• 한국식품저장유통학회지
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• 제23권6호
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• pp.759-764
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• 2016

본 연구의 목적은 가금류에서 문제가 되고 있는 살모넬라 신속검출을 위해 광학현미경 기반 이미징 시스템 적용에 앞서서 냉장온도로부터 손상된 살모넬라를 증균시키기 위한 최적의 배지를 선정하는 것이다. 대표적인 식중독 유발균주인 S. Typhimurium과 S. Enteritidis를 닭에 도말 하였고 $4^{\circ}C$에서 24시간 동안 저장한 후 BPW, LB, BHI, UPB, NB, 그리고 TSB 배지와 BG, RV, SC, SB 그리고 TBS 선택배지에 각각 6시간 동안 배양하였다. 배양 후, 2시간마다 살모넬라 균수를 측정하였고 그 결과 BHI와 BG를 선택되었다. 최종적으로 최적의 배지 선택을 위해 다양한 농도의 살모넬라를 닭에 각각 도말 후 6시간 동안 배양하면서 균수를 변화를 측정하였다. 그 결과 BHI가 냉해로부터 손상된 살모넬라를 증균시키기 위한 가장 최적의 배지로 선정되었으며 본 연구의 결과는 광학현미경 기반 이미징 시스템을 활용한 신속검출법 적용을 위한 증균배지로 이용될 것이다.

• 대한치과보철학회지
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• 제42권4호
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• pp.373-385
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• 2004

Statement of problem: The microbial adhesion on the surface of materials used in prosthodontics and restorative dentistry significantly influences microbial infection. Purpose: The purpose of this study was to evaluate the effect of how the degree of surface roughness of acrlyic resin affect the adhesion of bacteria. Material and methods: Resins were finished with $50{\mu}m$ and $250{\mu}m$ aluminium oxide particles by using sandblaster, by using stone point, and high polished with $Opa^{(R)}$ and Lace $motor^{(R)}$. The surface of acrylic resin attached by bacteria was directly touched on the surface of BHI agar, which was incubated. Bacteria colonies formed on BHI agar were counted in accordance with the degree of the surface roughness. Results: 1. The viable cell number of Streptococcus mutans increased on the acrylic resins incubated in BHI broth than in PBS. 2. The viable cell number of Streptococcus mutans increased on the acrylic resins incubated without agitation than with agitation, washed three times than six times, and incubated in broth added with 5% sucrose than without sucrose. 3. When Streptococcus mutans incubated in BHI broth, the number of Streptococcus mutans colonies formed on BHI agar was the largest on the acrylic resins finished with $250{\mu}m$ aluminium oxide particle using sandblaster. But when incubated in BHI broth containing sucrose, the number of colonies formed on that was the largest on the acrylic resins high polished using $Opal^{(R)}$ and Lace $motor^{(R)}$. 4. When Streptococcus sanguis was incubated in BHI broth with or without sucrose, the number of Streptococcus mutans colonies formed on BHI agar was the largest on the acrylic resins finished with $250{\mu}m$ aluminium oxide particle using sandblaster. 5. When Actinomyces viscosus was incubated in BHI broth with or without sucrose, the number of Streptococcus mutans colonies formed on BHI agar was the largest on the acrylic resins high polished using $Opal^{(R)}$ and Lace $motor^{(R)}$. Conclusion: These results indicated that when acrylic resins attached by bacteria were touched on the surface of BHI agar, the number of bacterial colonies formed on the agar was dependent on the bacterial species. Also, the result of this study was showed that increase in the surface roughness and the addition of sucrose increased retention of microbial cells.

