• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.3
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• pp.429-436
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• 1998

A bacteriological study of sea water and oyster in Charan Bay was conducted to evaluate sanitary conditions of the bay and compliance of waters with the recommended bacteriological criteria for the designated area of shellfish cultivation, The Samples were collected at 23 sampling stations(Fig. 1 and Fig. 2) estaslished once a month from January 1997 to December 1997, During the study period, temperature ranged from 4.7 to $25.6^{\circ}C$, transparency ranged from 3.3 to 6.2m chemical oxygen demand ranged from 1.67 to 2.18 mg/$\ell$, dissolved oxygen demand ranged from 5.4 to 10.0 mg/$\ell$ dissolved nitrogen ranged from 1.65 to 7.88 $\mu$g-at/$\ell$, phosphate ranged from 0.15 to 1.16 $\mu$g-at/$\ell$, Chlorophylla-a ranged from 0.95 to 12.69mg/$\ell$. The coliform group and fecal coliform MPN's of sea water were ranged from <1.8$\~$l,600 and <1.8$\~$540, respectively. The coliform group and fecal coliform MPN's of oysters were ranged from <18$\~$16,000 and <18$\~$1,400, respectively. The viable cell counts in oyster ranged from $1.5\times10^2$ to $7.5\times10^3$. The bacteriological criteria of sea water in shellfish growing area should be less than 70 per 100 ml of sea water for median value of coliform MPN, and below $10\%$ of the samples which contain over than 230 for coliform MPN or over than 43 for fecal coliform MPN. The sea water from 432 samples were complied water coliform criteria recommended for designated shellfish growing area. The coliform group, fecal coliform, classification of coliform group with IMViC reactions and pathogenic vibrios were analyzed. During the study period, infectious bacteria such as Vibrio cholerae, Salmonella sp, and Shigella sp, were not detected from the samples, but detection ratios of Vibrio parahaemolyticus and Vibrio vulnifirus were $7\~17\%$ in summer months.

• Food Science and Preservation
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• v.16 no.2
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• pp.223-229
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• 2009

The effects of 0.01%(w/v) chitosan-ascorbate(CA) and 10 ppm morea on the number of total microbes, Escherichia coli levels, and growth of food poisoning bacteria in dombaeki during storage at $10^{\circ}C$ over 6 days were investigated. Total microbes in meat, cartilage, and skin of untreated samples increased by 4.24, 3.81, and 2.20 logs compared to the zero timepoint, respectively, but, in CA-treated samples, counts fell by 2.66, 2.37, and 1.24 logs. Total microbial levels in morea-treated meat, cartilage, and skin showed similar tendencies but the effects were slightly less than seen in CA-treated samples. E. coli numbers in CA-treated meat, cartilage, and skin stored for 6 days decreased by 1.69, 1.25, and 1.52 logs respectively, compared with control samples. Morea-treated samples showed similar falls, but the effects were again slightly less than seen after CA-treatment. Both Salmonella and Vibrio parahaemolyticus were detected in untreated meat stored for 3 or 6 days. Food poisoning bacteria were found in both untreated and morea-treated samples stored over 6 days. However, no such bacteria were detected in CA-treated samples. Also, CA-treated meat, cartilage, and skin showed low degrees of degeneration. Thus, CA treatment enhanced shelf-life and dombaeki quality by inhibiting microorganism growth and tissue breakdown during storage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1343-1356
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• 2008

The evaluation of microbiological quality for school food samples collected from 19 selected middle and high schools located in Seoul was undertaken. Eighty-nine food samples consisting of 38 non-pretreated vegetables, 13 pre-washed and cut vegetables, 9 meats and poultry, 3 fish and shellfish, 7 dried fish, and shellfish and 20 processed foods were collected. Aerobic plate count, total coliforms, and Escherichia coli (E. coli ) were detected using $Petrifilm^{TM}$, and the food-borne pathogens were screened by multiplex PCR with species-specific primer sets. Sequentially, the quantitative and confirmative test of the food-borne pathogens were carried out with the selective media and biochemical kits. The contamination of coliform counts was observed on the pre-washed vegetables ($3.4{\sim}4.3\;log\;CFU/g$) and meats ($2.2{\sim}4.3\;log\;CFU/g$). Also, the cooked foods were heavily contaminated with coliform, ranging from 1.0 to $5.5\;log\;CFU/g$. E. coli counts were found in 16 raw and cooked food samples, exceeding the microbiological standards for the guideline of safety management for school foods. Through PCR detection, B acillus cereus was detected in 32 raw and cooked foods, and quantitatively found in pre-washed carrot, radish, and pan-broiled dried shrimp and filefish ranging from $2.3{\sim}3.6\;log\;CFU/g$, respectively. E. coli O157:H7 was detected on frozen pork sample and was confirmed with API kit. Campylobacter jejuni was found in 3 ready-to-eat type vegetables. Vibrio parahaemolyticus were found in 4 pre-washed vegetables and 2 cooked foods, indicating unsatisfactory quality based upon the microbiological standards of ready-to-eat vegetables and cooked foods by Korea Food and Drug Administration. Salmonella spp. was detected in frozen chicken sample and confirmed by API kit and latex antisera agglutination.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.8
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• pp.1049-1057
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• 2008

