• BMB Reports
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• 제29권1호
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• pp.63-67
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• 1996

In order to elucidate the molecular mechanism of plasmid incompatibility of broad host-range plasmid R1162, the plasmid-encoded replication protein RepIB was purified and tested for binding to the 20 bp direct repeat (DR) DNA sequence which is reiterated 3 and 1/2 times within the replicative origin of the plasmid. The RepIB protein specifically binds to the DR DNA. Point mutations in the DR which affect expression of plasmid incompatibility also coordinately affect binding. These results indicate that the incompatibility of broad host-range plasmid R1162 is exerted by the DR DNA by titrating the essential replication protein RepIB.

• Journal of Microbiology and Biotechnology
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• 제25권10호
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• pp.1614-1620
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• 2015

Plasmid-cured derivative strains of Bacillus anthracis are frequently used in laboratory studies. Plasmid incompatibility, which does not increase the risk of chromosomal mutation, is a useful method for plasmid curing. However, in bacteria containing multiple plasmids, it often requires the sequential introduction of multiple, specific incompatibility plasmids. This lengthy process renders the traditional plasmid incompatibility method inefficient and mutation-prone. In this study, we successfully cured plasmids pXO1 and pXO2 from B. anthracis A16 simultaneously using only one recombinant incompatible plasmid, pKORT, to obtain a plasmid-free strain, designated A16DD. This method may also be useful for the simultaneous, one-step curing of multiple plasmids from other bacteria, including Bacillus thuringiensis and Yersinia pestis.

• 한국미생물·생명공학회지
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• 제17권1호
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• pp.51-55
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• 1989

TOL 플라스미드와 NAH 플라스미드는 n-알칸을 자화하는 P. putida KCTC 2405에 접합에 의해 각각의 이동은 가능하나 두 플라스미드는 불화합성에 기인하여 본 균주내에 공존할 수 없었다. TOL plasmid에서 불화합성 체계는 남겨두고 tol 유전자만 이 CAM plasmid내로 transposition 되어 형성된 CAM::TOL* 플라스미드는 NAH 플라스미드와 P. putida KCTC 2405에서 공존할 수 있어 m-toluate, naphthalene, camphor 및 n-alkane(C8-C24)를 분해할 수 있는 P. putida 3SK 균주를 육종하였다. CAM::TOL* 플라스미드는 선택성 배지에서 안정하였으나 비선택성 배지에서는 불안정하였다.

• 미생물학회지
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• 제27권4호
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• pp.334-341
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• 1989

Toluate 분해 플라스미드를 pseudomonase cepacia SUB37에서 분리하여 분자량은 한천 젤 전기영동으로 측정한 결과 79. (119kb)로 확인되었다. 이 TOL플라스미드는 Pseudomonas의 다른 균주와 다른 속의 균주에 전달되었다. m-toluate 분해에서 가장 중요한 역할을 하는 catechol-2,3-oxygenase 활성을 P. cepacia SUB37과 transconjugant의 조효소액으로부터 측정한 결과, P. putida mt 2에서와 같이, meta pathway를 거쳐 m-toluate를 분해하는 유전자들이 plasmid에 암호화됨을 알수 있었다. P. cepacia SUB37 유래의 새로운 TOL plasmid는 IncP-4 불화합성군에 속하였고, 이것은 아마도 P. putida의 IncP-9 그룹의 TOL 플라스미드의 유도체로 사료된다.

• 미생물학회지
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• 제25권2호
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• pp.87-93
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• 1987

The properties of the plasmid pKU41 isolated from Pseudomonas putkda KU190 have been investigated, pKU41 was defined as an R plasmid having a transmissible ampicillin and tetracycline resistance determinant, and could be classified as a plasmid belonging to IncP-1 group according to incompatibility grouping.

• 대한수의학회지
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• 제29권2호
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• pp.59-67
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• 1989

This paper deals with the genetic properties of R plasmids in Salmonella originated from pigs and cattle. The plasmid DNA was examined for incompatibility, stability and fertility inhibition(Fi), and gel electrophoresis was performed for isolation of plasmid DNA. The results obtained were summerized as follows: 1. Among the 66 conjugative R plasmids from 44 pigs and 22 cattle, 61 R plasmids (92.4%) were $Fi^-$, whereas the remainder were $Fi^+$. 2. The Inc groups of 66 R plasmids were determined with 7 standard plasmids. Twenty-six R plasmids were classified into Inc group $I{\alpha}$, H1, H2 or F1, 40 R plasmids being not classified with standard plasmids used, and the Inc group $I{\alpha}$ (57.7%) was most frequent. 3. Inc groups $I{\alpha}$, H1, and F1 were identified in strains from swine, Inc groups H2 and F1 from cattle. 4. The plasmid DNA profiles in 16 Salmonella isolated from pigs and cattle were confirmed as being 1 to 10 fragments by the gel eletrophoresis. Their molecular weight ranged 1.0 to 90 megadalton. 5. The molecular weight of conjugative plasmids ranged 1.0 to 80 megadalton in 4 Salmonella (P-4, P-5, P-7 and P-8) isolated from pigs.

