• Microbiology and Biotechnology Letters
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• v.27 no.4
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• pp.286-291
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• 1999

By using autoradiography and phosphate medium, high phosphate accumulating bacteria were isolated from the soil of protected cultivation area and activated sludge. Selected strain, PO8, was gram-negative, rod/spherial(0.5~0.6$\times$1.0~1.2${\mu}{\textrm}{m}$ in size) and non-motile. PI4, another selected strain, was gram-negative, rod(0.4~0.5$\times$1.5~1.6${\mu}{\textrm}{m}$ in size) and motile. It also had flagella. According to their morphological, physiological and biochemical properties, the stains were identified as Acinetobacter lwoffi PO8 and Chromobacterium lividum PI4, respectively. A. lowoffi PO8 and C. lividum PI4 cultured in the P-1 medium containing 150ppm phosphate were able to uptake high phosphate up to 92% and 85%, respectively after 24 hours at 3$0^{\circ}C$ during liquid culture.

• Journal of Periodontal and Implant Science
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• v.33 no.2
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• pp.247-257
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• 2003

The purpose of this study was to evaluate the difference of subgingival bacterial compositions between periodontally healthy and diseased sites. Subgingival plaque samples were obtained from 100 sites in 20 untreated adult periodontitis patients(experimental group), and 100 sites in healthy individuals(contro1 group). Before sampling, probing pocket depth(PPD) and clinical level of attachment(CAL), Plaque Index(PI), and Sulcus Bleeding Index(SBI) were recorded for each sampled sites. Microbial samples were collected from the bases of gingival sulci or periodontal pockets with sterile curettes. The samples were examined under darkfield microscope(${\times}$400). At least 150 bacteria were evaluated and categorized on the basis of bacterial morphology and motility, i.e. cocci, non-motile rods, motile rods, and spirochetes. In control group, subgingival microbial flora consisted of 73.7% of cocci, 20.0% of non-motile rods, 4.3% of motile rods, and 2.0% of spirochetes. The microbial samples from experimental group consisted of 51.5% of cocci, 19.4% of non-motile rods, 17.6% of motile rods, and 11.6% of spirochetes. The proportion of cocci was higher in control group than in experimental group. Proportions of motile rods and spirochetes were higher in experimental group than in control group. The proportion of nonmotile rods in experimental group and control group was not significantly different. Sulcus Bleeding Index and Plaque Index showed high correlation with the bacterial composition. These findings suggests that examination of subgingival bacterial proportion may serve as more sensitive mirror of the local periodontal status than clinical parameters.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.3
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• pp.411-422
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• 1993

Osseointegrated dental implants are now an accepted part of the prosthetic treatment of fully and partially edentulous patients. Clinical studies have shown that osseointegrated dental implants may successfully be used as abutments for prosthetic rehabilitations, and that the supporting tissue can be kept in a stable and healthy clinical state for prolonged periods of time. The purpose of this study was to look for differences in the distribution in the bacterial morphotypes around natural teeth and osseointegrated dental implants. The subgingival plaque around natural teeth and implants was analysed by means of differential phase-contrast microscopy. In addition, clinical indices used to analyse natural teeth condition were used to compare the condition of natural teeth and implants. The results were as follows : 1. In implants of partially edentulous patients, the plaque index, sulcus bleeding index(P<0.05), pocket depth(P<0.01) were greater than natural teeth. 2. Gingival crevicular fluid volume was not significantly different between natural teeth and implants. 3. In implants of fully edentulous patients, the plaque index was greater than natural teeth(P<0.01) and implants of partially edentulous patients(P<0.05), but sulcus bleeding index was not significantly different. 4. In partially edentulous patient, coccoid cell proportion was greater in implants than natural teeth (P<0.05). 5. In implants of fully edentulous patients, coccid cell proportion was even greater than implants of partially edentulous patients(P<0.05) and natural teeth(P<0.01). 6. Among three groups, the proportions of non-motile rods, motile rods, spirochetes and others were not significantly different. 7. The proportion of motile bacteria was not significantly different among three group.

