Donguk Kim

Genetic diversity of a Korean echovirus 5 isolate and response of the strain to five antiviral drugs.

An outbreak of echovirus 5 (ECV 5) occurred in Korea in 2006, marking the first time this virus had been identified in the country since enterovirus surveillance began in 1993. Using a sample isolated from a young male patient with aseptic meningitis, we performed sequencing of the Korean ECV 5 strain and compared it with a prototype strain (Noyce). At the nucleotide level, the P1 region (85.3%) had the highest identity value; at the amino acid level, the P3 region (98.0%) had the highest identity value. The two strains shared all cleavage sites, with the exception of the VP1/2A site, which was TY/GA in the Noyce strain but TR/GA in the Korean ECV 5 isolate. In Vero cells infected with the Korean ECV 5 isolate, no cytotoxicity was observed in the presence of azidothymidine, acyclovir, amantadine, lamivudine, or ribavirin, when the drugs were administered at a CC50 value >100 μg/mL. Of the five drugs, only amantadine (IC50: 1 ± 0.42 μg/mL, TI: 100) and ribavirin (IC50: 22 ± 1.36 μg/mL, TI: 4.55) had any antiviral activity against the Korean ECV 5 isolate.

Complete Genome Sequence of Rotavirus Group C Isolated in South Korea

ABSTRACT Rotavirus group C is the major etiological agent associated with acute gastroenteritis in all human age groups. Here, we report the complete genome sequence of human group C rotavirus (GpC-RV) isolated in South Korea.

Analysis of Waterborne Pathogenic Bacteria among Total Coliform Positive Samples in the Groundwater of Chungcheongnam-do Province, Korea

Chungcheongnam-do Institute of Health and Environment Research *Department of Environmental Engineering, Chungnam National University ABSTRACTObjectives: To ensure the microbiological safety of groundwater, it was confirmed whether waterbornepathogenic bacteria in groundwater samples tested positive for total coliforms in the Chungcheongnam-doProvince region. Methods: Total colony counts, total coliforms and fecal coliforms were tested according to the process mandatedby the drinking water quality testing standards of Korea. DNA was extracted from the samples, tested positivefor total coliforms, and then subjected to real-time PCR to detect waterborne pathogenic bacteria.Results: A total of 115 samples were inadequate for drinking water. Thirty-one cases (27%) showed positive forfecal coliforms and nine cases (7.8%) showed total colony counts exceeding drinking water standards. Twenty-seven cases (23.5%) showed three items (total colony counts, total coliforms and fecal coliforms). Using the real-time PCR method, waterborne pathogens were detected in 57 cases (49.6%) in 115 samples. Seventy-eight casesof waterborne pathogenic bacteria were detected (including duplications): 27 cases of pathogenic E. coli (EPEC(19), ETEC (5), EHEC (1), EAEC (1) and EIEC (1)); 45 of Bacillus cereus; two of Yersinia spp.; two ofSalmonella spp.; one of Staphylococcus aureus; one of Clostridium perfringens.Conclusion: The real-time PCR method can offer rapid and accurate detection of waterborne pathogenicbacteria. Therefore, this assay could be an alternative to conventional culture methods and can further ensure themicrobiological safety of groundwater.Keywords: Groundwater, real-time PCR, total coliforms, waterborne pathogenic bacteria

Production and characterization of VP6-specific monoclonal antibodies against bovine group C rotavirus

dehydrating diarrhea in humans and animals. The importance of group C rotavirus (GpC-RV) infections has not been established as the studies on the GpC-RV have been hampered by the lack of an in vitro culture system. However, diarrheal diseases associated with GpC-RV have been gradually increasing worldwide. In this study, VP6 gene of bovine GpC-RV Korean isolate was expressed, and monoclonal antibodies (mAbs) against VP6 were produced and characterized. The VP6 gene was cloned and expressed based on a baculovirus expression system. Indirect fluorescence antibody (IFA), polymer chain reaction (PCR), and Western blot assays were used to confirm expression of VP6 gene synthesized by the recombinant baculovirus. Eleven mAbs against VP6 were produced using expressed VP6. Cross-reactivity of the mAbs was assessed with recombinant VP6 proteins from porcine GpC-RV and human GpARV, or different serotypes of group A rotavirus strains by IFA test. Some mAbs reacted with intact porcine GpC-RV Cowden strain as well as bovine GpC-RV VP6 recombinant baculoviruses, but not with human and animal GpA-RV strains. The VP6-specific mAbs might be useful to develop immunodiagnostic tests such as rapid diagnostic kit, IFA and enzyme-linked immunosorbent assay (ELISA) for detection of GpC-RV.