• 한국미생물·생명공학회지
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• 제18권4호
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• pp.433-436
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• 1990

접합에 의한 P.putida mt-2의 TOL를 CAM 함유 P.putida PpG1으로 이동시켜 형성된 접합주 P.Putida CST3A는 작아진 TOL(TOL$\Delta$)를 가지고 있었지만, m-toiuate를 분해할 수 있었다. 접합에 의한 이동실험은 CAM에 결합되어 CAM:TO* 플라스미드를 형성하고 있었다. 불화합성 Inc P9군에 속하는 NAH를 CAM:TOL* 과 TOL$\Delta$을 가지는 P.putida CST3A로 이동시키면 TOL$\Delta$의 방출이 관찰되었으나 m-toluate 대사에는 아무런 영향을 미치지 않았다.

• Journal of Microbiology and Biotechnology
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• 제20권8호
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• pp.1163-1178
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• 2010

Plasmids play important roles in horizontal gene transfer among Vibrionaceae, but surprisingly little is known about their replication and incompatibility systems. In this study, we successfully developed a bioinformatics-assisted strategy of experimental identification of seven Vibrio plasmid replicons. Comparative sequences analysis of the seven Vibrio plasmid replicons obtained in this study together with eight published Vibrionaceae plasmid sequences revealed replication-participating elements involved in the ColE1 mode of replication initiation and regulation. Like plasmid ColE1, these Vibrionaceae plasmids encode two RNA species (the primer RNA and the antisense RNA) for replication initiation and regulation, and as a result, the 15 Vibrionaceae plasmids were designated as ColE1-like Vibrionaceae (CLV) plasmids. Two subgroups were obtained for the 15 CLV plasmids, based on comparison of replicon organization and phylogenetic analysis of replication regions. Coexistence of CLV plasmids were demonstrated by direct sequencing analysis and Southern hybridization, strongly suggesting that the incompatibility of CLV plasmids is determined mainly by the RNA I species like the ColE1-like plasmids. Sequences resembling the conserved Xer recombination sites were also identified on the CLV plasmids, indicating that the CLV plasmids probably use the host site-specific recombination system for multimer resolution like that used by ColE1-like plasmids. All the results indicated that the 15 plasmids form a new ColE1-like group, providing a basis for the rapid characterization and classification of Vibrionaceae plasmids.

• 대한수의학회지
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• 제30권2호
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• pp.203-214
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• 1990

A total of 166 strains of Salmonella (S) typhimurium var copenhagen isolated from pigeons (164 strains) and aquatic birds (2 strains) were examined for the biochemical characteristics and plasmid profiles. All the strains were sensitive to ampicillin, chloramphenicol, gentamicin, kanamycin and sulfadimethoxine. But 13 strains(7.8%) were resistant to streptomycin (Sm), 2 (1.2%) to tetracycline, 2 (1.2%) to rifampicin, and 1 (0.6%) to nalidixic acid. Among drug resistant strains, only one strain resistant to Sm contained conjugative R plasmid which was fertility inhibition and incompatibility group $I_{\alpha}$. All the strains were sensitive to cobalt chloride, cupric sulfate, lead nitrate, mercuric chloride and silver nitrate. Of 166 isolates, 6 (3.6%) were resistant to sodium arsenate and 1 (0.6%) to potassium tellurite. Among 166 isolates, 1 (0.6%) was colicinogenic, 12 (7.2%) sucrose fermenters, and 166 (100%) maltose fermenters. Plasmid profiles were confirmed as being 4 or 5 plasmids, and their molecular weight ranged 3.2 to 60 megadalton (MD). All the strains harbored 60 Md plasmid. There are three patterns by the plasmid profile, 150 isolates (90.4%) were pattern I (3.2, 3.5, 33, 60Md), 14 (8.4%) pattern II (3.2, 3.5, 29, 60Md), and 2 (1.2%) pattern III (4.2, 7.8, 8.5, 15, 60Md). S typhimurium var copenhagen strains containing 60Md plasmid were resistant to killing by 90% normal guinea pig serum.

• 대한미생물학회지
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• 제22권1호
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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.