• Fisheries and Aquatic Sciences
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• v.25 no.4
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• pp.202-213
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• 2022

Antibiotic resistant Escherichia coli cases are increasing high especially in Southeast Asia. Illegal use of the antibiotic in the aquaculture farming may become the culprit of the outbreak and spread into environmental source. A study was conducted to: 1) detect the chloramphenicol (CAL)-resistant gene in E. coli isolated from three aquaculture farms and six rivers of northwestern Borneo and 2) investigate the correlation between cat gene with five common antibiotics used. Isolation of E. coli was done on Eosin methylene blue agar and characterized using indole, methyl red, Voges-Proskauer, citrate tests. E. coli isolates were subsequently tested for their susceptibility to five antibiotics commonly used in aqua-farming. The CAL-resistant E. coli were further analyzed for the presence of resistant genes (cat I, cat II, cat III, cat IV) using multiplex polymerase chain reaction. 42 bacterial colonies were isolated from a total of 80 individual water samples, 34 of which were identified as E. coli. Result showed 85.3% of the E. coli isolates were resistant to amoxicillin, 35.3% were resistant to tetracycline, 29.4% were resistant to CAL, 17.6% were resistant to nitrofurantoin and 8.8% were resistant to nalidixic acid. All of the 10 CAL resistant E. coli isolateswere detected with cat II genes; five isolates detected with cat IV genes; three isolates detected with cat III genes; and another two detected with cat I genes. Pearson correlation coefficient shows highly significant relationship between resistance pattern of CAL with amoxicillin; and CAL with tetracycline. Our findings provide the supplementary information of the CAL resistance gene distribution, thereby improving our understanding of the potential risk of antibiotic resistance underlying within this microbial ecosystem.

• Archives of Pharmacal Research
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• v.21 no.4
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• pp.470-474
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• 1998

A kanamycin producer, Streptomyces kanamyceticus IFO 13414 is highly resistant to kanamycin. Cloning of the kanamycin resistance genes in S. lividans 1326 with pIJ702 gave several kanamycin resistant transformants. Two transformants, S. lividans SNUS 90041 and S. lividan. SNUS 91051 showed similar resistance patterns to various aminoglycoside antibiotics. Gene mapping experiments revealed that plasmids pSJ5030 and pSJ2131 isolated from the transformants have common resistant gene fragments. Subcloning of pSJ5030 gave a 1.8 Kb gene fragment which showed resistance to kanamycin. Cell free extracts of S. lividans SNUS 90041, S. lividans SNUS 91051 and subclone a S. lividans SNUS 91064 showed kanamycin acetyltransferase activity. The detailed gene map is included.

• The Plant Pathology Journal
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• v.37 no.5
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• pp.489-493
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• 2021

Bacterial canker is a devastating disease of kiwifruit caused by the bacterium Pseudomonas syringe pv. actinidiae. Canker disease of kiwifruit in Korea has been controlled using streptomycin for more than two decades. Four streptomycin-resistant strains, belonging to biovar 2, which are found only in Korea, were collected between 2013 and 2014 from different orchards located in Jeju, Korea. The genetic background for streptomycin resistance among P. syringe pv. actinidiae strains were determined by examining the presence of strA-strB or aadA, which are genes frequently found in streptomycin-resistant bacteria, and a point mutation at codon 43 in the rpsL gene. All four streptomycin-resistant strains of P. syringe pv. actinidiae investigated in this study contained strA-strB as a resistant determinant. The presence of the aadA gene and a mutation in codon 43 of the rpsL gene was not identified.

