• 한국어병학회지
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• 제27권2호
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• pp.99-105
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• 2014

Biosensors consist of biochemical recognition agents like antibodies immobilized on the surfaces of transducers that change the recognition into a measurable electronic signal. Here we report a piezoelectric immunosensor made to detect Vibrio vulnificus. A 9MHz AT-cut piezoelectric wafer attached with two gold electrodes of 5mm diameter was used as the transducer of the QCM biosensor with a reproducibility of ${\pm}0.1Hz$ in frequency response. We have tried different approaches to immobilize antibody on the sensor chip. Concerning the orientation of antibody for the best antigen binding capacity, the antibody was immobilized by specific binding to protein G or by cross-linking through hydrazine. In addition, protein G was cross-linked on glutaraldehyde activated immine layer (PEI) or EDC/NHS activated sulfide monolayer (MPA). PEI was found to be more effective to immobilize protein G following glutaraldehyde activation than MPA. However, hydrazine chip showed a better capability to immobilize more IgG than protein G chip and a higher sensitivity. The sensor system was able to detect V. vulnificus in dose dependent manner and was able to detect bacterial cells within 5 minutes by monitoring frequency shifts in real time. The detection limit can be improved by preincubation to enrich the bacterial cell number.

• The Plant Pathology Journal
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• 제28권2호
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• pp.156-163
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• 2012

Stem rots caused by Rhizoctonia solani and Sclerotinia sclerotiorum have been known as devastating diseases in balloon flower plants. Antifungal activities of four fungicides, azoxystrobin, polyoxin B, trifloxystrobin and validamycin A were evaluated in vitro, showing effective suppression with mycelial growth of the fungal isolates on PDA media. Efficacies of the four fungicides were also demonstrated in stem tissues of balloon flower plants against R. solani and S. sclerotiorum. A commercially available Bacillus subtilis strain Y1336 was tested in terms of antagonistic biological control of stem rot disease of balloon flower plants. The bacterial strain revealed its antifungal activities against R. solani and S. sclerotiorum demonstrated by dual culture tests using paper discs and two plant pathogenic fungi on PDA media, as well as by plant inoculation assay, indicating that this antagonistic bacterial strain can be incorporated into disease management program for balloon flower stem rot diseases together with the four chemical fungicides.

• 한국자원식물학회지
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• 제12권2호
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• pp.152-160
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• 1999

1. 콩잎의 세균밀도는 4.60$\times$$10^2$~ 9.10$\times$$10^{5}$CFU/$\textrm{cm}^2$으로, 생육단계가 진전됨에 따라 세균밀도가 증가하는 경향이었다. 2. 콩나물 부패 세균의 밀도는 콩잎에서 0~5.00$\times$$10^3$CFU/$\textrm{cm}^2$으로, 부패세균의 밀도는 생육단계에 관련이 없었으나 재배지역과는 관련이 있었다. 3. 나물 콩 품종과 콩나물 부패세균의 밀도는 품종과 관련이 적었으며 생육단계와 작물의 부위에 따라 변이가 심하였다. 4. 콩잎에서 분리된 콩나물 부패세균은 Erwinia cypripedii, E. carotovora subsp. carotovora, Xanthomonas campestris pv. glycines, Staphylococcus sp., Micrococcus sp. 이며, E. carotovora subsp. carotovora, X. campestris pv. glycines가 밀도가 높았다.다.

• 한방안이비인후피부과학회지
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• 제17권3호
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• pp.33-37
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• 2004

