• 한국물환경학회지
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• 제26권1호
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• pp.28-34
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• 2010

This study was conducted to assess the validity of fecal coliforms to fecal streptococci ratio (FC/FS) for distinguishing the human from animal origin of fecal pollution in surface water. FC/FS ratio determined in effluent from municipal wastewater and human feces treatment plant (WWTP) and in downstream close to discharge of human feces was above 4 which indicates human origin. However FC/FS ratios determined seasonally in other water zones of the Nakdong River, even in the same sampling site, varied differently (above 4 or less than 0.7) due to different survival time of FC and FS and other environmental factors such as rainfall in watershed. Compared to other season, FC/FS ratios in winter were much lower regardless of the origin. It is concluded that the FC/FS ratio determined in surface water is not always valid for determining the origin of fecal pollution.

• 한국환경보건학회지
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• 제42권3호
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• pp.189-195
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• 2016

Objectives: To ensure the microbiological safety of groundwater, it was confirmed whether waterborne pathogenic bacteria in groundwater samples tested positive for total coliforms in the Chungcheongnam-do Province region. Methods: Total colony counts, total coliforms and fecal coliforms were tested according to the process mandated by the drinking water quality testing standards of Korea. DNA was extracted from the samples, tested positive for total coliforms, and then subjected to real-time PCR to detect waterborne pathogenic bacteria. Results: A total of 115 samples were inadequate for drinking water. Thirty-one cases (27%) showed positive for fecal coliforms and nine cases (7.8%) showed total colony counts exceeding drinking water standards. Twenty-seven cases (23.5%) showed three items (total colony counts, total coliforms and fecal coliforms). Using the real-time PCR method, waterborne pathogens were detected in 57 cases (49.6%) in 115 samples. Seventy-eight cases of waterborne pathogenic bacteria were detected (including duplications): 27 cases of pathogenic E. coli (EPEC (19), ETEC (5), EHEC (1), EAEC (1) and EIEC (1)); 45 of Bacillus cereus; two of Yersinia spp.; two of Salmonella spp.; one of Staphylococcus aureus; one of Clostridium perfringens. Conclusion: The real-time PCR method can offer rapid and accurate detection of waterborne pathogenic bacteria. Therefore, this assay could be an alternative to conventional culture methods and can further ensure the microbiological safety of groundwater.

• Environmental Engineering Research
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• 제21권2호
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• pp.211-218
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• 2016

Cheonggye-cheon is a partly restored urban stream located in central Seoul. We monitored fecal contamination using three different fecal indicators, total coliforms (TC), fecal coliforms (FC) and E. coli, to assess differences in each indicator on days of varying weather conditions. Presumptive TC, FC and E. coli colonies were identified by their 16S rRNA sequences. The results showed that enumeration of E. coli provided a better reflection of fecal contamination of the stream than TC and FC. The main sources of contamination were the inflow of fecal-polluted groundwater from the vicinity of a subway line and two inflowing streams. The fecal contamination was worsened on days with heavy rain because untreated sewage from a collecting facility flowed into the stream. Moreover, growth potential of fecal indicator (E. coli) in situ induced by algal exudates was measured. Our results suggest that an appropriate standard based on E. coli rather than TC and FC should be established for improving water quality management strategies of Cheonggye-cheon in the future.

• 한국환경보건학회지
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• 제39권6호
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• pp.513-521
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• 2013

Objectives: This study was performed in order to detect indicator bacteria in drinking spring water (DSW) samples in Seoul Metropolitan City, and to identify their genus through 16S rRNA sequencing and then assessing the genetic relation of their strains. Methods: For indicator bacteria detection and identification of total coliforms, we analyzed DSW between the spring and summer seasons. In particular, DSW samples were chosen from sites repeatedly found unsatisfactory in recent years. Results: Heterotrophic plate counts of DSW in the spring and summer season were investigated in the range of 0-550 and 0-800 CFU/mL, respectively. Total coliforms of these were 0-1,900 and 0-2,100 CFU/100mL, fecal coliforms were 0-600 and 0-550 CFU/100mL, and Escherichia coli were 0-7 and 0-326 MPN/100mL. The detection ratio of fecal pollution indicators and that of fecal coliforms increased to 58.6% in the summer from 12.5% in the spring and Escherichia coli increased to 51.4% from 4.7%. As a result of genetic analysis on the isolated bacteria, the genus of total coliforms was classified in the order of Enterobacter spp. 12.7%, Serratia spp. 7.3%, E. hermanii 6.4%, Rahnella spp. 5.5%, Hafnia spp. 4.5%, Escherichia coli 3.6%, Klebsiella spp. 3.6% in the spring season. In the summer season, it was classified in order of Klebsiella spp. 16.6%, Enterobacter spp. 13.0%, Escherichia coli 11.0%, Serratia spp. 8.6%, Raoultella spp. 7.0%, Kluyvera spp. 5.6% and Citrobacter spp. 3.0%. Conclusions: The increase of fecal pollution in summer indicates that special attention to drinking DSW is required.

