• Korean Journal of Microbiology
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• v.47 no.3
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• pp.218-224
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• 2011

Lactic acid bacteria (LAB) OA18 was isolated from yogurt prepared by using Kefir Grain as a starter. The OA18 strain was a Gram-positive, cocci-type bacterium, and able to grow anaerobically with $CO_2$ production. The OA18 strain grew well on MRS broth supplemented with 50 mM arginine at $30-37^{\circ}C$ and pH of 7.0-9.0. The optimum temperature and pH for growth are $37^{\circ}C$ and pH 7.0. The isolate fermented ribose, D-glucose, cellobiose, D-trehalose, but not L-xylose, D-melibiose, and inositol. The 16S rRNA gene sequence of the isolate showed 99.8% homology with the Enterococcus faecalis 16S rRNA gene (Access no. AB012212). Based on the biochemical characteristics and 16S rRNA gene sequence analysis data, it was identified and named as E. faecalis OA18. The E. faecalis OA18 strain showed a high ornithine-producing capacity in the presence of arginine and also showed an antimicrobial activity against Streptomyces strains such as Streptomyces coelicolor subsp. Flavus, S. coeruleorubidus, S. coeruleoaurantiacus, S. coelicolor, S. coeruleoprunus. The cell growth of E. faecalis OA18 strain was maintained in MRS broth with a NaCl concentration of 0-7%.

• Microbiology and Biotechnology Letters
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• v.41 no.1
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• pp.26-32
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• 2013

Butanol-resistant bacteria were isolated from butanol solvent. The cell growth of isolated strains declined with increasing concentrations of butanol, and isolated strain BRS02 displayed more resistance to 12.5 g/L of butanol than other isolated strains. In addition, strain BRS251, which was resistant to even higher concentrations of butanol, was developed by the mutation of BRS02 using UV. BRS251 could grow in LB medium containing up to 17.5 g/L of butanol, 32.5 g/L of propanol, or 6 g/L of pentanol, whereas the control strain Escherichia coli was found to be tolerant to 7.5 g/L of butanol, 20 g/L of propanol, or 2 g/L of pentanol. The isolated BRS02, a Gram(+) bacterium seen to have a cocci form under the microscope, grew in 6.5% NaCl. According to biochemical tests, BRS02 can metabolize and produce acid with D-galactose, D-maltose, D-mannitol, D-mannose, methyl-${\beta}$-Dglucopyranoside, D-ribose, sucrose, or D-trehalose, as carbon sources. Also, this strain showed resistance to bacitracin, vibriostatic agent O/129, and optochin, alongside positive activities for arginine dihydrolase, ${\alpha}$-glucosidase, and urease. The BRS02 strain was identified as Staphylococcus sp. by analyses of the 16S rRNA gene, phylogenetic tree, and biochemical tests.

• Korean Journal of Microbiology
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• v.39 no.4
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• pp.253-259
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• 2003

To assess microbiological indoor air quality in kindergartens, concentrations of viable airborne microorganisms were seasonally determined at three kindergartens in Ulsan from April, 2002 to January, 2003. Sampling was performed with an impaction-type air sampler and three different media. The numbers of bacteria grown on Staphylococcus medium were between 84 and 4,150 MPN/m3 with an average of 827 MPN/m3, and those on standard method agar ranged from 50 to 2,636 MPN/m3 with an average of 580 MPN/m3. The bacterial concentrations were highest in summer, followed by fall, spring, and winter, and were significantly correlated with indoor temperature. Among the colonies, 45.6~61.0% were observed as Gram-positive cocci and 8.5~20.6% were Gramnegative rods. Micrococcus species were the dominant organisms. The numbers of fungi ranged from 0 to 1,888 MPN/m3(661 MPN/m3 average) based on colony counts with dichloran rose bengal chloramphenicol agar. On average, the fungal concentrations were highest in summer and lowest in winter. Penicillium species and Aspergillus species were identified from the colonies. The obtained data can be utilized as a step to set a guideline for bioaerosols in indoor environment of schools.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.2
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• pp.85-92
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• 2018

Information on the prevalence of S. aureus and the current antimicrobial resistance profile is necessary in selecting the appropriate treatment of S. aureus infections in any part of the world. This study examined the frequency and antibiotic resistance list of S. aureus isolates obtained from clinical specimens at one hospital in Korea. A total of 1,746 gram positive cocci collected were identified as S. aureus. S. aureus isolates were obtained from different samples including sputum (N=565; 32.4%), endotracheal aspirate (358; 20.5%), wounds (329; 18.8%), blood (137; 7.8%), urine (67; 3.8%), and pus (59; 3.4%). All 1,545 S. aureus (100%) strains screened from sputum (565; 36.6%), endotracheal aspirate (388; 25.1%), wounds (329; 21.3%), blood (137; 8.9%), urine (67; 4.3%), and pus (59; 3.8%) were sensitive to glycopeptide (vancomycin, teicoplanin), oxazolidinone (linezolid) and stretogramin (quinupristin/dalfopristin). The prevalence of resistant S. aureus was significantly (P<0.01) lower in urine, blood, pus, wounds, and sputum than in endotracheal aspirates. As a result, there was a significant difference in the antibiotic resistance of S. aureus according to the clinical specimens.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.355-361
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• 2003

