• Journal of Veterinary Clinics
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• v.19 no.2
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• pp.159-164
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• 2002

The present study was conducted to investigate the antibiotic resistance of 24 Salmonella gallinarum isolated from 48 chicken samples of diagnosed fowl typhoid cases during the period from November 1998 to November 1999. And the isolates of S gallinarum were also tested for their invasion abilities to experimental infection as one of virulence tests, and the presence of virulence-related plasmid in S gallinarum isolates. The results obtained through this study were summarized as follows; 1. All of isolates from 48 cases of 24 farms were identified S gallinarum by biochemical and serological tests.2. Antimicrobial drug resistance test against 24 isolates showed that the isolates were resistant to Colistin(95.8%), and Penicillin(79.2%), Polymyxin B(75.0%), Streptomycin (65.2%), Gentamycin(54.2%), and Tetracycline(33.3%). 3. Mortality in chicken following peroral inoculation of four isolates of S gallinarum during 14-days inoculation pecked at 5 days(40%) after inoculation and all of experimental chickens died within 13 days after inoculation.4. Based on the pattern and number of isolated plasmid from each isolate, plasmid profiles were divided into five groups; group I with 3 plasmids, group II to group IV with 4 plasmids and group V with 5 plasmids.

• Applied Biological Chemistry
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• v.35 no.4
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• pp.227-231
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• 1992

The plasmids pSUPBT and pSUPBTR were constructed with a vector pSUP2021 and the BT toxin gene in the plasmid pES 1. The plasmids constructed were introduced into the antagonistic rhizobacteria P. fluorescens KR164 by conjugation and P. fluorescens having pSUPBT and pSUPBTR were named P. fluorescens KR164(pSUPBT)#2, KR164(pSUPBT)#3, KR164(pSUPBTR)#2 and KR164(pSUPBTR)#3, respectively. The BT toxin gene were identified in all transformants by Southern hybridization and the final product of BT toxin gene was identified only in P. fluorescens KR164(pSUPBTR)#3 by SDS-PAGE. This crystal toxin protein were also observed in electron microscopy.

• Korean Journal of Microbiology
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• v.29 no.3
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• pp.149-154
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• 1991

Escherichia coli/Corynebacterium glutamicum shuttle vectors, pECCG1 and pECCG2 were constructed by joining a 3.00 kb cryptic plasmid pCB 1 from C. glutamicum and a 3.94 kb plasmid pACYC 177 from E. coli. By trimming unessential parts and introducing mulitiple cloning site into the plasmid pECCG 1, a plasmid pECCG122(5.1kb) was constructed. All the shuttle vectors were stably maintained in C. glutamicum up to about 40 generations irrespective of kanamycin addition in the medium. Threonine operon (homoserine dehydrogenase/homoserine kinase) and dapA gene (dihydrodipicolinate synthetase) of C. glutamicum were cloned into the plasmid pECCG122, and the resultant plasmids were designated pTN31 and pDHDP19, respectively. They were used to study the effect of cloned foreign gene on the stability of the plasmid pECCG122. Plasmids pTN31 and pDHDP19 were segregated rapidly from C. glutamicum when cultured in the medium without kanamycin. In medium with $50\mu${\g/ml} of kanamycin, their segregation rates were much slower than those in medium without kanamycin, but the danamycin addition didn't guarantee the complete maintenance of the plasmids in C. glutamicum.

• New & Renewable Energy
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• v.19 no.4
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• pp.46-52
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• 2023

Methane is the second most emitted greenhouse gas after carbon dioxide. Despite lower emissions than those of carbon dioxide, methane receives significant attention owing to its more than 20-fold higher global warming potential. Consequently, the importance of research on methanotrophic bacteria, microorganisms capable of converting methane gas into high-value materials, is increasingly emphasized. In the case of methanotrophic bacteria, knowledge on episomal plasmids that can be used for genetic engineering remains lacking, which poses significant challenges to the engineering process. The replication origin sequences of natural plasmids within methanotrophic bacteria have been predicted through in silico methods. The basic characteristics of the replication origin, such as a high A/T ratio, repetitive sequences, and proximity to proteins related to replication, have been used as criteria for identifying the replication origin. As a result, a region with a sequence of 18 base pairs repeated eight times could be identified. The putative replication origin sequence thus identified generally takes the form of iterons, but it also possesses unique features such as the length of the gap between iterons and the repetition of identical iteron sequences. This information can be valuable for future design of episomal plasmids applicable to methanotrophs.

