• Title/Summary/Keyword: bacteria contamination

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Detection of Microbial Contamination in Commercial Berries

  • Cho, Kyu-Bong
    • Biomedical Science Letters
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    • v.23 no.4
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    • pp.333-338
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    • 2017
  • This study was performed to assess microbial contamination of Aronia melanocarpa, blueberry, raspberry, and cranberry sold in several markets. We investigated total aerobic bacteria and detected foodborne bacteria by multiplex PCR from Aronia melanocarpa, blueberry, raspberry, and cranberry. Total aerobic bacteria of each sample showed mean 3.54 log CFU/g for Aronia melanocarpa, mean 1.90 log CFU/g for blueberry, and mean 1.40 log CFU/g for raspberry, but not detected in cranberry. Specially, Aronia melanocarpa contained high total aerobic bacteria contamination among various berries and contamination level reached 4.17 log CFU/g in sample 5. To evaluate the effect of distribution conditions, we also investigated total aerobic bacteria of various berries. Total aerobic bacteria showed mean 2.89 log CFU/g for berries in refrigerated distribution and 1.40 log CFU/g in frozen distribution, but not in dry distribution. For assessment of foodborne bacteria contamination, we conducted PCR with multiplex primers of E. coli O157, S. aureus, B. cereus, V. parahaemolyticus, L. monocytogenes, Y. enterocolitica, Salmonella spp., Shigella spp. Among these foodborne bacteria, B. cereus was amplified in Aronia melanocarpa in sample 4 and blueberry in sample 1, 2, 3, and 5. The result of quantitative analysis of B. cereus contamination showed 4.08 log CFU/g of Aronia melanocarpa in sample 4 and higher contamination rate 4.07 log CFU/g of blueberry in sample 3. These results suggest that strict food safety control in harvest and distribution of various berries is necessary to prevent foodborne disease and improve microbiological safety.

Evaluation of Microbiological Contamination of Water Purifiers at Two Universities in Chungcheong Region

  • Jin Young Yun
    • Biomedical Science Letters
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    • v.29 no.4
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    • pp.256-262
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    • 2023
  • The purpose of this study is to investigate microbial contamination in water purifiers from two universities (A and B) in Chungcheong region and to evaluate about the harmfulness of the isolated bacteria to the human. The degree of microbiological contamination of six water purifiers at university A was investigated three times from July 2018 to September 2019, and nine water purifiers at university B were investigated in 2023. The isolated bacteria were biochemically identified using an API kit and Vitek-2 system, and then the bacteria were identified to the species level using MALDI-TOF MS. In addition, the possibility of human infection of the isolated bacteria was evaluated through a literature search. In July 2018 and September 2019, the number of bacteria isolated inside the faucet was below the acceptable standard for hot water, but exceed for cold water in all water purifiers. In January and September 2019, bacteria exceeding the acceptable standards were isolated nine times from the cold water of six water purifies (a total of 12 water purifiers). Bacteria identified by MALDI-TOF MS included anaerobic bacteria (Clostridium novyi, Clostridium themopalmarium etc.), Gram-positive bacilli (Microbacterium testaceum, Arthrobacter woluwensis etc.), and Gramnegative bacilli (Acinetobacter nosocomialis, Comamonas kerstersii etc.), which are difficult identify by biochemical methods. In conclusion, bacteria exceeding the acceptable standard were isolated from the cold water of most of the water purifiers. Most of the isolated bacteria were low-pathogenic bacteria from natural environment, but opportunistic bacteria that can cause infection in humans were also isolated from some water purifiers.

A Study of the Mask and Hand Contamination in Dental Clinic (치과에서의 마스크 및 손의 미생물 오염정도 비교)

