• YAKHAK HOEJI
• /
• v.30 no.1
• /
• pp.51-54
• /
• 1986

Fecal samples from Kim-Hae farm animals were examined for the frequency of gram-negative enteric organisms resistant to tetracycline, streptomycin, or penicillin. The propertions of antibiotic resistant to total organisms in fecal specimens of poultry, swine and cow were as follows: 95%, 92%, 70% for tetracycline, 100%, 27%, 9% for streptomycin, 18%, 1%, 1% for penicillin, respectively. The bacteria had multiresistance to antibiotics. These strains had more than one plasmid. From the transformation study, it was concluded that the resistance to streptomycin was attributed to one of these plasmids.

• Journal of Korean Society on Water Environment
• /
• v.28 no.6
• /
• pp.911-916
• /
• 2012

Recently, antibiotic resistant genes (ARGs) in the environment are emerging as pollutants, since these genetic contaminants can eventually be transferred to human pathogens. The aim of this study was to develop the experimental model of antibiotic resistant gene (ARG) plasmid transfer as a function of various environmental conditions. For this purpose, the multi drug resistant plasmid pB10, which is known to be originally isolated from a wastewater treatment plant, was selected as a model transfer plasmid and Escherichia coli $DH5{\alpha}$ containing pB10 was used as a model donor. Pseudomonas aeruginosa, an opportunistic pathogen, was selected as the recipient for the conjugation experiment. When the donor and recipient were exposed to various stressors including antibiotics and heavy metal as a function of the concentrations (10, 100 and, 1000 ppb), statistically increased plasmid transfer rate was observed at a concentration of 10 ppb of tetracycline and sulfamethoxazole compared to control (no antibiotic exposure). Accordingly, the developed experimental ARG model by various stressor is a promising tool for evaluating the dissemination of ARGs by micro-contaminants in aquatic environment.

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

• Korean Journal of Veterinary Research
• /
• v.30 no.2
• /
• pp.203-214
• /
• 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.

• Microbiology and Biotechnology Letters
• /
• v.24 no.4
• /
• pp.423-426
• /
• 1996

The complete nucleotide sequence of pKH6, a tetracycline-resistance (Tc$^{r}$) plasmid isolated from multi-drug resistant Staphylococcus aureus SA2, has been determined and compared with that of the staphylococcal Tc$^{r}$ plasmid pTl8l. The nucleotide sequences of the two plasmids are in agreement except for 7 nucleotides. All differences are caused by base pair substitutions. Among 6 substitutions, 3 occurred in coding regions. However, only two base substitutions in coding regions resulted in changes of amino acid sequences in two different ORFs of repC and Pre proteins.

• Microbiology and Biotechnology Letters
• /
• v.22 no.2
• /
• pp.158-163
• /
• 1994

Microorganisms capale of utilizing linear alkylbenzene sulfonates(LAS) as sole carbon source were isolated from industrial effluent by using LAS agar plates. The isolated strains were identified as Salmonella sp(BC-2) and Escherichia sp.(BC-3) from the results of morphological, cultural and biochemical tests. The optimal condition for the growth and biodegradation of LAS was the initial pH 7.0 and LAS concentration 0.1%. The isolated BC-2 and BC-3 strains harbored plasmid and LAS-degrading activity was lost when the plasmids were cured by mitomycin C. The plasmids were transformed into E. coli and transformants have the LAS-degrading activity. Isolated strains were examined for primary biodegradation rate of LAS in the medium by methylene blueactive substance(MBAS) method. Of these isolates, BC-2 and BC-3 strains degradated LAS upto 60% and high resistant to CdCl$_{2}$ and HgCl$_{2}$. Isolated strains were sensitive to chloramphenicol, kanamycin, rifampicin, streptomycin and tetracycline but resistant to ampicillin and lincomycin.] Its minimal inhibitory concentration(MIC) for ampicillin was more than 1500 $\mu $g/ml.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.35 no.2
• /
• pp.115-121
• /
• 2002

To develop a new method of conjugation and to determine the distribution of R plasimds, we isolated multi-drug resistant strains from fish pathogenic bacteria in the farms of south and east seacoasts of Korea. Out of the 134 isolates examined, 10 showed resistance to chloramphenicol, tetracycline, streptomycin, ampicillin, colistin, nalidixic acid, oxolinic acid and kanamycin. One out of 10 multi-drug resistance bacteria, Vibfio damsela JE1 (V. damsela JE1), contained transferable R plasmid of chlorarnphenicol- tetracycline resistance genes and other nucleic acids encoding ampicillin and kanamycin resistance. The presence of the R plasmid was confirmed by conjugation using the chromocult medium (CC) as a selective and differential medium for transconiugants with identification based on the growth or colors of the colonies. The frequency of R plasmid transfer with filter mating method was come out much higher than that of broth mating method and appeared to be dependent upon the mating time and temperature. The optimum conditions for filter mating method were found to be 30$^{\circ}C$ and 24hrs as mating temperature and period, respectively, Moreover, donor cells with R plasmid, both isolate and standard bacteria, were shown to have an ability to transfer the plasmid against Escherichia coli K-12 HB101 (E. coli HB101) and Edwardsiella tarda (E. tarda) RE14 at fairly high frequencies, finally, we isolated 3 isolates of Sphingomonas sp., carrying R plasmid from 12 multi-drug resistant bacteria in normal microflora of the flounder (Paralichthys olivaceus) group used for the isolation of V emsela JE1 four months before. The same size and gene transfer chayateristics of R plasimds with those of V damsela JE1 confirmed that normal microflora have the reservoir activity for R plasmid in natural aquatic environment.

