• Tuberculosis and Respiratory Diseases
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• v.50 no.3
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• pp.334-342
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• 2001

Background : RpoB gene mutations have been found in about 96-98% of rifampicin (RMP)-resistant Mycobacterium tuberculosis. Recent reports confirm that the in laboratory settings a rpoB gene mutation can be used as a surrogate marker for multi-drug resistant tuberculosis. However, its usefulness in clinical applications has not been evaluated. This study was performed to confirm whether mutation analysis of the rpoB gene of M. tuberculosis is useful in clinical settings. Methods : The medical records of 33 patients in whom rpoB gene analysis was conducted using an INNOLiPA Rif. TB assay (LiPA) from June, 1998, to July, 2000, at the Asan Medical Center were retrospectively reviewed in 33 patients. The clinical characteristics in addition to the drug susceptibility and LiPA results were analyzed. The drug susceptibility test was considered as a gold standard method for M. tuberculosis susceptibility and these results were compared with those of the rpoB gene study and sequencing analysis. Sequencing analysis of the rpoB gene was done in cases where there was a discrepancy between the results of the drug susceptibility an d rpoB gene study. Results : The mean age and sex ratio was $42{\pm}18$, and 24:9 (M:F), respectively. There were 19 RMP susceptible (58%) and 14 RMP-resistant cases (42%) according to the rpoB gene study. The mean time from the request to reporting the results of the rpoB gene study was $5.2{\pm}2.6$ days. The mean gap from reporting the rpoB gene study to reporting the susceptibility was $56{\pm}35$ days. Twenty-eight cases (85%) showed identical results compared with the drug susceptibility results, whereas five cases (15%) showed contradictory results. When compared with the sequencing analysis, of the five cases that showed contradictory results, two had LiP A analysis errors and the remaining three were identical to the sequencing results. The rpoB gene study was of assistance in choosing the appropriate drugs in 28 cases (85%). Conclusions : An rpoB gene study using an LiP A assay was useful in rapidly diagnosing RMP-resistant tuberculosis, which enabled a proper choice of the appropriate drugs in clinical practices. However, an LiPA assay always should be performed in conjunction with microscopy, culture, and susceptibility tests.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.714-722
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• 1998

Background: Rifampicin (RFP) is a key component of the antituberculous short-course chemotherapy and the RFP resistance is a marker of multi-drug resistant (MDR) tuberculosis. RPoB gene encodes the $\beta$-subunit of RNA polymerase of M. tuberculosis which is the target of RFP. And the mutations of rpoB gene have been found in about 96% of rifampicin resistant clinical isolates of M. tuberculosis. So in order to find a rapid and clinically useful diagnostic method in identifying the RFP resistance, we compared the PCR -line probe method with PCR-SSCP for the detection of the rpoB gene mutation in cultured M. tuberculosis. Methods: 45 clinical isolates were collected from patients who visited Sung Kyun Kwan University Hospital. The RFP susceptibility test was referred to the referral laboratory of the Korean Tuberculosis Institute. 33 were rifampicin resistant and 12 were rifampicin susceptible. The susceptibility results were compared with the results of the PCR-BSCP and PCR-line probe method. Results: We could find rpoB mutations in 27/33(81.8%) RFP-resistant strains by PCR-line probe method, and in 23/33 (69.7%) by PCR-SSCP and there was no significant difference between two methods. There was no mutation in rifampicinn susceptible strains by both methods. Conclusion: PCR-line probe method would be a rapid, sensitive and specific method for the detection of rifampicin resistant Mycobacterium tuberculosis.

• Tuberculosis and Respiratory Diseases
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• v.45 no.6
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• pp.1178-1187
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• 1998

Background : Recently the incidence of tuberculosis is increasing in many countries and control of the disease is further threatened by the emergence of multi-drug resistant tuberculosis. So rapid detection of drug resistance is very important. Pyrazinamide (PZA) is a first-line chemotherapeutic agent for tuberculosis. Now in Korea, we perform PZase activity test instead of actual pyrazinamide susceptibility test for the detection of PZA resistant M. tuberculosis. Recently the pncA gene, encoding the PZase of M. tuberculosis, was completely sequenced. And it was reported that the mutation of pncA gene would be associated with PZA resistance of M. tuberculosis. Therefore we performed this study to evaluate the possibility for the rapid detection of PZA resistant M. tuberculosis using PCR-SSCP of pncA gene. Method : 44 cultured clinical isolates of M. tuberculosis, BCG Tokyo strain. BCG French strain, and one M. bovis isolate were studied. We used H37Rv as the reference strain, The PZase activity test was done at the reference laboratory of Korean Tuberculosis Institute. DNA was extracted by bead-beater method and 561 bp fragment including pncA gene was amplified by PCR. The PCR product were digested by BstB I enzyme. SSCP was done using MDE gel. Of the 44 strains of M. tuberculosis, 22 strains were PZase-positive and other 22 strains were PZase negative. Results : Of the 22 PZase positive strains, 18 strains(82%) showed the same mobility compared with that of H37Rv and 4(18%) showed different mobility. Of the 22 PZase-negative strains, 19(86%) strains showed the same mobility pattern compared with that of H37Rv and 3(14%) showed different mobility. Naturally PZA-resistant BeG-French strain, BCG-Tokyo strain, and one M. bovis isolate showed the same band pattern each other, but their mobility were different from that of H37Rv. The results of PZase activity test and PCR-SSCP of pncA of M. tuberculosis were statistically significantly correlated each other (p<0.01). Conclusion : The PCR-SSCP after BstB I restriction of pncA gene of M. tuberculosis may be a useful method for the rapid detection of PZA-resistant M. tuberculosis.

