• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.5
• /
• pp.501-507
• /
• 2014

Norovirus (NoV) is a major cause of food poisoning outbreaks in Korea. Most NoV outbreaks originate from environmental contamination, but bivalves such as oysters are also important vectors. Oyster Crassostrea gigas contamination by NoV has been reported in Korea, but no quantitative analyses of NoV have been performed. We investigated the NoV concentration in 21 oyster samples from a Korean commercial oyster-growing area with confirmed fecal contamination from January to December 2012, using real-time reverse transcription-polymerase chain reaction. Additionally, we assessed the NoV concentration after heating to investigate the effects of heat treatment on NoV-infected oysters. In NoV-positive samples, the cycle threshold (Ct) values were 37.43-39.41 and 36.77-39.30, while viral concentrations were $8.97{\times}10^2-2.24{\times}10^2$ and $3.05{\times}10^2-7.47{\times}10^1$ copies/g for genogroups I and II, respectively. After heat treatment, NoV genogroup I decreased by 83.4%, 88.0%, 89.4% and 100% at $60^{\circ}C$, $68^{\circ}C$, $70^{\circ}C$, and $100^{\circ}C$, respectively, for 15 min, while genogroup II respectively decreased by 67.3%, 76.3%, 80.1%, and 89.8% under the same conditions.

• Journal of Food Hygiene and Safety
• /
• v.30 no.4
• /
• pp.350-358
• /
• 2015

This study was designed to evaluate the sanitary characteristics of sea water in a part of the south coast, Korea and to check the seawater which is in compliance with the recommended bacteriological criteria for shellfish cultivation. The samples of sea water were collected at 14 sampling stations established in the survey area between March 2014 and October 2014. Food poisoning caused by seafood consumption is often associated with pathogenic microorganisms originated from fecal contamination. Therefore, fecal coliform is very important criteria for evaluating the safety of fisheries in coastal areas. The range of geometric mean (GM) and the estimated 90th percentile values of total coliform were 4.1~83.1 MPN/100 mL, and 11.7~834.1 MPN/100 mL, respectively. The GM and the estimated 90th percentile values of fecal coliform were 2.5~22.7 MPN/100 mL and 2.5~170.0 MPN/100 mL, respectively. Therefore, the bacteriological safety of seawater at this shellfish-growing area met with the Korean Shellfish Sanitation Program (KSSP) criteria for a growing area. However, the values are seasonally exceed the KSSP criteria, suggesting that the monitoring and evaluation of seawater quality is very important in shellfish-growing area.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.45 no.6
• /
• pp.561-569
• /
• 2012

To evaluate the bacteriological water quality in Yongnam-Gwangdo, located in western Jinhae Bay, seawater samples were analyzed using sanitary indicator bacteria at 57 sampling stations. According to survey results from January 2007 to December 2009, the range of the geometric mean and the estimated 90th percentile for coliforms and fecal coliforms in the samples were <1.8-16.5 and 1.8-246.8 MPN/100 mL and <1.8-7.1 and 1.8-74.8 MPN/100 mL, respectively. The samples, including those taken from stations located in Wonmunman, Gwangdo, and Dangdong, showed high levels of microbial contamination caused by the climate and weather patterns in the marine environment. The bacteriological water quality in the area met Korean criteria for a designated shellfish growing area for export and National Shellfish Sanitation Program criteria for an approved shellfish growing area, except at station #49. A total of 24 direct pollution sources were discharged into the shellfish growing area. The radius of impact was calculated for each pollution source to assess the effect on the shellfish growing area. The calculated radius of impact for most of the pollution sources was below 300 m. However, the radius of impact for the combined pollution sources in Kyeonnaeryang was 93-1973 m. There were significant differences between the calculated closed sea area and actual monitoring results. The closed sea area values calculated from the fecal coliform load in drainage water tended to be higher than the actual monitoring results. Tidal currents and environmental factors such as salinity, water temperature, sunlight, and microbiological factors affect the survival of fecal indicator bacteria in seawater.

