• 한국환경보건학회지
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• 제40권2호
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• pp.88-97
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• 2014

Objectives: The aim of this study was to evaluate the occurrence of microbiological contamination of kitchen utensils and environments of food service operations at university located in Seoul, Korea. Methods: We collected swab samples from the surfaces of knives, chopping boards, floors, and drains, as well as drinking water and airborne bacteria samples from 20 food service operations. Three bacterial indicators and five food poisoning bacteria were measured quantitatively and qualitatively, respectively. We used selective culture media and the PCR assay targeting 16S rRNA gene for the microbiological analysis. Results: We detected bacterial indicators on knives or chopping boards in eight different food service operations and, three food service operations (I, M, and O) showed more than 3 log colony forming units $(CFU)/100cm^2$ on their knives, significantly higher than the others. The levels of bacterial indicators on the floors and drains in the cooking areas were much higher than those on the cooking utensils. S. aureus was detected on 10 floors and 8 drains. Culturable bacteria were identified in 5 drinking water samples, and food service operation B ($431.1CFU/m^3$) and C ($551.2CFU/m^3$) showed more than $400CFU/m^3$ of total airborne bacteria. Conclusions: These results suggest that some of food service operations in this study may require additional investigation to secure the microbial safety of cooking environments. In addition, further actions including hygiene education for employees and proper guidelines to maintain clean cooking environments should be prepared.

• 한국수산과학회지
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• 제54권6호
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• pp.904-911
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• 2021

For the safety assessment of microbiological and chemical hazards in dried sea mustard, fifteen samples of dried sea mustards Undaria pinnatifida were purchased from the supermarkets distributed throughout Korea. The contamination levels of total viable bacteria, coliforms, Escherichia coli, and nine pathogenic bacteria [Staphylococcus aureus, Salmonella spp., Listeria monocytogenes, Bacillus cereus, Vibrio spp., Clostridium perfringens, Enterohemorrhagic Escherichia coli (EHEC), Yersinia enterocolitica and Campylobacter jejuni/coli] were quantitatively or qualitatively assessed. Also, the heavy metals (lead, cadmium, total mercury, and inorganic arsenic), and radioactivity (¹³¹I, ¹³⁴CS+¹³⁷CS) were quantitatively assessed. This microbial and chemical analysis was performed using standard methods in Korean food code. The total viable bacteria ranged from 4.3×10² (5.0×10-1.5×10³) CFU/g. Coliforms and E. coli were not detected in all samples (ND, <1 log₁₀ CFU/g). All nine pathogenic bacteria were qualitatively detected as negative. The contamination levels of lead, cadmium, total mercury, and inorganic arsenic were 0.036 (0.015-0.051), 0.117 (0.088-0.156), 0.030 (0.017-0.048), and 0.058 (0.056-0.064) mg/kg, respectively. Radioactivity was also not detected in any sample. The microbial contamination levels determined in the current study may be potentially used as basis for performing microbial risk assessments of dried sea mustards.

• 한국수산과학회지
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• 제56권2호
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• pp.182-187
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• 2023

Fifteen samples of dried laver Pyropia tenera were collected from markets and processing plants in Korea for an assessment of their microbial and chemical hazards, in accordance with the Korean food code. The contamination levels of total viable bacteria, coliforms, Escherichia coli, and nine other pathogenic bacteria (Staphylococcus aureus, Salmonella spp., Vibrio parahaemolyticus, Clostridium perfringens, Listeria monocytogenes, Enterohemorrhagic Escherichia coli, Yersinia enterocolitica, Bacillus cereus, and Campylobacter jejuni) were evaluated The concentrations of heavy metals (lead, cadmium, total mercury, and total arsenic) and radioactive isotopes (¹³¹I, and ¹³⁴Cs+¹³⁷Cs) in the laver samples were also determined. The total viable count of bacteria was 2.62±0.80 (1.48-4.45) CFU/g. The contamination levels of lead, cadmium, total mercury, and total arsenic were 0.024±0.005 (0.018-0.035), 0.090±0.038 (0.041-0.146), 0.008±0.005 (0.003-0.018) and 1.315±0.372 (0.814-1.930) mg/kg, respectively. All samples tested negative for significant levels of radioactivity, the nine pathogenic bacteria, coliforms, and E. coli (<1.00 CFU/g). We assume that ensuring the microbiological and chemical safety of dried laver can increase the demand for its exportation. The present study may serve as a basis for microbiological and chemical hazard assessment of dried lavers.