The purpose of this study was to microbiologically evaluate common foods and preparation processes in three large (over 100 pyeong) western-style restaurants in Daegu. Microbiological testing was conducted for pathogens including E. coli, Salmonella spp., Listeria monocytogenes, Staphylococcus aureus, E. coli O157:H7, Vibrio parahaemolyticus, and Bacillus cereus, as well as total plate count and coliforms. Food samples selected for testing represent common menu items and preparation processes. These samples included: 1) hamburger steak (cooking process), 2) mashed potatoes (reheating process), and 3) salad (non-heating process). The results showed that E. coli and S. aureus were detected in the raw ground beef used to prepare hamburger steak, but they were not detected after cooking at $82{\sim}86^{\circ}C$, 10 min. Microbiological quality of the mashed potatoes was better after reheating than during storage in a refrigerator after cooking. Total plate count and coliforms increased, and E. coli was detected in the salad ingredients stored in the refrigerator before serving. In order to serve foods of good microbiological safety and quality in western-style restaurants, standard cooking and reheating temperatures must be maintained during the cooking and reheating processes, and sanitation standard operating procedures must be followed for washing and storage of non-heated and refrigerated menu items.

• Journal of Food Hygiene and Safety
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• v.17 no.1
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• pp.36-44
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• 2002

GC-l00X is non-corrosive alkaline ionic water (pH 12). It is composed of hydroxyl radicals and supplemented with xylitol. Its antimicrobial activity was examined against 6 major food-borne pathogens; Staphylococcus aureus FRI 913, Salmonella enterica serova Enteritidis ATCC 13076, S. enterica serova Typhimurium Korean isolate, Vibrio parahaemolyticus ATCC 17803, Escherichia coli O157:H7 ATCC 43894 and Pseudomonas aeruginosa KCTC 1637 at three different temperatures (4$^{\circ}C$, $25^{\circ}C$ and 36$^{\circ}C$) with or without an organic material (2% yeast extract), respectively. The antimicrobial activities showed over 4 log-reductions (1.0$\times$10$^4$CFU/ml reduction) against all pathogens reacted at 37$^{\circ}C$ for 3 hours in the absence of the organic material. The activities showed same results when GC-l00X was diluted with same volume of distilled water or standard hard water (CaCO$_3$300 ppm). Its antimicrobial activity was more effective and quicker in Gram-negative bacteria than Gram-positive bacteria. Its washing efficacy against E. coli O157:H7 exposed to the surfaces of tomatoes (grapes) was compared with that of the other sanitizers such as other kitchen synthetic detergent and 100-ppm chlorine water. For the toxicological evaluation of the sanitizers, viable counts of E. coli O157:H7 penetrated into the core of tomatoes after washing products were also compared. The result revealed that GC-100X stock solution and its 5% diluted solution had similar washing effects to 100-ppm chlorine water and more effective than the other kitchen synthetic detergent. This result indicated that GC- l00X had antimicrobial activity and no toxicological side effects, therefore, could be useful for a new sanitizer to use in flood safety and kitchen hygiene.

• Korean Journal of Medicinal Crop Science
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• v.9 no.2
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• pp.116-123
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• 2001

