• Title/Summary/Keyword: Resistant genes

Search Result 857, Processing Time 0.027 seconds

Mutations in the GyrA Subunit of DNA Gyrase and the ParC Subunit of Topoisomerase IV in Clinical Strains of Fluoroquinolone-Resistant Shigella in Anhui, China

  • Hu, Li-Fen;Li, Jia-Bin;Ye, Ying;Li, Xu
    • Journal of Microbiology
    • /
    • v.45 no.2
    • /
    • pp.168-170
    • /
    • 2007
  • In this research 26 Shigella isolates were examined by PCR and direct nucleotide sequencing for genetic alterations in the quinolone-resistance determining regions (QRDRs). We tested for the presence of qnr genes by PCR in 91 strains, but no qnr genes were found. The results did show, however, some novel mutations at codon 83 of gyrA ($Ser{\rightarrow}Ile$) and codon 64 of parC ($Ala64{\rightarrow}Cys,\;Ala64{\rightarrow}Asp$), which were related to fluroquinolone resistance.

HEMAGGLUTINATION AND COLONY HYBRIDIZATION FOR THE IDENTIFICATION OF ENTEROTOXIGENIC Escherichia coli ISOLATED FROM HEALTHY PIG

  • Choi, S.H.;Oh, M.J.;Sung, C.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.9 no.6
    • /
    • pp.671-677
    • /
    • 1996
  • Erythrocytes from three different animal species were used to determine mannose-sensitive hemagglutination (MSHA) and mannose-resistant hemagglutination (MRHA) of 755 isolates obtained from rectal swabs of healthy pig. In addition, colony hybridization using digoxigenin-dUTP labeled polynucleotide probes was performed for the detection of heat-stable and heat-labile enterotoxin genes carried by MRHA positive isolates. Of 755 strains, 9, 4 and 28 strains gave a positive MRHA with bovine, equine and pig erythrocytes, respectively. Of these isolates, 28 (3.7%) were characterized for positive MRHA by at least one blood. Seven isolates gave a positive MRHA with two kinds of blood. Three gave a positive MRHA with three kinds of blood. Twenty-eight strains, while positive in MRHA, yielded negative signals in the colony hybridization assay for the detection of heat-stable (STaI and STaII) and heat-labile (LT) enterotoxin genes in E. coli.

Identification of a Pathogen-Induced Glycine max Transcription Factor GmWRKY1

  • Kang, Sang-Gu;Park, Eui-Ho;Do, Kum-Sook
    • The Plant Pathology Journal
    • /
    • v.25 no.4
    • /
    • pp.381-388
    • /
    • 2009
  • On screening pathogen-resistant soybean, we identified a WRKY type transcription factor named a Glycine max WRKY1 (GmWRKY1). Expression of GmWRKY1 gene was induced in the soybean sprout by Pseudomonas infection. The GmWRKY1 was expressed in all of the tissues with high levels in stems, leaves and developing seeds. The protein Gm WRKY1 contains highly conserved two WRKY DNA-binding domains having two $C_2-H_2$ zinc-finger motif ($C-X_{4-5}-C-X_{22-23}-H-X-H$) in its N-terminal and C-terminal amino acid sequences. In electrophoresis mobility shift assay, the GmWRKY1 protein bound specifically to W-box elements in the promoters of defense related genes. These results demonstrated that GmWRKY1 is one of the soybean WRKY family genes and the plant-specific transcription factors for defense processes.

Rice Transformation by DNA Imbibition and Construction of Plant Vector (DNA imbibition을 이용한 벼의 형질전환과 vector 개발)

  • 유준희;남홍길정구흥
    • KSBB Journal
    • /
    • v.8 no.2
    • /
    • pp.104-109
    • /
    • 1993
  • A vector for plant transformation which had two reporter genes(Gus and Hpt genes) in a single plasmid was constructed. After rice embryos imbibed DNA solution, DNA uptake and gene expression in rice were monitored. Main expression sites of the Gus gene were meristem of root and coleoptiles. There was no difference in Hpt gene expression between a single Hpt vector and the constructed vector in viability of rice in the hygromycin medium after DNA imbibition, The genomic DNA and total RNA extracted from rice transformant survived in the hygromycin medium were subjected to PCR and RT PCR analysis, respectively. As a result, we found the existence of the Hpt gene and its expression in rice.