• Preventive Nutrition and Food Science
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• 제15권3호
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• pp.239-243
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• 2010

The antimicrobial effects of a commercially available, buffered sodium citrate (BSC) were evaluated for the reduction of total aerobic bacteria count, Salmonella Typhimurium, Escherichia coli O157:H7, Listeria monocytogenes and Staphylococcus aureus in a liquid medium and ground beef. BSC at 0, 1, 2 and 4.8% (wt/vol) or 0, 3, and 4.8% (wt/wt) was mixed into inoculated brain heart infusion (BHI) broth and ground beef (80% lean), respectively. BSC at concentrations of 1 and 2% did not inhibit growth of the pathogens tested in BHI broth. E. coli O157:H7 in BHI broth with 4.8% BSC was significantly reduced (p<0.05) by 3～4 log CFU/mL compared with the control for up to 4 days. At 4.8%, BSC treatment of ground beef most significantly reduced (p<0.05) total aerobic count and E. coli O157:H7 by 2.1 and 2.0 log CFU/g, respectively. This study indicates that the legally allowable level of 1.3% (wt/wt) BSC is not effective for reducing the pathogens tested in ground beef stored at $7^{\circ}C$.

• Journal of Dairy Science and Biotechnology
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• 제41권3호
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• pp.103-112
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• 2023

This study aimed to assess the effectiveness of 10 different pre-enrichment methods using Real-Time polymerase chain reaction (PCR) in support of the FDA method. When the initial Cronobacter spp. (Enterobacter sakazakii) inoculation was 7.2 CFU/g, the Ct values were observed in the following order: 21.37 (Enterobacteriaceae enrichment [EE] broth), 21.95 (brain heart infusion [BHI]), 22.72 (tryptic soy broth [TSB]), 23.02 (violet red bile lactose [VRBL]), 22.31 (TSB-0.1% sodium pyruvate [SP]), 23.43 (distilled water [DW]), 24.34 (phosphate buffered saline [PBS]), 24.95 (nutrient broth [NB]), 25.82 (TSB-0.6% yeast extract [YE]), and 28.27 (violet red bile glucose [VRBG]). For an inoculation of 1.82% CFU/g of Cronobacter spp. (E. sakazakii), the Ct values were recorded in this sequence: 20.34 (EE broth), 22.16 (TSB-0.6% YE), 22.37 (BHI), 22.71 (VRBL), 22.88 (TSB), 23.01 (DW), 23.19 (NB), 23.79 (TSB-0.1% SP), 24.66 (VRBG), and 24.70 (PBS). Finally, when the inoculum of Cronobacter spp. (E. sakazakii) was 0.182 CFU/g, the Ct values followed this order: 21.93 (VRBL), 23.07 (TSB-0.6% YE), 23.31 (DW), 23.47 (PBS), 23.70 (BHI), 24.14 (TSB-0.1% SP), 25.14 (TSB), 29.00 (VRBG), 31.55 (EE broth), and were undetected in the case of NB. Consequently, these results indicate that there were no significant differences among the 10 different pre-enrichment broths. Future studies should focus on exploring pre-enrichment broths that can improve the limit of detection at very low Cronobacter spp. (E. sakazakii) concentrations and enhance the selective recovery of Cronobacter spp. (E. sakazakii) under acid, antibiotic, cold, and heat damage conditions.

• 대한미생물학회지
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• 제9권1호
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• pp.13-18
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• 1974

