• Korean Journal of Veterinary Research
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• v.16 no.2
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• pp.159-163
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• 1976

One hundred and sixty one Escherichia coli strains isolated from 24 swine (11 swine fed with feedstuffs containing 7.5mg/kg of tetracycline and 13 swine not received antibiotic) were studied for the drug resistance and distribution of R factors. About 42 per cent of E. coli strains isolated from pigs of a herd fed with tetracycline (TC)-containing feeds were resistant to TC, streptomycin(SM), sulfisomidine(SA), ampicillin (AP) and kanamycin (KM), alone or in combination thereof, but none of the swine not receiving antibiotic containing feedstuffs excreted E. coli resistant to these drugs, Among resistant strains, 18.2% were found to be singly resistant to TC, whereas 81.8% were resistant to two or more antibiotics. The most common pattern was the triple resistant to TC, SM and SA(30.3%), and follolwed by double ones to TC and SM(24.2%). About one half of resistant strains carried R factors which were tranferable to the recipients by conjugation. In spite of feeding with feedstuffs containing only TC, high incidences of multiple resistance and R factors were observed in the E. coli isolated from these swine.

• Archives of Pharmacal Research
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• v.19 no.4
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• pp.286-291
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• 1996

Phenolic compounds are prevalent as toxins or environmental pollutants, but they are also widely used as drugs for various purpose including anticancer agent. A novel biphenolic compound, bis(2-hydroxy-3-tert-butyl-5-methylphenyl)methane (GERI-BPO02-A) was isolated from the fermentation broth of Aspergillus fumigatus F93 previously, and it has revealed cytotoxicity against human solid tumor cells. Its effective doses that cause 50% inhibition of cell growth in vitro against non-small cell lung cancer cell A549, ovarian cancer cell SK-OV-3, skin cancer cell SK-MEL-2 and central nerve system cancer cell XF498 were 8.24, 10.60, 8.83, $9.85\mug/ml$ respectively. GERI-BPO02-A has also revealed cytotoxicity against P-glycoproteinexpressed human colon cancer cell HCT15 and its multidrug-resistant subline HCT15/CL02, and its cytotoxicity was not affected by P-glycoprotein. We have also tested cytotoxicities of structurally related compounds of GERI-BPO02-A such as diphenylmethane, 1,1-bis(3,4dimethylphenyl)ethane, 2,2-diphenylpropane, 2-benzylpyridine, 3-benzylpyridine, $4,4^I-di-tert-butylphenyl$, bibenzyl, $2,2^I-dimethylbibenzyl$, cis-stilbene, trans-stilbene, 3-tert-butyl-4-hydroxy-5-methylphenyisulfide, sulfadiazine and sulfisomidine for studying of structure and activity relationship, and from these data we could suppose that hydroxyl group of GERI-BPO02A conducted important role in its cytotoxicity.

• Korean Journal of Veterinary Service
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• v.27 no.1
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• pp.17-29
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• 2004