  • PDF

Genetic and Functional Analyses of the DKxanthene Biosynthetic Gene Cluster from Myxococcus stipitatus DSM 14675

  • Hyun, Hyesook;Lee, Sunjin;Lee, Jong Suk;Cho, Kyungyun
    • Journal of Microbiology and Biotechnology
    • /
    • v.28 no.7
    • /
    • pp.1068-1077
    • /
    • 2018
  • DKxanthenes are a class of yellow secondary metabolites produced by myxobacterial genera Myxococcus and Stigmatella. We identified a putative 49.5 kb DKxanthene biosynthetic gene cluster from Myxococcus stipitatus DSM 14675 by genomic sequence and mutational analyses. The cluster consisted of 15 genes (MYSTI_06004-MYSTI_06018) encoding polyketide synthases, non-ribosomal peptide synthases, and proteins with unknown functions. Disruption of the genes by plasmid insertion resulted in defects in the production of yellow pigments. High-performance liquid chromatography and liquid chromatography-tandem mass spectrometry analyses indicated that the yellow pigments produced by M. stipitatus DSM 14675 might be novel DKxanthene derivatives. M. stipitatus did not require DKxanthenes for the formation of heat-resistant viable spores, unlike Myxococcus xanthus. Furthermore, DKxanthenes showed growth inhibitory activity against the fungi Aspergillus niger, Candida albicans, and Rhizopus stolonifer.

Role of LAMMER Kinase in Cell Wall Biogenesis during Vegetative Growth of Aspergillus nidulans

  • Choi, Yu Kyung;Kang, Eun-Hye;Park, Hee-Moon
    • Mycobiology
    • /
    • v.42 no.4
    • /
    • pp.422-426
    • /
    • 2014
  • Depending on the acquisition of developmental competence, the expression of genes for ${\beta}$-1,3-glucan synthase and chitin synthase was affected in different ways by Aspergillus nidulans LAMMER kinase. LAMMER kinase deletion, ${\Delta}lkhA$, led to decrease in ${\beta}$-1,3-glucan, but increase in chitin content. The ${\Delta}lkhA$ strain was also resistant to nikkomycin Z.

Azole Resistance Caused by Increased Drug Efflux in Candida glabrata Isolated from the Urinary Tract of a Dog with Diabetes Mellitus

  • Kim, Minchul;Lee, Hyekyung;Hwang, Sun-Young;Lee, Inhyung;Jung, Won Hee
    • Mycobiology
    • /
    • v.45 no.4
    • /
    • pp.426-429
    • /
    • 2017
  • A yeast-like organism was isolated from a urine sample of a 6-year-old neutered male miniature poodle dog with urinary tract infection, diabetes ketoacidosis, and acute pancreatitis. We identified the yeast-like organism to be Candida glabrata and found that this fungus was highly resistant to azole antifungal drugs. To understand the mechanism of azole resistance in this isolate, the sequences and expression levels of the genes involved in drug resistance were analyzed. The results of our analysis showed that increased drug efflux, mediated by overexpression of ATP transporter genes CDR1 and PDH1, is the main cause of azole resistance of the C. glabrata isolated here.

