• Journal of Food Hygiene and Safety
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• v.32 no.1
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• pp.50-56
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• 2017

The purpose of this study was to investigate the microbiological contamination of water and drinking cups in springs and to estimate the toxin gene, enterotoxin production ability and antibiotic susceptibility of foodborne pathogens. Ten spring water and 34 drinking cups were tested. The average number of total aerobic bacteria and coliform bacteria in spring water were 1.8 log CFU/mL and 1.2 log CFU/mL, and in drinking cups were $4.7log\;CFU/100cm^2$ and $1.7log\;CFU/100cm^2$. Salmonella spp., Staphylococcus aureus, E. coli O157:H7, Listeria monocytogenes, Vibrio parahaemolyticus, Yersinia enterocolitica were not isolated from all of samples but Bacillus cereus was detected in 5 (14.7%) of 34 drinking cups. The nheA and entFM genes were major enterotoxin genes in B. cereus isolated from drinking cups. All of B. cereus tested in this study produce non-heamolytic enterotoxin but only 2 isolates possessed heamolysin BL enterotoxin producing ability. B. cereus was resistant to ${\beta}-lactam$ antibiotics. These results revealed that the sanitary conditions of drinking cups in spring should be improved promptly. The substitution carrying a personal drinking cup for the public drinking cups equipped in springs is suggested to prevent food-borne illness.

• Korean Journal of Food Science and Technology
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• v.39 no.1
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• pp.71-76
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• 2007

Foodborne illness caused by Noroviruses (NVs) is increasing rapidly in Korea. This study developed an effective detection protocol for NVs found in contaminated oysters and lettuce through an investigation using the major steps of virus particle separation, concentration and RT-PCR. As a surrogate model for NVs, the cultivable feline calicivirus (FCV) that belongs to the same Caliciviridae family was used. Instead of using a time-consuming ultracentrifugation method, efficient methods based on solvent extraction and PEG precipitation procedure were applied. Direct homogenization of a 25g sample of whole oyster and lettuce in 175mL PBS provided the simplicity that would be needed in the actual field of food product examination. The overnight PEG precipitation step at $4^{\circ}C$ was reduced to 3 h by placing the reaction tube in ice and by adjusting the PEG concentrations. The application of the use of chloroform and 0.2 ${\mu}m$ syringe filtration together showed a better detection efficiency than the use of chloroform alone in removing PCR inhibitors for both oyster and lettuce samples. Also, dilution of the extracted RNA solution before PCR provided increased sensitivity. The improved detection protocol developed in this study could be efficiently applied to detect FCV and most likely NVs from oysters and lettuce.

• Journal of Microbiology and Biotechnology
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• v.17 no.7
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• pp.1152-1161
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• 2007

An immunochromatography (ICG) strip test based on a monoclonal antibody for the rapid detection of L. monocytogenes in meat and processed-meat samples was developed in this study. A monoclonal antibody (MAb) specific to L. monocytogenes was produced from cloned hybridoma cells (FKLM-3B12-37) and used to develop an ICG strip test. The antibody showed a stronger binding to L. monocytogenes than other Listeria species, and a weak cross-reaction to S. aureus based on an ELISA. The detection limit of the ICG strip test was $10^5\;cell/ml$. In total, 116 meat and processed-meat samples were collected and analyzed using both the ICG strip test and a PCR. The ICG strip test and PCR indicated L. monocytogenes contamination in 34 and 27 meat samples, respectively. The 7 meat samples not identified as L. monocytogenes positive by the PCR were also tested using an API kit and found to be contaminated by Listeria species. In conclusion, the ICG strip test results agreed well with those obtained using the PCR and API kit. Thus, the developed ICG has potential use as a primary screening tool for L. monocytogenes in various foods and agricultural products, generating results within 20 min without complicated steps.