• Journal of Korean Society of Environmental Engineers
• /
• v.33 no.11
• /
• pp.827-833
• /
• 2011

In this study, fecal nonpoint pollutant sources tracking were conducted on Ansan stream. Multiple Antibiotic Resistance Analysis (MARA) method used in this study is based on the premise that fecal bacteria derived from intestine of human or animal has each different resistance for antibiotics. First of all, a database for known sources should be established to use the method and then, an unknown sample was applied on the database to find unknown sources by statistical analysis. The Ansan stream was considered with divided condition into three parts: upper (livestock farming area), mid (old section of the city), and downstream (new section of the city) to search an environmental influence of the stream basin. As results of the statistical analysis, it could be estimated that the upper stream area was influenced by animals due to the nature of influence for the livestock farms located in this area because livestock were classified as percentages of 45.8% in 3-way method divided into livestock, pet and human. In case of midstream and downstream, the human influence was remarkable as percentage of 60% and 80%, respectively. From these results, it could be judged that the MARA method is useful in source tracking the non-point pollutant sources because the MARA results correspond to which predictable non-point pollutant sources by a field study. Also, it is expected that a more effective source tracking will be possible as establishing database of each area.

• Korean Journal of Microbiology
• /
• v.49 no.4
• /
• pp.424-428
• /
• 2013

To identify risk factors for Legionella contamination, water quality variables routinely measured in examination of natural and city waters were meta-analyzed for significance of correlation to Legionella incidences. For evaluation of abundance of Escherichia coli as a risk factor, which is currently used as an indicator of Legionella contamination in an official guideline in Korea, odds ratio (OR) of above-cutoff total coliform counts for Legionella presence/absence was used as the effect size in the meta-analysis. The OR was estimated as 1.05 (0.36-3.12, 95% CI), and the probability of having identical odds reached 0.92. Also, ORs from individual studies showed significant heterogeneity (P=0.008), which contributed to 63% of total variance of the ORs. In the case of heterotrophic plate count (HPC), the OR for Legionella presence/absence was 2.72 (2.04-3.63) with highly significant deviation from identical odds (P<0.0001). ORs from different studies were seemingly homogeneous ($Q_{df=8}$=12.7, P=0.12). Turbidity and concentrations of chlorine, iron ion and cupper ion were other routine variables that could be considered as risk factors. However, statistical measures from different studies were not uniform enough to develop an appropriate effect size while the number of studies reporting the variables was also small (3-5). In conclusion, HPC appeared to be appropriate as indicator of Legionella contamination, rather than fecal bacteria contamination. HPC may imply abundance of habitats (amoebas and biofilms) of Legionella in water. This result warrants further studies for standardizing protocols and cutoff values to infer Legionella risks from HPC.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.16 no.1
• /
• pp.31-36
• /
• 1983

This experiment was carried out to evaluate the sanitary quality of ground water in Pusan area(see Fig. 1). One hundred and thirty two water samples were collected from the 11 stations from October 1981 to Sept ember 1982. To evaluate the sanitary quality, coliform group, fecal coliform, viable cell count and composition of coliform group by IMViC reaction were observed. The median value of coliform group MPN of the samples were 59/100 ml in Udong and Daesindong, 68/100 ml in Suyeong, Yeonsandong and Sungjigog, 43/100 ml in Jenpodong and Mangmidong, 33/100 ml in Yeongdo and Dongrae, and 13.3/100 ml in Gammandong. Geometric mean of fecal coliform MPM was 4.1/100ml in Udong, 8.6/100 ml in Suyeong, 8.1/100 ml in Jenpodong, 6.1/100 ml in Daesindong and Dongrae, 8.7/100 ml in Yeongdo, 7.1/100 ml in Mangmidong, 6.5/100 ml in Yeonsandong, 9.1/100 ml in Sungjigog, 3.0/100 ml in Gammandong and 7.6/100 ml in Gupo. The seasonal difference of total coliform showed much more contamination in June or July when there were more climers than in December though it was caused by the rise of loafer temperature. With 50 percentile of total coliform MPN July was about 30 times higher than December for July was 163.5/100 ml and December 5.3/100 ml, Particularly, June was about 1.3 times higher than July in contamination because of a sudden increase of people using it. Composition of coliform was $7.64\%$ Escherichia coli, group, $42.86\%$ Citrobacter freundii group, $16.78\%$ Klebsiella aerogenes group and $32.72\%$ others. Plate count of samples was varied from 48 to $4.4{\times10}^2/ml$ during the study period.

