• The Journal of Natural Sciences
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• v.4
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• pp.103-142
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• 1991

These studies were carried out to select somatic hybrid using selectable marker genes of Nicotiana glauca transformed by NPTII gene and Solanum tuberosum transformed by T- DNA, and to study characteristics of transformant. The results are summarized as follows. 1. Crown gall tumors and hairy roots were formed on potato tuber disc infected by A. tumefaciens Ach5 and A. rhizogenes ATCC15834. These tumors and roots could be grown on the phytohormone free media. 2. Callus formation from hairy root was prompted on the medium containing 2, 4 D 2mg/I with casein hydrolysate lg/l. 3. The survival ratio of crown gall tumor callus derived from potato increased on the medium containing the activated charcoal 0. 5-2. 0mg/I because of the preventions on the other hand, hairy roots were necrosis on the same medium. 4. Callus derived from hairy root were excellently grown for a short time by suspension culture on liquid medium containing 2, 4-D 2mg/I and casein hydrolysate lg/l. 5. The binary vector pGA643 was mobilized from E. coli MC1000 into wild type Agrobacteriurn tumefaciens Ach5, A. tumefaciens $A_4T$ and disarmed A. tuniefaciens LBA4404 using a triparental mating method with E. ccli HB1O1/pRK2013. Transconjugants were obtained on the minimal media containing tetracycline and kanamycin. pGA643 vectors were confirmed by electrophoresis on 0.7% agarose gel. 6. Kanamycin resistant calli were selected on the media supplemented with 2, 4-D 0.5mg/1 and kanamycin $100\mug$/ml after co- cultivating with tobacco stem explants and A. tumefaciens LBA4404/pGA643, and selected calli propagated on the same medium. 7. The multiple shoots were regenerated from kanamycin resistant calli on the MS medium containing BA 2mg/l. 8. Leaf segments of transformed shoot were able to grow vigorusly on the medium supplemented with high concentration of kanamycin $1000\mug$/ml. 9. Kanamycin resistant shoots were rooting and elongated on medium containing kanamycin $100\mug$/ml, but normal shoot were not. 10. For the production of protoplast from potato calli transformed by T-DNA and mesophyll tissue transformed by NPTII gene, the former was isolated in the enzyme mixture of 2.0% celluase Onozuka R-10, 1.0% dricelase, 1.0% macerozyme. and 0.5M mannitol, the latter was isolated in the enzyme mixture 1.0% Celluase Onozuka R-10, 0.3% macerozyme, and 0.7M mannitol. 11. The optimal concentrationn of mannitol in the enzyme mixture for high protoplast yield was 0.8M at both transformed tobacco mesophyll and potato callus. The viabilities of protoplast were shown above 90%, respectively. 12. Both tobacco mesophyll and potato callus protoplasts were fused by using PEG solution. Cell walls were regenerated on hormone free media supplemented with kanamycin after 5 days, and colonies were observed after 4 weeks culture.

• The Journal of the Korean Society for Microbiology
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• v.7 no.1
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• pp.1-8
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• 1972

The authors made a study on the bacteriological identification about unidentified strains which were roughly screened by local health center, which an epidemic diarrhea was outbreak at Ham Yang Gun, Kyeongsang-Namdo in July 1971. And the authors made an attempt to bacteriological Identification, serotyping with slide agglutination, and determination of the susceptibility of identified strains to various chemotherapeutic agents. The results Were obtained as follows: 1. The isolated strains identified Shigella flexneri type 2b(2 strains) and Salmonella paratyphi B(4 strains). 2. Sensitivity test using with three concentrations chemotherapeutic agents(Paper disk used; Eiken chemical Co., Tokyo, Japan): (1) Shigella flexneri type 2b isolated strains were sensitive to kanamycin, colistin(100%) and penicllin(50%) respectively, but resistant to erythromycin, oleandomycin, leucomycin, chloramphenicol, tetracycline, dihydrostreptomycin and sulfadimethoxin(100%) respectively. (2) Salmonella paratyphi B isolated strains were sensitive to chloramphenicol, tetracycline, dihydrostreptomycin, kanamycin, sulfadimethoxine(100%) and colistin(50%) respectively, but resistant to penicillin, erythromycin, oleandomycin and leucomycin(100%) respectively. 3. Sensitivity test using with multodisk urinary code(Paper disk used; Oxoid, London): (1) Shigella flexneri type 2b isolated strains were sensitive to Bactrim, ampicillin, nitrofurantoin, nalidixic add and gentamicin(100%) respectively, but resistant to chloramhpenicol, tetracycline, sulfadiazine and Fanasil(100%) respectively. (2) Salmonell paratyphi B isolated strains were sensitive to Bactrim, chloramphenicol, ampicillin, nitrofurantoin, tetracycline, nalidixic acid, gentamicin(100%) and sulfadiazine(50%) respectively, but resistant to Fanasil(100%) and sulfadiazine(50%) respectively.