• 상하수도학회지
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• 제20권6호
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• pp.885-892
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• 2006

In order to investigate whether or not Total Coliforms (T.C.) and Fecal Coliforms (F.C.) are compatible as indicator microorganisms of waterbome enteric viruses, a total of 192 surface water samples from 24 locations in Korea were tested for T.C., F.C., and human enteric viruses from July 2003 to January 2006. Altogether, the number of T.C. in each samples was ranged from $0{\sim}5.3{\times}10^4$ colony forming unit(CFU)/100mL, and the number of F.C. ranged from $0{\sim}5.0{\times}10^3CFU/100mL$ per sample. Thirty-three percent of the samples tested positive for human enteric viruses after the total culturable virus assay. The results of the statistical analysis showed that T.C. and F.C. had a significant correlation with turbidity and temperature, but the waterbome enteric viruses did not. When compared to the number of T.C. or F.C. per sample, the concentration of waterbome enteric viruses was not found to be correlated. In conclusion, it is suggested that T.C. and F.C. may not be sufficient microbial indicators of waterbome enteric viruses in the samples analyzed in this study. However, further research is needed to find other microbial indicators of waterbome enteric viruses and to develop more advanced and sensitive methods to detect waterborne enteric viruses.

• Environmental Engineering Research
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• 제20권4호
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• pp.403-409
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• 2015

This study aims to investigate the use of a floating media filter (FMF) to eliminate waterborne microorganism in treated domestic wastewater for reuse in agriculture. A conventional sand filter (SF) was used concurrently to compare treated water quality. The total/fecal coliforms and somatic coliphage were employed as fecal indicators. The result showed that the FMF was fed with 3 times higher infiltration rate ($15m^3/m^2.h$) than that in the SF ($5m^3/m^2.h$), in which both filters gave similar coliform removal at 6 hours operation. The somatic coliphage elimination tended to increase with operational time for the FMF while that of the SF showed decreasing trend. When a 24 hour continuous operation was applied for the FMF, it showed better removal of somatic coliphage (78%), fecal coliforms (60%) and total coliforms (56%) than that of 6 hour operation. In conclusion, the FMF gave better performance than the SF did by producing a good quality of treated water for agriculture in terms of waterborne microorganisms including turbidity and suspended solids.

• 한국환경보건학회지
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• 제37권4호
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• pp.289-297
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• 2011

Objectives: To estimate the microbial contaminant load discharged from livestock farms, we randomly selected livestock farmers of cattle, swine, and fowl and collected bacterial strains from domestic animals' feces and compost samples. Recently, as multi-antibiotic-resistant bacteria and super bacteria showing resistance to a variety of antibiotics have been reported one after another, the ecological and health hazard of antibiotic-resistant bacteria is emerging as an important issue. Methods: Monitored indicator microorganism constituents were totak coliform (TC), fecal coliform (FC), and aerobic bacteria. The multi-antibiotic-resistant bacteria were identified from investigated indicator microorganisms by 16S rRNA sequencing. Results: By microbiological analysis, the largest population of aerobic bacteria ($1.5{\times}10^5$ CFU/g) was found in cattle fecal compost, and total coliforms ($1.1{\times}10^7$ CFU/g) and fecal coliforms ($1.0{\times}10^5$ CFU/g) were found primarily in swine fecal compost, while the lowest population was found in fowl fecal compost. Among the 67 strains separated from aerobic bacteria, five strains expressing high antibiotic resistance were selected in each sample. We found the multi-antibiotic resistant strains to be Shigella boydii, Staphylococcus lentus, Acinetobacter sp. and Brevibacterium luteolum. Conclusions: These results suggest that increasing numbers of multi-antibiotic-resistant bacteria in the environment have a close relation to the reckless use of antibiotics with livestock.

