• International Journal of Oral Biology
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• v.37 no.3
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• pp.103-108
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• 2012

The purpose of this study was to assess the efficacy of photodynamic therapy (PDT) using erythrosine and a halogen light source to treat a biofilm formed on a machined surface titanium disk in vivo. Ten volunteers carried an acrylic appliance containing six machined surface titanium disks on the upper jaw over a period of five days. After the five days of biofilm formation period, the disks were removed. PDT using 20 ${\mu}M$ erythrosine and halogen light was then applied to the biofilms formed on the disks. Experimental samples were divided into a negative control group (no erythrosine and no irradiation), E0 group (erythrosine 60s + no irradiation), E30 group (erythrosine 60s + halogen light 30s), and E60 group (erythrosine 60s + halogen light 60s). Following PDT, the bacteria in the biofilm were found to be detached from each disk. Each suspension with detached bacteria were diluted and cultivated on a blood-agar plate for five days under anaerobic conditions. The cultivated bacterial counts in the E60 group were significantly lower than the control group (86.4%) or E0 group (76.7%). In the experimental groups also, the light exposure time and bacterial counts showed a negative correlation. In conclusion, PDT using erythrosine and halogen light has bactericidal effects on biofilms formed on a titanium disk in vivo. Notably, applying 20 ${\mu}M$ erythrosine and 60 seconds of halogen light irradiation had a significantly potent effect.

• The Plant Pathology Journal
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• v.34 no.1
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• pp.11-22
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• 2018

Type VI secretion system (T6SS) has been discovered in a variety of gram-negative bacteria as a versatile weapon to stimulate the killing of eukaryotic cells or prokaryotic competitors. Type VI secretion effectors (T6SEs) are well known as key virulence factors for important pathogenic bacteria. In many Burkholderia species, T6SS has evolved as the most complicated secretion pathway with distinguished types to translocate diverse T6SEs, suggesting their essential roles in this genus. Here we attempted to detect and characterize T6SSs and potential T6SEs in target genomes of plant-associated and environmental Burkholderia species based on computational analyses. In total, 66 potential functional T6SS clusters were found in 30 target Burkholderia bacterial genomes, of which 33% possess three or four clusters. The core proteins in each cluster were specified and phylogenetic trees of three components (i.e., TssC, TssD, TssL) were constructed to elucidate the relationship among the identified T6SS clusters. Next, we identified 322 potential T6SEs in the target genomes based on homology searches and explored the important domains conserved in effector candidates. In addition, using the screening approach based on the profile hidden Markov model (pHMM) of T6SEs that possess markers for type VI effectors (MIX motif) (MIX T6SEs), 57 revealed proteins that were not included in training datasets were recognized as novel MIX T6SE candidates from the Burkholderia species. This approach could be useful to identify potential T6SEs from other bacterial genomes.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1397-1401
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• 2007

An in situ experiment was conducted to find out whether Tween 80 improves rice straw digestion through increased adhesion of major fibrolytic bacteria. Rice straw was sprayed with various levels of Tween 80 non-ionic surfactant or SDS ionic surfactant 24 h before incubation in the rumen of Holstein steers. Dry matter (DM) disappearance and adhesion of F. succinogenes, R. flavefaciens and R. albus on rice straw after in situ incubation were measured by real-time PCR. Application of Tween 80 increased DM disappearance, which was more noticeable at an application level of 1% compared to lower application levels. Application of SDS resulted in an opposite response in DM disappearance with highest reduction in DM disappearance at 1% level. In a subsequent in situ experiment, higher Tween 80 was applied to rice straw in an attempt to find the optimum application level. Tween 80 at 2.5% gave better DM disappearance than 1% with a similar result at 5%. Therefore, an adhesion study was carried out using rice straw treated with 2.5% Tween 80. Our results indicated that Tween 80 reduced adhesion of all three major rumen fibrolytic bacteria to rice straw. Present data clearly show that improved DM disappearance by Tween 80 is not due to increased bacterial adhesion onto substrates.

• Journal of Microbiology and Biotechnology
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• v.13 no.5
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• pp.673-679
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• 2003