Blood is one of the most important clinical specimens for the isolation of bacteria. A rapid isolation and a high isolation rate of bacteria are very important in blood culture because bacteremic patients are mostly in grave condition. Various blood culture media which support growth of most fastidious bacteria are available commercially. However, growth of bacteria are frequently delayed because of antibacterial activity of blood. Sodium polyanethol sulfonate(Liquoid) has been reported to inactivate the antibacterial substance and disrupt phagocytic cells. The beneficial effect of SPS is well recognized in the isolation of gram-positive bacteria. However, the effect does not seem to be prominent for gram-negative bacilli isolation mainly due to the rapidity of their growth. It has been experienced with Sal. typhi that the growth is much slower than that of other gram-negative bacilli. For the rapid growth of the organism, use of bile broth has been recommended. Although Sal. typhi is the most frequently isolated organism at present, about one half of total isolates are other organisms and, in case bile broth is used, other media which support growth of these organisms should be used together. Fluid thioglycollate medium(FTM) which is always used in blood culture to isolate anaerobes is inferior to brain heart infusion(BHI) for the isolation of aerobes. This study was done to determine the effect of SPS on the isolation of Sal. typhi from blood. During the Sep. 1973 to Sep. 1974 study period, 2460 blood cultures were made from the Severance hospital patients: BHI and FTM sets 1431 specimens, BHI with SPS(0.05%) and FTM sets 396 specimens, BHI and FTM with SPS sets 359 specimens, BHI and BHI with SPS sets 274 specimens. Mean incubation time required for the macroscopic detection of growth of Sal. typhi were 3.5 days on BHI and 2.7 days on BHI with SPS. The 0.8 day difference was statistically significant. On FTM the mean incubation time was 3.8 days while it was 2.9 days on FTM with SPS. The 0.9 day difference was statistically significant. The result on BHI with and without SPS sets showed faster growth on BRI with SPS in 7 specimens and slower growth in one specimen and the remaining 12 showed growth at the same time. These specimens had mean incubation time of 3.2 days on BHI and 2.3 days on BHI with SPS. The 0.9 day difference was statistically significant. This study indicates beneficial effect of SPS for the rapid isolation of Sal. typhi from clinical blood specimens.

• Restorative Dentistry and Endodontics
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• 제46권3호
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• pp.35.1-35.11
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• 2021

Objectives: Endosequence Bioceramic Root Repair Material (BC-RRM) is used in endodontic microsurgery. It is available as a paste and a putty. However, no studies to date have examined the sealing ability of these forms alone or in combination as root-end filling materials. Hence, this study aimed to compare the sealing properties of these 2 forms of BC-RRM. Materials and Methods: Forty-two extracted upper anterior teeth were divided into 3 experimental groups, a positive and negative control. After the root canal treatment, the root ends were resected, retroprepared and retrofilled with either putty, paste + putty or mineral trioxide aggregate (MTA). The teeth were mounted in tubes so the apical 3 mm was submerged in Brain Heart Infusion (BHI) broth. The coronal portions of the canals were inoculated with Enterococcus faecalis and BHI broth and incubated for 30 days. The broth in the tubes was analyzed for colony forming units to check for leakage of bacteria from the canal. The teeth from the groups were sectioned and analyzed using scanning electron microscopy (SEM). The Kruskal-Wallis test and analysis of variance were used to analyze the data with a significance level p < 0.05. Results: The BC-RRM and MTA groups showed similar sealing ability. The positive control showed leakage in all samples. The SEM imaging showed the presence of bacteria in all experimental groups at the material-tooth interface. Conclusions: No significant differences were noted in the experimental groups, providing sufficient evidence that any combination could be effectively used during endodontic microsurgery.

• 미생물학회지
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• 제51권4호
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• pp.407-418
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• 2015

본 연구는 백김치로부터 분리된 Lactobacillus paracasei BK57의 항균물질 생산을 위한 최적의 배양 조건을 검색하고, BK57 유산균으로 프레쉬 치즈를 제조한 후 균주의 활성과 유산 및 박테리오신 생산량을 측정하여 Listeria monocytogenes KCTC 3569에 대한 항균 활성을 조사하였다. 최대의 균 증식과 항균 물질 생산량은 pH 6.0으로 조정한 MRS broth에서 $37^{\circ}C$, 24시간 동안 호기적인 조건으로 배양했을 때 나타났다. 하지만, 효모추출물(2.0%)을 첨가한 전유 내에서 생성된 항균물질의 양과 유산균의 증식률은 MRS broth에서 보다는 다소 낮았다. 우유 내에서 L. monocytogenes의 저해율은 BK57 균주의 생균과 배양 상등액에 의해 높게 나타났으나, 유산균이 생산한 박테리오신에 의한 저해율은 우유 보다는 BHI broth 내에서 더 높게 나타났다. BK57 균주로 발효시킨 프레쉬 치즈를 $4^{\circ}C$와 $15^{\circ}C$에서 6일간 저장하는 동안 유산균수, 유산 생성량 및 박테리오신 활성은 유의한 변화가 없었다. 제조 직 후 프레쉬 치즈에 인위적으로 접종한 L. monocytogenes ($10^5CFU/ml$)의 균수는 각각의 온도대에서 6일 이내에 최소 15% 이상 감소되는 효과가 나타났으므로 BK57 균주를 발효유제품 제조에 이용할 경우 리스테리아균을 제어할 수 있는 생물학적 보존제로서의 가치를 확인하였다.

