• Journal of Animal Science and Technology
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• v.45 no.4
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• pp.659-666
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• 2003

Endoglucanase A from Clostridium thermocellum which is resistant to pancreatic proteinase was selected out of numbers cellulases then were expressed in lactobacilli. Recombinant lactobacilli expression vector, pSD1, harboring the endoglucanase gene from C. thermocellum under the control of its own promoter, was constructed. Both L. bulgaricus and L. plantarum were electrotransformed with pSD1. The endoglucanase activities of 0.120 and 0.144 U/ml were found in culture media of L. bulgaricus and L. plantarum containing pSD1, respectively. In vitro survival characteristics of the transformed lactobacilli were tested. Both L. bulgaricus and L. plantarum showed a similar resistance to low pH 3. Moreover, L. plantarum was bile-salt resistant in the presence of 0.3 and 1% oxgall. L. bulgaricus and L. plantarum showed a rather homogenous resistant pattern against the tested antibiotics. Both of the strains were resistant to amikacin, gentamicin, streptomycin, kanamycin, and colistin.

• The Journal of the Korean Society for Microbiology
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• v.22 no.1
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• pp.35-53
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• 1987

Multiply resistant Shigella strains isolated in Taegu area were subjected for the characterization of R plasmids. All strains isolated in 1984 and 1985 were susceptible to gentamicin, amikacin, and cephalothin, and most strains were susceptible to kanamycin (Km) and rifampin by agar dilution antimicrobial susceptibility test. The resistance frequency of S. flexneri against ampicillin (Ap) was higher than that of S. sonnei. The strains resistant to sulfisomidine (Su) and trimethoprim (Tp) were found at higher frequency in S. sonnei than in S. flexneri. The most prevalent resistance pattern of S. flexneri was chloramphenicol (Cm) tetracycline (Tc) streptomycin (Sm) Ap, followed by the pattern of CmTcSmSuApTp, CmTcSmSuApTp nalidixic acid, and CmTcSmSuAp in the decreasing order. The antibiogram of CmTcSmSuTp was found to be the most frequent pattern in S. sonnei. The ratio of conjugal transfer of S. flexneri was 47% and 75% of S. sonnei. The average number of plasmid harboring in Shigella was 4 and the size of plasmid ranged 1.3 to 134 megadalton (Mdal). Most S. flexneri carried plasmids of 2 to 3 Mdal and S. sonnei carried those of 3 to 4 Mdal size. The sizes of conjugative plasmids ranged 40-90 Mdal. The incompatibility group (Inc) F II plasmids (54-59 Mdal) were most frequent and rare Inc B plasmids (60 Mdal) of isolates in 1979 and 1980 and Inc FI (87 Mdal) of 1983 isolates were able to be classified by the colony test with standard reference plasmids. The R plasmids of known Inc group were tested for the restriction endonuclease analysis. The pattern of plasmids digested by EcoRl were apparently different by the Inc group but there was no significant difference between species or by the resistance patterns. Nonconjugative plasmids and their phenotypes were identified by transformation test. The transformants were resistant to less than two drugs. Colicin producing transformants carried the Col plasmid of 3.7 or 3.9 Mdal size. $Ap^r$ plasmids derived from S. sonnei were found to be mobilized by transfer factor RT641 to E. coli #CS100. $Ap^r$ plasm ids of same size shared by S. flexneri, S. sonnei, and E. coli were digested with Pstl. All of them showed two restriction fragments of 2.8 kilobase(kb) and 0.7kb. Other plasmids ($Sm^r\;Su^r$) derived from S. flexneri, S. boydii, and S. sonnei were digested with Pstl and they showed same restriction fragment patterns of 3.1kb and 2.9kb. The plasmid profiles of three strains of S. sonnei producing colicin and showing same resistance pattern of CmTcSmSuApTpKm appeared to be similar. Restriction patterns by EcoRl and the behavior of plasmids in conjugation or transformation process were also similar between those plasmids. The restriction patterns were significantly different between the plasmids of Inc FI group and those of unclassified Inc group.

