• Korean Journal of Veterinary Service
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• v.45 no.3
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• pp.171-180
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• 2022

The aim of this study was to investigate the prevalence of antimicrobial resistance and virulence factors in staphylococci isolated from canine otitis externa. A total 295 causative microorganisms were isolated. The most common isolated species were Staphylococcus (S) pseudintermedius (94 isolates) followed by Pseudomonas aeruginosa (60 isolates), S. schleiferi (25 isolates), Escherichia coli (23 isolates) and Proteus mirabilis (20 isolates). Staphylococci isolates were showed high resistance to penicillin (78.6%), erythromycin (55.9%), tetracycline (52.4%), clindamycin (51.7%) and ciprofloxacin (42.8%). Of the 145 staphylococci isolates, 49 (33.8%) methicillin-resistant staphylococci (MRS) were observed, distributed among S. pseudintermedius (n=34), S. schleiferi (n=6), S. epidermis (n=4), S. hominis (n=2), S. aureus, S. caprae and S. saprophyticus (n=1, respectively). Forty-three (87.8%) of 49 MRS and 10 (10.4%) of 96 methicillin-susceptibility staphylococci harbored mecA gene. About 80% of MRS were multidrug-resistant with resistance to at least one antibiotic in three or more antibiotic classes. Resistance genes blaZ (93/114, 81.5%), ermB (35/81, 43.2%), ermC (3/81, 3.7%), aacA-aphD (50/54, 92.5%), tetM (69/76, 90.7%) and tetK (6/76, 7.8%) were detected among resistant isolates. Virulence factors genes lukF and lukS were found in 100%(145/145) and 43.4%(63/145), respectively. Genes encoding ermA, eta, etb and tsst were not detected. To the best of our knowledge, this is the first study which investigated for the presence of genes encoding antimicrobial resistance and staphylococcal toxins in staphylococci isolated from canine otitis externa. A continuous monitoring and surveillance program to prevent antimicrobial resistance in companion animals is demanded.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.10
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• pp.1496-1511
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• 2015

The study aimed to compare the necrotic enteritis (NE)-induced transcriptome differences between the spleens of Marek's disease resistant chicken line 6.3 and susceptible line 7.2 co-infected with Eimeria maxima/Clostridium perfringens using RNA-Seq. Total RNA from the spleens of two chicken lines were used to make libraries, generating 42,736,296 and 42,617,720 usable reads, which were assembled into groups of 29,897 and 29,833 mRNA genes, respectively. The transcriptome changes were investigated using the differentially expressed genes (DEGs) package, which indicated 3,255, 2,468 and 2,234 DEGs of line 6.3, line 7.2, and comparison between two lines, respectively (fold change ${\geq}2$, p<0.01). The transcription levels of 14 genes identified were further examined using qRT-PCR. The results of qRT-PCR were consistent with the RNA-seq data. All of the DEGs were analysed using gene ontology terms, the Kyoto Encyclopedia of Genes and Genomes (KEGG) database and the DEGs in each term were found to be more highly expressed in line 6.3 than in line 7.2. RNA-seq analysis indicated 139 immune related genes, 44 CD molecular genes and 150 cytokines genes which were differentially expressed among chicken lines 6.3 and 7.2 (fold change ${\geq}2$, p<0.01). Novel mRNA analysis indicated 15,518 novel genes, for which the expression was shown to be higher in line 6.3 than in line 7.2 including some immune-related targets. These findings will help to understand host-pathogen interaction in the spleen and elucidate the mechanism of host genetic control of NE, and provide basis for future studies that can lead to the development of marker-based selection of highly disease-resistant chickens.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.72.2-73
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• 2003

We found a soybean (Glycine max) cultivar 561 that was strongly resistant to a virulent bacterial strain of a Pseudomonas spp. Further identification revealed that the Pseudomonas spp. was a strain of Pseudomonas aeruginosa. Furthermore we identified specific genes involved in the resistance of soybean 561 and analyzed the pattern of gene expression against the Pseudomonas infection using differential-display reverse transcription PCR (DDRT-PCR). More than 126 cDNA fragments representing mRNAs were induced within 48 hours of bacteria inoculation. Among them, 28 cDNA fragments were cloned and sequenced. Twelve differentially displayed clones with open reading frames had unknown functions. Sixteen selected cDNA clones were homologous to known genes in the other organisms. Some of the identified cDNAs were pathogenesis-related genes (PR genes) and PR-like genes. These cDNAs included a putative calmodulin-binding protein, an endo-1,3-1,4-b-D-glucanase, a b-1,3-endoglucanase, a b-1,3-exoglucanase, a phytochelatin synthetase-like gene, a thiol pretense, a cycloartenol synthase, and a putative receptor-like sorineithreonine protein kinase. Among them, we found that four genes were putative pathogenesis-related genes (PR) induced significantly by the p. aeruginosa infection. These included a calmodulin-binding protein gene, a b-1,3-endoglucanase gene, a receptor-like sorine/threonine protein kinase gene, and pS321 (unknown function). These results suggest that the differentially expressed genes may mediate the strong resistance of soybean 561 to Pseudomonas aeruoginosa.

