• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.1005-1011
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• 2005

Widespread distributions of repetitive DNA elements in bacteria genomes are useful for analysis of genomes and should be exploited to differentiate food-borne pathogenic bacteria among and within species. Enterobacterial repetitive intergenic consensus (ERIC) sequence has been used for ERIC-PCR genomic fingerprinting to identify and differentiate bacterial strains from various environmental sources. ERIC-PCH genomic fingerprinting was applied to detect and differentiate four major Gram-negative food-borne bacterial pathogens, Esherichia coli, Salmonella, Shigella, and Vibrio. Target DNA fragments of pathogens were amplified by ERIC-PCR reactions. Dendrograms of subsequent PCR fingerprinting patterns for each strain were constructed, through which relative similarity coefficients or genetic distances between different strains were obtained numerically. Numerical comparisons revealed ERIC-PCR genotyping is effective for differentiation of strains among and within species of food-borne bacterial pathogens, showing ERIC-PCR fingerprinting methods can be utilized to differentiate isolates from outbreak and to determine their clonal relationships among outbreaks.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.611-617
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• 2005

Dispersed repetitive DNA elements in genomes of microorganisms differ among and within species. Because distances between repetitive sequences vary depending on bacterial strains, genomic fingerprinting with interspersed repetitive sequence-based probes can be used to distinguish unrelated organisms. Among well-known bacterial repetitive sequences, Repetitive Extragenic Palindromic (REP) sequence has been used to identify environmental bacterial species and strains. We applied REP-PCR to detect and differentiate four major Gram-negative food-borne bacterial pathogens, E. coli, Salmonella, Shigella, and Vibrio. Target DNA fragments of these pathogens were amplified by REP-PCR method. PCR-generated DNA fragments were separated on 1.5% agarose gel. Dendrograms for PCR products of each strain were constructed using photo-documentation system. REP-PCR reactions with primer pairs REP1R-I and REP2-I revealed distinct REP-PCR-derived genomic fingerprinting patterns from E. coli, Salmonella, Shigella, and Vibrio. REP-PCR method provided clear distinctions among different bacterial species containing REP-repetitive elements and can be widely used for typing food-borne Gram-negative strains. Results showed established REP-PCR reaction conditions and generated dendrograms could be used with other supplementary genotyping or phenotyping methods to identify isolates from outbreak and to estimate relative degrees of genetic similarities among isolates from different outbreaks to determine whether they are clonally related.

• Journal of Food Hygiene and Safety
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• v.27 no.4
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• pp.366-374
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• 2012

Recently pathogenic E. coli is one of the main foodborne pathogens resulting in many patients in Korea. To understand the characteristics of pathogenic E. coli outbreaks in Korea, the epidemiological investigation reports of pathogenic E. coli outbreak in 2009 (41 reports) and in 2010 (27 reports) were collected in the web site of the Korea Centers for Disease Control and Prevention, reviewed and analysed in this study. The main places of the pathogenic E. coli outbreaks were food catering service area (64.8%) and restaurants (25.0%). The main type of the pathogens were EPEC (44.7%) and ETEC (34.2%). EAEC and EHEC was responsible for 10.5 and 9.2%, respectively. Eight of 68 outbreak cases were caused by more than 2 types of pathogenic E. coli which implicates the complicated contamination pathways of pathogenic E. coli. The incidence rate of pathogenic E. coli was $33.6{\pm}30.5%$ and the main symptoms were diarrhea, stomach ache, nausea, vomiting, and fever etc. The two identified food sources were identified as frozen hamburger pattie and squid-vegetable mixture. To improve the food source identification by epidemiological investigation, food poisoning notification to the agency should not be delayed, whole food items attributed the outbreak should be collected and detection method of the various pathogenic E. coli in food has to be improved. In conclusion, the characteristics between the EHEC outbreaks in the western countries and the EPEC or ETEC outbreaks in Korea needs to be distinguished to prepare food safety management plan. In addition, the development of the trace back system to find the contamination pathway with the improved detection method in food and systemic and cooperative support by the related agencies are necessary.

• Food Science of Animal Resources
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• v.35 no.4
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• pp.502-506
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• 2015

The aim of this study was to investigate the antimicrobial resistance profiles of and the enterotoxin gene distribution in 4 strains of Staphylococcus aureus (S10-2, S10-3, S12-2, and S13-2) isolated from 90 bulgogi samples. The S. aureus enterotoxin H gene (seh) was found in all the strains, while the S. aureus enterotoxin A gene (sea) was found only in 3 of the 4 strains. The S10-2 strain expressed a combination of enterotoxin genes - seg, seh, sei, sej, selm, and seln. The strains S10-2 and S13-2 were resistant to ampicillin and penicillin G, and all the isolated strains were resistant to tetracycline. The S10-2 strain was the only mecA-positive strain; it was also resistant to β-lactam antibiotics. Thus, genes encoding enterotoxin as well as those conferring antibiotic resistance were identified in the S. aureus strains isolated from pork bulgogi. These results represents the potential occurrence of MRSA in pork bulgogi, and the need for a monitoring system for pork bulgogi in order to prevent an outbreak of staphylococcal food poisoning.