• The Journal of the Korean Society for Microbiology
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• v.6 no.1
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• pp.21-27
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• 1971

Recent reports confirm that R factors is widespread in Korea among Enterobacteriaceae isolated from humans. However, no reports have been made concerning the incidence of transferable drug resistance in domestic animals in this country. A total of 211 isolates of Escherichia coli, including 94 strains from dogs, 76 strains from pigs, 30 strains from chickens, and 21 strains from cow milk, were examined for drug resistance and distribution of R factors. And, respective two strains of Salmonella E group and Salmonella cholerasuis which were isolated from dogs and pigs, respectively were also examined for the same purposes. Of 211 strains of E. coli isolated, 66.8% were found to be resistant to 8 antibacterial agents such as streptomycin(SM), tetracycline(TC), chloramphenicol(CP), ampicillin sodium(AP), nalidixic acid(NA), gentamicin(GM), and polymyxin B(PX). Among the isolates, 86.2% of the strains from dogs, 70% of the strains from chickens, 43.4% of the strains from pigs, and 28.6% of the strains from milk, respectively, were found to be resistant to the drugs. The following percentage of resistance of E. coli to each individual drugs was encountered: of 94 strains from dogs, AP, 64.9%; SM, 20.2%; NA, 12.8%, CP and PX, 8.5% each; GM, 2.1% each; GM, 2.1%. Among 76 strains from pigs, 42.2% and 2.6% each were resistant to TC, AP and PX, respectively. Among 30 strains from chickens, 43.3% were resistant to SM, TC, AP, respectively, and no strains were resistant to the other drugs. No strains of the isolated from milk were resistant to the drugs, except that 28.6% were resistant to SM and AP, respectively. Of the strains from dogs, multiply resistant strains(56.8%) were more than singly resistant one(43.2%) and sixteen different drug resistant patterns were observed. The most frequently encountered patterns were AP TC AP and SM CP AP NA. Of the isolates from other sources, the most frequently encountered resistant patterns were as follows: TC among the strains from pigs; SM TC AP from chickens; SM AP from milk. Of the resistant strains from dogs, 32% carried R factors and the most common resistance patterns of R factors were AP TC AP and SM TC CP, whereas 35.2% of the resistant strains from pigs carried R factors of which the most common encountered pattern was TC. Of the resistant strains from chickens, 46.9% carried R factors of which the most common patterns were SM TC TC AP and AP, whereas 50% of the resistant strains from milk carried R factors of which the most common pattern was SM. Of 4 strains of Salmonella isolated, no strains were resistant to the drugs, except that only one strain of Salmonella E group isolated from a dog was resistant to AP. The strain did not harbor R factor.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.5
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• pp.494-499
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• 2017

This study evaluated the abundance of fecal coliforms in oysters Crassostrea gigas, sea squirts Halocynthia roretzi and sea cucumbers Apostichopus japonicus in fisheries along the coast of Korea in 2014, and investigated the prevalence of antimicrobial resistance in Escherichia coli isolated from these fishery products. The ranges of fecal coliforms found in oysters, sea squirts and sea cucumbers were <18-20, <18-330 and <18-3,300 MPN (most probable number)/100 g, respectively. Sea squirts contained the greatest range of E. coli (<20-140 MPN/100 g), followed by sea cucumbers (<20-130 MPN/100 g) and oysters (<20-20 MPN/100 g). A total of 26 strains of E. coli were isolated from 34 sea squirt, 25 sea cucumber and 13 oyster samples. Strains thus isolated were tested for their susceptibility to 22 antimicrobial agents used in Korea for medical or veterinary therapy. E. coli isolates showed the greatest resistance to ampicillin (84.6%), followed by trimethoprim (34.6%), nalidixic acid (34.6%), tetracycline (30.8%), pipemidic acid (26.9%), streptomycin (23.1%), chloramphenicol (23.1%), trimethoprim/sulfamethoxazole (23.1%), and gentamicin (15.4%). Resistance to at least one antimicrobial agent was present in 88.5% of E. coli isolates. Of the 26 isolated, six strains (23.1%) were resistant to multiple antimicrobial agents.

• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.359-366
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• 2002

Bacillus polyfermenticus SCD which is commonly called as Bisroot strain is being used for functional foods through the treatment of long-term intestinal disorders, since the live strains in the form of active endospores can successfully reach the target intestine in humans. The cells of B. polyfermenticus SCD were treated for 4h in artificial gastric juice (pH 2.0,3.0) and bile acid. Final viability of the strain in artificial gastric Juice (pH 2.0, 3.0) is reached to 62.8% and 81.2% respectively B. polyfermenticus SCD is resistant to antibiotics such as streptomycin, rifampicin, nystatin and ampicilin. B. polyfermenticus SCD is well known supplies the nutrients by synthesizing vitamin $B_1$, $B_2$, C and K. B. polyfermenticus SCD produces various digestive enzymes and the enzymes enable to completely digest diets in our body. Above all, $\alpha$-amylase and pretense activities are very higher than B. subtilis KCTC 1020, about two fold and twenty five fold respectively. B. polyfermenticus SCD is very stable during long-term storage period in phosphate buffers of wide-range pH, solutions of various concentrations of sodium chloride, 5% glucose solution and water.

• Journal of Veterinary Clinics
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• v.16 no.2
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• pp.375-380
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• 1999

This study was conducted to develop an intrauterine inseminator (IUI) to deposit of frozen semen into uterus and to evaluate the results obtained after artificial insemination by IUI. Two Japanese spitzs (2 to 4 years of age) were used as semen donors. Semen was collected by manual masturbation into sterile glass collection tubes and separated into 3 fractions with only the sperm-rich fractions retained for further examination. Sperm motility >70%, sperm concentration of 200 to $400{\times}10^6 cells/ml$$\times$g for 5 min and poured out the suspended solution, and then diluted with 2 ml Tris-buffer which was consisted of 2.4 g Tris, 1.4 g citric acid, 0.8 g glucose, 0.1 $\mu\textrm{g}$/ml streptomycin, 100 IU/ml penicillin, 20 ml egg yolk to 100 ml mili-Q water (Ext I) or supplemented with 8 ml glycerol and 1 ml Equex STM paste to 100 rnl (Ext II). The diluted semen was cooled to 5$^{\circ}C$ in cold room, where the temperature in the sample reached 5$^{\circ}C$. Two h after beginning the cooling procedure, 2 ml of Ext II, also at 5$^{\circ}C$, was added and mixed by gently reversing the tubes several times during 1 h. The final sperm concentration for freezing was approximately $50{\times}10^6 cells/ml$. After equilibration, the semen was loaded into 0.5 ml straw and frozen on the liquid nitrogen vapour in styrofoam box. The straws were thawed at 7$0^{\circ}C$ for precisely 6 sec. After thawing of each straw, the frozen semen can survived over 50% motility. All the females were inseminated twice with 1 ml of $25{\times}10^6 cells/ml$

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.1
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• pp.60-66
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• 1996

Bradyrhizobium japonicum with different colony morphology populated in five Yeongnam soils of Korea was examined for intrinsic antibiotic resistance to eight antibiotics, serological property by immunoblot and immunodiffusion, and protein profile differentiation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Colony morphological distribution of one hundred and twenty B. japonicum isolates was 47% for "dry". 41% for "wet", and 12% for "dry/wet" type. The total isolates showed such a strong correlation between the morphology and antibiotic resistance. Colony morphology, which though was dominantly consisted of the same type within a serogroup, wasn't absolutely linked to serological property of B. japonicum. Based on these data, colony morphology was too simple to identify variations with B. japonicum isolates : antibiotic resistance such complicated compared with serological analyses.

• Journal of Periodontal and Implant Science
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• v.25 no.2
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• pp.279-289
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• 1995