• Research in Plant Disease
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• v.15 no.2
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• pp.72-76
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• 2009

It was investigated the responses of BaYMV resistant genes to Korean BaYMV(Barley yellow mosaic virus) strains. BaYMV was distributed dominantly with about 51% detection ratio among the three investigated virus such as BaYMV, BaMMV(Barley mild mosaic virus) and SBWMV(Soil-borne wheat mosaic virus) in ELISA test. Double infection with BaYMV and BaMMV was detected also higher as 38.8%, however, BaMMV sole infection ratio was lower with only 1.4%. The 11 BaYMV resistant genes were tested their responses to four Korean BaYMV strains, BaYMV-N, H, I and M. Generally, rym 3 genes showed resistant to Korean BaYMV strains and rym 4m and 5a also was better. Three genes, rym 1+5(Mokusekko-3), rym 3(Ea 52, Baitori) and rym 5a(Solan) showed resistant responses to BaYMV-N type. In -H strain test, seven genes that rym 2(Mihori Hadaka 3), rym 3(Ea 52, Haganemugi, Baitori), rym 4m(Diana, Franka), rym 5a(Solan), rym 7(Hor 3365), rym 9(Bulgarian 347), rym 12(Jochiwon Covered 2) were considered as resistant. The three genes that rym 1+5, rym 3 and rym 5a was effective to -I strain, and rym 3, rym 4m and rym 5a showed resistant to -M strain.

• Journal of Plant Biotechnology
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• v.42 no.4
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• pp.284-289
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• 2015

Powdery mildew (Podosphaera xanthii) commonly occurs in cultivated fields of melon (Cucumis melo L.). It inflicts a lot of damages. Therefore, breeding resistant lines is essential. Development of a resistant line by integrating resistance gene takes a long time. In addition, break down of developed resistance by generating new virulent fungus strains increases disease susceptibility. This phenomenon was related to races of powdery mildew. Therefore, it is important to develop a DNA marker to genetically analyze race-specific resistance genes of melon powdery mildew to breed resistant lines. To date, a total of 28 races of Podosphaera xanthii have been reported in the literature. In Japan, 10 races have been reported in the Ibaraki region. We developed a system to characterize the races of Podosphaera xanthii and confirmed eight out of those 10 races in the Ibaraki region. In Korea, only one race has been characterized to date. However, some different races were detected. Through genetic analysis of resistant lines and susceptible lines of powdery mildew, resistance genes of race1 (Pm-X, PXB, and Pm-R 1), race N1 (PXA), race 2 (Pm-w and Pm-R 2), race 3 (Pm-X3), and race 5 (Pm-X5 and Pm-R5) were identified in melon. These related genes of race 1, 3, N1, 5, and race 1, 2, 5 were located at linkage group II and V, respectively. In race 1, resistance gene was located in the linkage group XII. In addition, each race-specific marker related to specific resistance gene was developed. Using race information and race selection system obtained in this study, resistant line can be bred to develop resistant cultivar for several areas. Furthermore, this will make it more easily and economically to breed resistant lines by using selected markers.

• Biomedical Science Letters
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• v.11 no.4
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• pp.455-463
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• 2005

Resistance to isoniazid (INH), which is one of the most important drugs in Mycobacterium tuberculosis chemotherapy, has been associated with mutations in genes encoding the mycobacterial catalse-peroxidase (katG), the enoyl acyl carrier protein (ACP) reductase (inhA), alkyl hydroperoxide reductase (ahpC), beta-ketoacyl acyl carrier protein synthase (kasA), and NADH dehydrogenase (ndh). In this study, we examined INH-resistance related genes in 50 INH-resistant and 24 INH-susceptible isolates by PCR-sequence analysis. In brief, mutations at the katG gene were found at codon 315 alone (2/50), at codon 463 alone (19/50), and both at 315 and 463 (29/50). However, while mutations at codon 315 were only detected in INH-resistant isolates, mutations at codon 463 were also detected in INH-susceptible isolates indicating mutations at 463 alone do not seem to confer resistance to INH. Similar to the case of katG 463, some of inhA mutations were also found among INH-susceptible isolates. For example, whereas mutations at 8 upstream of the start codon (UPS) and 15 UPS of the inhA gene were detected only in INH-resistant isolates, mutations at 101, 115, and 125 UPS were detected only in INH-susceptible isolates. Many different kinds of mutations were detected in INH­resistant isolates at ahpC, oxyR gene, and intergenic region of the oxyR-ahpC genes. Howerver, the mutations were not found oxyR and the intergenic regions in INH-susceptible isolates. No mutations were found at either kasA or at ndh gene among INH-resistant isolates. In conclusion, some of mutations such as katG 315, inhA promotor region, and oxyR-ahpC seem to be strongly related to INH-resistance. Currently we are developing a molecular diagnostic method based on these results.