• Korean Journal of Veterinary Research
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• v.28 no.1
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• pp.83-87
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• 1988

The in vitro drug susceptibility of 83 strains of Bordetella bronchiseptica recovered from Korean pigs with atrophic rhinitis was investigated by the use of disk diffusion method. The majority of the organisms were highly resistant in order of prevalence to penicillin(98.7%), ampicillin(91.5%), streptomycin(90.3%), triple sulfa(83.1%), and trimethoprim/sulfamethoxazole(70.7%) while none of them were resistant to gentamicin, only 3.6% to colistin, chloramphenicol and kanamycin and 6.0% to tetracycline. The percentage of the organism resistant to bicozamycin, cephalothin and neomycin were 34.9%, 34.1% and 18.4%, respectively. A high prevalence of multiple drug resistance was observed and the 3 most common resistant patterns among 35 patterns noted were Am Pc Sm Sss Sxt(26.5%), Am Cf Pc Sm Sss Sxt(12.%) and Am Bm Pc Sm Sss Sxt(9.6%) patterns.

• YAKHAK HOEJI
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• v.37 no.6
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• pp.621-624
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• 1993

The clirical isolate Staphylococcus aureus SA2 had four kinds of plasmids and was resistant to ampicillin, chloroamphenicol, clindamycin. erythromycin, gentamicin, kanamycin, methicillin, streptomycin, tetracycline and tobramycin. Transformation experiment demonstrated that 4.14kb plasmid(pKH7) encoded resistance to chloramphenicol. The cleavage map of pKH7 was determined by restriction enzyme mapping techniques. The cleavage map is given for BstEll, Hindlll, Hpall, and Xbal. The above restriction endonucleases have a single site, but nucleases BamHl, Bgll, BglII, EcoRl, EcoRV, HaeIII, Hpal, Kpnl, Pstl, PvnII, Sall, Smal, and XhoI have no site on this plasmid.

• Journal of fish pathology
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• v.1 no.2
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• pp.95-101
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• 1988

During the period from August through October, 1988, 50 isolates of Edwardsiella tarda were isolated from 6 diseased cultured Channa argus in Dunchi island and Myung-ghi, near Pusan in Korea were examined by studying their biochemical and antibiotical reactions. The ill animals moved slowly and irregular-formed swimming at the surface of the corner. The symthoms were necrosis with hemorrhage on the body surface, head, gill region, and mouth. Some fish were observed dropsy of the belly. The bacteria grew slowly on Double Salmonella-Shigella agar, 24h, at $37^{\circ}C$ to form relatively small size (2mm diameter), smoothed and convexed form with transient or black in center of the colonis. They gave negative reactions to Voges-Proskauer, Simmon's citrate, urea, KCN (in growth), gelatin, arginine dehydrolase, phenylalanine deaminase and many sugars. The isolates showed positive reactions to $H_2S$ (in KIA agar), indol, Methyl-Red, motility, lysine and ornithine decarboxylase, and gas from glucose. 8 drugs tested as chloramphenicol, colistin, gentamicin, kanamycin, lincomycin, nalidixic acid spectinomycin, and tetracycline. All cultures were resistant to colistin, lincomycin and spectinomycin respectibly, but sensitive to kanamycin and nalidixic acid. Three strains showed resistance to chloramphenicol and 2 isolates among them were resistant to two drugs(gentamicin and tetracycline), coincidentally.

• Korean Journal of Veterinary Research
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• v.31 no.3
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• pp.279-284
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• 1991

To investigate the epidemiological aspects of listeriosis, serotypes of L monocytogenes and antimicrobial susceptibilities of Listeria spp isolated from chicken carcases and chicken slaughter house environmental specimens were determined. Of 28 L monocytogenes strains, 12 strains(42.9%) were serotype 4, and the remaining 16 strains were untypable. Peak distributions of minimum inhibitory concentration$({\mu}g/ml)$ of the isolates were $0.78{\mu}g/ml$ for ampicillin, $0.39{\mu}g/ml$ for erythromycin and penicillin G, $1.56{\mu}g/ml$ for tetracycline and $6.25{\mu}g/ml$ or $12.5{\mu}g/ml$ for chloramphenicol, and $3.13{\mu}g/ml$ to > $100{\mu}g/ml$ for kanamycin and neomycin. Most of 214 isolates were sensitive to ampicillin and erythromycin, but 20. 1~78. 0% of the strains were resistant to tetracycline, kanamycin, penicillin-G and neomycin. Single or double drug resistance were observed in 75.8% of the resistant strains. The most common resistance patterns were Nm P-G(37.4%) in double pattern and P-G(23.7%) in single pattern.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.6
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• pp.826-832
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• 2023