• 한국임상수의학회지
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• 제19권1호
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• pp.7-13
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• 2002

This study was examined the microbiological adequacy of fish feed treated with high-dose irradiation (5 kGy). 125 flounder (Paralichthys olivaceus) were grouped into 5 and then the fishes were fed the following feeds for 28 days: (1)standard feed; (2)standard feed, inoculated with Edwardsiella tarda ($1{\times}10^8-1{\times}10^9CFU/g$ of feed); (3)standard feed, inoculated with Vibrio anguilarum ($1{\times}10^8-1{\times}10^9CFIT/g$ of feed); (4)standard feed, inoculated with Streptococcus faecalis ($1{\times}10^8-1{\times}10^9CFU/g$ of feed); (5)standard feed, inoculated with Edwardsiella tarda, Vibrio anguillarum and Streptococcus faecalis, and then irradiated the mixed feed to 5 kGy. The flounders feed the mixed diet with Edwardsiella tarda, Wbrio anguillarum or Streptococcus faecalis inoculated feed were showed severe cumulative mortalities of 60, 48 and 52% respectively. The gross and histological changes were observed on the fishes. However, fishs fed with the feed of bacteria inoculation before irradiation demonstrated excellent protection against the bacteria-related disease. The results from experiments with bacteria inoculated feed indicated that the irradiation methods employed were capable of preventing contamination of the fishs with pathogenic bacteria.

• 한국식품위생안전성학회지
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• 제17권2호
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• pp.55-60
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• 2002

In order to investigate the microbiological contamination of spring water, we performed the standard plate count, coliform and psychrotrophilic bacteria in 109 spring waters in Seoul. Of 109 spring waters, geometirc mean standard plate count was 0.19 CFU/ml, and the highest in Mt. Boolam, 4..43 CFU/ml and Mt. Dobong, 3.86 CFU/ml, but not detected in Mt. Woomyun and Mt. Cheonggye. Four spring waters have shown over 100 CFU/ml in standard plate count. The geometric mean psychrotrophilic bacteria was 49.2 CFU/ml, the most prevalent spring water was Mt. Nam, 125 CFU/ml, the lowest Mt. Woomyeun. Among a total of 109, coliform was detected from 21 spring waters(19.3%) and the geometric mean of coliform was 0.005 MPN/100ml. The isolated genera of coliform were 7 isolates of E. coli(33%), 5 Klebsiella(24%), 4 Enterobacter(19%), 3 Citrobacter(14%) and 2 Serratia(10%), respectively. The 22 spring waters(20.2%) failed to meet the standard limits of drinking water based on regulation in Korea. The inappropriate rate of standard plate count in spring water was 4.5%, that of coliform was 81.1% and both of them was 13.6%. There was the significant correlation between standard plate count and psychrotrophilic bacteria in spring water(r=0.95, p<0.01).

• 한국수산과학회지
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• 제52권2호
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• pp.180-184
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• 2019

Aerobic bacteria, coliforms, Escherichia coli, and pathogenic bacteria were investigated in laver Porphyra sp. samples from various regions of Korea. The mean bacterial counts were $6.9{\pm}0.87log\;CFU/g$ (range 4.0 to 7.7) log CFU/g in dried laver, $2.83{\pm}4.36log\;CFU/g$ in roasted laver, and $4.93{\pm}1.43log\;CFU/g$ in seasoned laver. Coliforms were most abundant (mean count: $2.1{\pm}1.01log\;CFU/g$) in dried laver. No pathogenic bacteria, including Staphylococcus aureus, Salmonella spp. Vibrio parahaemolyticus, or Listeria monocytogenes, were detected in any of the samples. Aerobic microorganisms were the most diverse microorganisms in dried laver. Staphylococcus spp. were predominant, but S. aureus was not detected. Standardization of laver production is necessary to ensure a hygienic product because laver products are often ingested without heating or cooking, and the production process is simple.

• 한국식품영양학회지
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• 제30권2호
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• pp.203-210
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• 2017

The purpose of this study was to compare hand washing awareness and microorganism contamination on the hands for evaluating the difference between awareness and conditions of hand hygiene. The average number of total aerobic bacteria and coliform was 2.7 log CFU/hand and 1.8 log CFU/hand, respectively. Coliform bacteria were detected in all of the students tested in this study. The questionnaire survey data obtained via a direct interview were collected from 100 university students with microorganism analysis. A majority (90%) of the students recognized that good hand hygiene is important in order to prevent food poisoning. In the hand washing survey data, the responses suggesting "always washed" from "before eating food", "after handling money", "after finishing study" and "after visiting patients" were observed in 18, 13, 15 and 33 out of the 100 students, respectively. The questionnaire data of hand washing frequency and time duration showed that 14 students and 6 students answered "more than 8 times of hand washing per day" and "more than 30 seconds of hand washing time", respectively. These results indicated that improper hand washing practices and poor hand hygiene were identified in the majority of the students. This emphasizes the difference between awareness and conditions of hand hygiene. Repeated hand washing education about the frequency, time duration and methods is constantly required to improve hand hygiene. Installation of hand washing equipment in the space of a restaurant and cafeteria is suggested for enhancing hand hygiene before eating food.