• Journal of fish pathology
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• v.7 no.1
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• pp.37-46
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• 1994

A total 103 strains of Edwardsiella tarda was isolated from eel culture-ponds and examined for drug resistance, distribution and transferabilities of R plasmids. The drugs used were lincomycin(LM), penicillin(PM), sulfamethazine(SF), sulfadimethoxine(SD), cephalosprin(CP), chloramphenicol(CH), streptomycin(SM), oxytetracycline(OT), ampicillin(AP), oxolinic acid(OA), kanamycin(KM), amikacin(AK), gentamicin(GM) and enrofloxacin(EF). Two strains were resistant to the all drugs used, and all isolates were multiply resistant to drugs(at least 8 among 14 drugs), mostly restricted to LM(103 strains), PM(103 strains), SD(103 strains), SF(103 strains), CP(102 strains), CM(101 strains), SM(100 strains), OT(94 strains), AM(92 strains), OA(80 strains), KM(60 strains), AK(30 strains), GM(19 strains) and EF(14 strains), in combination at high degree showing 34 different drug resistant patterns. The most frequently encountered patterns were LM PM SD SF CP CH SM OT AP OA KM(22 strains, 22.4%) followed by LM PM SD SF CP CH SM OT AP OT(12 strains, 11.7%). LM PM SD SF CP CH SM OT AP(7 strains, 6.8%), LM PM SD SF CP CH SM OT AP OA KM AK GM(6 strains, 5.8%) and LM PM SD SF CP CH SM OT AM OX KM AK GM(6 strains, 5.8%). Transfer experiment of drug resistance showed that of 103 resistant strains, 100 strains(97%) transferred part or all resistance to all drugs, indicating that most isolates carried conjugally transferrable R plasmids determining multiple drugs. The most frequently observed transferarble R plasmids were LM PM SD SF CP CH SM OT AP OA(10 strains), LM PM SD SF CP CH SM OT AP OX KM(7 strains) and LM PM SD SF CP CH AP OA(7 strains). These results sugested that eel culture-ponds were highly contaminated with different strains of Edwardsiella tarda, and that contaminated bacteria might be highly multiple resistant strains to drugs, carring transferable R plasmids.

• Current Research on Agriculture and Life Sciences
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• v.5
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• pp.52-58
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• 1987

The yeast S. cerevisiae DBY747 was transformed with E. C - S. C shuttle vector YIp5, YEp13 and YRp7 by the method of spheroplast. The transformation frequency of YEp13 and YRp7 in S. cerevisiae DBY747 was $1.2{\times}10^3$ and $1.0{\times}10^2$ per $10{\mu}g$ of DNA, respectively. The transformants with YIp5 plasmid incapable of autonomous replication in S. cerevisiae were not detected in the condition of this experiment, but YIpS plasmid expressed the gene carried on it when cotransformed with a helper plasmid such as YEp13 or YRp7 : autonomously replicating plasmid. When plasmids were used in covalently closed circular form, cotransformation frequency of Ylp5-YEpl3 and Ylp5-YRp7 was 210 and 95 per $10{\mu}g$ of DNA, respectively. In cotransformation of linear plasmids, transformation frequency of the same cohesive ends was similar to that of noncomplementary cohesive ends. Transformants by the cotransformation with circular plasmids have been shown much higher frequency than with linear plasmids in S. cerevisiae DBY 747. The mitotic segregation stability test suggested that the cotransformant of YIpS-YEp13 was more stable than that of YIpS-YRp7.

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.162.2-162
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• 1995

No Abstract, See Full Text

• Proceedings of the Microbiological Society of Korea Conference
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• 1998.04a
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• pp.58.1-58.1
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• 1998

• Journal of Microbiology and Biotechnology
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• v.6 no.4
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• pp.292-294
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• 1996

To investigate the relationship between two tetracycline resistance ($Tc^r$) plasmids, the 24.82-kb pKHl and the 4.44-kb pKH6, of Staphylococcus aureus isolated in Korea, cloning of the 4570-bp HindIII fragment into pBluescript II $KS^+$ after partial digestion of the $Tc^r$ plasmid pKHl with HindIII and sequence determination of that fragment were carried out. Analysis of the sequences revealed that the 4570-bp HindIII fragment contained a 4011-bp fragment of the small $Tc^r$ plasmid pKH6 flanked by the partial sequences of IS431mec. It was concluded from the above result that the pKHl was produced by integration of the partial sequence of the pKH6 into another plasmid via IS431mec.

• Korean Journal of Veterinary Research
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• v.29 no.2
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• pp.69-73
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• 1989

Nine strains of Yersinia species isolated from pigs and dogs in Korea, comprising 5 strains of Yersinia enterocolitica, 2 strains of Y kristensenii and each strain of Y pseudotuberculosis and Y intermedia, were examined for the presence of virulence-associated plasmids, calcium dependency and provocation of guinea pig conjuntivitis($Ser{\acute{e}}ny$ test). Three strains of Y enterocolitica isolated from pigs were positive in calcium dependency and harbored one plasmid of about 45 megadalton, but negative in $Ser{\acute{e}}ny$ test.