• Journal of Microbiology and Biotechnology
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• 제5권6호
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• pp.309-314
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• 1995

Samples were collected from a commercial ethanol production plant to enumerate the bacterial contamination in each step of a starch based ethanol production process. Though the slurry of raw material used in the process carried bacteria with various colony morphology in the order of $10^4$ per ml, only the colonies of white and circular form survived and propagated through the processes to the order of $10^8$ per ml at the end of fermentation. Almost all of the bacterial isolates from the fermentation broth were lactic acid bacteria. Heterofermentative Lactobacillus fermentum and L. salivarius, and a facultatively heterofermentative L. casei were major bacteria of an ethanol fermentation. In a batch fermentation L. fermentum was more detrimental than L. casei to ethanol fermentation. In a cell-recycled fermentation, ethanol productivity of 5.72 g $I^{-1} h^{-1}$ was obtained when the culture was contaminated by L. fermentum, whilst that of the pure culture was 9.00 g $1^{-1} h^{-1}$. Similar effects were observed in a cell-recycled ethanol fermentation inoculated by fermentation broth collected from an industrial plant, which showed a bacterial contamination at the level of 10$^8$ cells per ml.

• 대한임상검사과학회지
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• 제48권3호
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• pp.237-241
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• 2016

2016년 4월부터 6월까지 제주특별자치도에 위치한 대중음식점, 커피전문점 및 제과 제빵점 등에서 제공하는 일회용 물티슈를 대상으로 미생물의 오염도를 평가하였다. 사용된 재료는 일회용 물티슈 55종을 사용하였다. 대중음식점 일회용 물티슈 55종의 평균 세균 수는 $4.14{\times}10^3CFU/mL$이었으며, 세균이 자라지 않은 물티슈는 5종이었다. 가장 높게 측정된 세균 수는 2종의 물티슈에서 $16.67{\times}10^3CFU/mL$ 이상으로 나타났다. 순수 분리한 총 균수는 71균주이며, 이 중 황색포도알균(Staphylococcus aureus) 15균주, 녹농균(Pseudomonas aeruginosa) 3균주를 동정하였다. 이는 대중음식점에서 공급하는 물티슈의 세균 오염도가 심각하다는 것을 반영하며 기회감염의 원인이 되는 Staphylococcus aureus와, Pseudomonas aeruginosa가 발견된 것은 주목할 만하다고 볼 수 있다. 본 연구를 통해 한 번 사용 후 버리는 일회용품이며, 수개월 내지는 1~2년 보관하면서 사용하는 제품인 일회용 물티슈의 위생관련 기준 마련에 기초자료를 제공하고 대중음식점 등에 대한 위생관리 감독 강화와 개선방안 및 개인 위생관리 및 국민보건 수준향상에 기여 하고자 한다

• 기본간호학회지
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• 제6권3호
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• pp.359-368
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• 1999

Background : The purpose of this study was to determine whether cleansing the perineum and urethral meatus and using midstream urine affect the rate of bacterial contamination of urine specimens, and to determine the optimum urine collection method. We studied 41 asymptomatic healthy nursing school students. Women who were menstruating were not excluded from this study. Method : The first and midstream urine samples were collected during consecutive urinationsby each woman. The first sample was not a clean-catch specimen, and the second one was a clean-catch specimen. Both specimens were studied by urinalysis and bacterial culture with standard methods. Results : 41 women met the study criteria and 39 successfully completed the study. None of the urine cultures were positive. 68.3% of the non clean-catch first urine cultures, 53.7% of the non clean-catch midstream cultures, 33.3% of the first clean-catch urine culteres and 30.8% of the midstream clean-catch urine were found to be contaminated. There was a significant difference in the bacterial contamination rates between the first and midstream urine, and the clean-catch and non clean-catch urine(p=0.035, p =0.001 respectively). On urinalysis, 7.3% of the non clean-catch first urine, 7.3% of the non clean-catch midstream urine, 2.6% of the clean-catch first urine and 2.6% of clean-catch midstream urine were found to be above grade 2. Conclusions : According to our results, the bacterial contamination rate was the lowest in midstream and clean catch urine specimens. Threrfore it is recommended that the midstream clean-catch technique is the standard practice for collecting urine specimens for bacterial culture in women.