• Korean Journal of Veterinary Service
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• v.43 no.1
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• pp.23-29
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• 2020

Hepatitis E Virus (HEV) infection is a worldwide disease and the primary cause of acute viral hepatitis in the world. It can be isolated from many different species including pigs. HEV is a zoonotic pathogen and foodborne disease. The main animal reservoir is domestic pigs. It is usually asymptomatic in pig but it is a public health concern, causing acute hepatitis in humans of varying severity. This study focused on the presence of HEV in pig and pork product. One hundred feces and one hundred fifty serum samples were randomly collected from pigs in slaughterhouses in Gwangju from November in 2018 to February in 2020. In addtion, seventy-five pork products were collected from markets in Gwangju. Feces and pork product samples were examined for the presence of HEV RNA using an reverse-transcription realtime PCR (RT-qPCR) assay. Serum samples were tested for the presence of HEV-specific IgG antibodies using Enzyme-linked immunosorbent assay (ELISA). HEV antigen and antibody positive rates were 3.0% (3/100) and 19.3% (29/150), respectively, in Gwangju and nearby areas such as Jeonnam and Jeonbuk. However, HEV antigen was not detected from any of pork product in this study. In conclusion, the prevalence of HEV should be continuously monitored because HEV was sporadically detected in Gwangju and nearby areas.

• Parasites, Hosts and Diseases
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• v.45 no.3
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• pp.213-218
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• 2007

The prevalence of liver and intestinal fluke infections was surveyed on residents of Savannakhet Province, Laos. Fecal specimens were collected from a total of 981 residents in 4 Mekong riverside villages and examined by the Kato-Katz thick smear technique. The results revealed that the overall helminth egg positive rate was 84.2%, and the positive rate for small trematode eggs, including Opisthorchis viverrini, heterophyids, or lecithodendriids, was 67.1 %. To obtain adult flukes, 38 small trematode egg positive cases were treated with a 20-30 mg/kg single dose of praziquantel and purged. Diarrheic stools were then collected from 29 people and searched for helminth parasites using stereomicroscopes. Mixed infections with O. viverrini and 6 kinds of intestinal flukes were found, namely, Haplorchis taichui, Haplorchis pumilio, Haplorchis yokogawai, Prosthodendrium molenkampi, Phaneropsolus bonnei, and echinostomes. The total number of flukes collected was 7,693 specimens (av. no. per treated person; 265.3). The most common species was O. viverrini, followed by H. taichui, P. molenkampi, echinostomes, H. pumilio, P. bonnei, and H. yokogawai. The results indicate that foodborne liver and intestinal fluke infections are prevalent among residents of Savannakhet Province, Laos.

• Korean Journal of Plant Resources
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• v.27 no.5
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• pp.415-420
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• 2014

Toxoplasmosis is an important cause of foodborne, inflammatory illnesses, as well as congenital abnormalities. Currently available therapies are ineffective for persistent chronic disease and congenital toxoplasmosis or have severe side effects which may result in life-threatening complications. There is an urgent need for safe and effective therapies to eliminate or treat this cosmopolitan infectious disease. The aim of this study was to investigate the in vitro anti-Toxoplasma activities of Suaeda maritime, one of the halophytes, using tachyzoit of T. gondii RH strain infected HeLa cells. As the results, the selectivity of Suaeda maritime extract was 6.63, which was higher than Sulfadiazine selectivity (2.06). Also, we perfomed the cell proliferation inhibition test and the morphological study to evaluate the anti-T. gondii activity of Suaeda maritime extract with HeLa cells. As the results, the inhibition rate of the Suaeda maritime extract was high inhibition rate. This indicates that the Suaeda maritime extract may be used for new anti-T. gondii agent.

• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.103-108
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• 2020

Shiga toxin-producing Escherichia coli (STEC) is an important pathogenic bacteria and can cause severe foodborne disease. For STEC detection, conventional culture methods have disadvantages in the fact that conventional culture takes a long time to detect and PCR can also detect dead bacteria. To overcome these problems, we suggest a bacteriophage amplification assay, which utilizes the ability of bacteriophages to infect living cells and their high specificity. We used a combination of six bacteriophages infecting E. coli to make the bacteriophage cocktail and added ferrous ammonium sulfate as a virucidal agent to remove free-bacteriophages. When cherry tomato and paprika were artificially inoculated with the cocktail at a final concentration of around 3 log CFU/mL and were enriched for at least 5 h in mTSB broth with Novobiocin, approximately 2-3 log PFU/mL were detected through the bacteriophage amplification assay. Therefore, bacteriophage amplification assay might be convenient and a useful method to detect STEC in a short period of time.