Glutamine and urea, abundant in body fluids or plasma, yield net ammonium ions upon hydrolysis by ${\gamma}-glutamyl$ transpeptidase (${\gamma}-GTP$) and urease, respectively, and these two enzymes are largely produced from Helicobacter pylori. To investigate bacterial potential of ammonium production, we first quantified those in whole-cell systems and found that the relative ratio of their amounts varied greatly, especially with pH values and the cell's aging. During the H. pylori cultivation, the ratio appeared to be inversely proportional to each other, showing a progressive increase of the ${\gamma}-GTP$ with decreasing of the urease. Under the urease-defective conditions due to low pH or coccoids, the bacterial cells still possessed a considerable amount of ${\gamma}-GTP$, which was found exclusively in the external compartment, therefore, the cell's ammonium production was found to be solely dependent upon glutamine, and the external ammonium concentration was constant without any contribution of urea concentration. Such ammonium constancy would definitely have an adverse effect on the host, because of its absolute requirement for vacuolar degeneration by H. pylori VacA, maximized at approximately 10 mM $NH_4Cl$. It was also found that, by using the metal-saturated membrane vesicles, ammonium ions were likely to be involved in the pH-dependent cation-flux across the H. pylori membrane, where the role of ${\gamma}-GTP$ in ammonium homeostasis around cells was suggested, especially under the hostile conditions against H. pylori.

• Journal of Chest Surgery
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• v.11 no.1
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• pp.35-41
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• 1978

After the advent of the effective antimicrobial drugs, empyema of the pleural cavity came to be considered an infrequent disease. However, in recent years the problem of empyema is increasing, probably due to bacterial changes associated with the use and misuse of antimicrobials as well as alterations in the host associated with increased longevity and chronic disease. During the 10 years period from 1957, Sop. to 1977, Aug., we experienced 152 cases of empyema, of which 37 were scheduled on open thoracotomy drainge for chronic empyema. 1. The ratio of male to female was 3.6:1 with male predominance and 64% of total was above 40 years old in age distribution. 2. The cardinal symptoms were fever[70%], dyspnea[40.5%], and sputum[40.5%]. The leucocytosis were observed in 75.7% of all cases. The hemoglobin level showed subnormal in 21.6% of all cases. 3- The underlying pathology predisposing to empyema were postoperative empyema [35.1%] and tuberculosis[32.4%] in order. 4. The pathologic organisms by bacterial culture in 37 patients were Pseudomonas [24.3%], Staphylococccus [21.6%], Streptococcus [21.6%]., no growth [8. 1%] and the remainders. 5. The late results were as follow; a. Spontaneous closure was seen in 10 patients and all of them belongs to non-tuberculous group. Their mean duration was 14 months. b. Still opened are eight; 6 in tuberculous group, remainders in non-tuberculous group. c. Secondary closure was performed in 6 patients, of which 5 cases showed successful secondary closure but one failed. The mean duration from OTD to secondary closure was 46.3 days. d. Eleven patients were not followed. e. Two patients were expired; one was due to progressive cachexia and pulmonary insufficiency, the other due to gastrointestinal bleeding unrelated to empyema.

• The Plant Pathology Journal
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• v.32 no.3
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• pp.216-227
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• 2016

Biological control agents (BCAs) from different microbial taxa are increasingly used to control bacterial wilt caused by Ralstonia solanacearum. However, a quantitative research synthesis has not been conducted on the role of BCAs in disease suppression. Therefore, the present study aimed to meta-analyze the impacts of BCAs on both Ralstonia wilt disease suppression and plant (host) growth promotion. The analysis showed that the extent of disease suppression by BCAs varied widely among studies, with effect size (log response ratio) ranging from -2.84 to 2.13. The disease incidence and severity were significantly decreased on average by 53.7% and 49.3%, respectively. BCAs inoculation also significantly increased fresh and dry weight by 34.4% and 36.1%, respectively on average. Also, BCAs inoculation significantly increased plant yield by 66%. Mean effect sizes for genus Pseudomonas sp. as BCAs were higher than for genus Bacillus spp. Among antagonists tested, P. fluorescens, P. putida, B. cereus, B. subtilis and B. amyloliquefaciens were found to be more effective in general for disease reduction. Across studies, highest disease control was found for P. fluorescens, annual plants, co-inoculation with more than one BCA, soil drench and greenhouse condition were found to be essential in understanding plant responses to R. solanacearum. Our results suggest that more efforts should be devoted to harnessing the potential beneficial effects of these antagonists, not just for plant growth promoting traits but also in mode of applications, BCAs formulations and their field studies should be considered in the future for R. solanacearum wilt disease suppression.

• Korean Journal of Veterinary Service
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• v.39 no.3
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• pp.159-166
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• 2016

