• Tuberculosis and Respiratory Diseases
• /
• v.55 no.4
• /
• pp.344-352
• /
• 2003

Background : The prevalence of multidrug resistant tuberculosis (MDR-TB), resistant to isoniazid (INH) and rifampin (RFP), was 5.3% worldwide in 1995 and its increment has raised important public health problems. Resistance to RFP, one of the key drugs in the treatment of tuberculosis, results in grim clinical outcome. Recently rapid detection of RFP-resistant mutations in rpoB gene based on PCR method has become available. This study evaluated the prevalence of RFP resistance in first diagnosed, treatment failure, and recurred patients using INNO-LiPA test, and compared the results of INNO-LiPA with those of conventional mycobacterial drug susceptibility test. Methods : Forty-six patients, who were diagnosed of pulmonary tuberculosis and had revealed positive sputum AFB smear, were enrolled in this study from 1998 to 2002. The cases were classified as one three groups; first diagnosed, treatment failure, or recurred. RFP resistance was studied using an INNO-LiPA Rif. TB kit and compared with that obtained from drug susceptibility based on M. tuberculosis culture study. Results : Twenty-one out of 46 patients were enrolled under first diagnosis of pulmonary tuberculosis, 17 under treatment failure with first line drugs, and 8 under recurrence. The positive and negative predictive values of INNO-LiPA test in diagnosis in RFP resistant tuberculosis compared with conventional mycobacterial drug susceptibility test were 85.7% and 76.0%, respectively. INNO-LiPA result revealed rpoB gene mutation in 20 (80.0%) out of 25 patients who were diagnosed as treatment failure or recurrence, but in only 4 (19.0%) out of 21 patients who were first diagnosed as pulmonary tuberculosis. Conclusion : This study showed that RFP resistance could be diagnosed rapidly and accurately using INNO-LiPA test and that this test might be helpful for choosing second line anti-mycobacterial drugs. It might be of great help in clinical diagnosis and decision when used in complimentarily with drug susceptibility test based on M. tuberculosis culture.

• Tuberculosis and Respiratory Diseases
• /
• v.56 no.3
• /
• pp.248-260
• /
• 2004

Background : As an effective regimen for isoniazid (INH)-resistant pulmonary tuberculosis, several treatment regimens have been recommended by many experts. In Korea, a standard regimen has not been established for INH-resistant tuberculosis, and the treatment by individual physicians has been performed on an empirical bases. The purpose of the present study was to retrospectively describe the treatment characteristics and evaluate the treatment outcomes of patients with INH-resistant tuberculosis. Materials and Methods : Sixty of 69 patients reported to have INH-resistant tuberculosis from 1994 to 2001 were retrospectively analyzed. Exclusion criteria included: death from other causes, with the exceptions of tuberculosis and incomplete treatment, including a patient's transfer-out. Results : A previous tuberculosis history was found in 28 (46.7%) patients. The sputum smear for acid-fast bacilli was positive in 44 (73.3%) patients, and 30 (50.0%) had cavitary disease. Streptomycin resistance coexisted in 25.0% of isolates. INH was to be prescribed continuously, even after INH resistance was reported, in 86.0% of patients. The treatment regimens were diverse between the patients according to drug regimen composition and treatment duration. The most frequent prescribed regimen included rifampin, ethambutol and pyrazinamide, with and without INH, for the full 12-month term of treatment. Treatment failure occurred in 13 (21.7%) patients. Cavitary disease (p=0.005) and a treatment regimen with second-line drugs, excluding rifampin (p=0.015), were associated with treatment failure. One patient experienced a relapse. Conclusions : Standardized treatment guidelines will be needed in Korea to improve the treatment efficacy for INH-resistant tuberculosis.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.1
• /
• pp.180-189
• /
• 2016

The widespread occurrence of drug-resistant Mycobacterium tuberculosis places importance on the detection of TB (tuberculosis) drug susceptibility. Conventional drug susceptibility testing (DST) is a lengthy process. We developed a rapid enzymatic color-reaction-based biochip assay. The process included asymmetric multiplex PCR/templex PCR, biochip hybridization, and an enzymatic color reaction, with specific software for data operating. Templex PCR (tem-PCR) was applied to avoid interference between different primers in conventional multiplex-PCR. We applied this assay to 276 clinical specimens (including 27 sputum, 4 alveolar lavage fluid, 2 pleural effusion, and 243 culture isolate specimens; 40 of the 276 were non-tuberculosis mycobacteria specimens and 236 were M. tuberculosis specimens). The testing process took 4.5 h. A sensitivity of 50 copies per PCR was achieved, while the sensitivity was 500 copies per PCR when tem-PCR was used. Allele sequences could be detected in mixed samples at a proportion of 10%. Detection results showed a concordance rate of 97.46% (230/236) in rifampicin resistance detection (sensitivity 95.40%, specificity 98.66%) and 96.19% (227/236) in isoniazid (sensitivity 93.59%, specificity 97.47%) detection with those of DST assay. Concordance rates of testing results for sputum, alveolar lavage fluid, and pleural effusion specimens were 100%. The assay provides a potential choice for TB diagnosis and treatment.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.6
• /
• pp.2223-2235
• /
• 2013