Immunostimulating effects of lactic acid bacteria as biological response modifier is a subject of growing interest, but the knowledge of these focused on some bacteria as Lactobacillus and Bifidobacterium. In this study, we investigated the effects of Pediococcus pentosaceus EROM101 on the immunostimulating and anti-cancer activity in murine model. P. pentosaceus was mainly found in Kimchi and fermented sea food and is facultatively anaerobic, catalase-netative, gram-positive cocci arranged in pairs, tetrads and clusters. The immunostimulating effects of P. pentosaceus EROM101 were evaluated using IgA production assay of Peyer's patch and proliferation assay of exudated immune cells of Balb/C mice fed P. pentosaceus EROM101 for 3 weeks. The macrophage and splenocyte proliferation were enhanced by orally administrated of P. pentosaceus EROM101. Also, IgA production in Peyer's patch increased by P. pentosaceus EROM101. Anti-cancer activity of P. pentosaceus EROM101 was appeared in Sarcoma 180 tumor-bearing ICR mice. However, this bacterium lysate itself appeared to have noncytotoxic substance against Sarcoma 180 cell in vitro. These results suggested that P. pentosaceus EROM101 reinforce immune system and therefore was revealed to be anti-cancer activity in mice.

• Journal of fish pathology
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• v.36 no.2
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• pp.277-286
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• 2023

Korean rockfish, Sebastes schlegelii, is a representative bony fish that belongs to the family Scorpaenidae and the order Scorpaeniformes. It has high ecological and economic value and is widely cultivated in many East Asian countries, including South Korea, Japan and China. One of streptococci, Streptococcus iniae, is Gram-positive cocci with a negative reaction for catalase and oxidase. The Korean rockfish shows clinical signs when infected with S. iniae, such as body darkening, bleeding, enlarged kidneys, blurred eyes, abdominal distension, etc., ultimately leading to death. The Korean rockfish causes significant economic losses every year in South Korea due to streptococcosis. In this study, we identified bacteria from the fish using polymerase chain reaction and conducted analyses of hemolytic activity and biochemical tests using API 20 STREP and API ZYM systems. Results of confirming the hemolytic activity (n=4) observed in alpha-type hemolysis (25%), beta-type hemol- ysis (50%), and gamma-type hemolysis (25%) of isolates. The biochemical test results exhibited sig- nificant variation among S. iniae. Additionally, we performed intraperitoneal injection with S. iniae in the fish and analyzed the phylogenetic tree using housekeeping genes of S. iniae, including cpsD, arcC, glnA, groEL, gyrB, mutS, pheT, prkC, rpoB, and tkt, via multilocus sequence typing (MLST). The lethal dose (LD₅₀) showed strong pathogenicity, such as 3.34 × 10 colony-forming unit (CFU)/ml for 23FBStr0601 strain and 7.16 × 10 CFU/ml for 23FBStr0602 strain. 23FBStr0603 strain showed relatively low pathogenicity at 1.73 × 10⁵ CFU/ml. The strains 23FBStr0601 and 23FBStr0602, which showed strong pathogenicity, clustered into one monophyletic group. The 23FBStr0603 strain showed weak pathogenicity and formed a monophyletic group with KCTC 3657.

• Tuberculosis and Respiratory Diseases
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• v.49 no.2
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• pp.217-224
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• 2000

Background : It is well known that when macrophages are stimulated with endotoxin, they produce a wide variety of cytokine mediators, including TNF-$\alpha$ and IL-1$\beta$. However, there is an alteration in the macrophages' responsiveness when they are challenged with repeated bouts of endotoxin, termed "endotoxin tolerance" which is regarded as a self-protective phenomenon from continuous stimulation. In this study, endotoxin tolerance in the peripheral blood monocytes of sepsis patients was evaluated. Methods : Fourteen patients with organism-documented sepsis were included. The severity of illness was evaluated by APACHE II score. Peripheral blood monocytes were isolated from the patients and diluted to $1{\times}10^5$ well. After stimulation with endotoxin (LPS of E. coli O114 : B4, 100 ng/ml), they were incubated at $37^{\circ}C$ in 5% $CO_2$ incubator for 24 hours. Supernatant was collected for the measurement of TNF-$\alpha$ and IL-1$\beta$ with ELISA method. Peripheral blood monocytes of seven healthy volunteers were used as control. Results : The APACHE II score (mean$\pm$SD) of the patients at the time of blood sampling was 12.2$\pm$5.7. The primary infection foci were urinary tract infection, pneumonia, subacute bacterial endocarditis, and catheter related infection, etc. The causative organisms were gram negative rods (10 cases), gram positive cocci (6 cases) with two cases of mixed infection. Serum TNF-$\alpha$ could be measured in 4 cases with 29.9$\pm$27.7 pg/ml. Serum IL-1$\beta$was measurable in only one patient. The TNF-$\alpha$ level of supernatant of cultured peripheral blood monocytes was 2,703$\pm$2,066 pg/ml in patients and 2,102$\pm$1914 pg/ml in controls. The IL-1$\beta$level of supernatant was 884$\pm$1,050 pg/ml in patients and 575$\pm$558 pg/ml in controls. There was no difference of TNF-$\alpha$ and IL-1$\beta$ level between patients and controls. Conclusion : We cannot prove the phenomenon of endotoxin tolerance in this study. Future study needs to be focused on the more severe sepsis patients who were taken for sampling earlier. Addition of serum to the culture medium could be an another valuable option for the success of this study.