• Korean Journal of Veterinary Research
• /
• v.44 no.1
• /
• pp.89-98
• /
• 2004

This study was carried out to investigate the serotype, and antimicrobial susceptibility and analyze the plasmid profile for the 145 isolates of L. monocytogenes isolated from livestock products and these product processing plants in Gyeongnam, Korea. All of L. monocytogenes strains belonged to serotype 1/2b (57.9%), 1/2a (20.0%), 4b (11.4%), 1/2c, 3b, 4c (each 2.9%) and 4d (0.7%). Serotype 1/2b, 1/2a, 4b from each source were found predominantly. Serotype 1/2b was predominantly higher than other serotype, and there was no significant difference between serotypes isolated from livestock products and product processing plants. 4b was major serotype isolated from raw milk and pork, and serotypes isolated from beef, chickens and slaughterhouse were 1/2b and 1/2a. The susceptibility of 145 strains of L. monocytogenes to 14 antibiotics commonly used in veterinary and human therapy was determined by disk diffusion method. All of L. monocytogenes strains were susceptible to amikacin, ampicillin, cephalothin, chloramphenicol, gentamicin, kanamycin, neomycin and penicillin. L. monocytogenes strains had the highest resistance with colistin (100%), oxytetracycline (44.8%), tetracycline (43.4%) followed by erythromycin (2.8%), spectinomycin (1.4%) and streptomycin (0.7%). Tetracycline resistance, and serotype distribution of the isolates from sample sources were significantly different. Resistance to at least one antibiotic was observed in all of them and 7 different resistant profiles were recorded. The most common resistance pattern were CL-OTC-TC (colistin-oxytetracycline-tetracycline) (42.8%). Among all tested isolates, two different plasmid profiles were observed. Of the 97 examined strains, 14 (14.4%) contained either the 8 and 11 kb plasmid or the 11 kb.

• Korean Journal of Microbiology
• /
• v.23 no.1
• /
• pp.56-63
• /
• 1985

We have characterized the plasmids of zymomonas, and constructed E. coli-Zymomonas shuttle vector. Plasmids have been detected in four strains of Zymomonas mobilis. All strains tested had at least one plasmid ranging in size from about 1.7 to 46kb. Antibiotics resistances of Z. mobilis were tested to select the host strain. All strains were very sensitive to tetracycline and chloramphenicol. Homology tests between the plasmids in four strains showed that the plasmids of ATCC10988 is highly homologous to those of ZM1, and that there is no homology between plasmids of ZM4 and Agll. The 1.7kb plasmid of ATCC10988, named as pZM886, also has no homology with plasmids of ZM4. A hybrid plasmid, designated to pBZ41, was constructed from pZM886 and pBR322. A restriction map of pBZ41 was established. Replicon of pZM886 didn't operate in E.coli and pBR322 seemed not to replicate in Zymomonas. pBZ41 was transfered from E. coli to Zymomonas by conjugal mobilization. The transconjugants were resistant to tetracycline and maintained pBZ41 stably.

• Journal of Life Science
• /
• v.15 no.6 s.73
• /
• pp.863-870
• /
• 2005

One hundred and twenty three strains of Mycoplasma pneumoniae were isolated from patients with respiratory diseases from February 2002 to April 2005 in Busan, Korea. The MICs of tetracycline and erythromycin up to $90\%$ of the 123 M. pneumoniae isolates tested were $0.5\~1.0$, and $0.5\~512{\mu}/ml$, respectively. Plasmid DNA was not isolated from all of the M. pneumoniae isolates. Out of 323 strains of M. pneumoniae, 57 ($46.3\%$) stains contain tetM gene on their chromosomal DNA, and 60 ($48.8\%$) strains were mutated in domain V of 23S rRNA for erythromycin resistance. Out of 63 strains of M. pneumoniae which were not mutated in domain V of 235 rRNA for erythromycin resistance, 36 ($57.1\%$) strains contained tetM gene, and out of 60 strains of M. pneumoniae which were mutated in domain V of 23S rRNA for erythromycin resistance, 21 ($35.0\%$) strains contained tetM gene. These results suggest that the isolation rate of erythromycin and tetracycline resistant M. pneumoniae is higher than those of other countries, and erythromycin and tetracycline are not first choice drug for M. pneumoniae infection in Korea, and it need confirm by a nationwide surveilance of antimicrobial resistance.