This study was carried out to investigate antioxidative, antimicrobial activity and the effect on hepatotoxicity in various extracts of Artemisia iwayomogi. The herb has been used widely for jaundice, hepatitis and liver cirrhosis in chinese medicine. Solid yield by various extraction solvents, 18.1%, was the highest in water extract. To find antioxidative activity in Artemisia iwayomogi was estimated radical scavenging effect by DPPH method in various extracts and change of the POV(peroxide value) of various extracts added in soybean oil during 20 days at $60^{\circ}C$. Radical scavenging effect by DPPH method was the most effective in methanol extract. Added 1,000ppm water extract and methanol extract in soybean oil, the POV of them, 46.8(meq/kg) and 50.8(meq/kg) were lower than that of control, 79.1(meq/kg), during 20 days storage. After antimicrobial activity of various extracts of Artemisia iwayomogi on bacteria was carried out by paper disc method, it found that the ethanol extract was the strongest activity on Vibrio parahaemolyticus. In vivo experiment was to investigate the effect of Artemisia iwayomogi water extract(AIWE) on hepatotoxicity by carbon tetrachloride$(CCl_4)$ in rats. The experiment groups were divided into five groups for recovery(for 3 days) and three groups for protection(for 10 days) in rat liver. The weights and morphological changes of liver and the body weight were examined in each groups. Compared with $CCl_4$ treatment groups$(CCl_4\;only)$, liver and liver/body(%) weights of AIWE pretreatment groups for 3 days and AIWE posttreatment groups for 10 days were declined. In macrography, fibrious exudates and swelling of liver were decreased in AIWE treatment groups. Accumulation of lipid droplets and necrosis of hepatocytes were also decreased in AIWE treatment groups in microscopically. In these results, AIWE seems to enhance hepato-protective and recoverable effect on $CCl_4$ induced hepatotoxicity in rats.

• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.367-375
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• 2010

The bacteriological and physiochemical analysis of sea water and sediments in Tongyeong harbor was conducted to evaluate sanitary conditions. The samples were collected at 8 stations established once a month from June, 2008 to May, 2009. During the study period, the range of temperature was from 6.7 to $25.2^{\circ}C$, transparency ranged from 1.2 to 2.6 m, chemical oxygen demand ranged from 1.90 to 2.92 mg/L, dissolved oxygen ranged from 6.2 to 10.5 mg/L, dissolved nitrogen ranged from 0.052 to 0.098 mg/L, phosphate ranged from 0.044 to 0.065 mg/L, respectively. Seafood, if eaten raw, carries the risk of food poisoning. Seafood poisoning is often cause by pathogenic microorganism originating from fecal contamination, such as Salmonella sp., Shigella sp. and norovirus. Fecal coliforms are an important indicator of fecal contamination. Therefore, data on fecal coliform are very important for evaluating the safety of fisheries in coastal areas. So, we investigated the sanitary indicate bacteria. The coliform group and fecal coliform MPN's of sea water in Tongyeong harbor were ranged from < 1.8~22,000/100 mL (GM 164.9 MPN/100 mL) and < 1.8~7,900 MPN/100 mL (GM 33.7 MPN/100 mL), respectively. Total coliform were detected 97.0% in 96 of samples and 68.9% of total coliforms were fecal coliforms. These results similar to another seawater detection ratio of total coloforms and fecal coliforms. The Vibrios was isolated and identified with VITEK system. Four hundred eighty strains that were obtained from sea water samples in Tongyeong harbor Detection ratio Vibrio alginolyticus, 34.2%, Vibrio parahaemolyticus, 13.8%, Vibrio vulnificus 10.0%, and V. mimicus 12.5% respectively. Vibrio cholerae O1, was not detected. During the study period, the ranges of water content, ignition loss, COD, and acid volatile sulfates in sediments in Tongyeoung harbor were 41.0~57.4%, 7.8~10.5%, 6.51~9.30 mg/g, 0.04~0.09 mg/g, respectively. Heavy metals in sediment of Tongyeoung harbor were Cd, $0.10{\pm}0.05$; Cu, $4.79{\pm}8.20$; As, $1.95{\pm}0.17$; Hg, $0.10{\pm}0.07$; $Cr^{6+}$, $0.34{\pm}0.12$; Zn, $125.33{\pm}16.40$; Ni, $16.43{\pm}1.93$ mg/kg.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.192-199
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• 2010

The alone and combined effects of bacteriocin produced from Enterococcus faecalis MJ-213 and potassium sorbate against the food-borne pathogenic bacteria were studied. Bacteriocin minimal inhibitory concentration (MIC) values for Staphylococcus aureus ATCC 6538 and Salmonella enteritidis ATCC 13076 were 50 and 100 ${\mu}g$/ml, respectively. Bacteriocin (100 ${\mu}g$/ml) alone was active against S. aureus and S. enteritidis, but it was lower in antimicrobial effectiveness than the combination of bacteriocin (100 ${\mu}g$/ml) with potassium sorbate (100 ${\mu}g$/ml), which reduced initial counts (6 log cycle) of S. aureus and S. enteritidis by 1 and 3 log cycle, respectively. The bactericidal activity of bacteriocin of E. faecalis MJ-213 heated at $100^{\circ}C$ for 30 min or $121^{\circ}C$ for 15 min was markedly decreased as compared with the control. Moreover, the activity of bacteriocin was completely abolished by pepsin or protease II, but not affected by ${\alpha}$-amylase or lipase. The activity of bacteriocin adjusted to pH 6.0-8.0 showed almost the same inhibition ratio compared with the bacteriocin unadjusted pH, and though the inhibition ratio against pathogenic bacteria was reduced than the control, the bacteriocin was stable at pH 4.0 or 10.0, relatively. Furthermore, the combined treatment of bacteriocin and potassium sorbate than the alone treatment of bacteriocin significantly decreased (p<0.05) the viable cell counts of S. aureus or S. enteritidis inoculated on grind beef during storage at $4^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.252-260
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• 2009

