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ABSTRACT: Among the traditional fermented vegetables in Korea, Dongchimi is a type of kimchi with a large water base. We aimed to investigate the survival of norovirus surrogates during Dongchimi fermentation. Dongchimi spiked with feline calicivirus (FCV) or murine norovirus (MNV) was prepared following a traditional recipe. Dongchimi was initially fermented at room temperature overnight and then kept at 4 °C. The number of lactic acid bacteria, pH, acidity, and virus titer were measured 0, 1, 2, 3, 5, 7, 10, 15, 20 days after fermentation. During the fermentation process, lactic acid bacteria and acidity increased. At the end of the fermentation, population of FCV and MNV decreased about 4.12 and 1.47 log units, respectively. Based on the significant reduction of norovirus surrogate during Dongchimi fermentation, we conclude that the risk of norovirus in Dongchimi may be low.
Food Microbiology 09/2012; 31(2):210-4. · 3.28 Impact Factor
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ABSTRACT: This study aimed to develop a specific and sensitive reverse transcription polymerase chain reaction enzyme-linked immunosorbent assay (RT-PCR-ELISA) for detecting hepatitis E virus (HEV). Eight sets of primers and biotinylated probes designed in the ORF2-ORF3 overlapping region of HEV were tested for sensitivity. The ability of nested reverse transcription polymerase chain reaction (RT-PCR) and RT-PCR-ELISA to detect HEV was compared. RT-PCR-ELISA was 10-100 times more sensitive than nested RT-PCR and could detect 0.01 ng/μl HEV in swine stool samples. In terms of specificity, RT-PCR-ELISA did not falsely detect HEV when other viruses such as hepatitis A virus, rotavirus, norovirus genotype I, norovirus genotype II, and Feline calicivirus were present. Therefore, RT-PCR-ELISA appears to be a sensitive and specific method for detecting HEV.
Food and Environmental Virology 03/2012; 4(1):14-20. · 1.56 Impact Factor
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ABSTRACT: This study was conducted to determine the concentration and optimal treatment time of chlorine for reducing feline calicivirus (FCV) and murine norovirus (MNV) as surrogates of norovirus (NoV) on stainless steel surfaces and to develop a predictive inactivation method using a response surface methodology. The reduction levels of FCV VR-782 and MNV on stainless steel surfaces after treatment with various concentrations of chlorine (0 to 5,000 ppm) for various times (0 to 5 min) were measured. The reduction values of both FCV and MNV on stainless steel surfaces after 5,000 ppm of chlorine treatment for 5 min were 5.20 TCID(50) per coupon. The predictive results obtained by central composite design were analyzed by standard analysis of variance. The application of multiple regression analysis was related to the following polynomial equations: (i) FCV (log TCID(50) per coupon) = -0.3714 + 0.8362x(1) + 0.0011x(2) + 0.0001x(1)x(2) - 0.1143x(2)(1) -0.0001x(2)(2) (x(1), time; x(2), concentration) and (ii) MNV (log TCID(50) per coupon) = + 0.0471 + 0.0807x(1) + 0.0011x(2) + 0.0001x(1)x(2) -0.0910x(2)(1) -0.0001x(2)(2) (x(1), time; x(2), concentration). It was concluded that these polynomial equation models of reduction of FCV and MNV could be used to determine the minimum concentration of chlorine and exposure times to control human NoV on food contact surfaces.
Journal of food protection 01/2012; 75(1):184-8. · 1.94 Impact Factor
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ABSTRACT: This study aimed to develop a specific and sensitive duplex reverse transcription polymerase chain reaction enzyme-linked immunosorbent assay (duplex RT-PCR-ELISA) for hepatitis A virus (HAV) and hepatitis E virus (HEV). Duplex RT-PCR-ELISA could detect and differentiate HAV and HEV with specific probes. When ELISA technique was used to detect probe-bound RT-PCR products, duplex RT-PCR-ELISA could detect as little as 0.1 ng/μL HAV and HEV from clinical samples. Human norovirus, enterovirus, poliovirus, murine norovirus and feline calicivirus were used for the specificity test; all were negative. Therefore duplex RT-PCR-ELISA can be used for the simultaneous detection of HAV and HEV in contaminated fecal samples.
Journal of virological methods 07/2011; 175(1):137-40. · 2.13 Impact Factor
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ABSTRACT: The prevalence of asymptomatic norovirus (NoV) infection was investigated in children registered for kindergarten in Korea during the winter and summer. Children with no gastrointestinal symptoms, including diarrhea and abdominal pain, during the 2 weeks before and following sample collection were included in this investigation. NoV presence and genetic identification were determined with real-time reverse transcriptase-polymerase chain reaction and conventional nested reverse transcriptase-polymerase chain reaction. The prevalence of NoV in asymptomatic children was 5.5% in the winter and 3.5% in the summer, respectively. GII.4 was the most prevalent NoV genotype, but GII.2 and GI.10 were also found during genetic analysis. This study demonstrates that asymptomatic NoV infection may be an important source of transmission in kindergarten children.
Foodborne Pathogens and Disease 11/2010; 7(11):1427-30. · 2.26 Impact Factor
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ABSTRACT: This study was conducted to determine the prevalence of Arcobacter species identified or isolated from retail meats in Korea. Multiplex PCR assays for the detection of Arcobacter species were performed for 360 chicken, 100 pork, and 106 beef samples. Arcobacter butzleri and Arcobacter cryaerophilus were detected in 18.9 and 3.3% of chicken samples, respectively. However, Arcobacter species were not found in any of the pork and beef samples. Biochemical testing of isolates selected after enrichment revealed 38 A. butzleri isolates in chicken samples, but no A. cryaerophilus isolates were detected. In this study, A. butzleri was the most prevalent Arcobacter species in chicken meat, and contamination with Arcobacter species in pork and beef may be less prevalent in Korea.
Journal of food protection 07/2010; 73(7):1313-6. · 1.94 Impact Factor