• Journal of the Korean Society of Tobacco Science
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• v.21 no.1
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• pp.70-76
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• 1999

KF 116 was TMV resistant tobacco plant and KB 301 was PVY resistant plant transformed with TMV CP gene and PVY CP gene, respectively. These resistant plants were cross-fertilized and the 4 lines of the TMV-PVY resistant plants were selected from F1 hybrid plants. The rate of PVY-resistant plant in these hybrids was 100 percent and that of TMV-resistant plants including delay type was 90-98 percent at 4 weeks after virus inoculation. It was confirmed that the TMV and PVY CP genes were integrated into the genome of hybrid plants by genomic PCR, and Southern blot hybridization. The genome of F1 hybrid plants had one copy and 4 copies of PVY-CP gene and TMV-CP gene, respectively, and CaMV 35S promoters were not methylated, regardless of the difference symptom development to TMV.

• BMB Reports
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• v.51 no.9
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• pp.450-455
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• 2018

Tamoxifen (TAM) is commonly used to treat estrogen receptor (ER)-positive breast cancer. Despite the remarkable benefits, resistance to TAM presents a serious therapeutic challenge. Since several HOX transcription factors have been proposed as strong candidates in the development of resistance to TAM therapy in breast cancer, we generated an in vitro model of acquired TAM resistance using ER-positive MCF7 breast cancer cells (MCF7-TAMR), and analyzed the expression pattern and epigenetic states of HOX genes. HOXB cluster genes were uniquely up-regulated in MCF7-TAMR cells. Survival analysis of in slico data showed the correlation of high expression of HOXB genes with poor response to TAM in ER-positive breast cancer patients treated with TAM. Gain- and loss-of-function experiments showed that the overexpression of multi HOXB genes in MCF7 renders cancer cells more resistant to TAM, whereas the knockdown restores TAM sensitivity. Furthermore, activation of HOXB genes in MCF7-TAMR was associated with histone modifications, particularly the gain of H3K9ac. These findings imply that the activation of HOXB genes mediate the development of TAM resistance, and represent a target for development of new strategies to prevent or reverse TAM resistance.

• The Plant Pathology Journal
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• v.21 no.1
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• pp.47-54
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• 2005

Identification of host genes involved in disease progresses and/or defense responses is one of the most critical steps leading to the elucidation of disease resistance mechanisms in plants. Soybean mosaic virus (SMV) is one of the most prevalent pathogen of soybean (Glycine max). Although the soybeans are placed one of many important crops, relatively little is known about defense mechanism. In order to obtain host genes involved in SMV disease progress and host defense especially for virus resistance, two different cloning strategies (DD RT-PCR and Subtractive hybridization) were employed to identify pathogenesis- and defenserelated genes (PRs and DRs) from susceptible (Geumjeong 1) and resistant (Geumjeong 2) cultivars against SMV strain G7H. Using these approaches, we obtained 570 genes that expressed differentially during SMV infection processes. Based upon sequence analyses, differentially expressed host genes were classified into five groups, i.e. metabolism, genetic information processing, environmental information processing, cellular processes and unclassified group. A total of 11 differentially expressed genes including protein kinase, transcription factor, other potential signaling components and resistant-like gene involved in host defense response were selected to further characterize and determine expression profiles of each selected gene. Functional characterization of these genes will likely facilitate the elucidation of defense signal transduction and biological function in SMV-infected soybean plants.

• KSBB Journal
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• v.28 no.1
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• pp.54-59
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• 2013

Three isolates, E. faecium P1, P2 and P3, from intestinal drugs of three phamaceutical companies, four clinical vancomycin resistant isolates, E. faecium V1, V2, V3 and E. faecalis V4, and three isolates, E. faecalis DW01, DW07 and DW14, from infant feces were tested for the presence of virulence genes, ace, agg, esp, efaA, gelE, sprE, vanA and vanB as well as fsrABC, regulatory genes of gelE and sprE, cylMBA, cytolysin activation genes and cpd, cob and ccf, pheromone genes by PCR and for their phenotype activities such as protease, biofilm formation, cell clumping and hemolysis. The genes encoding cell surface adherence proteins, ace, agg, esp and efaA, were predominantly amplified from the vancomycin resistant strain V4 and the fecal isolates DW01, DW07 and DW14. Both protease and biofilm formation activity were detected only from E. faecalis V4 from which the PCR products of gelE and spreE as well as fsrABC were amplified. The pheromone genes were amplified from the V4, DW01, DW07 and DW14 strains and these strains showed clumping activity. Biofilm formation was observed from the strains DW01, DW07 and DW14, all of which produced PCR products of pheromone, and V4 as well. Whole cytolysin regulator genes were amplified from DW01, DW07 and DW14 and ${\beta}$-hemolysis activity was detected from these strains. Any virulence genes or activities except the pheomone gene ccf were not detected from the pharmaceutical isolates, E. faecium P1, P2 and P3.