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

• Journal of fish pathology
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• v.23 no.1
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• pp.37-45
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• 2010

In this study, we carried out research on the level of single and multi-drug resistance of bacteria isolated from cultured flounder Paralichthys olivaceus. One hundred sixty one bacteria were isolated from cultured olive flounder Paralichthys olivaceus in Korea and the isolates consisted of Edwardsiella tarda (n=32), Vibrio ichthyoenteri (n=37), Vibrio spp. (n=54), Streptococcus parauberis (n=28) and Streptococcus spp. (n=10). These E. tarda isolates were highly resistant in the order of tetracycline (84.4%) and oxolinic acid (71.9%). V. ichthyoenteri and Vibrio spp. showed resistance ampicillin (94.6% and 81.5%) and tetracycline (56.8% and 42.6%). S. parauberis isolates were resistant ampicillin (57.1%), tetracycline (57.1%) and erythromycin (35.7%). Of the isolates, 84.4% of E. tarda, 73.0% of V. ichthyoenteri, 57.4% of Vibrio spp., 42.8% of S. parauberis and 70.0% of Streptococcus spp. isolates exhibited multi-drug resistance against more than two antibiotics.

• Toxicological Research
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• v.24 no.1
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• pp.29-36
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• 2008

The present study investigated the anti-proliferative and chemosensitizing effects of Crinum asiaticum var. japonicum against multi-drug resistant (MDR) cancer cells. The 80% methanol extract, chloroform ($CHCl_3$) fraction and butanol (BuOH) fraction of C. asiaticum inhibited the growth of mitoxantrone (MX) resistant HL-60 (HL-60/MX2) cells. When HL-60/MX2 cells were treated with the $CHCl_3$ and BuOH fractions, DNA ladder and sub-G1 hypodiploid cells were observed. Furthermore, the fractions reduced BcI-2 mRNA levels, whereas Bax mRNA levels were increased. These results suggest that the inhibitory effect of C. asiaticum on the growth of the HL-60/MX2 cells might arise from the induction of apoptosis. Treatment of HL-60/MX2 cells with the fractions markedly decreased the mRNA levels of the multi-drug resistance protein-1 and breast cancer resistance protein. The $CHCl_3$ fraction and hexane fraction increased MX accumulation in HL-60/MX2 cells. These results imply that the $CHCl_3$ fraction of C. asiaticum plays a pivotal role as a chemosensitizer. We suggest that components of C. asiaticum might have a therapeutic potential for the treatment of MDR leukemia.

• Journal of Chest Surgery
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• v.33 no.3
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• pp.231-239
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• 2000

Background: This retrospective study tries to identify specific risk factors that may increase complication rates after the surgical treatment of tuberculous destroyed lung. Material and method: A retrospective study was performed on forty-seven patients, who received surgical treatment for tuberculous destroyed lung in the Department of Thoracic and Cardiovascular Surgery at Hanyang University Hospital from 1988 to 1998, to identify specific preoperative risk factors related to postoperative complications. Fisher's exact test was used to identify the correlations between the complications and right pneumonectomy, preoperative FEV1, predicted postoperative FEV1, massive hemoptysis, postoperative persistent empyema. Result: Hospital mortality and morbidity rates of the patients who received surgical treatment for tuberculous destroyed lung were 6.4% and 29.7%, respectively. In view of the hospital mortality and morbidity rates as a whole, predicted postoperative FEV1 less than 0.8L(p<0.005), preoperative FEV1 less than 1.8L(p=0.01), massive hemoptysis(p<0.005), postoperative persistent positive sputum cultures(p<0.0005), and the presence of multi drug resistant tuberculosis(p<0.05) presented statistically significant correlations. Among the postoperative complications, bronchopleural fistula, the most common complication, was found to have statistically significant corrleations with the preoperative empyema(p<0.05) and postoperative persistent positive sputum cultures(p<0.05). Conclusion: Although mortality and morbidity rates after surgical treatment of tuberculous destroyed lung were relatively low, when predicted postoperative FEV1 was less than 0.8L, when preoperative FEV1 was less than 1.8L, when massive hemoptysis was present, when postoperative sputum cultures were persistently positive, and when multi drug resistant tuberculosis was present, the rates were significantly higher.