• Korean journal of applied entomology
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• v.27 no.2
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• pp.63-67
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• 1988

Biotypes of the brown planthopper(BPH), Nilaparvata lugens St l, population migrated from maninand China in to southern coastal regions of Korea were investigated in 1985-1987 by honeydew excretion test using Korean cultvars,, 'Milyang 23'(no resistant gene), 'Cheongcheo-ngboy'(bph 1 gene), 'Milyang 63'(bph 2 gene) and 'Gayabyeo'(bph 1 and bph 2 gene). There was a correlation between the amount of honeydew excreted and the ability of each biotype to infest resistant cultivars: 'Milyang 23' with no resistant gene was highiy susceptible to bioty-pe-1, 2 and 3 ; 'cheongcheongbyeo' with resistant bph 1 was susceptible to biotype-2: and 'Milyang 63' with resistant bph 2 gene was highiy resistant to biotype-1, 2 and 3. Percent biotype dis-tribution of the female BPH collected in the southern coastal regions of Korea showed that in 1985, 1986 and 1987, the BPH biotype-1 was predominant accounting for 64.7%, 61.2% and 57.9%, respectivley, whereas bitype-2 was 22.0%, 21.9% and 29.7%, and biotype-3 was 13.3%, 17.0% and 12.6%, repestively.

• Korean Journal of Clinical Laboratory Science
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• v.41 no.1
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• pp.24-30
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• 2009

Rifampicin (RIF) and isoniazid (INH) are the most important drug for the treatment of Mycobacterium tuberculosis. Mutations correlated to rifampicin and isoniazid-resistance have been detected in rpoB gene and katG gene, respectively. Of the rifampicin-resistant isolates, 90% showed mutations in rpoB gene at codon 507 to 533. Isoniazid-resistant isolates analysed had a mutation in katG at codon 315. The aim of this study is to develop a pyrosequencing-based approach for rapid detection of ripampin or isoniazid resistant M. tuberculosis based on characterization of all possible mutation in the target region. For this study, the DNA selected from 35 cases of MTB PCR positive clinical sample such as bronchial washing, sputum, and pleural fluid. RIF or INH resistant was analyzed by pyrosequencing data of rpoB and katG gene. 28 (80%) and 7 (20%) of 35 MTB PCR positive DNAs were occured rifampicin-sensitivity and resistant, respectively. For INH, 30 (85.7%) and 5 (14.5%) cases were detected isoniazid-sensitivity and resistant, respectively. When pyrosequencing analysis was compared with ABI sequencing analysis, both analysis were presented same result, but pyrosequencing analysis was more rapid than ABI sequencing analysis. In conclusion, we found that pyrosequencing technology offers high accuracy, specificity, short turn around time and a high throughput in detection of rifampicin or isoniazid resistance in M. tuberculosis.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.113-113
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• 2017

Downy mildew (DM), caused by several species in the Peronosclerospora and Scleropthora genera, is a major maize (Zea mays L.) disease in tropical or subtropical regions. DM is an obligate parasite species in the higher plants and spreads by oospores, wind, and mycelium in seed surface, soil, and living hosts. Owing to its geographical distribution and destructive yield reduction, DM is one of the most severe maize diseases among the maize pathogens. Positional cloning in combination with phenotyping is a general approach to identify disease resistant gene candidates in plants; however, it requires several time-consuming steps including population or fine mapping. Therefore, in the present study, we suggest a new combination strategy to improve the identification of disease resistant gene candidates. Downy mildew (DM) resistant maize was selected from five cultivars using the spreader row technique. Positional cloning and bioinformatics tools identified the DM resistant QTL marker (bnlg1702) and 47 protein coding genes annotations. Eventually, 5 DM resistant gene candidates, including bZIP34, Bak1, and Ppr, were identified by quantitative RT-PCR without fine mapping of the bnlg1702 locus. Specifically, we provided DM resistant gene candidates with our new strategy, including field selection by the spreader row technique without population preparation, the DM resistance region identification by positional cloning using bioinformatics tools, and expression level profiling by quantitative RT-PCR without fine mapping. As whole genome information is available for other crops, we propose applying our novel protocol to other crops or for other diseases with suitable adjustment.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.4
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• pp.1863-1869
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• 2014