• Journal of Pharmaceutical Investigation
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• 제3권4호
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• pp.5-15
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• 1973

An investigation was carried out on a basis of the bacteriological examination with a view to detecting the degree of bacterial contamination for the 77 samples collected from the locally-sold liquid specialties. It's test period was 50 days from July 10 to August 30, 1971. Specially, the survey has put emphasis on the population of general bacteria and the identification of coli-form group, staphylococcus species, streptococcus species, bacillus species, fungi, and yeast species from liquid samples. The results obtained are summarized as follows; (1) For the 77 samples tested, the contamination of general bacteria was found out as minimun 0, i,e., maximum, $12{\times}10^4$ and the total average $45{\times}10^2$ per milliliter. (2) Although streptococcus species could not be detected with the samples, the contamination of the coli-form and staphylococcus species means the strong suggestion of the possibility of pathogenic bacterial contamination. (3) Specially, the products which stay in the neutral pH range and use suspending agents need to care for the microbial contamination in the manufacturing crocess. (4) It is thought necessary to perform the microbiological quality control in the liquid preparations only at least. (5) As the microbial contamination degree in the liquid decreases according to the elapse of time, the microbiological quality control will have to be carried out immediately after the completion of the manufacturing process in order to know the accurate degree. (6) The author thinks that the main reason of the microbial contamination in the liquid is the contamination during the manufacturing process. (7) For the purpose of prevention of the microbial contamination in liquid, therefore, it is more important to make efforts for the rationalization of manufacturing process, the improvement of equipment and environment, the specific training of workers for hygienic knowledges, etc. rather than the use of preservatives for the preparations.

• Journal of Periodontal and Implant Science
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• 제26권1호
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• pp.103-116
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• 1996

This study was performed to observe the bacterial adhesion and penetration to e-PTFE membrane following guided tissue regeneration(GTR) procedure and to evaluate the association of the membrane exposure and bacterial contamination with the clinical outcome. For the study, ten infrabony defects in 9 patient were treated by mucoperiosteal flap operation including placement of the e-PTFE membrane. The treated teeth were monitored weekly for the membrane exposure, gingival recession and gingival inflammation. The membranes were retrieved after 4 to 6 weeks, examined by SEM for bacterial contamination and adherent connective tisue elements, and observed under LM for the bacterial penetration into membrane. Three months postsurgery, the defect sites were clinically reexamined for the changes in attachment level and probing depth. Comparison of the ultrastuctural findings and clinical outcome revealed that extent of membrane exposure and bacterial contamination of the membrane was inversely associated with clinical attachment gain. From this finding, the extent of membrane exposure and the bacterial contamination on the apical portion of the e-PTFE membrane at the time of removal seemed to be a critical determinant on the clinical outcome of GTR and the membrane exposure needs to be controlled for optimal results.

• 대한의생명과학회지
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• 제28권4호
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• pp.317-321
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• 2022

Due to COVID-19 pandemic, wearing face masks is obligatory to prevent respiratory virus transmissions in the community. However, there are few studies of the desirable number of wearing a face mask, and how to store them for reuse. Therefore, in this study, a survey was conducted among 208 healthy adults, and 27 kf-94 masks worn for 1, 2, and 3 days were collected. To estimate the risk of bacterial contamination, we analyzed the extent of bacterial contamination of the BHI medium and 16S rRNA gene sequencing. With an increase in the number of days of using the mask, the degree of bacterial contamination of the used mask gradually increased. As a result of 16S rRNA PCR performed for strain identification, Staphylococcus, known as a pathogenic bacterium, was identified the most. In conclusion, we found that wearing a cotton KF mask provides an optimal environment for microbes, which are related to the skin and respiratory system, to thrive. Therefore, it is also important to reduce the risk of bacterial infection of the face mask with appropriate sterilization methods.

