• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2002.11a
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• pp.168-168
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• 2002

• Clinical and Experimental Pediatrics
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• v.52 no.1
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• pp.61-67
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• 2009

Purpose : The rate of drug-resistant tuberculosis (DR-TB) in children is an indicator of the effectiveness of TB control programs in the community. This study aimed to assess the prevalence of DR-TB in children and evaluate TB management. Methods : Between January 1999 and July 2007, drug susceptibility tests for anti-TB drugs were employed for patients aged less than 19 years with culture-positive TB. Results : A total of 607 cases (16.6%) were resistant to at least one anti-TB drug as follows: isoniazid (INH; 13.8%), rifampin (8.9%), pyrazinamide (4.2%), streptomycin (3.7%), ethambutol (EMB; 5.9%), and para-aminosalicylic acid (PAS; 1.9%). Multidrug-resistant (MDR) TB was found in 276 cases (7.6%); extensive drug resistant (XDR) TB, in 5 cases (0.2%). The rate of resistance to at least one anti-TB drug in children aged >15 years (16.1%) was significantly lower than that in children aged <15 years (20.5%) (P=0.016). The rate of resistance to at least one anti-TB drug and multidrug-resistance in this survey decreased significantly (P<0.001) as compared to the previous survey (1987-1995). The rate of resistance to INH, EMB, and PAS also significantly decreased (P<0.05). Conclusion : The rate of DR-TB in children in Korea has decreased over time; however, it remains higher than that in other countries. MDR-TB and XDR-TB are the emerging problems in Korean children. Therefore, the selection of effective drugs through drug susceptibility tests and evaluating risk factors of resistant TB is essential to successful therapy and a decreased incidence of DR-TB.

• The Korean Journal of Pesticide Science
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• v.11 no.4
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• pp.320-330
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• 2007

Mitochondrial 16S DNA sequences of Bemisia tabaci which were collected on rose greenhouse of Iwol and Jinchen in Chungbuk and red pepper field of Miryang, Gyeongnam, were analyzed. The mtCOI PCR product of B. tabaci collected on red pepper field of Miryang were digested with EcoT14I (Sty I) into two fragments 555bp and 311bp, while the PCR product of B. tabaci collected on rose greenhouse of Iwol were digested with Sty I into two fragments of 560bp and 306bp. As a result, B. tabaci collected on red pepper reveal biotype Q and those on rose greenhouse was biotype B. These was difference between two biotypes in insecticide susceptibility, and the biotype B was more susceptible than biotype Q. As a result of foliar systemic test, root-uptake systemic test and residual effect, the biotype B was more susceptible. In case of inhibition effect on enzyme activities of fenitrothion (organophosphorous) and fenothiocarb (carbamate), those of biotype Q was higher than those of biotype B. These results indicate that biotype Q was more resistant than biotype B against 12 insecticides.

• Korean journal of applied entomology
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• v.55 no.3
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• pp.257-266
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• 2016

Subtropical insect pests expand their habitats by migration to temperate zones along with global climate change. A subtropical insect pest, Maruca vitrata, is infesting leguminous crops including azuka beans in Korea and gives significant economic damages. Its great genetic variation raised an issue of the origin of a Korean M. vitrata population. To understand the genetic character of the Korean population, its cytochrome oxidase subunit 1 (cox 1) gene was sequenced and phylogenetically analyzed with other regional populations. The world populations of M. vitrata were grouped into three clusters: Asia-African, American, and Oceanian. The Korean population was classified into Asia-African cluster. To characterize the insecticide susceptibility of the Korean population, seven different insecticides (4 neutoxic insecticides, 1 insect growth regulator, 2 biopesticides) were assessed. Young larvae of M. vitrata were relatively susceptible to all tested insecticides. However, old larvae were much less susceptible than young larvae. No test insecticides effectively (> 50%) killed the old larvae of M. vitrata within 7 days.

• Korean journal of applied entomology
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• v.34 no.4
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• pp.328-333
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• 1995

Susceptibilies of tow-spotted spider mite (Tetranychus urticae Koch) collected at 6 locations were assessed to 15 acaricides. The response to acaricides were almost similar in female adults and eggs. There were considerable difference in susceptibility depending on the acaricide treated and the region from which the population was collected. The population showing resistance ratio of more than 20 with respect to certain acaricide was regarded as a resistant population to the acaricide. The resistant populations in terms of female adult were as follows: Suwon population to azocyclotin, cyhexatin, and fenbutatin-oxide; Taejon population to dicofol and fenbutatin-oxide; Chongju population to dicofoll Chinju populatin to cyhexatin, dicofol, and fenbutatin-oxide. The resistant populations in terms of egg were as follows; Suwon population to bifenthrin, clofentezine, hexythiazox, and tetradifon; Kunwi, Chongju, and Kwangju populations to bifenthrin; Taejon population to amitraz and bifenthrin; Taejon populatin to amitraz and bifenthrin; Chinju population to amitraz, bifenthrin, clofentezine, dicofol, and tetradifon. However, the female adults and eggs of all field populations were susceptible to abamectin, chlorfenson, and fenpyroximate. This tendency was also reported previously in the susceptible strain from laboratory.

