, 10, 1, 0.1 and 0.01 microg/ml) to examine the efficacy of artemisinin against N. caninum tachyzoites intracellular multiplication. In long-term studies, at 20 or 10 microg/ml for 11 days, artemisinin reduced N. caninum and completely eliminated all microscopic foci of N. caninum. At 1 microg/ml for 14 days, artemisinin reduced N. caninum and completely achieved elimination of all microscopic foci of N. caninum. There was no apparent toxicity to host cells in long-term studies. In short-term studies, at > or = 0.1microg/ml, artemisinin reduced N. caninum tachyzoites intracellular multiplication, significantly (P < 0.05) and appeared to depend on the artemisinin concentrations. Pretreatment of host cells or N. caninum tachyzoites with artemisinin had no effect on N. caninum tachyzoites intracellular multiplication. These results demonstrate that artemisinin inhibited N. caninum tachyzoites intracellular multiplication.

Review of Zoonotic Parasites in Medical and Veterinary Fields in the Republic of Korea

Zoonotic parasites are animal parasites that can infect humans. The major zoonotic protozoa in the Republic of Korea are Babesia bovis, Chilomastix mesnili, Cryptosporidium parvum, Endolimax nana, Entamoeba coli, Entamoeba hitolytica, Giardia lamblia, Iodamoeba bütschlii, Pneumocystis carinii, Sarcocystis cruzi, and Toxoplasma gondii. The major zoonotic helminths in Korea include trematodes, cestodes, and nematodes. Trematodes are Clonorchis sinensis, Echinostoma hortense, Echinostoma spp., Fasciola hepatica, Heterophyes nocens, Metagonimus yokogawai, and Paragonimus westermani. Cestodes are Diphyllobothrium latum, Dipylidium caninum, Echinococcus granulosus, Hymenolepis nana, Raillietina tetragona, sparganum (Spirometra spp.), Taenia saginata, T. solium, and T. asiatica. Nematodes are Ancylostoma caninum, Brugia malayi, Capillaria hepatica, Dirofilaria immitis, Gnathostoma dololesi, Gnathostoma spinigerum, Loa loa, Onchocerca gibsoni, Strongyloides stercoralis, Thelazia callipaeda, Trichinella spiralis, Trichostrongylus orientalis, Trichuris trichiura, and Trichuris vulpis. The one arthropod is Sarcoptes scabiei. Many of these parasites have disappeared or were in decline after the 1990s. Since the late 1990s, the important zoonotic protozoa have been C. parvum, E. nana, E. coli, E. hitolytica, G. lamblia, I. buetschlii, P. carinii and T. gondii. The important zoonotic helminths have been C. sinensis, H. nocens, M. yokogawai, P. westermani, D. latum, T. asiatica, sparganum, B. malayi, T. orientalis, T. callipaeda and T. spiralis. However, outbreaks of these parasites are only in a few endemic areas. The outbreaks of Enterobius vermicularis and head lice, human parasites, have recently increased in the kindergartens and primary schools in the Republic of Korea.

Prevalence of Bartonella henselae and Bartonella clarridgeiae in cats and dogs in Korea.

Blood, saliva, and nail samples were collected from 54 dogs and 151 cats and analyzed for the presence of Bartonella henselae with a novel nested polymerase chain reaction (PCR) method. Bartonella (B.) henselae was detected in feral cat blood (41.8%), saliva (44.1%), and nail (42.7%) samples. B. henselae was also detected in pet cat blood (33.3%), saliva (43.5%), and nail (29.5%) samples and in pet dog blood (16.6%), saliva (18.5%), and nail (29.6%) samples. Nine samples were infected with B. clarridgeiae and 2 were co-infected with B. henselae and B. clarridgeiae of blood samples of dogs. This report is the first to investigate the prevalence of B. henselae and B. clarridgeiae in dogs and cats in Korea, and suggests that dogs and cats may serve as potential Bartonella reservoirs.

Anti-protozoal efficacy of medicinal herb extracts against Toxoplasma gondii and Neospora caninum

The purpose of this study was to determine whether alcohol extracts of herbs (Sophora flavescens Aiton, Sinomenium acutum (Thunb.) Rehder and E.H. Wilson, Pulsatilla koreana (Yabe ex Nakai) Nakai ex T. Mori, Ulmus macrocarpa Hance and Torilis japonica (Houtt.) DC.) from South Korea, possess in vitro anti-protozoal activity against cultures of Toxoplasma gondii and Neospora caninum. These herbs have been used as human anti-parasitics in Asian countries for many years. Alcohol extracts of these herbs were serially diluted to final concentrations ranging from 625 to 19.5 ng/ml in media and added to wells containing either T. gondii or N. caninum tachyzoites in equine dermal (ED) cells. Parasite growth inhibition was measured using 3H-uracil incorporation as compared to untreated controls. T. japonica inhibited T. gondii proliferation by 99.3, 95.5, 73.0 and 54.0% in the range from 156 to 19.5 ng/ml, and S. flavescens inhibited T. gondii proliferation by 98.7, 83.0 and 27.2% in the range from 156 to 39 ng/ml. T. japonica inhibited N. caninum proliferation by 97.8, 97.9, 85.3 and 46.4% in the range from 156 to 19.5 ng/ml. S. flavescens inhibited N. caninum proliferation by 98.6, 97.0, 69.5 and 14.0% in the range from 156 to 19.5 ng/ml. Toxicity to host cells was noted when concentrations of T. japonica and S. flavescens exceeded 625 ng/ml. The herb extracts from S. acutum, Pulsatilla koreana, and U. macrocarpa also showed toxicity at higher levels but did not achieve the same inhibition effects at the lower concentrations against T. gondii and N. caninum as T. japonica and S. flavescens.

