• Journal of Food Hygiene and Safety
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• 제13권3호
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• pp.305-312
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• 1998

In order to investigate the species, serobiological characteristics and antibiotic sensitivity of Pseudomonas spp, we isolated Pseudomonas spp from 57 spring waters around Seoul area for spring, summer and autumn and identified Pseudomonas spp by biochemical characteristics and serological method. And also we tested the antibiotic sensitivity test by discdiffusion method. Of 57 spring waters tested, Pseudomonas spp were isolated from 33 spring waters(57.9%). Isolation rate of Pseudomonas spp in spring season was 28.1%, summer 21.1% and autumn 28.1%. Only 1 spring water was detected Pseudomonas spp in all seasons and 9 (15.8%) were detected for 2 seasons and 13 (22.8%) were for only 1 season. Isolation rate of Pseudomonas spp at Mt. Cheonggye was 50% and followed by Mt. Bookhan 35.7%, Mt. Daemo 33.3%, Mt. Dobong 29.6%, Mt. Surak 25.9%, Mt. Woomyun 22.2% and Mt. Bulam 7.4%. Of 44 Pseudomonas spp, 22 strains (50%) were identified by Ps. putida, Ps. aeruginosa, Ps. fluorescens and Ps. mendocina were identified 6 strains (13.6%), respectively. 4 strains (9.1%) were identified by Ps. aureofaciens. Of 6 Ps. aeruginosa, serotype A was 2 strains, B, E, G, and K was 1 strain, respectively. Of 44 Pseudomonas spp, resistance rate to amoxicillin was 90.9% and followed by chloramphenicol 84.1%, tetracycline 84.1%, carbenicillin 81.8%, nalidixic acid 68.2%, neomycin 38.6%, streptomycin 31.8%, gentamicin 4.6%, kanamycin 4.6% and colistin 2.3%. Ps. aeruginosa was more sensitive to carbenicillin than other Pseudomonas spp isolated from spring waters in Seoul area but more resistant to kanamycin, and Ps. aureofaciens was no resistant to streptomycin. Among multiple drug resistance, resistance to 5 drugs was 31.8%, 4 drugs 15.9%, 7 drugs 13.6%, 1 drug and 2 drugs 4.6%, and 8 drugs 2.3%, respectively. The multiple resistance patterns detected highestly were NA-CB-C-TE-AMC (18.2%), NA-CB-N-C-TE-AMC (13.6%), CBC-TE-AMC (11.4%) and NA-CB-N-C-TE-AMC-S (9.1%).

• Journal of Food Hygiene and Safety
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• 제22권4호
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• pp.359-364
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• 2007

This study was conducted to determine the optimum condition of extraction and antioxidant activity of ethanol extracts of Epimedium koreanum Nakai based on the icariin quantity. Also, further organic solvent fractions of hexane, chloroform, ethyl acetate and butanol were obtained from the ethanol extract of Epimedium koreanum Nakai at different temperatures. Total ethanol extraction yield of wild grape seed ranged from 11.8% to 39.3% depending on the concentration of icariin as well as different ethanol concentration, extraction temperature and time condition. Among different extraction temperatures and time, the highest extraction yield of 39.3% was obtained at 70% ethanol for 3 hour at $50^{\circ}C$ in the sample containing the 0.596% icariin (KE9412). In the meantime, the strongest free radical scavenging effect $(RC_{50})$ with $18.9{\mu}g/mL$ in the KE9412 sample was observed in 70% ethanol extract of Epimedium koreanum Nakai extracted for 7 hour at $70^{\circ}C$, while $RC_{50}$ with $35.2{\mu}g/mL$ was observed in the KE9405 (0.20% icariin content) sample at same condition. Also, antioxidant activity of ethanol extracts of Epimedium koreanum Nakai increased as icariin concentration increased. Among each fraction obtained from organic solvents, butanol fraction was found to have the strongest $RC_{50}\;(39.2{\mu}g/mL)$ and followed by ethylacetate $(49.0{\mu}g/mL)$, water $(118.8{\mu}g/mL)$, ethylacetate $(119.8{\mu}g/mL)$, and chloroform fraction $(138.5{\mu}g/mL)$ respectively.