This study aimed to understand temporal and spatial trends of rainfall characteristics in South and North Korea. Daily rainfall observed at the 65 stations in South Korea between 1963 and 2010 and the 27 stations in North Korea between 1973 and 2010 were analyzed. Rainfall Indicators for amount, extremes, frequency of rainfall were defined. Province-based indicators in the recent 10 years (i.e., between 2001 and 2010) were compared to those in the past (i.e., between 1963/1973 and 2000 for South/North Korea). In the recent 10 years, all the indicators except for the number of wet days (NWD) and 200-yr frequency rainfall (Freq200) increased in South Korea and all the indicators except for the annual mean daily rainfall over wet days (SDII) and annual total rainfall amount (TotalDR) decreased in North Korea. Furthermore, we performed the Mann-Kendall trend test based on the annual indicators. In some stations, decreasing trends in the past and increasing trends in the recent 10 years were found, and such opposite trends between two periods suggest he limitation in predicting and analyzing the rainfall characteristics based on the average. Results from this study can be used in analyzing the impact of climate change and preparing adaptation strategies for the water resources management.

• Korean Journal of Microbiology
• /
• v.37 no.4
• /
• pp.277-283
• /
• 2001

The emergence of extended spectrum beta-lactamase(ESBL) producing bacteria is causing very serious problems in Korea. Although there have been many reports about these bacteria isolated from patients and clinical specimens, there is no report of ESBL-producing organisms isolated from natural evironment in Korea. This is the first study on the ESBL producing bacteria out of the medical system in Korea. Twenty-six ESBL producing bacteria were isolated only from sewerage plant drain water at Kwang-an beach among the sampling collected sites including snakehead fish plants in Myungi, Aquaculture Engineering Lab. in Pukyong National University and two public-bathrooms in Pusan, Korea. ESBL producing bacteria were identified by double-disk synergy test, conjugation, isoelectric focusing values and PCR. The species of ESBL producing bacteria were Enterobacter cloacae(4 strains), E. sakazakii(8 strains), Klebsiella pneumoniae subsp. pneumoniae(8 strains) and K. pneumoniae subsp. ozaenae(6 strains). TEM and SHV specific PCR products were detected from all the ESBL strains produced TEM+SHV products on the PCR plates. The pI values of ESBL produced by Klebsiella pneumoniae subsp. pneumoniae, K. pneumoniae subsp. ozaenae, Enterobacter cloacae, and E. sakazakii were 5.9, 5.9+5.4; 5.9, $5.9+5.4;{\ge}8.5$, 8.0+5.4, and 8.0+5.4, respectively on the IEF. Seven strains of the isolates were transfered their genes to E. coli RG488 $Rif^r$ by conjugation.

• Korean Journal of Microbiology
• /
• v.45 no.3
• /
• pp.281-285
• /
• 2009

In this study, we compared the BacT/Alert liquid culture system with Ogawa and $L\ddot{o}wenstein$-Jensen (L-J) media for sputum culture and drug susceptibility test (DST) of Mycobacterium tuberculosis. Rapid liquid culture systems have been widely employed both for primary cultures of M. tuberculosis from clinical specimens and for drug susceptibility test because of its greater sensitivity and faster turn-around time than the conventional egg-based culture methods (Ogawa, $L\ddot{o}wenstein$-Jensen media). Sputum specimens were decontaminated with N-acetyl-L-cysteine (NALC)-4% NaOH and inoculated into the BacT/Alert culture bottles and Ogawa media. 95 from among 135 sputa were smear-positive, 97 (71.9%) were culture-positive by the BacT/Alert culture system, while 89 (65.9%) were positive by Ogawa media. The mean time to culture-positive by the BacT/Alert process system was about 11.3 days, which was significantly shorter than that by Ogawa media (22.4 days). Of 32 M. tuberculosis cultures examined for drug sensitivity, the concordant rate between the two methods (BacT/ Alert liquid culture system, $L\ddot{o}wenstein$-Jensen media) ranged from 87.5% for isoniazid and 90.6% for rifampicin.

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