Clostridium perfringens, Salmonella thyphimurium and S. Montevideo isolated from the intestines of dead broiler chickens in Korea were tested for antibacterial effects to purifed bee venom. Purified bee venom from Apis mellifera L. has been used as natural antimicrobial compounds in pigs, cows, dairy cattle and chicken farms in Korea. To investigate antibacterial effect of purified bee venom was evaluated by agar well diffusion method, minimum inhibitory concentraion (MIC), minimum bactericidal concentration (MBC), and postantibiotic effect (PAE). Purified bee venom exhibited significant inhibition of bacterial growth of C. perfringens, S. thyphimurium and S. Montevideo with MIC value of 0.85, 0.68 and $0.69{\mu}g/mL$, respectively. The MBC value of purified bee venom against C. perfringens, S. thyphimurium and S. Montevideo were 3.33, 2.66 and $2.86{\mu}g/mL$. Furthermore, the results of PAE values against C. perfringens, S. thyphimurium and S. Montevideo showed the bacterial effect with 3.5, 4.0 and 3.5 hr. Stability of pufifed bee venom at acidity from pH 1 to pH 8 for 24 hr was the antibacterial activity for C. perfringens, S. thyphimurium and S. Montevideo and melittin contents. Also purified bee venom processed through the heating for 15 min, there was no signification loss of the antibacterial activity and melittin at below $100^{\circ}C$. These results obtained in this study suggest that purified bee venom might be utilized as a feed additive in poultry diets.

• Korean Journal of Veterinary Research
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• v.56 no.2
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• pp.125-127
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• 2016

Gradual mortality of look down fish (Selene vomer) was observed in a private aquarium in Seoul, showing abnormal swimming behavior and lethargy. A bacterial pathogen from kidney was cultured, identified, and confirmed as Vibrio harveyi using Vitek System 2 and 16S rRNA gene sequencing. A predominant bacterial strain, SNUVh-LW2 was proved to be most closely related to isolates from China by phylogenetic analysis with minimum evolution method. Also, tetracycline was considered as the most sensitive antibiotic agent via antibiotic susceptibility test. The group of fish was treated according to the diagnostic result and no more mortality was observed.

• Textile Coloration and Finishing
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• v.18 no.2 s.87
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• pp.8-14
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• 2006

The pigment extraction of Opuntia ficus-indica has been conducted to develop useful natural dyes in place of synthetic dyes which are suspected to bring serious environmental pollutions. The dyeing ability on wool fabric by addition of ascorbic acid and several mordants were investigated by means of color measurement. In addition, the fastness of washing, perspiration, rubbing, light, dry cleaning, effect on bacterial reduction and UV-B protection were also investigated. From these investigation, it is suggested that the pigment extracted from Opuntia ficus-indica can be used as a source of natural dyes and the obtained result are as follows. 1. Maximum absorption band (${\lambda}max$) of Opuntia ficus-indica extract is 533nm. 2. The wool fabric dyed with Opuntia ficus-indica extract has stable color by the addition of ascorbic acid and is achieved with addition of 0.1% ascorbic acid, 0.5% several mordant, and three repeated dying at $50^{\circ}C$ for 1.5hr. 3. The wash fastness of the dyed wool fabric when it is washed with neutral detergent is more effective than alkaline detergent. The dry cleaning fastness of the dyed wool fabric is more excellent. In addition, the perspiration fastness of the dyed wool fabric is increased by mordanting method. And than the rubbing fastness of the dyed wool fabric is showed excellent under dryness and wetness. Light fastness of the dyed wool fabric, however is showed inferiority. 4. The wool fabric dyed with Opuntia ficus-indica extract is showed effective bacterial reduction and UV-B protection is increased remarkably.

• Journal of Microbiology and Biotechnology
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• v.31 no.5
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• pp.705-709
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• 2021

Porphyromonas gingivalis (P. gingivalis) is a major bacterial pathogen that causes periodontitis, a chronic inflammatory disease of tissues around the teeth. Periodontitis is known to be related to other diseases, such as oral cancer, Alzheimer's disease, and rheumatism. Thus, a precise and sensitive test to detect P. gingivalis is necessary for the early diagnosis of periodontitis. The objective of this study was to optimize a rapid visual detection system for P. gingivalis. First, we performed a visual membrane immunoassay using 3,3',5,5'-tetramethylbenzidine (TMB; blue) and coating and detection antibodies that could bind to the host laboratory strain, ATCC 33277. Antibodies against the P. gingivalis surface adhesion molecules RgpB (arginine proteinase) and Kgp (lysine proteinase) were determined to be the most specific coating and detection antibodies, respectively. Using these two selected antibodies, the streptavidin-horseradish peroxidase (HRP) reaction was performed using a nitrocellulose membrane and visualized with a detection range of 10³-10⁵ bacterial cells/ml following incubation for 15 min. These selected conditions were applied to test other oral bacteria, and the results showed that P. gingivalis could be detected without cross-reactivity to other bacteria, including Streptococcus mutans and Escherichia fergusonii. Furthermore, three clinical strains of P. gingivalis, KCOM 2880, KCOM 2803, and KCOM 3190, were also recognized using this optimized enzyme immunoassay (EIA) system. To conclude, we established optimized conditions for P. gingivalis detection with specificity, accuracy, and sensitivity. These results could be utilized to manufacture economical and rapid detection kits for P. gingivalis.