  • Pyo, Eunji;Lee, Kyunghee
    • Journal of The Korean Society of Integrative Medicine
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    • v.7 no.3
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    • pp.85-94
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    • 2019
  • Purpose: The purpose of this study was to observe the degree of mask contamination in dental hygienist for general and oral bacteria and to identify areas of mask contamination after treatment. Methods: Masks were collected with every fifty dental hygienists who currently working in the department of preventive dentistry, prosthodontics, and orthodontics in Busan. The mask bacteria were collected in specific upper and side parts of the mask. Hand germs were collected using sterile cotton swabs, and then placed in a sterile conical tube. These were transferred to the laboratory. Hand germs and mask bacteria were incubated with nutrient broth (NB) and brain heart infusion broth (BHI) for 24 hrs and each cultured with NB and BHI plate at $37^{\circ}C$ for 48 hrs. Collected data were analyzed using the SPSS Window 20. Results: The number of bacteria was observed in the order of the department of preventive dentistry ($10.1{\times}10^5CFU/ml$), prosthodontics ($14.7{\times}10^5CFU/ml$), and orthodontics ($23.3{\times}10^5CFU/ml$) in the hand. In general bacteria, the difference of contamination was seen by the parts of the mask, but there was no significant difference. However, the oral bacteria were observed highly contaminated upper part of the mask in preventive dentistry. The mask contamination according to the medical departments was observed. Especially, the contamination of mask in preventive dentistry was significantly higher than other departments in oral bacteria. Conclusion: This study suggested that correct mask replacement and recognition of contamination areas can contribute to the prevention of infectious disease. and it would be necessary to increase hand hygiene performance to prevent cross-infection with masks. Also, this study may give an idea for making guidelines for mask management and supporting to establish clear criteria for the education program of personal protective equipment.

Tracing surrogate bacteria inoculated on hide through the beef slaughtering process

  • Kim, Seongjoon;Kim, Sukwon;Kim, Sung Kwan;Choi, Kwanghoon;Kim, Jinman;Choe, Nonghoon
    • Korean Journal of Veterinary Research
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    • v.62 no.1
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    • pp.5.1-5.5
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    • 2022
  • Many countries have imposed regulations relating to concerns that hide contamination will affect the cleanliness of abattoirs. However, South Korea has not indicated any clear criteria. The purpose of this study is to use surrogate bacteria to measure the contamination in abattoirs caused by contaminated cattle hides. The swab contact method and plate count method are used. Surrogate bacteria are found in most internal environments after the final process. These surrogates remained on the carcass even after the final washing process. This paper is the first study in South Korea that use surrogate bacteria to analyze contamination levels in abattoirs.

Care Strategy of Sample-wearing Cosmetic Contact Lens for Preventing from Microbial Contamination (샘플착용 미용 콘택트렌즈의 세균 오염에 대한 관리방법)

  • Ko, Hoon;Kim, Eun Hye;Lee, Heum-Sook;Park, Mijung
    • Journal of Korean Ophthalmic Optics Society
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    • v.13 no.1
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    • pp.21-26
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    • 2008
  • Purpose: To investigate the proper care system of sample-wearing cosmetic contact lens (SWCCL). Methods: Research on the actual condition about SWCCL was examined in fifty cosmetic contact lens wearer in their 10s and 20s by the questionnaire. Also, the extents of the contamination of gram-negative bacteria and fungi were measured in SWCCL after wearing for 2, 4 and 6 weeks, and it was investigated whether the proper care system could prevented the contamination. Results: As the result of the questionnaire, people purchased the cosmetic contact lens after trying SWCCL with a mean of 4.5. The contamination of gram-negative bacteria and fungi were significantly increased in SWCCL-wearing period-dependent manner. In both Group 1 (rubbing SWCCL and exchanging preserving solution every wearing of SWCCL) and Group 2 (only exchanging preserving solution every wearing of SWCCL without rubbing SWCCL), the contamination of gram-negative bacteria and fungi were prevented perfectly. In the case of Groups having every-week care, the proliferation of gram-negative bacteria and fungi were somewhat suppressed, and rubbing was helpful of decreasing the contamination. The biweekly care had scarcely any effect for preventing the contamination. Conclusions: By exchanging the preserving solution every wearing of SWCCL, the contamination of gram-negative bacteria and fungi could be suppressed perfectly.

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A study on Investigation of Fecal Contamination Indicator Bacteria for Management of Source Water Quality (상수원 수질관리를 위한 분변오염 지표세균에 관한 연구)