The First Case of Capillaria hepatica Infection in a Nutria (Myocastor coypus) in Korea

This study reports the first case of Capillaria hepatica infection in a nutria in Korea. Ten nutrias, captured near the Nakdong River, were submitted to our laboratory for necropsy. White-yellowish nodules were found in the liver of 1 of the nutrias at necropsy. Histologically, the lesions were granulomatous, and infiltrations of lipid-laden macrophages, eosinophils, and several multinucleated giant cells were observed. The lesions consisted of numerous eggs and necrotic hepatocytes. The eggs were lemon-shaped and had polar plugs at the ends of both long sides. The eggs were morphologically identified as those of C. hepatica. Worldwide, C. hepatica infection in nutrias is very rare. Nutrias are a kind of livestock, as well as wildlife; therefore, an epidemiological study for parasitic infections needs to be conducted.

Cytologic and immunohistochemical characterization of a lung carcinoid in a dog

An 11-year-old neutered male Yorkshire Terrier was presented to the Haemaru Referral Animal Hospital with a history of unresponsive tracheal collapse and an incidental finding of a lung nodule in the left caudal lung lobe on radiography. Thorough physical examination and imaging studies revealed no other masses. Cytologic examination of C-arm mobile fluoroscopy-guided fine-needle aspirates revealed numerous free nuclei and a low number of small round cells with moderate to abundant pale basophilic cytoplasm. Some cells contained indistinct basophilic granules in their cytoplasm, and extracellular pink material was noted. A caudal lung lobectomy was performed, and histologic evaluation of the mass revealed round to polygonal cells with abundant eosinophilic granular cytoplasm and round nuclei with mild anisokaryosis and 0-3 mitotic figures per high-power field. Cells were arranged in packets separated by fine fibrovascular stroma, suggestive of a pulmonary neuroendocrine neoplasm, specifically a carcinoma/carcinoid. The cells were immunoreactive for chromogranin A and neuron-specific enolase, and negative for cytokeratin, synaptophysin, calcitonin, thyroglobulin, parathyroid hormone, CD79a, light lambda, and vimentin. With these findings the tumor was diagnosed as a primary lung carcinoid. Eleven months after resection, there was no evidence of tumor regrowth or metastasis. The absence of necrosis, few mitotic figures, minimal pleomorphism, and benign behavior of this tumor resembled those of a typical carcinoid in humans.

An autochthonous case of canine visceral leishmaniasis in Korea.

A 12-year-old spayed female mixed-bred dog presented with nasal bleeding of 2 days duration and a skin nodule in the left flank. No abnormalities were found in coagulation profiles and blood pressure. Cytological evaluation of the nodule revealed numerous characteristic round organisms having a nucleus and a bar within macrophages and in the background, consistent with leishmaniasis. In vitro culture was unsuccessful but PCR of the nodular aspirate identified the organisms as Leishmania infantum, and the final diagnosis was canine leishmaniasis. No history of travel to endemic countries was noted. Because the dog had received a blood transfusion 2 years before the illness, serological screening tests were performed in all donor dogs of the commercial blood bank using the commercial Leishmania ELISA test kit, and there were no positive results. Additional 113 dogs with hyperglobulinemia from Seoul were also screened with the same kits but no positive results were obtained. To the best of the authors knowledge this is the first autochthonous case of canine leishmaniasis in Korea.

GC/MS analysis of high-performance liquid chromatography fractions from Sophora flavescens and Torilis japonica extracts and their in vitro anti-neosporal effects on Neospora caninum

We analyzed alcoholic extracts of herbs possessing anti-neosporal activity against Neospora (N.) caninum. To identify the chemical components of Sophora (S.) flavescens and Torilis (T.) japonica associated with anti-neosporal activity, specific fractions were isolated by high-performance liquid chromatography (HPLC). In vitro activity of the fractions against N. caninum was then assessed. Gas chromatography/mass spectrometry (GC/MS) was used to identify and quantify specific anti-neosporal molecules in the herbal extracts. Almost all HPLC fractions of S. flavescens and T. japonica had higher levels of anti-neosporal activity compared to the not treated control. Active constituents of the extracts were sophoridane, furosardonin A, and tetraisopropylidene-cyclobutane in S. flavescens; 5,17-β-dihydroxy-de-A-estra-5,7,9,14-tetraene, furanodiene, and 9,12-octadecadienoic acid (Z,Z)-(CAS,1) in T. japonica.