• Journal of fish pathology
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• v.30 no.2
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• pp.89-96
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• 2017

The majority of freshwater ornamental fish are imported and distributed domestically, causing high risk of exposure to exotic pathogens and drug resistant bacteria in Korea. Aeromonas hydrophila is known as a common species of fresh water bacteria and opportunistic fish pathogen, as well as a species causing zoonotic infection. In this study, we isolated motile aeromonads from various imported freshwater ornamental fish and studied the characters of the isolates. Imported freshwater ornamental fish were purchased on day 1 after the fish were deposited in the aquarium. Bacteria were isolated from the liver, kidney and spleen of fish using 0.5% NaCl containing tryptic soy agar medium. Bacteria were grouped on the basis of their morphological characteristics. The colonies with clear zone on starch-ampicillin agar (SA agar) were tentatively identified as Aeromonas spp. Two hundred and twenty-six strains, about 70% of total isolates were assumed to be Aeromonas spp. Nine isolates were further identified based on the result of the API 20E test and PCR using primers specific for A. hydrophila 16S rRNA gene. The isolates were identified as A. hydrophila and the API 20E test showed differences in trisodium citrate, D-sucrose, D-melibiose, amygdalin and L-arabinose availability between the nine isolates and standard A. hydrophila. The susceptibilities of the isolated bacteria to 10 antibacterial agents were confirmed by the disk diffusion method. Isolated strains were found to be resistant to amoxicillin and ampicillin and sensitive to florfenicol. However, 7 isolates showed multiple drug resistances to erythromycin, oxytetracycline, nalidixic acid etc. Pathogenicity of the isolates was determined by the artificial challenge test on goldfish (Carassius auratus). Three isolates caused 60 ~ 80% mortality in goldfish within 5 days after the initiation of challenge. These results indicate that multiple drug resistant, highly pathogenic and exotic A. hydrophila can spread to domestic aquarium and the preventive treatment of fish before sale is necessary.

• Journal of Environmental Science International
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• v.6 no.3
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• pp.249-258
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• 1997

Mercury- and cadmium-resistant bacteria were Isolated from an Industrial complex wastewater of Taejon area. All of them were motile, gram negative rods. In the results of physicochemical test and VITEK card test. HM1 was Identified with Achetobacter cd- coaceucus, CM3 was Identified 65 Commonas acidovorns, HM2, HM3, CMI , and CM4 were Pseudomonas sp., but HM4 and CM2 were unidenteed. They were tested for subceptlbility to 14 heavy metals. Mercury-resistant bacteria(HM1, HM2, HM3, and HM4) were sensitive to low concentration(100~400ppm) of $Cd^{2+}$, $Co^{2+}$. $Zn^{2+}$, and Ni2+, while cadmium-resistant bacteria(CM1, CM2, CM3, and CM4) showed resistance up to the high concentration(600~ 1, 200ppm) of these metal loons. As a result of resistance spectrum test of mercury-resistant bacteria, HM1 was broad-spectrum strain, HM2. HM3, and HM4 were narrow-spectrum stratas. Transmission electron microscopic examination of cell wall of HM1 culture grown with and without 100ppm of $HgCl_2$ showed remarkably merphological abnormalities. In the result of atomic absorption spectrometric analysis of cadmium-resistant bacteria grown at 200ppm of $CdCl_2$ for 6h, all of them accumulated cadrnium(14ppm~57ppm) In cell. In cadinium-resistant bacteria, CM1, CM2, and CM4 were spared from the Inhibitory effect of $Cd^{2+}$ by the addition of $Mn^{2+}$, CM4 were also spared from the Inhibitory effect of $Cd^{2+}$ by the addition of $Mn^{2+}$ as well as $Zn^{2+}$.

• Korean Journal of Microbiology
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• v.12 no.1
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• pp.37-51
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• 1974

Three strains which accumulated large quantities of L-hlutamic acid as the chief product of metabolism in the presence of glucose and inorhanic ammonium salt under the aerobic condition sere newly isolated. These strains have the general characters as follows: Gram-positive, short fod-shaped, non-sporulating, non-motile, and facultative anaerobe. A change of cell shates was not almost observed in their life cycles and neither a phenomenon of cell-elongation nor a pleomorphism was recognized in any cases. Together with rigid stability in Gram-stain, these characters as above indicated evidences that newly isolates would belong to genus Brevibacterium clearly differentiated from genus Corynebacterium. At the same time the newly isolates, in addition to nutritional requirement of biotin and thiamine, showed the distinctive character of requirement of special amino acid such as histidine or cysteine for their considerable growth. These physiological characters including nitrates reduction, reaction on milk, and slow formation of acid from sugar also were useful in confirming that these bacteria would be Brevibacterium ammoniagenes.