• Journal of Food Hygiene and Safety
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• 제23권3호
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• pp.264-270
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• 2008

Phytic acid(PA) (Inositol hexaphosphate, $IP_6$) is a naturally occurring polyphosphorylated carbohydrate that is present in substantial amounts in almost all plants and mammalian cells. Recently PA has received much attention for its role in anticancer activity. In the present study, the preventive effects of PA on colon carcinogenesis were investigated. Six-week old Fisher 344 male rats were fed a AIN-93G purified diet and PA(0.5% or 2% PA in water) for 8 weeks. The animals received two ($1^{st}\;and\;2^{nd}$ week) injections of azoxymethane(AOM, 15 mg/kg b.w.) to induce colonic aberrant crypt foci(ACF). After sacrifice, the total numbers of aberrant crypts(AC) and ACF in colonic mucosa were examined after staining with methylene blue. Blood and serum were analyzed with a blood cell differential counter and an automatic serum analyzer. AOM induced the total numbers of $142.3{\pm}22.3$ ACF/colon and $336.6{\pm}55.1$ AC/colon. PA at the doses of 0.5 and 2% decreased the numbers of ACF and AC/colon in a dose-dependent manner. The numbers of ACF/colon and AC/colon by PA at the dose of 0.5% were $124.4{\pm}28.5\;and\;302.7{\pm}67.3$, respectively. PA at the dose of 2% significantly decreased the ACF and AC numbers to $109{\pm}18.1\;and\;254.8{\pm}50.6$, respectively(p<0.01). Especially, 2% PA significantly reduced the number of large ACF(${\geq}4$ AC/ACF) from $26.8{\pm}6.2$ ACF/colon to $15{\pm}6.7$ ACF/colon(p<0.01). Although some parameters in blood counts and serum chemistry were changed compared with the control, no specific toxicity was found. These findings suggest that phytic acid can be a chemopreventive agent for colon carcinogenesis resulting from inhibition of the development of ACF in the F344 rat.

• Journal of Food Hygiene and Safety
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• 제31권6호
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• pp.393-398
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• 2016

The objective of this study was to isolate pathogenic Escherichia coli from fresh vegetables with selective media and Petrifilm, and identify a suspicious colony using biochemical identification. Twenty gram of lettuce, twenty gram of cabbage and ten gram of sprout were prepared, and a 5-strain mixture of pathogenic E. coli (Enterohemorrhagic E. coli NCCP11142, Enterotoxigenic E. coli NCCP14037, Enteropathogenic E. coli NCCP14038, Enteroaggregative E. coli NCCP14039, Enteropathogenic E. coli NCCP15661) was inoculated to obtain 1, 2 and 3 log CFU/g. Eighty to ninety milliliter of buffered peptone water (BPW) was placed and pummeled for 60 s. As a results, the Petrifilm method was all positive, but enrichment method of qualitative analysis was negative except for 3-log CFU/g inoculated lettuce. Regarding biochemical identification of pathogenic E. coli, the identification rates were dependent on type of methods and vegetables; lettuce: API 20E 100% (44/44), Microgen GNA 100% (44/44) and Food System 66.7% (10/15), cabbage: API 20E 64.7% (22/34), Microgen GNA 50% (16/32) and Food System 60% (9/15), sprout: API 20E 65.1% (28/43), Microgen GNA 62.3% (27/43) and Food System 53.3% (8/15). These results could be useful in determining an appropriate method to detect pathogenic E. coli in fresh vegetables.

• Journal of Food Hygiene and Safety
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• 제31권6호
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• pp.439-444
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• 2016

In the present study, the performance of culture methods using two selective agars and real-time PCR were compared for selective isolation of Cronobacter in powdered infant formula and dried pumpkin. Two food samples were spiked with the pathogen and then preenriched in distilled water. A small portion of preenrichment (10 mL) was incubated in Enterobacteriaceae enrichment both, followed by inoculation onto Druggan-Forsythe-Iversen agar (DFI agar) and Cronobacter sakazakii chromogenic plating agar (R&F agar). The preenrichment and enrichment (1 mL each) was used in real-time PCR assay. In powdered infant formula (PIF), no statistical difference was observed between both culture methods and real-time PCR with preenrichemt (p > 0.05). However, the number of positives obtained by R&F agar and real-time PCR was much higher than that of culture method using DFI agar in dried pumpkin (p < 0.05). In particular, R&F agar yielded a significantly greater selectivity than DFI agar in dried pumpkin (p < 0.05). Real-time PCR and R&F agar, which are currently recommended by US FDA, could be used as an alternative detection tools for the isolation of Cronobacter in PIF and ingredient of child foods such as dried pumpkin that has high number of competing natural microflora.

