• 한국연초학회지
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• 제20권1호
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• pp.66-70
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• 1998

TMV resistant lines (TRLs) originated from the Blo plant of Nicotiana tabacum cv. NC82 transformed with TMV coat protein cDNA which initially showed delayed disease symptom were selected for increased resistance in each subsequent generation. The result of field experiment of the transgenic tobacco lines in the fifth generation for TMV resistance and their response to other tobacco diseases (black shank, bacterial wilt, and powdery mildew) is described in this report. When fifteen TRLs of the fifth generation were tested for TMV resistance by mechanically inoculating the individual plants, over 95 percent of the plants of 6 lines showed complete resistance even 8 weeks after the inoculation. Average frequency of the resistant plants in TRLs of the fifth generation 8 weeks after the inoculation was 87%. Stable insertion and expression of TMV coat protein cDNA in the fifth generation of the transgenic tobacco plant were confirmed by PCR and immunoblot hybridization, respectively. All TRLs were resistant to the black shank but were susceptible to the bacterial wilt disease and the powdery mildew to the same degree as non-transgenic NC82 was. Therefore, it was indicated that the phenotypes related at least to disease resistance were not changed in the transgenic tobacco. Key words : TMV CP cDNA, TMV resistant tobacco plant, transformation.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.576-576
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• 2003

• Journal of Microbiology and Biotechnology
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• 제13권6호
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• pp.872-880
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• 2003

Three vectors, pSG1, 2, and 3, which facilitate in vivo expression technology (IVET) in Gram-negative bacteria, were developed. Vectors pSG1and 2 are derivatives of ColE1, and pSG3 is a derivative of an R6K replicon. These vectors contain oriT sites that allow mobilization when the RK2 Tra functions are provided in trans. These vectors contain promoterless lacZ (pl-lacZ) and promoterless aph (pl-aph) transcriptionally fused together, which allow qualitative and quantitative measurements of the expression of genes in the genome of bacterial cells. pSG1 and 3 contain gentamicin-resistance genes, and pSG2 carries a streptomycin-/spectinomycin-resistance gene, allowing for selection of recombinants generated by a single crossover between a library fragment cloned into a pSG vector and the identical region in the genome of a bacterial species from which the library fragment originated. These vectors were successfully applied to the generation of random fusions at high rates in the genomes of four representative Gram-negative bacteria. In addition, the expression level of ${\beta}-galactosidase$ and the degree of resistance to kanamycin in cells with fusions generated by these vectors were found to be linearly correlated, proving that these vectors can be used for IVET.

• Advances in environmental research
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• 제12권1호
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• pp.1-15
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• 2023

Wastewater of anthropogenic origin is known to harbor various bacteria that are known to be of potential risk to human health and environment. It is of utmost importance to monitor such water sources. Coliforms present in the sewage water samples of municipal sewage treatment plants located at three different places in the South Gujarat region (Surat, Navsari and Vapi) of India were analyzed for their coliforms load as well as tested for their drug resistance. Using cultivation-based techniques microbial load and drug resistance (Amoxicillin, Tetracycline, Ciprofloxacin, Erythromycin, Trimethoprim and Sulphamethoxazole) were analyzed. Water treatment statistically significantly decreased the bacterial load in Vapi and Navsari samples. The optical density of with and without antibiotics of all the three locations was shown to increase significantly after 72 hours. Of all the isolates tested, except isolate 'VA5' (resisted up to 90 ㎍ of Ampicillin) all other isolates resisted 256 ㎍ concentration of antibiotics tested. This study indicates that the sewage water is being contaminated with drugs and/or antibiotics due to industrial and/or anthropogenic activities. Regular monitoring of the water quality is required followed by implementation of environmental laws for reducing the pollutants, that are of human health and environment concern.

• Journal of Veterinary Science
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• 제23권2호
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• pp.23.1-23.15
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• 2022

Background: Antibacterial agents play important roles in the treatment of bacterial infections. However, the development of antimicrobial resistance (AMR) and carry-over of substances into the environment are several problems arising during oral treatment of bacterial infections. We assessed AMR development in commensal Escherichia coli (E. coli) in enrofloxacin treated and untreated animals. In addition, we examined fluoroquinolone in the plasma and urine of treated and untreated animals, and in sedimentation dust and aerosol. Methods: In each trial, six pigs were treated with enrofloxacin via powder, granulate or pellet forms in two time periods (days 1-5 and 22-26). Four pigs served as untreated controls. The minimum inhibitory concentration (MIC) was determined to evaluate AMR development. Analysis of enro- and ciprofloxacin was performed with high performance liquid chromatography. Results: Non-wildtype E. coli (MIC > 0.125 ㎍/mL) was detected in the pellet treated group after the first treatment period, whereas in the other groups, non-wildtype isolates were found after the second treatment period. E. coli with MIC > 4 ㎍/mL was found in only the pellet trial. Untreated animals showed similar susceptibility shifts several days later. Bioavailability differed among the treatment forms (granulate > pellet > powder). Enro- and ciprofloxacin were detected in aerosols and sedimentation dust (granulate, powder > pellet). Conclusions: This study indicates that the kind of the oral dosage form of antibiotics affects environmental contamination and AMR development in commensal E. coli in treated and untreated pigs.