• Tuberculosis and Respiratory Diseases
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• v.66 no.3
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• pp.198-204
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• 2009

Background: First-line drugs, if sensitive, are the most potent drugs in the treatment of multidrug-resistant tuberculosis (MDR-TB). This study examined the frequency and risk factors associated with acquired drug resistance to first-line drugs during a standardized treatment using first-line drugs in patients with MDR-TB. Methods: This study included patients who were diagnosed with MDR-TB at the National Masan Tuberculosis Hospital between January 2004 and May 2008, treated with standardized first-line drugs, and for whom the preand post-treatment results of the drug susceptibility test were available. Their medical records were reviewed retrospectively. Results: Of 41 MDR-TB patients, 14 (34.1%) acquired additional resistance to ethambutol (EMB) or pyrazinamide (PZA). Of 11 patients initially resistant to isoniazid (INH) and rifampicin (RFP), 3 (27.3%) acquired additional resistance to both EMB and PZA, and 3 (27.3%) to PZA. Of 18 patients initially resistant to INH, RFP and EMB, 6 (33.3%) acquired additional resistance to PZA. Of 6 patients initially resistant to INH, RFP and PZA, 2 (33.3%) acquired additional resistance to EMB. Ten of the 41 MDR-TB patients (24.4%) changed from resistant to susceptible. No statistically significant risk factors associated with acquired resistance could be found. Conclusion: First-line drugs should be used cautiously in the treatment of MDR-TB in Korea considering the potential acquisition of drug resistance.

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

• Korean journal of applied entomology
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• v.56 no.4
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• pp.427-434
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• 2017

The susceptibility of Dermanyssus gallinae adults, collected from poultry farms in 5 regions, to 11 acaricides was investigated. When bifenthrin and formic acid with pyridaben were diluted 100 times, bifenthrin showed 100% acaricidal activity; however, formic acid with pyridaben showed less than 20% acaricidal activity for poultry farms in 3 regions (Gyeongju, Chilgok, and Geumsan) except Yeoncheon and Anseong. The carbamate compound, carbaryl showed 100% acaricidal activity in most of the regions, except Gyeongju. A phosphorus compound, dichlorvos showed 100% activity in most of the regions, yet 66.7% acaricidal activity in Yeoncheon. The susceptibility of D. gallinae from poultry farms in Yeoncheon and Anseong to most acaricides was high; however, in the other farms, the susceptibility of D. gallinae varied depending on the acaricide. Clothianidin, thiamethoxam, fenitrothion, and formic acid with pyridaben showed differences in acaricidal activity among regions. Therefore, farmers should concentrate during the selection of these acaricides. However, carbaryl, cartap hydrochloride, dichlorvos, and bifenthrin showed high activity against D. gallinae collected from poultry farms in five regions. Therefore, these acaricides could be used in most of these regions. To control D. gallinae effectively, the alternation of acaricides is necessary, and indiscriminate pesticide use should be avoided. Therefore, this study can serve as a basis for controlling D. gallinae.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5012-5018
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• 2011

According to the nationwide survey of tuberculosis from 1965 to 1995, the incidence and drug resistance rate of tuberculosis have been decreased in Korea, but the prevalence of multidrug resistance of Mycobacterium tuberculosis is still a serious problem. The purpose of this study is to investigate the drug resistance rate and pattern of tuberculosis in Daejeon from 2001 to 2008. Of the total 581cases where the drug susceptibility test was performed, resistance to at least one anti-TB drug was found in 104 cases(17.9%) of these, 68(11.7%) were resistant to at least INH and 41(7.1%) were resistant to at least RFP. Single-drug resistance was found for isolates from 37(6.4%) ; 18(3.1%) of these were resistant to INH and 5(0.9%) to RFP. Multidrug resistance, where TB was resistant to at least isoniazid and refampin, was found in 35 cases(6.0%). and Factors associated with MDR-TB included age under 40-60.The drug-resistance rate of pulmonary TB, especially MDR-TB, is higher in the initial treated patients at a private referral hospital than in those in the pubulic sector. Initial drug resistance is common and the drug susceptibility test is informative for pulmonary TB patients who have not received previous TB treatment. The need for an improved control program, coupled with early diagnosis of MDR-TB, to reduce the spread and development of resistance. Multidrug resistance rate is still problem in korea. Efforts to decrease multidrug resistance rate either independently or in cooperation with the pubulic sector will be needed.

• Tuberculosis and Respiratory Diseases
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• v.59 no.3
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• pp.250-256
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• 2005

Background : Fluoroquinolone drugs are an important anti-tuberculous agent for the treatment of multi-drug resistant tuberculosis. However, many drugs belonging to the fluoroquinolones have different cross resistance to each other. Methods : Sixty-three ofloxacin (OFX) resistant and 10 pan-susceptible M. tuberculosis isolates were selected, and compared for their cross resistance using a proportion method on Lowenstein-Jensen media, containing ofloxacin (OFX), ciprofloxacin (CIP), levofloxacin (LVX), moxifloxacin (MXF), gatifloxacin (GAT) and sparfloxacin (SPX), at concentrations ranging from 0.5 to $3{\mu}g/ml$. DNA extracted from the isolates was directly sequenced after amplifying from the gyrA and gyrB genes. Results : The 63 OFX resistant M. tuberculosis isolates showed complete cross resistance to CIP, but only 90.5, 44.4, 36.5 and 46.0% to LVX, MXF, GAT, and to SPX, respectively. Fifty-one of the isolates (81.0%) had point mutations in codons 88, 90, 91 and 94 in gyrA, which are known to be correlated with OFX resistance. The Gly88Ala, Ala90Valand Asp94Ala mutations in gyrA showed a tendency to be susceptible to MXF, GAT and SPX. Only 4 isolates had mutations in the gyrB gene, which did not affect the OFX resistance. Conclusion : About 60% of the OFX resistant M. tuberculosis isolates were susceptible to GAT, SPX and MXF. These fluoroquinolones may be useful in the treatment of TB patients showing OFX resistance.