• Journal of the Korean Society of Marine Environment & Safety
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• 제16권3호
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• pp.269-274
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• 2010

Present state of nationwide marine facilities reported to Minister of Land, Transport and Maritime Affairs{MLTM} in Korea for two years 2008 and 2009 was analyzed, and management plan was proposed in this study. As of the end of 2009, total number of nationwide marine facilities was reported to be 672 and to be scattered along the coasts all over the nation. 124 marine facilities reported to Masan regional maritime affairs and port office occupied 18.5% of total nationwide number. 69 marine facilities reported to Mokpo regional office and 69 marine facilities reported to Pohang regional office occupied 10.3%, respectively. 181 marine facilities reported to Busan and Masan regional offices occupied 26.9%, meaning that about a quarter of total nationwide marine facilities concentrated in Southeastern Sea of Korea centering around Busan and Masan. 320 oil and noxious liquid substances storage facilities occupied 47.6% of total nationwide number. 11 pollutant storage facilities occupied 1.6%. 178 ship construction, repair and scrap facilities occupied 26.5%. 7 cargo handling facilities occupied 1.0%. 12 waste storage facilities occupied 1.8%. none of marine facilities for tourism, housing and restaurant were reported. 88 water intake and outlet facilities occupied 13.1%. 37 fishing spots at play occupied 5.5%. 13 other marine facilities occupied 1.9%. 6 integrated marine science base facilities occupied 0.9% of total nationwide number. The guidance and the public relation for national report system of marine facilities, the improvement of national report system and management plan, the advancement and complement of national report affairs-handling guides, and the voluntary participation in national report system and the performance of duties by the owners of marine facilities were proposed for better management plan of marine facilities.

• Journal of the Korean Society of Marine Environment & Safety
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• 제16권3호
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• pp.275-285
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• 2010

Present state of nationwide marine facilities reported to 12 regional maritime affairs and port offices of MLTM in Korea for two years 2008 and 2009 was analyzed based on region and type of facilities, and national management plan was proposed in this study. As of the end of 2009, 8 types of marine facilities were reported to Yeosu regional maritime affairs and port office, while only 3 types of facilities were reported to Pohang, Daesan and Jeju regional offices, respectively. Oil and noxious liquid substances storage facilities belonged in the type of facility which was reported to all of 12 regional offices, and ranged from 11 facilities reported to Pyeongtaek regional office to the respective 38 facilities to Yeosu and Masan regional offices. In pollutants storage facilities, 4 facilities were reported to Masan regional office, 2 facilities to Donghae and Mokpo regional offices, respectively, 1 facility to Yeosu, Gunsan and Pyeongtaek regional offices, respectively, and none of facilities to the other regional offices. Ship construction, repair and scrap facilities belonged in the type of facility which was reported to all of 12 regional offices, and 45% of the facilities were concentrated in Southeastern Sea of Korea centering around Busan and Masan. In cargo handling facilities, 3 facilities were reported to Busan and Masan regional offices, respectively, 1 facility to Daesan regional office, and none of facilities to the other regional offices. In wastes storage facilities, 5 facilities were reported to Ulsan regional office, 4 facilities to Gunsan regional office, 2 facilities to Incheon regional office, 1 facility to Yeosu regional office, and none of facilities to the other regional offices. 65% of nationwide water intake and drainage facilities were concentrated in the areas of Pohang and Mokpo, and 78% of nationwide fishing spots at play were concentrated in the area of Masan. In other marine facilities, 4 facilities were reported to Donghae regional office, 3 facilities to Masan regional office, 2 facilities to Yeosu and Pyeongtaek regional offices, respectively, 1 facility to Incheon and Ulsan regional offices, respectively, and none of facilities to the other regional offices. In integrated marine science base facilities, 3 facilities were reported to Jeju regional office, 1 facility to Yeosu, Ulsan and Gunsan regional offices, respectively, and none of facilities to the other regional offices. The management based on the circumstances of regional offices, the management based on the characteristics of the type of facilities, the amendment of the relevant rules and regulations, facility owner's full knowledge and observance of the relevant rules and regulations with regard to the relevant type of facilities, and positive management actions from national point of view were proposed for national management plans of marine facilities.

• Microbiology and Biotechnology Letters
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• 제35권1호
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• pp.17-25
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• 2007