A multiresidual analysis was performed to determine 12 sulfonamides(sulfacetamide, sulfadiazine, sulfisomidine, sulfathiazole, sulfapyridine, sulfamerazine, sulfamethazine, sulfamonomethoxine, sulfisoxazole, sulfamethoxazole, sulfaquinoxaline, and sulfadimethoxine) in beef and pork simultaneously. The multiresidual analysis for the sulfonamides currently used was able to analyze 5 kinds of sulfonamides at the same time. The method of this 12 sulfonamides multiresidual analysis in this study was matrix solid-phase dispersion(MSPD) by high performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LC/MS). The recovery rate of the materials was measured by MSPD method with 3 different extraction solvents; Dichloromethane, DCM: Ethylacetate(3:1), DCM:EA(9:1). Also, samples (84 beef and 205 pork samples) which were positive by EEC-4 plate test from 2001 to 2003 were tested to investigate the kinds of sulfonamides using HPLC. The results from the study were as follows; 1. The recovery rate of the materials was measured by MSPD method with 3 different extraction solvents; Dichloromethane, DCM:Ethylacetate(3:1), DCM:EA(9:1). The method of extraction solvent with DCM:ethyl acetate(9:1) was the most excellent(87.7∼99.3%) in separation and reappearance. 2. In the LC/MS analysis. of sulfonamides, signal to noise ratio was showed relatively high in the positive mode and special ion in the quality analysis was determined via [M+H]$\^$+/ and m/z 156. A spectrum of sulfonamides was showed from all 12 sulfonamides. 3. The samples positive by the EEC-4 plate, a screening test method, were categorized by sulfonamides through Charm II and confirmed the kinds of sulfonamides through HPLC. 1) Among 84 beef samples positive by EEC-4 plate, 20 samples were positive by Charm II and identified as 7 sulfamethazine, 9 sulfadimethoxine, 1 sulfamonomethoxine and 3 unknown status. 2) Among 205 pork samples positive by EEC-4 plate, 42 samples were positive by Charm II and identified as 19 sulfamethazine, 1 sulfadimethoxine, 4 sulfamonomethoxine and 5 unknown status.

• The Journal of the Korean Society for Microbiology
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• v.35 no.3
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• pp.239-250
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• 2000

Sixty-eight clinical isolates of Stenotrophomonas maltophilia from inpatients of 2 university hospitals in Taegu were epidemiologically analyzed by using the minimum inhibitory concentrations of 25 antimicrobial drugs, biochemical reaction, pulsed-field gel elctropgoresis (PFGE), and PCR with enterobacterial repetitive intergenic consensus sequences as primer (ERIC-PCR). 1. All the strains were susceptible to minocycline. More than 57% were susceptible to sulfisomidine (Su), ciprofloxacin (Ci), Ofloploxacin (Of), nalidixic acid (Na), and chloramphenicol (Cm), and $19{\sim}35%$ to ceftazidime (Cd), trimethoprim (Tp), Ticacillin-clavulanic acid, and cefoperazone-sulbactam. Most isolates were resistant to ${\beta}$-lactam antibiotics such as ampicillin (Ap), carbenicillin (Cb), cefotaxim (Ct), cefoxitin (Cx), and aminoglycosides including gentamicin (Gm), tobramycin (Tb), amikacin (Ak). 2. All the isolates were multiply resistant of 5 to 17 drugs and showed 40 different resistance pattern types. 3. All the strains showed very similar biochemical reactions except ${\beta}$-galactosidase and nitrate reduction test. Fourteen strains selected randomly were classified 10 different pattern type by PFGE and ERIC-PCR. These two methods showed identical result. Four strains isolated from wound in 1994 showed similar MIC pattern and identical API 20NE profile, PFGE, and ERIC-PCR pattern indicating episodes of cross-infection among patients. These results indicate that PFGE or ERIC-PCR profile has comparable discriminatory power for epidemiological typing of S. maltophilia.

• 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.

• The Journal of the Korean Society for Microbiology
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• v.22 no.3
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• pp.295-300
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• 1987

Salmonella strains isolated from blood in the Dong-san hospital, Taegu during the period from 1971 to 1986 were studied for species distribution, drug resistance, and R plasmids. The number of strains was 2,527 and all of them were classified into S. typhi and S. paratyphi A. Approximately 300 strains were isolated in the period from 1974 to 1976 and 1978, 268 in 1982, and 204 in 1983, but the numbers isolated in the 1980's have a tendency to decrease as compared with those of the 1970's. S. typhi occupied 85% or more of strains isolated until 1976, but the isolation frequency decreased yearly with some variation, and S. paratyphi A increased gradually from 1974. Only 4 strains of S. paratyphi A were resistant to some drugs, and the resistance was not transferred to E. coli by conjugation. S. typhi resistant to drugs were 15 in 1971 through 1973, 24 in 1974, and 13 in 1975, but afterwards only few resistant strains were isolated. These strains were resistant to two or more drugs; chloramphenicol(Cm), tetracycline(Tc), streptomycin(Sm), sulfisomidine(Su), ampicillin(Ap), and kanamycin(Km) and no strain resistant to other drugs tested was found. Strains resistant to 3 or less drugs didn't transfer the resistance to E. coli by conjugation. There were 15 strains resistant to four or more drugs, and were isolated in years from 1972 to 1976. These strains transferred the resistance to E. coli, and the resistance was considered to be mediated by R plasmids. Transfer frequency was higher at $25^{\circ}C$ than at $37^{\circ}C$ and patterns of transferred resistance were Cm, Tc, Sm, Su; Ap, Km; Cm. R plasmids having markers of Cm, Tc, Sm and Su were classified into Inc H1.