• Journal of Food Hygiene and Safety
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• v.17 no.1
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• pp.45-54
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• 2002

Hazard Analysis Critical Control Point System (HACCP) is recognized worldwide as a science-based and systematic approach for food safety. This has been initiated to establish the HACCP system in Korean slaughterhouses by suggesting some of effective implementation ways. An awareness level survey using questionnaire for 124 owners and 363 employees of the slaughterhouses, and 170 government officers responsible for HACCP duties was performed. This study shows that only 34.7% of owners, 21.1% of employees, and 57.1% of government officers have good understanding of HACCP, but 93.5%, 88.9% and 93.6% respectively have the willingness of HACCP implementation. Major benefits in HACCP implementation in the slaughterhouse raised by respondents were improvement of hygiene level of the plant (54.1%), increase of meat sale (17.6%), pride of the production of safe meat for human consumption (9.6%) and increase of meat export (7.5%), while major obstacles were financial difficulties (33.2%), poor levels of the facilities and equipments in the plants (27.3%), poor level of personal hygiene (19.4%), and lack of understanding of HACCP (12.3%). The most urgent measures which respondents raised to implement HACCP system effectively in the slaughterhouses at the moment were the Improvement of levels of facilities and equipments in the plants (36.6%), the establishment of HACCP base through education and training (19%), special benefits to HACCP implementing plant (11.8%), and close relationship between government and the industry (10.3%). The present study shows some of effective ways to implement HACCP in slaughterhouses.

• Journal of Food Hygiene and Safety
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• v.31 no.3
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• pp.216-221
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• 2016

This study was performed to evaluate the bactericidal efficacy of a fumigation disinfectant containing 35% paraformaldehyde against Salmonella Typhimurium (S. Typhimurium). In this study, the efficacy test of a fumigant against S. Typhimurium was carried out according to French standard NF T 72-281. The S. Typhimurium working culture suspension number (N value), all bacteria numbers on the carriers exposed to the fumigant (n1, n2, and n3), the number of bacterial suspensions by the pour plate method (N1), the number of bacterial suspensions by the filter membrane method (N2), and the mean number of bacteria recovered on the control carriers (T value), were obtained from the preliminary test. In addition, the reduction number of S. Typhimurium exposed to the fumigant (d value) was calculated using the T value, the mean number of bacteria in the recovery solution (n'1) and the mean number of bacteria on carriers plated in agar (n'2). The N value was $5.5{\times}10^8$ colony forming units (CFU)/mL, and n1, n2, and n3 were higher than 0.5N1, 0.5N2 and 0.5N1, respectively. Additionally, the T value was $3.5{\times}10^6CFU/carrier$. In terms of the bactericidal effect of the fumigant, the d value was 5.25. According to the French standard for fumigants, the d value for an effective bactericidal fumigant should be greater than 5. The results indicated that the fumigant containing 35% paraformaldehyde had an efficient bactericidal activity against S. Typhimurium, and, therefore, can be used to disinfect food materials and kitchen appliances contaminated with foodborne bacteria.

• Journal of Food Hygiene and Safety
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• v.26 no.4
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• pp.330-335
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• 2011

This study was performed to determine the transfer rates of each foodborne pathogen from pork meat packaging during the processing. We analyzed the transfer rate of Listeria monocytogenes from contaminated pork meat to worker's hands (wearing polyethylene gloves, PEG; cotton gloves, CG; and bare hands), cutting boards and knives, and vice versa. Transfer rate of CG 100.00% was higher than that of bare hands 2.513% and PEG 1.511%. In particular, when wearing Co, the transfer rate from the CG to bare hands with CG was 0.08%. Also, the range of transfer rates from contaminated pork meat to cutting board and knife was 0.352-3.791%. In contrast, transfer rates from the workers' hands (with PEG/CG and bare hands) to cutting board, knife, and pork meat ranged from 0.001 to 0.141%. There was a lower transfer rate from workers' hands than from pork meat. These findings indicate that use of PEG could effectively reduce or prevent the cross-contamination compared to CG and provide important information concerning the consecutive transfer of L. monocytogenes during food processing.