Objective: The aim of this work is to investigate the antibacterial activity of the Sohporaflavanone G isolated from Sophora flavescens (S. flavescens), as the development of microbial resistance to antibiotics make it essential to constantly look for new and active compounds effective against pathogenic bacteria. Method : Sophoraflavanone G was isolated from the dried roots of Sophora flavescens Aiton (Leguminosae) by bioassay?guided fractionation. We investigated the effect of sophoraflavanone G on oral bacterial at various concentrations after incubation of 24 h in strains in the dose?dependent manner. Results: The structure of active compound, Sophoraflavanone G having a lavandulyl group at C?8, was elucidated on the basis of spectral data especially 1H?NMR and I3C?NMR. The antimicrobial activity showed that Sophoraflavanone G exhibited antimicrobial activilies against all the bacteria tested (MICs, 0.39 - 6.25 ㎍／ml). Sophoraflavanone G showed the strong antimicrobial activity against all the facultative bacteria and microaerophilic bacteria (MICs, 0.78 - 1.56 ㎍／ml) and also Sophoraflavanone G showed the strong antimicrobial activity against obligate anaerobic bacteria (MICs, 0.39 - 6.25 ㎍／ml).

• Restorative Dentistry and Endodontics
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• 제16권1호
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• pp.226-235
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• 1991

Therapeutic use of antibiotics in the pulpal disease should reduce the clinical symptoms and pathogenic microflora in the pulp. The purpose of this study was focused on local drug delivery into the root canal in endodontic therapy. Monolithic films from polycaprolactone and polyethylene glycol preparations with minocycline were prepared, and then the antimicrobial effect of these films on necrotic canal was tested. A total 17 necrotized pulp teeth were sampled before and 1 week after insertion of film into the pulp. Bacterial culture were performed with anaerobical condition and seeded in the 5 selective and non - selective media for 7 days in $37^{\circ}C$ of anaerobic chamber. Bacterial identification were performed with Gram staining, biochemical test, and API kit There was significantly decreased of anaerobic and aerobic microflora of 13 among 17 patients after therapy. Among the identified microflora, Streptococcus species, black - pigmented species and Fusobacterium species were significantly reduced 1 week after treatment with local delivery antibiotics. Furthermore, clinical symptoms included in pain and local swelling were continuousely reduced after therapy. These results suggest that local drug delivery with minocycline is effeicient to treat the endodontic involved teeth for releasing clinical symptoms and microbiological shifting.

• 한국임상수의학회지
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• 제36권2호
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• pp.98-101
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• 2019

Lactobacillus spp. are the bacteria most commonly used as probiotics and it has been proven that they inhibit pathogenic bacterial growth and improve skin repair in humans. This study was conducted to investigate the growth inhibitory effect of Lactobacillus on Staphylococcus pseudintermedius, the most commonly isolated pathogen in canine pyoderma, and whether Lactobacillus could inhibit the adhesion capability of S. pseudintermedius to canine corneocytes. For this study, L. salivarius and S. pseudintermedius were isolated from healthy beagle fecal samples and the skin surface of dogs with skin infection, respectively. S. pseudintermedius was co-cultured with L. salivarius to assess the inhibitory effect. For the adhesion assay, corneocytes were collected from healthy beagle ventral abdominal skin. Both bacterial species attached to corneocytes and were assessed in number. As a result, L. salivarius significantly inhibited the growth of S. pseudintermedius in the culture medium. Moreover, L. salivarius reduced attachment of S. pseudintermedius in the adhesion assay. These results suggest that L. salivarius has an inhibitory effect on S. pseudintermedius and may be effectively used in the topical therapy of canine skin infections.

• 식품보건융합연구
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• 제9권6호
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• pp.9-19
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• 2023

Lactobacillus plantarum and Leuconostoc mesenteroides are crucial functional starters and predominant isolates in a wide range of fermented foods, particularly kimchi, whose constituents exhibit bioactive properties. We previously developed a methodology using anion exchange resins to purify peptidyl compounds from Lb. plantarum LBP-K10. Antibacterial cultures of Lb. plantarum LBP-K10 were obtained from the respective cultures' supernatants and filtrates. However, conclusive evidence of the efficacy of kimchi filtrates in eradicating pathogenic bacteria is lacking. We aimed to simulate the potential effects of antibacterial filtrates that contained antibacterial compounds which were derived from cultures of Lb. plantarum LBP-K10. We acquired the kimchi filtrates using a combination of centrifugation and filtration methodologies, without the requirement for inoculation. The filtered liquid from Chinese cabbage kimchi, inoculated with Lb. plantarum LBP-K10 as a starter culture, and the non-inoculated liquid from Chinese cabbage kimchi (referred to as CCK and CCKRef, respectively) were were examined. CCK demonstrated greater inhibitory activity and a more significant bactericidal effect against the bacterial indicator strains. The minimum inhibitory concentration demonstrated comparable outcomes in tests against both Gram-positive and Gram-negative bacteria. This research offers a groundbreaking examination that displays the effectiveness of profiling peptidyl compounds within kimchi filtrates for curing bacterial infections.