The kinds and quantity of antimicrobial agents used for cattle (animal industry) may be considerable, suggesting the possibility that pathogenic bacteria which cannot be extirpated by the existing antimicrobial agents could appear. Ten cattle, pig and chicken farms, respectively, were randomly selected from 5 provinces in Korea and the samples were collected from excrement, manure, underground water, farmers' hands and the neishboring environment. h total of 299 samples were examined and 197 of Escherichia coli, 13 of Campylobacter jejun/coli, 223 of Enterococcus faecium/faecalis and 42 of Staphylococcus aureus isolates were collected. All isolates were screened for antimicrobial resistance: 69.4% of E. coli (137/197 strains), 78.6% of S. aureus (33/42 strains), and 82.1% of E. faecium/faecalis (183/223 strains) were resistant to one antimicrobial agent and all of C. jejuni/coli Isolates showed the resistance to one antimicrobial agent. Meanwhile, the multiple resistance ratio for more than 4 lines of antimicrobial agent was 19.2% of E. coli (38/197 strains), 11.9% of S. aureus (5/42 strains), 15.4% of C. jejuni/coli (2/13 strains) and 6.2% of E. faecium/faecalis (14/223 strains). The antimicrobial resistance ratio of bacteria isolated from the cattle farm showed lower than that of bacteria isolated from the pig or chicken farm, which might be related to the quantify of antimicrobial agents consumed. And one strain of vancomycin resistant E..faecium (VREF) were isolated from the excrement of chicken and stream, respectively. Generally, the ratio of VREF collected in animal farm environments is lower than that of VREF collected in medical environment.

• Journal of the Korean Society of Marine Environment & Safety
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• 제23권5호
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• pp.513-523
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• 2017

We evaluated the viability of phytoplankton along the salinity gradient in the flood and ebb tides of spring tide of February and the ebb tide of neap tide of March 2017 in the Seomjin River Estuary. Additional laboratory experiments were also conducted to determine the reason of the pH changes along the salinity gradient using the field natural sample in February. In field, saltwater was well mixed at downstream vertically and the salinity gradient was horizontally appeared toward upstream of freshwater zone. There were strong negative correlations between salinity and nutrient (nitrate + nitrite R=0.99, p<0.001, and silicate R=0.98, p<0.001), implying that those two nutrients of freshwater origin were gradually diluted with mixing the saltwater. On the other hands, relatively high phosphate concentration was kept in the stations of saltwater over 15 psu, indicating that it was caused by resuspended sediments of Gwangyang Bay and downstream by tidal water mixing.Among phytoplankton community structure in winter, Eucampia zodiacus have occupied to be c.a. 70 % in the most stations. Based on the field survey results for survivability of phytoplankton by phytoPAM instrument, there was positive correlations between salinity and chlorophyll a (R=0.82, p<0.001) and, salinity and active chlorophyll a (R=0.80, p<0.001), implying that the dominant marine diatom species may have significantly damaged in low salinity conditions of upstream. Also, maximum mortality rate of phytoplankton caused by low salinity shock was appered to be 75% in the upstream station. In particular, the pH in spring tides of February had tended to increase with high phytoplankton accmulated stations, suggesting that it was related with absorption of $CO_2$ by the photosynthesis of dominant diatom. In laboratory experiments, phytoplankton mass-mortality caused by low salinity shock was also occurred, which is confirmed with reducing the photosynthetic electron transport activity. Following the phytoplankton mass-mortality, bacteria abundance was significantly increased in 24 hours. As a result, the mass-proliferating bacteria can produce the $CO_2$ in the process of biodegradation of diatoms, which can lead to pH decrease. Therefore, marine phytoplankton species was greatly damaged in freshwater mixing area, depending on along the salinity gradient that was considered to be an important role in elevating and reducing of pH in Seomjin River Estuary.

• Food Science and Preservation
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• 제14권1호
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• pp.35-41
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• 2007

As the consumption of environmentally friendly agricultural products increases, food safety is at the forefront of public health concerns. We analyzed the biological hazards of 26 species of leaf vegetables and 4 species of fruit according to types of cultivation (conventional or organic filming) and distribution system (giant retailers or organic food stores) using various culture media, automatic bacterial identification systems, and microscopy, Total bacterial count of unwashed agricultural product ranged from $5.2{\times}10^{3}\;to\;1.5{\times}10^{5}\;CFU/mL$ (from 0.1 g of agricultural products), and the average count dropped 25-fold (range, 8-60-fold) after water washing. Microbial levels of washed organic agricultural products were $6.0{\times}10^{2}-1.9{\times}10^{4}\;CFU/mL$, and were not significantly different f개m the microbial loads on conventionally farmed produce. There was no significant difference in bacterial count from agricultural produce purchased from giant retailers or organic food stores. Total microbial count of Chinese cabbage, welsh onion, red chicory and kale were comparatively high, and Enterobacter cloacae was isolated most frequently. Parasites were detected in agricultural products purchased from conventional farm products in the stores of giant retailers, and in organic food stores, and parasite prevalence was especially high in Chinese cabbages and welsh onion. The study indicated that cultivation methods and distribution systems did not cause significant differences in biological contamination levels of agricultural produce. Some vegetables and fruits were highly contaminated effective sanitizing methods to reduce these biological hazards are needed.