  • 장현정;이용욱
    • Journal of Environmental Health Sciences
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    • v.29 no.1
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    • pp.19-27
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    • 2003
  • Coliforms is currently being used as the standard of environmental water qualify to evaluate the level of source water quality especially condition of fecal contamination. However, not properly applied to water quality management. So in this study, in addition to Coliforms, fecal contamination indicator bacteria turk at Feral Coliforms(FC), E. coli, Fecal streptococci(FS), Clostridium and environmental parameters related with it's distribution were investigated on a monthly basis in 6 water intakes of Han River. The mean of BOD, DO, SS and pH, benchmarks of source water management were maintained the second grade of environmental water quality standard applied to Han River but Coliforms exceeded it. Distribution of Coliforms ranged from 1.0×10¹ to 2.7 10/sup 5/ CFU/ml, FC ranged from ND to 5.3×10¹ CFU/ml, E. coli ranged from ND to 9.2×10¹ CFU/ml, FS ranged from ND to 2.5×10¹CFU/ml, they were steepy rise on July and August in common when rainfalls was heavy and water temperature was high, but Clostridium perfringens ranged from 1.7×10¹to 1.7×10¹CFU/ml not fluctuate by month. Statistical analysis of sampling data showed that most significant correlations occurred among FC and Coliforms(r = 0.840), E. coli(r = 0.792), FS(r = 0.687) and environmental parameters(temperature, turbidity, SS, rotor were all r > 0.60) while no significant correlation was observed between ammonia generally recognized fecal contamination indicator and bacteria. Identification of the coliforms showed that Enterobacter, Klebsiella, Citrobacter were comprised of 32%, 24%, 16% respectively, and E. coli were 7% of it. while E. coli was made up 85.9% of FC. The mean value of FC/Coliforms ratio, 5.2(0.1-42) were higher in Amsa, Guui than Jayang. Fecal coliforms, as those are able to reflect more particularly the extent of the fecal contamination, were considered useful in deciding the level of water treatment while monitoring the fecal contamination from the source of water supply. Therefore, it is expected that the water quality is going to be managed more efficiently by using fecal coliforms supplementarily to total coliforms which are current standard item of water-quality environment.

Analysis of Contamination of Bacteria from Raw Materials, Utensils and Workers' Hands to Prepared Foods in Foodservice Operations (원재료, 조리기구와 조리원 손에 의한 급식소 조리음식의 미생물오염 실태 분석)

  • Bae, Hyun-Joo
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.5
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    • pp.655-660
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    • 2006
  • The purpose of this study was to analyze the microbiological hazards of prepared foods, raw materials, utensils and workers' hands and to evaluate cross-contamination of bacteria in foodservice establishments. Aerobic plate counts, coliforms, E. coli, E. coli O157:H7, Salmonella spp., Staphylococcus aureus and Listeria monocytogenes were tested. According to the microbiological evaluation, there were many cases of contamination of bacteria. Staphylococcus aureus was detected in chicken stew (Korean type), Japchae, Bibimbap and Kongnamul-muchim at the A foodservice establishment and Jwieochae-jorim at the B foodservice establishment. E. coli was detected in Ojingeochae-muchim at the C foodservice establishment. E. coli O157:H7, Salmonella spp. and Listeria monocytogenes were not detected in any of the tested samples. Critically, microbiological contamination of raw materials, utensils and workers' hands could result in contamination of prepared foods, thus, attention needs to be given to sanitation of raw materials, workers' hands and utensils to reduce or eliminate contamination of bacteria.

A Study on the Drinking Water Quality and Contamination Sources in a Rural Area (일부 농촌지역의 오염원 현황과 먹는 물 수질에 관한 조사연구)

  • 김탁수;이용미;김문선;김성연;신해철;최경호;정문호
    • Journal of Environmental Health Sciences
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    • v.30 no.2
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    • pp.98-103
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    • 2004
  • To evaluate the quality of drinking water and contamination sources in a rural community, this study was carried out on the summer of 2003 at Shin-Dong Myun, Chun-Cheon, Gang-Won province. Seventy three drinking water samples were collected from three different types of water supply systems. Sources of contamination were identified and the public perception of water quality area were evaluated. The findings of this study are as follows; Drinking water was mainly obtained from Local Water and Simple Piped Water Supply Systems, and pollution sources varied over the study area. Most of residents (>63%) were satisfied with the quality of drinking water and could not identify any contamination sources. Corresponding to this perception, measured water quality parameters generally met the Drinking Water Quality Standards (>64%). However, approximately 35.6% of samples exceeded the regulation for Nㅒ$_3$$^{-}$$_{-}$N, coliform, and general bacteria. The water quality was significantly different among the three water supply systems, and between the potentially contaminated areas and the rest of the areas (p<0.05). In the potentially contaminated areas, the levels of coliform and general bacteria contamination were significantly higher than the rest of the areas (p<0.05). The coliform and general bacteria values of Simple Piped Water were significantly higher than Own Piped Water's, and the NO$_3$$^{-}$$_{-}$N values of Own Piped Water were significantly higher than those of water's (p<0.05). Based on this study, NO$_3$$^{-}$$_{-}$N, coliform, and general bacteria were identified as a major problem of drinking water. To regularly manage drinking water supply systems, to identify contamination sources, and to add drainage systems are required in the study area.