• 한국물환경학회지
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• 제32권3호
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• pp.271-280
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• 2016

The aim of this study was to analyze spatial and temporal patterns of bacterial pollution levels and the relationship between bacterial pollutants and environmental parameters at the main stream and tributaries of Nakdong River. Water quality data including total coliform and fecal coliform were compiled from a total of 50 monitoring sites (30 at the main stream and 20 at the tributaries) along with rainfall and discharge data for three consecutive years from 2012 to 2014. During the study periods, the geometric mean values of total coliforms and fecal coliforms in the main stream were 74 (22~465) CFU/100 mL and 8 (3~42) CFU/100 mL, respectively. The geometric mean values of total coliforms and fecal coliforms in the tributaries were 275 (36~5,145) CFU/100 mL and 6 (1~1,352) CFU/100 mL, respectively. High concentrations of fecal coliforms were observed at Gumi (M 10), Hyeonpung (M 19), Hapcheon (M 23), and Namji (M 25) in the main stream, whereas Gamcheon (T 6), Bakcheon (T 7), Geumho-gang (T 8), and Gyeseongcheon (T 16) were identified as pollution hot spots in the tributaries. Although bacterial pollution levels showed complex behavior across monitoring sites and time, the highest coliform concentrations were routinely observed in the monsoon season between July and September of each year, indicating that the pollution levels were strongly dependent on precipitation in addition to other physiochemical parameters. Statistically significant correlations were found between fecal coliform concentrations and precipitation (r=0.403, p<0.01), followed by SS (r=0.425, p<0.01), nutrient TP (r=0.388, p<0.01), organic matter COD (r=0.322, p<0.01), and PO₄-P (r=0.317, p<0.01) in the main stream in the order of correlation coefficient from high to low.

• 한국수산과학회지
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• 제43권1호
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• pp.25-32
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• 2010

A Sanitary survey in an Important shellfish-growing area of Biin Bay in Seocheon-gun Korea, was conducted to evaluate bay conditions and compliance with the bacteriological criteria for areas designated for the production of shellfish for export. Seawater samples were collected monthly at 55 sampling stations established in the survey area from January 2006 to December 2008. Bacteriological water quality did not change in response to a small rainfall (10.0 mm), but it increased abruptly in response to rainfall to 62.5 mm The most probable number (MPN) value for total coliforms and fecal coliforms in 1, 980 seawater samples ranged from <1.8 to >1, 600 MPN/100mL and from <1.8 to 330 MPN/100mL, respectively. The geometric mean and estimated $90^{th}$ percentile value for total coliforms ranged from 2.0 to 10.3 MPN/100mL and from 7.0 to 42.6 MPN/100mL respectively. The geometric mean and estimated percentile value for fecal coliforms ranged from 1.8 to 4.0 MPN/100mL and from 1.9 to 18.3 MPN/100mL, respectively. Accordingly, the bacteriological water quality of Biin Bay met the National Shellfish Sanitation Program (NSSP) and Korea Shel1fish Sanitation Program(KSSP) criteria for areas designated for shellfish production for export in Korea.

• 한국수산과학회지
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• 제51권5호
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• pp.535-541
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• 2018

This study evaluated the sanitary state of seawater and shellfish in Yongnam-Gwangdo area from January 2014 to December 2016. The sampling stations for sanitary survey in Yongnam-Gwangdo area were composed of 41 seawater stations and 5 oyster Crassostrea gigas stations. The samples were collected monthly at each station. Shellfish-borne disease is associated with bacteria and viruses in the presence of fecal coliforms. Bacteriological pollution levels of shellfish increase with seawater quality. Therefore, fecal coliforms are very important criteria for evaluating the safety of fisheries in coastal areas. The geometric mean and the estimated 90th percentile ranges of total and fecal coliforms for seawater were 1.8-11.7, 2.8-233.6, <1.8-6.7 and 1.8-100.2 MPN/100 mL, respectively. The range of E. coli levels for oysters was <20-1,300 MPN/100 g. Based on various standards, the sanitary condition in Yongnam-Gwangdo area was evaluated as follows: clean area (Korean criteria), conditionally approved area (US criteria) and class B (EU criteria).