The most important object of periodontal treatment is the perfect regeneration of destructed periodontal tissue. The healing of periodontal lesion is affected by several cells & factors, which result in formation of long juntional epithelium, root resorption, bony ankylosis or connective tissue attachment. And ideal healing is enhanced by epithilial exclusion or periodontal ligament cell activation. In this investigation, I studied the effect of Zizyphus Fructus extract which enhances biologic activity& collagen synthesis, on the chemotaxis & cell nature. The cells were obtained from interdental area & middle third area of the freshly extracted teeth for the orthodontic purpose. And they were fully incubated in${\alpha}-MEM$ solution containing $100{\mu]g/ml$ penicillin & $100{\mu]g/ml$ streptomycin followed by 6 generation incubation. The test cells were collected by trypsin-EDTA & centrifuge in the fully incubated cells, counted by Hernacyotmeter, incbated $5{\times}10^5/ml$ cells for 24 hours, re-incubated 24 hours in media containing natural extract and photographed. The cells were incubated for 4 hours in 48 well microchemotaxis chamber bisecting upper & lower chamber by 8ug/m pore polycarbonate membrane coating 5mg/ml gelatin solution. The migrated cells in microscope were counted, which meaned cell chemotaxis activity. The study had shown that the morphology of cell was spindle-shaped as the control group, and the subextract test groups were not significantly different. In gingival fibroblasts, the chemotaxis effect of PDGF was statistically significant compared to control group. The Zizyphus Fructus extract was more or less enhanced chemotaxis effect and in $1{\mu}g/ml$ concentration the chemotaxis effect was slightly elevated compared with $10{\mu}g/ml$ concentration. But, among the subextracts, it was not significantly defferent. In PDL cells, the chemotaxis effect of PDGF in statistically significant, and the zizyphus Fructus extract had shown the enhanced effect. The effect was slightly higher in $1{\mu}g/ml$ concentration than 10g/ml concentration,and no significance among the subextracts.

• Journal of Dairy Science and Biotechnology
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• v.31 no.2
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• pp.143-152
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• 2013

Aminobutyric acid (GABA), a major inhibitory neurotransmitter in the central nervous system of animals, has several physiological effects including anti-hypertensive, diuretic, tranquilizing, and anti-stress properties, in humans. The purpose of this study was to investigate Lactobacillus plantarum K74, which was isolated from kimchi and selected as a strain with a high ability to produce GABA, to develop a new starter culture for fermented milk production. L. plantarum K74 produced $134.52{\mu}g/mL$ GABA in MRS broth containing 1% MSG, $212.27{\mu}g/mL$ GABA in MRS broth containing 2% MSG, and $234.63{\mu}g/mL$ GABA in MRS broth containing 3% MSG. The optimum growth temperature of L. plantarum K74 was $34^{\circ}C$, reaching a pH of 4.4 after 18 hours of growth. L. plantarum K74 was most sensitive to novobiocin out of 16 different antibiotics tested, and was most resistant to kanamycin and polymyxin B. L. plantarum K74 did not produce ${\beta}$-glucuronidase, a carcinogenic enzyme, and was comparatively tolerant to bile juice and low pH. Furthermore, it displayed resistance to Escherichia coli, Salmonella typhimurium, and Staphylococcus aureus at rates of 54.9%, 46.3%, and 0.7%, respectively.

• The Plant Pathology Journal
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• v.28 no.1
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• pp.32-39
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• 2012

Efficacy of different control methods was evaluated for disease management of tomato bacterial wilt caused by $Ralstonia$ $solanacearum$. All six chemical pesticides applied to the bacterial suspension showed $in$ $vitro$ bactericidal activities against $R.$ $solanacearum$. Minimal inhibitory concentrations (MICs) of copper hydroxide (CH), copper hydroxide-oxadixyl mixture (CH+O), and copper oxychloride-dithianon mixture (CO+D) were all 200 ${\mu}g/ml$; MIC of copper oxychloride-kasugamycin (CO+K) mixture was 100 ${\mu}g/ml$; MICs of both streptomycin- validamycin (S+V) and oxine copper-polyoxine B mixture (OC+PB) were 10 ${\mu}g/ml$. Among these chemical pesticides, treatment of the detached tomato leaves with the 5 pesticides (1 mg/ml), except for OC+PB delayed early wilting symptom development caused by the bacterial inoculation ($10^6$ and $10^7$ cfu/ml). Four pesticides, CH, CH+O, CO+K and S+V, showed disease protection in pot analyses. Six plant essential oils, such as cinnamon oil, citral, clove oil, eugenol, geraniol and limonene, differentially showed their antibacterial activities $in$ $vitro$ against $R.$ $solanacearum$ demonstrated by paper disc assay. Among those, cinnamon oil and clove oil exert the most effective activity for protection from the wilt disease caused by the bacterial infection ($10^6$ cfu/ml). Treatment with cinnamon oil and clove oil also suppressed bacterial disease by a higher inoculum concentration ($10^7$ cfu/ml). Clove oil could be used for prevention of bacterial wilt disease of tomato plants without any phytotoxicity. Thus, we suggest that copper compounds, antibiotics and essential oils have potency as a controlling agent of tomato bacterial wilt.