• Journal of the Korean Dietetic Association
• /
• v.4 no.2
• /
• pp.235-244
• /
• 1998

Hand washing is an important component of hygiene program for food handlers. Hands can be a source of direct or indirect contamination of foods with pathogenic microorganisms. In this study, the effectiveness of hand washing methods and the use of 70% alcohol solution against transient skin bacteria was tested in an university foodservice facility. 70% alcohol solution is sprayed for 5 seconds automatically when hands are placed in the dispenser. Samples were taken using swab technique in meat cutting area, vegetable trimming area, and vegetable cutting area: before and after washing hands according to planned methods, and after being sprayed with 70% alcohol solution after washing hands. The bacteriological analysis of total plate counts, coliform, fecal coliform of food handlers' hands was done. Statistical data analysis was completed with Mann-Whitney U test and Kruskal-Wallis model using the SPSS program. The levels of initial contamination of workers' hand were significantly different by the work areas($x^2$=9.156, p<0.01). Workers in the vegetable trimming area had more heavily soiled hands than in the other work areas. Mean of TPC counts and coliform was 8.97×$10^5$ CFU/12.4$cm^2$, 2.93×$10^2$ MPN/12.4$cm^2$ respectively, but fecal coliform was not detected. Transient bacteria were removed from hands after washing and using 70% alcohol solution but were not removed completely. Mean reduction percentage in TPC varied among work areas and ranged from 93.19% to 94.99%, and in coliforms from 97.31% to 100%. A significant difference in TPC was found between before and after hand disinfection (Z=-2.714, p<.01) and between standardized hand washing procedures and un-standardized hand washing procedures(z=-2.301, p<.01). Subjects using the hand sanitizer showed a great elimination of TPC(99.45% reduction), but this effect was valid only after following proper washing procedures. Based on the results, the most effective hand washing method was recommended as the combination of the standardized hand washing procedure with warm-water and use of the 70% alcohol solution. The results can be used to develop hand hygiene programs and training strategies for enhancing hand hygiene practices for food handlers in foodservice operations.

• Journal of environmental and Sanitary engineering
• /
• v.4 no.2 s.7
• /
• pp.47-59
• /
• 1989