Clostridium perfringens causes diarrhea and other diseases in humans and animals. We investigated the prevalence, toxin gene profiles, and antimicrobial resistance of C. perfringens isolated from commercial jeotgal sample. C. perfringens was isolated from 11 of 22 commercial jeotgals. All C. perfringens strains were positive for the alpha toxin gene, but not for the beta, epsilon, iota, CPE or NetB toxin genes; therefore, all strains were identified as type A C. perfringens. However, the beta2 toxin gene was identified in 54.5% of isolates. Disk diffusion susceptibility tests showed that most isolates were resistant to kanamycin (90.9%), nalidixic acid (72.7%), oxacillin (54.5%), erythromycin (27.3%), ciprofloxacin (9.1%) and clindamycin (9.1%). However, all strains were susceptible to 14 other antimicrobial including amoxicillin, ampicillin, and chloramphenicol. The average minimum inhibitory concentrations against C. perfringens of clindamycin, kanamycin, and nalidixic acid were 128.0, 128.0, and 54.0 ㎍/mL, respectively. These results provide new insight into the necessity for sanitation of commercial jeotgal, and provide evidence to help reduce the risk of contamination with antimicrobial-resistant bacteria.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.850-857
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• 2022

Seventy-five Vibrio parahaemolyticus isolates from the surface seawater of the Geum River Estuary area, on the west coast of Korea, were analyzed for the presence of virulence genes and susceptibility to 17 different antimicrobials. All 75 isolates were examined for the presence of two virulence genes (tdh or trh) using polymerase chain reaction; Only one of the isolates possessed the tdh or trh gene. According to the results of disk diffusion susceptibility tests, all of the strains were resistant to penicillin G, 92.0% were resistant to ampicillin, 82.7% were resistant to amoxicillin, 2.7% were resistant to ciprofloxacin, 2.7% were resistant to trimethoprim, 1.3% were resistant to cephalothin, and 1.3% were resistant to erythromycin. However, all of the strains were susceptible to amikacin, cefoxitin, chloramphenicol, gentamycin, kanamycin, nalidixic acid, nitrofurantoin, rifampin, streptomycin, and tetracycline. The average minimum inhibitory concentrations for ampicillin for V. parahaemolyticus was 557.6 ㎍/mL. These results not only provide novel insight into the necessity for seawater sanitation in Geum river estuary area, but they help reduce the risk of contamination of antimicrobial-resistant bacteria.

• Korean Journal of Veterinary Service
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• v.23 no.1
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• pp.19-28
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• 2000

There are several main antibacterial susceptibility tests, such as agar dilution method, broth dilution method and disk diffusion technique. Especially, for minimal inhibitory concentration (MIC) test, agar dilution method has been widely used. But that method is so complicated and bothering that it's difficult to treat a large amount of strains. On the other hand, modified broth dilution method(add 1% glucose and 0.018% phenol red as a pH indicator to broth) is fast and easy to perform. Most of all, it can visualize the result by color. The MICs of 22 antibiotics Including penicillins, aminoglycosides, cephalothin, chloramphenicol, lincomycin, ceftiofur, vancomycin and quinolones, erythromycin, colistin. sul-fadimethoxine, trimethoprim for arcanobacterium pyogenes 14 strains, actinobacillus pleuropneu-moniae 41 strains and pasteurella multocida 37 strains, which were collected from porcine during 1996 ∼ 1999, were determined by modified broth dilution method. Actinobacillus pleuropneumoniae was highly susceptible to all kinds of quinolones such as ciprofloxacin, enrofloxacin and norfloxacin and to all aminoglycosides, like gentamicin, apramycin, kanamycin and ampicillin, cephalothin and ceftiofur. But It was quite resistant to solfadimethoxin, colistin and vancomycin. Pasteurella multocida was found to have high susceptibility to ampicillin, cephalothin, chlorampenicol and gentamicin but had mid-degree susceptibility to other aminoglycosides. In addition, it was susceptible to norfloxacin and nalidixic acid, but not to newer fluoroquinolone like ciprofloxacin and enrofloxacin and it was resistant to colistin and kanamycin. Arcanobacterium pyogenes was highly susceptible to most of quinolones such as cipoofloxacin, enrofloxacin and norfloxacin and gentamicin and penicillin G. But it also obtained high resistance against the early quinolone, nalidixic acid and aminoglycosides such as amikacin, apramycin and kanamycin and erythromycin, chlorampenicol, tetracyclin and vancomycin.

• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.435-439
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• 2000

Explants of lettuce (Lactuca sativa L.) were cocultured with A. tumefaciens LBA 4404 harboring ${\gamma}$-tocopherol methyltransferase (${\gamma}$-TMT) gene from Arabidopsis thaliana. These explants were transferred to MS medium supplemented with 50 mg/L kanamycin, 500 mg/L carbenicillin, 0.1 mg/L NAA and 0.5 mg/L BA. After 4 weeks, kanamycin resistant shoots were obtained from the explants on the selection medium. The putative transgenic shoots were transferred to rooting MS medium supplemented with 50 mg/L kanamycin and 250 mg/L carbenicillin. Stable incorporation of the Arabidopsis ${\gamma}$-TMT cDNA into lettuce genomic DNA was confirmed by PCR and Southern analysis. HPLC analysis showed that $\alpha$- to ${\gamma}$-tocopherol ratio increased over four fold in a transgenic lettuce line indicating successful expression of the transgenic Arabidopsis ${\gamma}$-TMT in lettuce.