• Journal of Food Hygiene and Safety
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• v.16 no.3
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• pp.159-167
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• 2001

Staphylocorccus aureus is gram positive, facultatively anaerobic, non-sporulative coccus, and positive for coagulase and DNase. The food-poisoning outbreak of Staphylococcus aureus increases in the world, and third occurrence happened in our country. Of 105 isolates (25.4%) obtained 413 focal samples of food-poisoning suspicious patients. In those cases, the enterotoxins were detected from a total of 45 isolates (42.9%), 9 isolates(20.0%) were A type, 33 isolates (73.3%) were H types, 2 isolates (4.4%) were G type and 1 isolate was a I type enterotoxin. Among the isolates possessing staphylococcal enterotoxins, 29 isolates had H type only(64.4%), 5 isolates had A type only and 4 isolates had both A and H type. Two isolates had G type only and 1 isolate had I type only. In the antibiotic susceptibility, 48 isolates (46%) had at least one antibiotic resistance among 105 isolates, 34 isolates (70.8%) were resistant to penicillin. 1 isolate (2.1%) to ampicillin, 3 isolates (6.3%) to erythromycin and kanamycin. Seven were resistant to more than two antibiotics and especially 1 isolate was resistant to penicillin-ampicillin-nitrofurantoin.

• Journal of the Korean Society of Food Culture
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• v.9 no.5
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• pp.457-465
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• 1995

The purpose of the present study is to identify potentially hazardous factors which can contribute to the outbreak of foodborne disease and to represent more practical management methods in terms of environmental sanitation and facilities for the kitchen. 230 Korean-style restaurants in Seoul were assessed and analyzed by the restaurant total area. Facilities and sanitary check-lists were developed to evaluate the facilities and sanitary conditions of sampled restaurants. The sanitary condition of kitchen, guest room and other area were assessed by the sanitary score. The basic cooking machinery and utensil were properly facilitated but automation machinery were equiped below 10% sampled restaurants. The kitchen area were not properly sufficient to total area. Sanitary condition of kitchen, guest room, cooking appliance and stored foods were evaluated as the unsatisfactory state with potentially hazardous. Concrete guidelines should be made in terms of following item; establishment for the kitchen space expansion, facilities for the improvement of the working environment and sanitary condition of foods cooked. Additionaly, it need to practice the effective education and training program for the foodservice manager and employees.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.10
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• pp.1611-1618
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• 2005

The microbiological examinations were conducted for the hygienic evaluation on three Korean restaurants during summer season in Busan, Korea. Total one hundred and sixty swabbed samples using sponge were collected from the surface of facilities and utensils at restaurants and total and coliform counts were measured. Also thirty- six air samples were collected at inside of three restaurants for measuring total, coliform, Staphy-lococcus and mold and yeast counts. All collected samples kept in an ice-packed box were transported to the laboratory and analyzed. The results demonstrated that most swabbed samples were highly contaminated with microorganisms and coliforms. The degree of contamination depended on the sampling sites. Averages of total counts of surface swab samples were ranged from not detectable to 2.14$\times\10^{9}$/200 $cm^{2}$, while those of coliforms from not detectable to 8.34$\times\10^{7}$/200 $cm^{2}$/200 $cm^{2}$. Microorganisms also detected from most agar strips of air samples for total, coliform, Staphylococcus and mold and yeast counts. The severely contaminated sites were floor, trench, water bottle, plastic drainer, rubber gloves, shelves, and unsealed wet towel. Those sites should be focused and controlled according to control Points of sanitation standard operating Procedures. Also, periodic microbiological examination in addition to visual examination should be applied on those highly contaminated sites for reducing risk of foodborne disease outbreak at restaurants

• Journal of Food Hygiene and Safety
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• v.16 no.3
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• pp.168-177
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• 2001

Sanitary management practices were assessed to insure the safety of school foodservice, to prevent the outbreak of foodborne illness, and to improve the quality of school foodservice. To accomplish these objectives, a survey was conducted and analyzed on elementary and high school foodservice operations located in Seoul area. A Questionnaire from based on HACCP standards was developed and used for self-reported evaluation of the school foodservice managers on their sanitary management practices. The results were analysed by examining their activities and identifying weaknesses in those activities. The questionnaire was composed of three sectors with all 53 questions; 33 questions for time-temperature management, 5 for personal hygiene and 15 for equipment/facility sanitation. Five-point-scale was used on the questionnaire answers. Among the schools responded,253 (98.4% of the total) were elementary schools and 19 (1.6%) were high schools. Among the three sectors, personal hygiene performance was mostly well conducted by marking average 4.06$\pm$0.57. Equipment/facility sanitation came next by marking average 3.84$\pm$0.53. Time-temperature marked average 3.45$\pm$0.46. “Storage after cooking (2.03$\pm$0.94)”was identified as the least managed activities because the school foodservice operations were not equipped well with hot holding and/or cold holding. “Separate use of sink per usage (3.03$\pm$1.10)” and “proper location of hand washing facility (3.07$\pm$1.13))” were identified as the least practiced activities in equipment/facility sanitation sector. To enhance these practices, proper number of sinks and hand washing facilities should be equipped first within the kitchen area.

• Journal of Food Hygiene and Safety
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• v.26 no.4
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• pp.296-301
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• 2011

This study was to evaluate the growth potential of E. coli O157:H7 in lettuce leaf extracts and on lettuce leaf surface at various temperatures. The pathogen can survive and multiply in the extracts and leaf surface of lettuce. The population of E. coli O157:H7 in the lettuce extracts reached to 4.79 log CFU/mL at $37^{\circ}C$. The multiplication of pathogen in lettuce extracts initiated within 10 hours of inoculation over $15^{\circ}C$ conditions. And it can survive in the lettuce leaf extracts at $4^{\circ}C$ for 100 hours at least. And this pathogen can multiply on lettuce leaf surface and the population of pathogen on the lettuce leaf surface increased to 1.82 log CFU/g at $25^{\circ}C$. At $37^{\circ}C$, the pathogen density increased to 1.53 CFU/g within 3 days after inoculation. At all temperature, irrespective of the inoculation level, similar trends in growth of E. coli O157:H7 were observed. These results emphasize the growth potential of E. coli O157:H7 in lettuce leaf extract and on lettuce leaf surface. To reduce the risk of outbreak, it is important to maintain the cold chain system during storage before the consumption.