• Journal of Food Hygiene and Safety
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• v.25 no.2
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• pp.122-128
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• 2010

From April to December in 2009, microbial investigation is accomplished for 100 frozen foods asked to microbial control team that corresponds with total aerobic viable bacteria, coliform group, Escherichia coli, Enterococcus spp. and antibiotic resistance patterns of Enterococcus spp. isolates are investigated. Average of total erobic viable bacteria numbers is $4.3{\times}10^4CFU/g$. Average of coliform group numbers is $4.3{\times}10^3CFU/g$. Average f Enterococcus spp. numbers is $1.8{\times}10^3CFU/g$. Escherichia coli from 100 frozen foods is not detected and detection ate is 0.0%. 22 Enterococcus spp. are isolated from 100 frozen foods. 12 of 22 Enterococcus spp. strains are identified as E. faecium. 7 of 22 Enterococcus spp. strains are identified as E. faecalis. 2 of 22 Enterococcus spp. trains are identified as E. gallinarum. 1 of 22 Enterococcus spp. strains is identified as E. hirae. Enterococcus spp. solates show a high resistance to erythromycin, rifampin, tetracycline, ciprofloxacin, chlorampenicol, penicillin and susceptibility to vancomycin, ampicillin, gentamicin, strepomycin, linezolid. 15 of 22 Enterococcus spp. strains are multi-resistant and the most frequent multi-resistant pattern is erythromycin-rifampin for 6 Enterococcus spp. strains.

• Korean Journal of Microbiology
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• v.54 no.1
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• pp.53-59
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• 2018

The objective of this study was to investigate the plasmid profiling of multi-drug resistant (MDR) Vibrio in influent (inflow) and effluent (discharged) water samples of fish farms in Jeju, South Korea. MDR isolates identified through disc diffusion susceptibility tests, were subjected to plasmid profiling. One hundred fifty Vibrio isolates were obtained from each influent and effluent water sample. All MDR isolates were subjected to plasmid profiling. Greater number of bacteria were enumerated from effluents (61%) comparing to influents (39%). High incidence of neomycin, sulfamethoxazole, amoxicillin and oxytetracycline resistance was observed among the isolates, which was higher in effluent samples. In contrast, Vibrio isolates were more susceptible to florfenicol, chloramphenicol, ciprofloxacin, and nalidixic acid. Among 99 (influent 39 and effluent 60) MDR isolates, a total of 58 (influent 38 and effluent 20) were found to bear plasmids ranging from 1.7 kb to >10 kb and showed 19 different antibiograms according to the size of plasmids. MDR isolates showed six and four distinct plasmid profiles in influent and effluent, respectively. Effluent samples contained more plasmid-carrying MDR Vibrio isolates with more diverse plasmid profiles and antibiograms, suggesting that fish farm tanks may serve as a reservoir of antibiotic resistance genes. The presence of plasmid-carrying MDR Vibrio isolates in fish farm effluent water may contribute to the dissemination of antibiotic resistance genes to the environments, which ultimately poses threat to human health.

• Korean Journal of Breeding Science
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• v.41 no.1
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• pp.1-8
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• 2009

This study was carried out to breed and develop high quality and functional nutrient tomato with multi disease resistance as well as a stable growing adaptation for fresh market usage under protected plastic houses cultivation. The materials were used 5 inbred lines and their 6 hybrids of large tomato group, which have been bred and developed from 1999 to 2007 in Division of Plant Resource Department of Chungnam National University. Fruit weight showed hybrid vigor effect that $F_1$ hybrids weighed more than their parent lines, fruit shape formed three type of oblate, deep oblate and globe shape, in firmness and pericarp thickness have got a high significant correlation, inbred DN611 line was measured the most firm fruit with 6.04 mm pericarp thickness. In fruit color at maturity, pink color crossed to red color appeared all red fruit color in the $F_1$ hybrids, it means red skin color is a dominant gene compared to pink skin color is a recessive gene in tomato, while between fruit skin color and shoulder part color showed no any co-relationship. The sugar content and titratable acid of $F_1$ hybrids inherited an intermediate data of their parent lines, the flavor of KP543 inbred line and the hybrid (JB535 x KP543) revealed the better taste with high brix and proper titratable acid content$^{*}$. In beta carotene content DN611 line showed 2~3 times higher than other materials so that its 3 hybrids contained an increased level of beta carotene, lycopene content was not so much difference among inbred lines and $F_1$ hybrids, of them MD508 contained higher of 8.72 mg and hybrid (JB535 x JA517) had 8.05 mg lycopene content per 100 g fruit, overall pink skin color and red skin color measured a higher lycopene content than yellow and orange skin color at ripe stage. In disease resistance test by PCR marker for Fusarium race2 (I2), Nematode (Mi1), ToMV ($Tm2^2$), Cladosporium (Cf9), (JB535 x JA517) hybrid have got multi-resistance with homozygote band in Nematode, ToMV, Cladosporium and heterozygote band in Fusarium race2. Through this breeding program we could select high quality and functional nutrient with multi resistant $F_1$ hybrids and inbred lines in tomato which are two best hybrids (JB535 x MD508), (JB535 x JA517), additionally developed high beta carotene inbred line DN611 and increased the level of lycopene inbred line MD508. These results will be very useful to make a high quality tomato variety continuously.