• 대한소아치과학회지
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• 제29권1호
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• pp.92-99
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• 2002

현재 치과계에서 가장 효과를 인정받는 대체 감미료로 자일리톨이 있으며, 최근 관련상품이 증가 하고 있다. 하지만 많은 관련 상품은 제품에서 자당이 차지하는 부분 모두를 자일리톨로 대체하지 못하고 부분대치하고 있기 때문에 자당 존재하의 조건에서 자일리톨의 항우식 작용이 임상적으로 더 중요하다고 할 수 있다. 본 연구의 목적은 자당과 자일리톨의 다양한 농도비의 조건에서 자일리톨의 항우식 작용의 정도를 규명하고자 함이며 자당과 자일리톨의 농도비를 달리한 각 실험용액에서 S. mutans의 합성수산화인회석에 대한 부착능과 치아미세경도 변화량을 측정하였으며 아래와 같은 결과를 얻었다. 1. 자당과 자일리톨의 혼합시 배지에 자당만을 추가한 대조군에 비해 S. mutans의 합성수산화인회석 입자 표면에 대한 부착을 유의하게 감소시킬 수 있는 자일리톨의 최소 부착억제 농도비는 자당과 자일리톨이 25:75 이었다(P<0.05). 2. 법랑질 미세경도 측정 결과 자당만 첨가한 1군에 비해 자당과 자일리톨이 50:50인 4군부터 미세경도 감소치가 유의하게 줄어들었다(P<0.01).

• Journal of Microbiology
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• 제43권4호
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• pp.370-374
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• 2005

Bacteriocin ST311LD is approximately 2.3 kDa in size. Low levels of bacteriocin activity were recorded in BHI and M17 broth (800 AU/ml) and in $10\%$ (w/v) soy milk (3,200 AU/ml). No bacteriocin pro-duction was recorded in $10\%$ (w/v) molasses, despite good growth. Optimal levels (12,800 AU/ml) were detected in MRS broth which had been supplemented with tryptone (20.0 g/l), saccharose (5.0 or 10.0 g/l) or vitamin C (1 ppm). Increased potassium levels did not result in higher levels of activity, and glycerol (1.0 g/l) inhibited the production of bacteriocin ST311LD.

• 한국축산식품학회지
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• 제41권1호
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• pp.164-171
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• 2021

Listeria monocytogenes is a representative foodborne pathogen and causes listeriosis. Enterococcus faecium CJNU 2524 was confirmed to produce a bacteriocin with anti-listerial activity. To establish optimal culture conditions for the production of the bacteriocin from E. faecium CJNU 2524, different media (MRS and BHI broth) and temperatures (25℃, 30℃, and 37℃) were investigated. The results showed that the optimal culture conditions were MRS broth and 25℃ or 30℃ temperatures. The crude bacteriocin was stable in a broad range of pH conditions (2.0-10.0), temperatures (60℃-100℃), and organic solvents (methanol, ethanol, acetone, acetonitrile, and chloroform). The bacteriocin activity was abolished when treated with protease but not α-amylase or lipase, indicating the proteinaceous nature of the bacteriocin. Finally, the bacteriocin showed a bactericidal mode of action against L. monocytogenes. Therefore, it can be a biopreservative candidate for controlling L. monocytogenes in dairy and meat products.