• Journal of Environmental Health Sciences
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• v.15 no.1
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• pp.63-73
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• 1989

The purposes of this study were to find out the heavy metal and antibiotic resistant coliform bacteria from mineral water and the resistant factors. For the experiment, mineral water samples were taken from A area and B area during the period from march to July, 1988. The results of the experiment were as follows 1. From mineral water, eleven resistant coliforms and one susceptible coliform were isolated. 2. All resistant isolates harbored diverse plasmids of ranged ca. 14-54kb. 3. Susceptible coliform harbored a only plasmid of ca. 2.8 kb. 4. All resistant isolates harbored common size of plasmid of ca. 14kb. 5. As a result of the transformation and agarose gel electrophoresis experiments, resistant factor was R-plasmid. In conclusion, It is suggested that heavy metal contamination of mineral water is the selective pressure for the plasmid encoding the tolerance. Heavy metal resistance, in some case, is present with antibiotic resistance. Therefore, heavy metal contamination of mineral water induces antibiotic resistant bacteria.

• Microbiology and Biotechnology Letters
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• v.14 no.2
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• pp.133-137
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• 1986

17S-ribosomal RNA gene from the hygromycin resistant protozoan Tetrahymena thermophila hmr 3 was cloned on E. coli vector pBR 322 as part of study to work the 17S-rRNA structure and the mechanism of hygromycin resistance. The 17S-rDNA was inserted into the Hind 111 site of pBR 322. The clones having recombinant plasmid were selected by the method of colony hybridization with a 17S-rDNA probe of wild type B1868. The orientation of 17S-rDNA insert was located near the tetracycline resistant gene of pBR 322 in a clone 5-19 with the recombinant plasmid.

• Journal of environmental and Sanitary engineering
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• v.3 no.2 s.5
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• pp.23-41
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• 1988

Two hundred and eighty-six strains of Salmonella species were isolated from the twelve provincial institutes of health and 19 general hospitals of urban and rural areas in Korea from January to December in 1986. The antimicrobial susceptibility test of these cultures was done by the method of agar diluton. The resistance frequency of Salmonella cultures was $29.7\%$. Among these resistant cultures, the most provalent resistance pattern of Salmonella was ampicillin, carbenicillin, chloramphenicol, tetracycline, streptomycin, and its resistance frequency was $15\%$. In plasmid profile of resistance strains, average number of plasmid harboring in Salmonella was 1-4 and molecular weight of plasmid ranged 1.6 to 70 megadalton (Md.). Plasmid pattern of strains isolated from Seoul and Kang-won showed the same or similar profiles. Plasmid pattern was identical in the same resistance pattern.

• Biomedical Science Letters
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• v.1 no.1
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• pp.55-72
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• 1995

Forty gentamicin-resistant isolates of Enterococcus faecalis were selected from various clinical materials, determined their antimicrobial susceptibility, and studied there R-plasmid characteristics and polypeptide patterns. All of the isolates were susceptible to vancomycin. The MICs($\mu$/ml) of antimicrobial agents to the isolates were as follows; the MIC of gentamicin was 128 and $\geq$2040, ampicillin 1 and 1, chlorarmphenicol 2 and 8, erythromycin 32 and 256, and vancomycin 1 and 2. E. faecalis HL-1 strain had 8 plasmid DNA elements, HL-2 and HL-3 strains had 6, HL-4 had 7, HL-5 had 4, and HL-6 had 5. The 51.7 Kb of gentamicin resistance plasmid DNA was conjugally transferred from two strains of E. faecalis HL-1 and HL-6 to S. aureus SK 982. The plasmid transfer frequency between S. aureus SK 982 and E. faecalis HL-1 or E. faecalis HL-6 was 6.3$\times10^{-4} and 3.7$\times10^{-5}$, respectively. Plasmid curing ratio after the treatment of ethidium bromide(10$\mu$/ml) to E. faecalis tarnsconjugants R-1 and R-6 were about 51% and 67%, respectively. The tetracycline gene was located in 2.15 Kb plasmid of E. faecalis HL-1, but it was not found in the E. faecalis HL-6 by Southern blot analyses. The antigenic components of E. faecalis HL-1, HL-6, R-1 and R-6 strains were analyzed by SDS-PAGE and immunoblotting. The E. faecalis strains had 7 to 16 polypeptide bands, however their major proteins were 97.8 and 26.8 Kd. At the Immunoblotting, 97.8, 95.8, 74.8, 63.5, 33.7 and 26.8 Kd polypeptides of the strains showed major antigenic activities with patient's sera infected intra-abdominally with an E. faecalis strain.