The amplification of telomerase component (TERC) gene could play an important role in generation and treatment of haematological malignancies. This present study was aimed to investigate copy number amplification status of TERC gene in chronic myeloid leukaemia (CML) patients who were being treated with imatinib mesylate (IM). Genomic DNA was extracted from peripheral blood of CML-IM Resistant (n=63), CML-IM Respond (n=63) and healthy individuals (n=30). TERC gene copy number predicted (CNP) and copy number calculated (CNC) were determined based on $Taqman^{(R)}$ Copy Number Assay. Fluorescence in situ hybridization (FISH) analysis was performed to confirm the normal signal pattern in C4 (calibrator) for TERC gene. Nine of CML patients showed TERC gene amplification (CNP=3), others had 2 CNP. A total of 17 CML patients expressed CNC>2.31 and the rest had 2.31>CNC>1.5. TERC gene CNP value in healthy individuals was 2 and their CNC value showed in range 1.59-2.31. The average CNC TERC gene copy number was 2.07, 1.99 and 1.94 in CML-IM Resistant patients, CML-IM Respond and healthy groups, respectively. No significant difference of TERC gene amplification observed between CML-IM Resistant and CML-IM Respond patients. Low levels of TERC gene amplification might not have a huge impact in haematological disorders especially in terms of resistance towards IM treatment.

• Journal of Microbiology and Biotechnology
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• v.26 no.12
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• pp.2043-2050
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• 2016

Exploring novel antibiotics is necessary for multidrug-resistant pathogenic bacteria. Because the probiotics in soybean food have antimicrobial activities, we investigated their effects on multidrug-resistant Acinetobacter baumannii. Nineteen multidrug-resistant A. baumannii strains were clinically isolated as an experimental group and 11 multidrug-sensitive strains as controls. The growth rates of all bacteria were determined by using the analysis for xCELLigence Real-Time Cell. The combination of antibiotics showed synergistic effects on the strains in the control group but no effect on the strains in the experimental group. Efflux pump gene adeS was absent in all the strains from the control group, whereas it exists in all the strains from the experimental group. Furthermore, all the strains lost multidrug resistance when an adeS inhibitor was used. One strain of probiotics isolated from soybean food showed high antimicrobial activity for multidrug-resistant A. baumannii. The isolated strain belongs to Bacillus subtilis according to 16S RNA analysis. Furthermore, E. coli showed multidrug resistance when it was transformed with the adeS gene from A. baumannii whereas the resistant bacteria could be inhibited completely by isolated Bacillus subtilis. Thus, probiotics from soybean food provide potential antibiotics against multidrug-resistant pathogenic bacteria.

• Journal of Microbiology
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• v.45 no.4
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• pp.350-357
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• 2007

This study was conducted in an effort to evaluate the antimicrobial activity and antibiotic-resistant gene regulation from Saliva miltiorrhiza Bunge on methicillin-resistant Staphylococcus aureus (MRSA). A variety of solvent fractions and methanol extracts of S. miltiorrhiza Bunge were tested in order to determine its antimicrobial activities against S. aureus and MRSA. As a result, the hexane fraction of S. miltiorrhiza Bunge evidenced the highest levels of antimicrobial activity against S. aureus and MRSA. The MICs of the hexane fraction against various MRSA specimens were $64. The hexane fraction evidenced inhibitory effects superior to those of the chloroform fraction. The results showed inhibition zones of hexane (16 mm) and chloroform (14 mm) fractions against MRSA KCCM 40511 at $1,000{\mu}g/disc$. The hexane and chloroform fractions inhibited the expression of the resistant genes, mecA, mecR1, and femA in mRNA. Moreover, the results of Western blotting assays indicated that the hexane and chloroform fractions inhibited the expression of the resistant protein, PBP2a. These results reveal that the hexane and chloroform fractions of S. miltiorrhiza Bunge may prove to be a valuable choice for studies targeted toward the development of new antimicrobial agents.

• BMB Reports
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• v.39 no.4
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• pp.457-463
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• 2006

Insulin resistance is commonly observed in patients prior to the development of type 2 diabetes and may predict the onset of the disease. We tested the hypothesis that impairment in insulin stimulated glucose-disposal in insulin resistant patients would be reflected in the gene expression profile of skeletal muscle. We performed gene expression profiling on skeletal muscle of insulin resistant and insulin sensitive subjects using microarrays. Microarray analysis of 19,000 genes in skeletal muscle did not display a significant difference between insulin resistant and insulin sensitive muscle. This was confirmed with real-time PCR. Our results suggest that insulin resistance is not reflected by changes in the gene expression profile in skeletal muscle.