Whereas the numbers of childcare centers and kindergartens are increasing rapidly, systematic management to control the food safety of foodservice operation is not yet well established. Samples from 12 centers in Seoul and Gyeonggi Province were collected to assess the microbiological quality of 32 raw materials, 24 cooked foods, 76 food-contact surfaces (knives, cutting boards, dish towels and gloves), 17 employees' hands and 12 air-borne bacteria. The microbiological analyses were performed for aerobic plate counts (APC), Enterobacteriaceae, E. coli and 7 pathogens (B. cereus, C. jejuni, C. perfringens, L. monocytogenes, Salmonella spp., S. aureus, and V. parahaemolyticus). Among raw materials, E. coli ($1.39{\sim}2.08\;\log\;CFU/g$) were detected in 4 out of 6 meats and 7.46 log CFU/g of APC in tofu. High enterobacteriaceae levels of 4.23, 5.14 and 4.19 log CFU/g were found in cucumber salad, steamed spinach with seasonings and steamed bean sprout with seasonings, respectively. No pathogens were found in all samples except for C. perfringens detected from raw spinach and raw lotus root. Only APC and enterobacteriaceae were found in food-contact surfaces. Two of the 23 knives and three of the 24 kitchen boards showed over 500 CFU/$100\;cm^2$ of APC; also, APC levels (5.03 to 5.44 log CFU/g) were detected in 4 of the 12 dish towels. Only one glove showed Enterobacteriaceae (2.44 log CFU/glove) contamination. Enterobacteriaceae were found in 2 employees' hands ($2.37{\sim}4.44\;\log\;CFU$/hand) among the 16 employees. The contamination levels of air-borne bacteria were shown unacceptable in two (2.25 and 2.30 log CFU/petri-film/15 min) out of the 12 kitchen areas. These results suggest that the microbiological hazards in some foods and environments are not well controlled and thus a guideline should be provided to ensure the food safety in childcare center and kindergarten foodservice operations.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.12
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• pp.1895-1904
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• 2015

Foodborne illness associated with food service establishments is an important food safety issue in Korea. In this study, foodborne pathogens (Bacillus cereus, Clostridium perfringens, Escherichia coli, pathogenic Escherichia coli, Listeria monocytogenes, Salmonella spp., Staphylococcus aureus, and Vibrio parahaemolyticus) and hygiene indicator organisms [total viable cell counts (TVC), coliforms] were analyzed for food and environmental samples from foodservice establishments at schools in Gyeonggi province. Virulence factors and antimicrobial resistance of detected foodborne pathogens were also characterized. A total of 179 samples, including food (n=66), utensil (n=68), and environmental samples (n=45), were collected from eight food service establishments at schools in Gyeonggi province. Average contamination levels of TVC for foods (including raw materials) and environmental samples were 4.7 and 4.0 log CFU/g, respectively. Average contamination levels of coliforms were 2.7 and 4.0 log CFU/g for foods and environmental swab samples, respectively. B. cereus contamination was detected in food samples with an average of 2.1 log CFU/g. E. coli was detected only in raw materials, and S. aureus was positive in raw materials as well as environmental swab samples. Other foodborne pathogens were not detected in all samples. The entire B. cereus isolates possessed at least one of the diarrheal toxin genes (hblACD, nheABC, entFM, and cytK enterotoxin gene). However, ces gene encoding emetic toxin was not detected in B. cereus isolates. S. aureus isolates (n=16) contained at least one or more of the tested enterotoxin genes, except for tst gene. For E. coli and S. aureus, 92.7% and 37.5% of the isolates were susceptible against 16 and 19 antimicrobials, respectively. The analyzed microbial hazards could provide useful information for quantitative microbial risk assessment and food safety management system to control foodborne illness outbreaks in food service establishments.