• Korean Journal of Microbiology
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• v.23 no.2
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• pp.138-146
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• 1985

A Bacillus licheniformis ATCC31667 gene coding for a glucose isomerase has been cloned and expressed in glucose isomerase negative mutant of Escherichia coli. A recombinant plasmid, constructed by ligation of a EcoRI fragment of B.licheniformis chromosomal DNA to vector plasmid pBR322, was expressed glucose isomerase positive in E.coli LE392-6 with growth on minimal medium containing xylose as a sole carbon source. This recombinant plasmid, designated pBGI6, had the insery of 4.1Kb of Bacillus gene in EcoRI site, and restriction map of the plasmid was established. The plasmid pBG16 was very stable after 10days of serial transfer to a fresh medium. The activity of glucose isomerase from the transformed cell containing pBGI6 was increased about 20 fold than its wild type of host.

• Journal of Microbiology and Biotechnology
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• v.27 no.9
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• pp.1711-1715
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• 2017

In this study, we characterized the $bla_{NDM-5}$-bearing plasmid in a Klebsiella pneumoniae isolate that had lost the plasmid during serial passage. We determined the complete sequences of the plasmid pCC1410-2, which was extracted from a K. pneumoniae ST709 isolate collected at a Korean hospital from which two NDM-5-producing K. pneumoniae isolates were subsequently isolated. As a result, the pCC1410-2 plasmid had a backbone structure that was similar to those of two plasmids previously reported from the same hospital, but lacked some antibiotic resistance genes ($bla_{TEM-1}$, rmtB, mphR(A), mrx(A), and mph(A)). A 9-bp repeating unit encoding three amino acids (Gln-Gln-Pro) was inserted in TraD in pCC1410-2. Thus, the pCC1410-2 plasmid might be transferred from the previously identified carbapenem-resistant K. pneumoniae, but some delections and inversions might have occurred during the process. We compared the transfer frequency and stability of the plasmids. The relative frequency of conjugative transfer and stability in the host were significantly lower in pCC1410-2 than in previously reported $bla_{NDM-5}$-bearing plasmids in Korea. A low transfer frequency and instability in the host may cause underestimation of carbapenemase-producing Enterobacteriaceae in the clinical setting and in surveillance studies.

• The Journal of the Korean Society for Microbiology
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• v.13 no.1
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• pp.31-36
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• 1978

Twenty strains of Salmonella paratyphi A, 55 of S. typhi, 7 of Shigella flexneri, and 14 of Sh. sonnei which were isolated in Taegu area in 1977, were tested for the susceptibility to antimicrobial drugs. All strains of S. paratyphi A were resistant to sulfisomidine(Sa), but none was resistant to chloramphenical(Cm), tetracycline(Tc), streptomycin(Sm), ampicillin, nalidixic acid, kanamycin, gentamicin, amikacin, 1:20 mixture of trimethoprim and sulfamethoxazole, carbenicillin, cephaloridine, and rifampicin. Only one strain. of S. typhi was multiply resistant to Cm, Tc, Sm, and Sa, but all strains were susceptible to the other drugs tested. The resistant strain carried R plasmid; R(Cm Tc Sm Sa). All strains except one were highly resistant to Cm, Tc, Sm, and Sa, and all except one of multiply resistant strains carried R plasmid; R(Cm Tc Sm Sa).