In order to investigate the bacteriological contamination of water in Han river, the survey was carried out in eight reservoirs of Seoul water supply during the period from January to December in 1985. 1. The counts by means of total bacteria in eight reservoirs by standard plate count method were as follows: $7.7\times10^2$ per ml in Paldang reservior, $9.6\times10^3$ per ml in Gueiri, $8.4\times10^4$ per ml in Doogdo, $1.6\times10^6$ per ml in Bogwang, $2.5\times10^6$ per ml in Noryangjin, $2.2\times10^6$per ml in Seon yoo, $5.9\times10^6$ per ml in Yungdeungpo and $1.9\times10^7$per ml in Gayang. 2. The average counts of total coliform in eight reservoirs by MPN method were as follows : $2.4\times10$ per 100 ml in Paldang, $5.6\times10^2$ per 100 ml in Gueiri, $2.3\times10^3$ per 100 ml in Doogdo, $5.1\times10^4$ per 100 ml in Noryang-jin, $1.2\times10^5$ per 100 ml in Bogwang, $6.2\times10^4$ per 100 ml in Seonyoo, $1.1\times10^5$ per 100 ml in Yungdeungpo and $2.8\times10^5$ per 100 ml Gayang. 3. The counts by means of fecal coliform in eight reservoirs by MPN method were as follows : non detection per 100 ml in Paldang, 5.2 per 100 ml in Gueiri, $1.2\times10^2$ per 100 ml in Doogdo, $1.6\times10^3$ per 100ml in Bogwang, $2.0\times10^3$per 100ml in Noryangjin, $6.6\times10^2$ per 100ml in Seonyoo, $1.2\times10^3$ per 100 ml in Yungdeungpo and $2.5\times10^3$per 100 ml in Gayang. 4. The counts by means of fecal streptococci in eight reservoirs by MPN method were as follows: non detection per 100 ml in Paldang and Gueiri, $6.9\times10$ per 100 ml in Doogdo, $3.2\times10^2$ 102 per 100 ml in Bogwang, $2.9\times10^2$ per 100 ml in Noryangjin, $3.0\times10^2$ per 100 ml in Seonyoo, $4.0\times10^2$ per 100 ml in Yungdeungpo and $14\times10^3$ per 100 ml in Gayang. 5. The counts means of pseudomonas aeruginosa in eight reservoirs by MPN method were as follows; non detection per 100 ml in Paldang, 2.4 per 100 ml in Gueiri, $1.5\times10$ per 100 ml in Doogdo, $2.0\times10$ per 100ml in Bogwang,$6.2\times10$ per 100mI in Noryangjin, $2.1\times10$ per 100ml in Seonyoo, $6.4\times10$ per 100mI in Yungdeungpo and $7.1\times10$ per 100ml in Gaynag.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.38 no.2
• /
• pp.118-128
• /
• 2005

Surface sediment samples from 31 stations in Jinhae Bay were analyzed to evaluate the pollution by sewage from the spatial distribution of the fecal sterol, coprostanol. The sums of eight sterols (coprostanol, epicholestanol, epicoprostanol, cholesterol, cholestanol, brassicasterol, stigmasterol and $\beta$-sitosterol) were in the range of $2,703-27,154{\cal}ng/{\cal}g$ dry weight. The concentrations of the coprostanol in the sediments, which is a good tracer of sewage-derived organic contamination, were in the range of $76-3,964{\cal}ng/{\cal}g$ dry weight. The levels of coprostanol were much higher (almost one order of magnitude) at stations close to the big cities such as Masan and Jinhae. However, those levels were comparable to or lower than those previously reported in other foreign locations. Some ratios of coprostanol to other sterols and multivariate analysis could provide us with the information on the origin of the sterols being from sewage, plankton, and/or benthos. Those showed sewage dominance at the stations near the cities Masan and Jinhae, plankton dominance at the center of Jinhae Bay and mainly marine fauna origin at the mouth of Jinhae Bay. These results suggest that the contents of sterols and some ratios of these components are quite powerful tracer for the detection of the origin of the organic contaminants in the coastal environments.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.45 no.5
• /
• pp.414-422
• /
• 2012

This study evaluated the effect of the inland pollution sources on the bacteriological water quality in Narodo area after rainfall events. Following 16 mm of rainfall, the water discharged from Dohwa Stream and contaminants from Balpo village had a very limited effect on bacteriological water quality in adjacent area and the affected area did not extend to the designated area. In comparion, after 33 mm of rainfall, the density of fecal coliforms at stations located in the mouth of Dohwa stream and the discharg point of contamination sources located in Balpo village were lower than after 16 mm of rainfall. These results were obtained during an extreme high tide near the coast the contaminants discharged from Dohwa stream and Balpo village. Therefore, it is necessary to conduct a detailed survey to examine the dffects of tides on the diffusion characteristics of the contaminants discharged from Dohwa stream and Balpo village in order to manage of Narodo area efficiently.