• Plant Disease and Agriculture
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• v.5 no.2
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• pp.105-110
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• 1999

Bacterial leaf spot by Xanthomonas campestris pv. vesicatoria has been known to cause serious problem in red pepper in Korea. However recent survey showed that most smptoms in the leaves were mixed with two different symptoms one was leaf spot and the other was canker. bacteria isolated from canker were identified as Clavibacter michiganensis subsp. michiganensis on the basis of biochemical and physiological characteristics. The causal bacteria were non-motile rod-shaped and Gram-positive. The lesions on pepper leaves appeared at first as small blisters or pimple-like white spots which enlarged in size at a later stage. The centers of some of the spots became necrotic and brown and were surrounded by a white halo. Pathogenicity tests were performed on pepper cv. Alchan seedling by spraying of bacterial suspension. During 1997 and 1998 total 17% of 527 fields surveyed were infected by C. michiganensis subsp. michiganensis. The canker of red pepper caused by C. michiganensis subsp. michiganensis was first identified in this study in Korea, and new name "gueyangbyung" was tentatively given to the disease.

• Journal of Periodontal and Implant Science
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• v.24 no.3
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• pp.503-512
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• 1994

The purpose of this study was to assess the clinical and microbiological effect of chlorhexidine rinse following scaling and root planing on periodontits. 10 patients with periodontal disease were selected for the study. They had not taken antibiotics for months and no history of dental treatment for 6 months before the study. They were good in general health. Patients received a scaling and root planing under local infiltration anesthesia, chlorhexidine rise group were subjected to twice a day 0.1% chlorhexidine rinse for a period 2 week. After initial clinical(plaque index, gingival index, probing pocket depth), microbiological and BANA tests were determined, each subject received a single session of scaling and root planing but no oral hygiene instructions. Clinical indices were measured, microbial parameters and BANA test were reassessed 1, 2 and 4 weeks after treatment. The results were as follows : 1. Plaque index, gingival index and pocket depth in chlorhexidine rinse group and control group were not significantly reduce during all weeks when compared chlorhexidine rinse group with control groups. Plaque index in chlorhexidine rinse group and control group were siginificantly reduced at 1, 2, 4weeks(P<0.05), gingival index and pocket depth wee ignificantly reduced at 2, 4weeks in both groups(P<0.05). 2. Perecntage of cocci and motile rods was significantly changed at 1, 2, 4weeks in chlorhexidine rinse group(P<0.05), control group was significantly changed at 4weeks in control group(P<0.05), intergroup difference was significantly at 2weeks in cocci and 4weeks in motile rods(P<0.05). 3. Percentage of non-motile rods in all group were not significantly changed when compared with those of baseline. 4. Percentage of spirochetes was significantly reduced at 4 week(P<0.05), control group was not significantly reduced during all weeks. 5. BANA test scores was significantly reduced during all weeks in chlorhexidine rinse group(P<0.05), control group was not significantly reduced during all weeks. The result showed that clinical and microbiological effect following scaling, root palning and chlorhexidine on periodontal disease.

• Journal of Periodontal and Implant Science
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• v.24 no.2
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• pp.376-389
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• 1994

A study was conducted to compare the effects of chlorhexidine mouthrinse and chlorhexidine acetate powder with periodontal pack during 4 weeks following periodontal surgery. Twelve patients were treated with Modified Widman flap procedures and devided into three groups of four patients each; control group, chlorhexidine mouthrinse group, chlorhexidine acetate powder group. Each group wasn't significant difference in clinical and microbiologic parameters at preoperation. Examination regarding plaque index, gingival index, pocket depth, change of gingival color postsurgically, pain index were performed by each methods and observed bacteria in gingiva by phase contrast microscope. Evaluations were made at 7, 14 and 28 days postsurgically. The results were as follows: l. In comparison of results revealed no significant differences in Plaque Index, Gingival Index, pocket depth and change of gingival color postsurgically. 2. The pocket depth of three experimental groups were significant reduced at 4 weeks. 3. Chlorhexidine mouthrinse group and chlorhexidine acetate powder group with periodontal pack were significant differences in pain index at 3, 4 days postsurgically. 4. Cocci and Non-motile rods were increased at 1, 2 weeks. But, motile rod and spirochete were increased at 4 weeks.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.2
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• pp.121-127
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• 2005

A heterotrophic nitrifying bacterium was isolated from the compost and analyzed for its characteristics. This bacterium was found to be a Gram positive rod, catalase positive, and motile. Nitrite production was detected on the ammonium acetate medium through the violet color formation. BBL test showed that this strain has high homology with Bacillus strains. Phylogenetic analysis using 16S rDNA revealed that the bacterium has 94% of similarity with Mycobacterium smegmatis strain.