• The Journal of the Korean Society for Microbiology
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• v.22 no.3
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• pp.251-258
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• 1987

A total of 58 strains of Enterobacter species isolated from clinical specimens at Kyungpook National University Hospital in Taegu and Yonsei University Hospital in Seoul were tested for the molecular characterization to investigate the nosocomial infection through the study of R plasmids which might spread among Gram negative organisms regardless of their originated strains. All strains resistant to ampicillin, cefoxitin and cephalothin but susceptible to moxalactam were subjected to the further test for the determination of in detail MIC value against 23 drugs of common use including beta-lactam antibiotics and R plasmid profile analysis. The reistance frequency of strains against carbenicillin (53.4%) was similar to those against chloramphenicol, tobramycin, and sulfisomidine. Though the MIC values of resistance criteria against ceftazidime, aztreonam, imipenem, and norfloxacine in NCCLS manual were not available but MIC ranges of strains tested were very low. There were differences in patterns and frequencies of resistance between the strains isolated in Seoul and Taegu isolates. Seoul isolates showed a tendency of higher multiplicity of resistance than those of Taegu isolates. The resistances against cefoxitin, cephalothin, cefoperazone, cefotaxime, nalidixic acid, and rifampin were not conferred to the conjugally transferable R plasmid. The approximate molecular size of conjugally transferable R plasmids ranged 30 to 151 megadalton, and one or 2 to 3 R plasmids were identified in each transconjugants.

• Journal of Microbiology and Biotechnology
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• v.17 no.1
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• pp.162-167
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• 2007

A genetic transfer system for introducing foreign genes to biomining microorganisms is urgently needed. Thus, a conjugative gene transfer system was investigated for a moderately thermophilic, extremely acidophilic biomining bacterium, Acidithiobacillus caldus MTH-04. The broad-hostrange IncP plasmids RP4 and R68.45 were transferred directly into A. caldus MTH-04 from Escherichia coli by conjugation at relatively high frequencies. Additionally the broad-hostrange IncQ plasmids pJRD215, pVLT33, and pVLT35 were also transferred into A. caldus MTH-04 with the help of plasmid RP4 or strains with plasmid RP4 integrated into their chromosome, such as E. coli SM10. The $Km^r\;and\;Sm^r$ selectable markers from these plasmids were successfully expressed in A. caldus MTH-04. Futhermore, the IncP and IncQ plasmids were transferred back into E. coli cells from A. caldus MTH-04, thereby confirming the initial transfer of these plasmids from E. coli to A. caldus MTH-04. All the IncP and IncQ plasmids studied were stable in A. caldus MTH-04. Consequently, this development of a conjugational system for A. caldus MTH-04 will greatly facilitate its genetic study.

• The Journal of the Korean Society for Microbiology
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• v.21 no.1
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• pp.33-45
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• 1986

On hundred and forty stains of shigella cultures isolated from the twelve hygiene laboratories of cities and provincial general hospital laboratories in 1983 were tested for their resistance to thirteen antimicrobial drugs and their R-plasmid transfer. Antimicrobial drugs were used amikacin, ampicillin, cephalothin, chloramphenicol, gentamicin, kanamycin, nalidixic acid, rifampicin, streptamycin, tetracycline, tobramycin, cefoperazone and piperacillin. All strains were resistant to one or more of thirteen antimicrobial drugs but 94.3% were susceptible to amikacin, gentamicin and tobramycin of total isolated. The most strains commonly found resistance was to chloramphenicol (94%) followed by streptamycin (93%), tetracyline (92%) piperacillin (90%) ampicillin (83%), cefoperazone (42%), nalidixic acid (14%), cephalothin (17%), rifampicin (22%) and kanamycin (6%), sixty percent of strains among 140 were resistance to ampicillin, chloramphenicol, streptomycin, tetracycline at the same time. The transfer of drug resistance by conjugation was tested and ninety four strains (94.3%) were resistant to one or more drugs were found to transfer their drug resistance of E. coli. percentage of transfer frequency by conjugation was one strains (54%), the transfer frequency of drug resistance varied by donor strains and recipients, but not by selecting drugs. Resistance to nalidixic acid was not transferred by conjugation to recipients. Percentage of plasmid curing after the treatment of acriflavine, acridine orange was about 8%. Among strains cured two strains were tested compare original strains with them in biochemical properties in arginine dihydrolase and arabinose fermentation reaction. It was found to growth curves of No.2 shigella flexneri, serotype 1b, and its derivatives cured with acriflavine in $M{\ddot{u}}ller$ Hinton broth medium (pH 7.4, $38^{\circ}C$) by temperature Gradient Biophoto Recorder TN-1120 (Tokyo, Japan).