• Journal of Periodontal and Implant Science
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• 제26권1호
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• pp.133-142
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• 1996

Ten intrabony defects in 10 patients were treated by flap surgery including root surface debridement and placement of an expanded polytetrafluoroethylene(ePTFE) membrane. The membranes were removed after 4-6 weeks. This study was performed to examine the retrived ePTFE membrane by scanning electron microscopy(SEM) for bacterial contamination and adherent connective tissue elements, and to compare it with clinical conditions. The cervical portion of the membrane, which in most cases had become partially exposed to the oral cavity, had a bacterial deposit. Small bacterial colonies and a scatter of single cells in some instances extended into the apical portion of the membrane. Fibroblast-like cells, erythrocytes and fibrous structures were seen in the apical portion of the membrane. Outer surface of membrane tends to more bacterial contamination than inner surface(p<0.01), and upper portions more than lower portions(P<0.01). Comparison of ultrastructural findings and clinical conditions revealed that extent of bacterial contamination of the membrane correlated with gingival inflammation and extent of membrane exposure, but it was not significant statistically. The results suggested that gingival inflammation and membrane exposure affect periodontal regeneration by the use of ePTFE membrane.

• 한국식품영양학회지
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• 제3권1호
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• pp.13-22
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• 1990

Nangmyun-broth was collected as samples from 25 common restaurants in Bucheon to examine it's sanitary condition. The main course of bacterial contamination was persuited for it's sanitary improvement. Bacterial count in summer sample was not greatly different from that in winter, resulting in total count 1.7$\times$10i1m1, lactic acid bacteria 8.7$\times$106/ml, coliform group 1 2$\times$105/ml, Staphylococcus aureus 6.5$\times$102/ml. Bacterial contamination occurred remarkably with the use of storage barrel in which remnent Nangmyun-broth was still resting, because the remnant Nangmyun-broth contained high level of bacteria Good santary condition in Nangmyun-broth was obtained by the use of clean barrel which had been washed with tap water or sterilizied with steam before filling fresh Nangmyun -broth for cold storage. The growth of Escherichia coli and Staphylococcus aureus was inhibited in the presence of acetic acid(0.01~0.05%) or mustart(0.1~0.5%)

• Journal of Pharmaceutical Investigation
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• 제3권4호
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• pp.16-27
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• 1973

An investigation was carried out on a basis of the examination with a view to detecting the degree of microbial contamination for the 82 samples collected from the locally-sold liquid preparations. The results obtained are summarized as follows ; 1. Total viable Bacteria(TVB) per ml. in test sample shows min. 0 and Max. $8.0{\times}10^5$. Among the test samples, 2 items of Herb medicines have shown the highest bacterial contamination degree. 2. The number of unsuitable products are 9(11.0%) of the 82 items tested. Comparing with the study of 1971 (18 or 23.4% of 77 items), this fact suggests that the more than 50% decreasing tendency has come from the technical preventive efforts on bacterial contamination. 3. E. coli, Staph. aureus, and Pseudomonas aeruginosa could not be detected with the test sample. 4. The number of confirmable mycotic contamination in the test samples has been revealed as 17 items (20.7%). 5. Chiefly, the causative organisms of the contamination are proved to be bacilli and fungi broadly distributed in nature. 6. Generally, the neutrality of the pH had greatly increased the number of products unsuitable on the specification of TVB. pH >7.0 No. of unsuitable items 0/4 (0.0%) pH 6.0-7.0 No. of unsuitable items 4/9 (44.4%) pH 4.0-6.0 No. of unsuitable items 5/45(11.1%) pH <4.0 No. of unsuitable items 0/24(0.0%) 7. The viability of general bacteria has shown a rather decreasing tendency in time.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권1호
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• pp.31-38
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• 2005

Thorough screening of donors medical and social history, extensive serological and bacterial screening combined with developed processing and sterilization methods have improved the safety of the allogeneic tissues in recent decades. The risk of bacterial infection through allogenic tissue transplantation is one of the major problems facing tissue banks. The purpose study is to report the contamination rate in 358 retrieved tissues obtained strictly aseptic conditions, between 2001 and 2002 in Korea Tissue Bank. Samples from 9 donors(total 13 donors) were used in blood culture, and in 7 donors the blood culture were negative. Of the 358 tissues cultured in their entirety, 186(52%) were initially culture negative and 177(48%) were positive. Organism low pathogenicity were cultures from 20.2% of the tissues. To minimize the bacterial load, donors should be obtain in operating rooms, using aseptic techniques with only a few personnel for procurement. The procurement cultures from donors and retrieved tissues with multiple should be carefully interpreted. Blood cultures should be taken account, since these can help to find contamination not detect swab culture. A prospective cohort study is needed to determine which of the varied processing and sterilization methodologies gives the best quality.