• Natural Product Sciences
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• 제6권1호
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• pp.36-39
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• 2000

Acorenone, a diterpene isolated from Acorus gramineus, showed strong resistance inhibitory activity against multi-drug resistant microorganisms such as Staphylococcus aureus SA2, which has resistance to 10 usual antibiotics including chloramphenicol (Cm). At the level of $5\;{\mu}g/ml$ when combined with $50\;{\mu}g/ml$ of Cm. Bacterial resistance to Cm is due to the presence in resistant bacteria of an enzyme, chloramphenicol acetyltransferase (CAT), which catalyses the acetyl-CoA dependent acetylation of the antibiotic at C-3 hydroxyl group. To elucidate the mechanism of resistant inhibitory effect, the acorenone which had the strongest resistant inhibitory activity, was investigated on the CAT assay. As the result, the combination of Cm and acorenone showed the strongest inhibitory activity on CAT as noncompetitive and dose dependent manner.

• 한국미생물·생명공학회지
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• 제28권1호
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• pp.1-7
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• 2000

The bacterial strain JW-2 which conferred resistance against paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride) was isolated from soil. The strain was identified as an Ochrobactrum anthropi based on its morphological, physiological, biological and fatty acid composition, and was designated as Ochrobactrum anthropi JW-2. We compard paraquat resistance of O. anthropi JW-2 with Escherichia coli J105. In the presence of 100mM paraquat, E. coli JM105 was not grown whereas the growth rate of O. anthropi was about 70% of control. We compared the sensitivity of O. anthropi JW-2 and E. coli J105 to redox-cycling compounds such as paraquat, plumbagin or menadione, which are known to exacebate wuperoxide generation. O. anthropi JW-2 did not show cross-resistance to plumbagin or menadione. superoxide dismutase activity was increased in paraqunt-treated E. coli JM105 while it was not increased in O.anthropi JW-2. These results suggest that the mechanism of paraquat resistance in O.anthropi JW-2 is probably due to selectively decreased permeability toward paraquat by membrane protein.

• Journal of Microbiology and Biotechnology
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• 제18권6호
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• pp.1095-1100
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• 2008

The role of exopolysaccharides (EPSs) from a plant growth-promoting rhizobacterium, Burkholderia gladioli IN26, on elicitation of induced systemic resistance was investigated. A purified EPS induced expression of PR-1a::GUS on tobacco and elicited induced resistance against Colletotrichum orbiculare on cucumber. The maximum level of disease protection was noted when seeds were soaked in 200 ppm of the EPS. Our results indicate that EPS from specific rhizobacteria can elicit induced resistance and suggest that bacterial EPS might be a useful elicitor of resistance under field conditions.

• Archives of Pharmacal Research
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• 제12권3호
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• pp.176-180
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• 1989

Four bacterial strains having inducible resistance to erythromycin were isolated from soil samples in Korea and characterized. MLS inducibility was checked in each strain. Cloning of inducible resistance gene(s) has been tried. Four isolates were identified as B. anthracis, Micrococcus luteus, Streptococcus faecium and B. licheniformis, in which erythromycin, oleandomycin, cirramycin and carbomycin acted as resistance inducers respectively. The resistance gene cloned from B, licheniformis 597 strain using pBS 42 vector was found to have a 3.2 kb insert.

• The Plant Pathology Journal
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• 제17권2호
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• pp.83-87
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• 2001

Disease resistance in plants is often controlled by gene-for-gene mechanism in which avirulence (avr) gene products encoding by pathogens are specifically recognized, either directly or indirectly by plant disease resistance (R) gene products. Recent studies arising from molecular cloning of a number of R genes from various plant species that confer resistance to different pathogens and corresponding avr genes from various pathogens resulted in the accumulation of a wealth of knowledge on mode of action of gene-for-gene interaction. Specially, members of the NBS-LRR class of R genes encoding proteins containing a nucleotide binding site (NBS) and carboxyl-terminal leucine-rich repeats (LRRs) confer resistance to very different types of phytopathogens, such as bacteria, fungi, oomycetes, viruses, nematodes and aphids. This article reviewed the molecular events that occur up-stream of defense response pathway, specially, bacterial avr gene protein recognition mediated by NBS-LRR type R gene product in plant based on current research results of well studied model plants.