• 식물병연구
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• 제30권1호
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• pp.88-94
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• 2024

In July 2021, symptoms of soft rot were observed on the stems of Ficus carica in Yeongam, Jeollanamdo, Korea. To accurately diagnose the cause, infected stem was collected and bacterial strain was isolated. Among these, the pathogenic strain KNUB-08-21 was identified as Pectobacterium aroidearum through 16S rRNA gene sequencing and phylogenetic analysis based on the concatenated sequences of the dnaX, leuS, and recA genes. The affiliation of the isolate with this bacterial species was also confirmed by its biochemical characteristics obtained using API ID 32 GN system. Artificial inoculation confirmed the strain's pathogenicity in figs, causing significant damage to both stems and fruits. To our knowledge, this is the first report of P. aroidearum causing soft rot disease in F. carica in Korea.

• Journal of Microbiology and Biotechnology
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• 제34권4호
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• pp.854-862
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• 2024

Lactobacillus is a commonly used probiotic, and many researchers have focused on its stress response to improve its functionality and survival. However, studies on persister cells, dormant cells that aid bacteria in surviving general stress, have focused on pathogenic bacteria that cause infection, not Lactobacillus. Thus, understanding Lactobacillus persister cells will provide essential clues for understanding how Lactobacillus survives and maintains its function under various environmental conditions. We treated Lactobacillus strains with various antibiotics to determine the conditions required for persister formation using kill curves and transmission electron microscopy. In addition, we observed the resuscitation patterns of persister cells using single-cell analysis. Our results show that Lactobacillus creates a small population of persister cells (0.0001-1% of the bacterial population) in response to beta-lactam antibiotics such as ampicillin and amoxicillin. Moreover, only around 0.5-1% of persister cells are heterogeneously resuscitated by adding fresh media; the characteristics are typical of persister cells. This study provides a method for forming and verifying the persistence of Lactobacillus and demonstrates that antibiotic-induced Lactobacillus persister cells show characteristics of dormancy, sensitivity of antibiotics, same as exponential cells, multi-drug tolerance, and resuscitation, which are characteristics of general persister cells. This study suggests that the mechanisms of formation and resuscitation may vary depending on the characteristics, such as the membrane structure of the bacterial species.

• Pediatric Infection and Vaccine
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• 제23권1호
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• pp.40-45
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• 2016

목적: 소아에서 급성 인두편도염의 원인균의 분포를 조사하고자 하였다. 방법: 2010년 3월부터 2011년 3월까지 급성 인두편도염 환자의 인두 후부에서 검체를 채취하여 원인바이러스와 세균을 분석하였다. 결과: 615명의 환자 중, 세균이 분리된 경우는 40례(6.5%), 바이러스가 검출된 경우는 310례(50.4%)이었다. 분리된 세균 중 A군 사슬알균이 31례(77.5%)로 가장 많았고, 검출된 바이러스 중에는 adenovirus가 가장 많았으며(203명; 65.5%), 그 다음으로 rhinovirus (65명; 21.0%), enterovirus (43명; 13.9%) 순이었다. 기침, 콧물, 결막염은 바이러스 감염 환자에서, 연구개의 발적과 점상출혈은 세균 감염 환자에서 더 많았다. 결론: 급성 인두편도염 환자에서 바이러스 감염이 세균 감염에 비해 많았으며 임상양상에 차이를 보였다. 따라서 급성 인두편도염 환자에서 무조건적인 항생제의 사용을 피하고 임상양상의 차이를 감안하여 치료를 결정해야 하겠다.