Transfer rates of pathogenic bacteria during pork processing

  • Park, Jung min;Koh, Jong Ho;Cho, Min Joo;Kim, Jin Man
    • Journal of Animal Science and Technology
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    • v.62 no.6
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    • pp.912-921
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    • 2020
  • We examined the rates of pathogenic bacterial cross-contamination from gloves to meat and from meat to gloves during pork processing under meat-handling scenarios in transfer rate experiments of inoculated pathogens. The inoculated pork contained ~5-6 Log10 CFU/g pathogenic bacteria like Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), Listeria monocytogenes (L. monocytogenes), and Salmonella enterica subsp. enterica (Sal. enteritidis). On cotton gloves, after cutting the pork, the cutting board, knife, and cotton gloves showed 3.07-3.50, 3.29-3.92 and 4.48-4.86 Log10 CFU/g bacteria. However, when using polyethylene gloves, fewer bacteria (3.12-3.75, 3.20-3.33, and 3.07-3.97 Log10 CFU/g, respectively) were transferred. When four pathogens (6 Log10 CFU/g) were inoculated onto the gloves, polyethylene gloves showed a lower transition rate (cutting board 2.47-3.40, knife 2.01-3.98, and polyethylene glove 2.40-2.98 Log10 CFU/g) than cotton gloves. For cotton gloves, these values were 3.46-3.96, 3.37-4.06, and 3.55-4.00 Log10 CFU/g, respectively. Use of cotton gloves, polyethylene gloves, knives and cutting boards for up to 10 hours in a meat butchering environment has not exceeded HACCP regulations. However, after 10 h of use, 3.09, 3.27, and 2.94 Log10 CFU/g of plate count bacteria were detected on the cotton gloves, cutting board, and knives but polyethylene gloves showed no bacterial count. Our results reveal the transfer efficiency of pathogenic bacteria and that gloved hands may act as a transfer route of pathogenic bacteria between meat and hands. The best hand hygiene was achieved when wearing polyethylene gloves. Thus, use of polyethylene rather than cotton gloves reduces cross-contamination during meat processing.

Research on Bacterial Contamination Levels in Apartment Tower Elevators (주거용 아파트 엘리베이터의 미생물 오염도와 영향요인 조사)

  • Shim, Won-Bo;Seo, Ju-Hee;Lee, Chae-Won;Jeong, Myeong-Jin;Kim, Jeong-Sook;Kim, Hyoung-Kab;Chung, Duck-Hwa
    • Journal of Environmental Health Sciences
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    • v.39 no.5
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    • pp.456-464
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    • 2013
  • Objectives: The aim of this study was to investigate the microbial contamination levels in elevators in apartment buildings and to provide information on such microbial contamination. Methods: A total of 144 samples, including from the exterior buttons, interior buttons, elevator handrails, walls, ventilators and airborne bacteria were collected in the morning and afternoon from July to August 2013 for six different elevators. The samples were used to detect sanitary indicator bacteria (total bacteria, coliform, and Escherichia coli), pathogenic bacteria (E. coli O157, L. monocytogenes, Salmonella spp., B. cereus, S. aureus) and fungi. Results: Contamination levels of total bacteria were 0.3-3.8 and 0.0-2.4 log CFU/100 $cm^2$ in the morning and afternoon, respectively. In the case of coliform bacteria, the levels were 0.0-3.7 log CFU/100 $cm^2$ in the morning and 0.0-0.3 log CFU/100 $cm^2$ in the afternoon. However, E. coli was not detected among all samples. Bacillus cereus, pathogenic bacteria, was only detected in 13 (11%) among 144 samples. E. coli O157, L. monocytogenes, Salmonella spp. and S. aureus were not detected among all samples. Comparing the samples collected in the morning and afternoon, we could confirm that the samples in the afternoon were cleaner. Conclusions: This study indicates that the samples in the afternoon were cleaner because these samples were collected following routine cleaning. Also, the levels of contamination in the elevators were low and the sanitary conditions were comparatively well-managed. Therefore it is deemed necessary for elevators be cleaned regularly to provide good conditions for people using elevators.