• The Journal of the Korean Society for Microbiology
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• v.17 no.1
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• pp.21-34
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• 1982

One hundred and twenty-one strains each of Escherichia coli isolated from stools of 60 patients who received various antimicrobial drugs in hospital for more than one week and apparently healthy 60 students who have no history of taking antimicrobial drugs during recent one month, were tested for their resistance to 13 antimicrobial drugs. The frequency of resistance strains was highest to tetracycline with 69.2%, and followed by streptomycin(Sm), sulfisomidine(Su), chloramphenicol(Cm), ampicillin(Ap), and carbenicillin(Cb) in the decreasing order, ranging from 61.2% to 39.3%. Strains resistant to kanamycin(Km), cephaloridine(Cr), and trimethoprim(Tp) occupied about one-fourth of strains, and only four strains were resistant either one or more of nalidixic acid, gentamicin and amikacin, and no strain was resistant to rifampicin. The frequency of resistant strains to Cm, Ap, Km, Cr, and Cb was much higher among patient isolates than student strains, but strains resistant to the other drugs showed almost the same frequencies between patient and student isolates. There was a marked difference in average minimum inhibitory concentrations of between resistant and susceptible strains, suggesting that the resistance to drugs is the plasmid origin. Seventy-six percent of strains were resistant to one to 10 drugs tested, and no much difference was observed between strains from patients and students. However, strains resistant to four or more drugs were much more frequently found among patient isolates than student strains, with the increasing tendency of multiply resistant strains among patient isolates following the increase in the number of resistant drugs. The transfer of drug resistance by conjugation was tested and 98 strains(67.5%) among 145 which were resistant to two or more drugs were found to transfer their drug resistance to E. coli. Among 74 strains resistant to 7 or more drugs, all except one transferred the resistance, and the number of strains with transferable resistance decreased, as the number of resistant drugs decrease. A R plasmid from randomly selected p13 strain was tested for the incompatibility group, and the plasmid was classified into Inc F II. R plasmM DNA bands were identified by polyacrylamide gel electrophoresis.

• The Journal of the Korean Society for Microbiology
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• v.22 no.1
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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.

• The Journal of the Korean Society for Microbiology
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• v.12 no.1
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• pp.11-18
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• 1977

A total of 665 strains of Escherichia coli isolated in Korea from stools of patients who were treated with antimicrobial drugs, doctors, and students were tested for the drug resistance and distribution of R plasmids. Approximately 25 to 41% of isolates were resistant to chloramphenicol, tetracycline, streptomycin, sulfisemidine and ampicillin(AP), and 9.5% were resistant to kanamycin. Nalidixic acid-resistant strains were only rarely encountered. The prevalence of resistant strains was significantly higher among patients than doctors and students. Strains multiply resistant to four or more drugs were significantly more prevalent among patient isolates than those from doctors and students, while no difference on the incidence of strains resistant to three or less drugs was noted among isolates from the three groups. The persons carrying strains resistant to four or more drugs were more frequently found among patients than doctors and students. Quite large proportions of drug-resistant strains transferred their resistance to drug-sensitive E. coli, with frequent transfer of whole resistance and AP resistance. Strains having higher multiplicity of resistance showed a tendency toward higher incidence of resistance transfer, irrespective of the origins of strains.