• 한국동물위생학회지
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• 제36권3호
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• pp.203-208
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• 2013

This survey was conducted to evaluate the microbial contamination level of butcher's shops in Seoul, Korea. For microbial inspections, a total of 584 samples (146 cotton work gloves, 146 utensils and equipments, 154 beef samples, 138 pork samples) were collected from butcher's shops. E. coli and pathogenic bacteria such as Staphylococcus aureus, Yersinia enterocolitica, Listeria monocytogenes, Salmonella spp., and E. coli O157:H7 were tested in the samples. As a result, the level of aerobic plate count (APC) ranged ${\leq}10^4\;CFU/cm^2$ from utensils and equipments, $10^1{\sim}10^9$ CFU/glove from cotton work gloves and ${\leq}10^6$ CFU/g from meat. The APC level of E. coli ranged ${\leq}10^1\;CFU/cm^2$ from utensils and equipments, ${\leq}10^5$ CFU/glove from cotton work gloves, and ${\leq}10^3$ CFU/g from meat, respectively. Staphylococcus aureus was detected in 2 beef samples, 1 pork sample, and 10 used cotton work gloves. Yersinia enterocolitica was detected in 3 beef samples, 1 pork sample, and 3 used cotton work gloves. Listeria monocytogenes was detected in 2 used cotton work gloves. In order to improve the sanitation status of butcher's shops, application of HACCP (Hazard Analysis Critical Control Point) or SSOP (Sanitation Standard Operating Procedure), regular hygiene education, and continuous monitoring for microorganisms will be required.

• Journal of Dairy Science and Biotechnology
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• 제23권1호
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• pp.65-71
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• 2005

Powered infant formula and baby food contaminated with Enterobacter sakazakii were reported to cause infection among infants and to be associated with sporadic cases and outbreaks of sepsis, menigitis, cerebritis, and necrotizing enterocolitis. Salmonella contamination of infant formula has also been responsible for multiple outbreaks. Other species of Enterobacteriaceae in powdered infant formula may be causative agents, about which there has been no report. Other pathogenic bacteria have been isolated from powdered infant formula but they were not associated with outbreaks among infant. While Enterobacter sakazakii caused disease in all age groups, premature infants under 28 days old and with birth weight are most sensitive to its infection. Even if low contamination level of the bacteria in powdered infant formula and baby food may not cause infection, the possibility to multiplicate during preparation and storage of reconstituted formula may increase. The etiological factors and pathogenecity of S. sakazakii have not been elucidated. There were wide variability in phenotype and genotype between its strains. S. sakazakii has been isolated from factory facility and surroundings more frequently than Salmonella and thus factory environment should be the source for post-processing contamination of the formula with S. sakazakii. Considering current technology to manufacture power infant formula and baby food it is impossible to sterilize powdered formula but the frequency of outbreak hazard by S. sakazakii can be reduced by pasteurizing the formula base before drying and shortening storage time of the reconstituted formula.

• 한국수산과학회지
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• 제57권1호
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• pp.15-22
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• 2024

This study assessed microbial contamination in seven fried fish pastes sold in Southeast Asian traditional markets during summer. It measured viable cell count, coliforms, Escherichia coli, fungi, and Staphylococcus spp. It also qualitatively analyzed Vibrio parahaemolyticus, Salmonella spp., Bacillus cereus, Listeria monocytogenes, and Clostridium perfringens. The average viable cell count, coliforms and fungi were detected as 6.34 (3.84-8.13), 2.16 (1.00-3.55), and 3.92 (1.85-7.74) log₁₀ CFU/g, respectively. Staphylococcus spp. was detected at 4.59 (2.10-7.63) log₁₀ CFU/g. Some samples had high contamination levels: viable cell count (8.13 log₁₀ CFU/g), fungi (7.74 log₁₀ CFU/g) and S. aureus (7.63 log₁₀ CFU/g). However, E. coli was not detected in any samples (ND, <1 log₁₀ CFU/g). V. parahaemolyticus, Salmonella spp., B. cereus, L. monocytogenes, and Cl. perfringens were also not detected in the samples. The microbial contamination data provide insight into managing microbial contamination and ensuring the safety of fried fish pastes in traditional summer markets.