Negative regulators in RANKL-induced osteoclastogenesis

  • Lee, Jun-Won;Kim, Kab-Sun;Kim, Nack-Sung
    • International Journal of Oral Biology
    • /
    • v.32 no.1
    • /
    • pp.1-5
    • /
    • 2007
  • Receptor activator of nuclear factor ${\kappa}B$ ligand (RANKL) induces osteoclast formation from hematopoietic cells via up-regulation of positive regulators, including $NF-{\kappa}B$, c-Fos, microphthalmia transcription factor (Mitf), PU.1, and nuclear factor of activated T cells (NFAT) c1. In addition to the positive regulation by these transcription factors, RANKL appears to regulate negative regulators such as MafB and inhibitors of differentiation (Ids). Ids and MafB are abundantly expressed in osteoclast precursors, bone marrowderived monocyte/macrophage lineage cells (BMMs). Expression levels of these genes are significantly reduced by RANKL during osteoclastogenesis. Overexpression of these genes in BMMs inhibits the formation of tartarate-resistant acid phosphatase (TRAP)-positive multinuclear osteoclasts by down-regulation of NFATc1 and osteoclast-associated receptor (OSCAR), which are important for osteoclast differentiation. Furthermore, reduced expression of these genes enhances osteoclastogenesis and increases expression of NFATc1 and OSCAR. Taken together, RANKL induces osteoclastogenesis via up-regulation of positive regulators as well as down-regulation of negative regulators.

Induced Mutant Animal Models for Studying the Genetics of Hypertension and Atherosclerosis

  • Oh, Goo-Taeg
    • Toxicological Research
    • /
    • v.17
    • /
    • pp.289-292
    • /
    • 2001
  • Gene targeting allows precise, predetermined changes to be made in a chosen gene in the mouse genome. To date, targeting has been used most often for generation of animals completely lacking the product of a gene of interest. Models of essential hypertension have been produced by mutated genes relating renin angiotensin system. The most significant contribution to understanding the genetic etiology of essential hypertension is probably the demonstration that discrete alterations in the expression of a variety of different genes can individually cause changes in the blood pressures of mice, even when the mice have all their compensatory mechanisms intact. These effects are readily detected in animals having moderate decreases in gene function due to heterozygosity for gene disruptions or modest increases due to gene duplication. As a species the mouse is highly resistant to atherosclerosis. However. through induced mutations it has been possible to develop lines oj mice that are deficient in apolipoprotein E, a ligand important in lipoprotein clearance, develop atherosclerotic lesions resembling those observed in humans. The atherosclerotic lesions in apoE-deficient mice have been well characterized, and they resemble human lesions in their sites of predilection and progression to the fibroproliferative stage. Other promising models are mice that are deficient in the low-density lipoprotein receptor. Considerable work still remains to be done in dissecting out in a rigorous manner the effects of alterations in single genes on the induction or progression of atherosclerosis and on the control of blood pressures. Perhaps even more exciting is the opportunity now becoming available to breed animals in which the effects oj precise differences in more than one gene can be studied in combination.

  • PDF

Identification and Characterization of Coronatine-Producing Pseudomonas syringae pv. actinidiae

  • Han, Hyo-Shim;Koh, Young-Jin;Hur, Jae-Seoun;Jung, Jae-Sung
    • Journal of Microbiology and Biotechnology
    • /
    • v.13 no.1
    • /
    • pp.110-118
    • /
    • 2003
  • Pseudomonas syringae pv. actinidiae strains, which cause canker disease in kiwifruit, were collected from kiwifruit orchards in Korea and identified using biochemical and physiological tests. The nucleotide sequences of the 16s rDNA and 16s-23s internally transcribed spacer of the isolates were found to be Identical to those of' the pathotype strain, Kwl 1, of P syringae pv. actinidiae. Remarkably, no coding sequence for phaseolotoxin biosynthesis or phaseolotoxin- resistant ornithine carbamoyltransferase was found by PCR amplification in any of the new Korean isolates of pseudomonas syringae pv. actinidiae, although this was clearly identified in the control pathotype Kwl 1 reference strain. In contrast, three primer sets derived from the coronatine biosynthetic gene cluster and DNA from the Korean strains yielded amplified DNA fragments of the expected size. A sequence analysis of the PCR products revealed that P. syringae pv. actinidiae and the Korean strains of pv. actinidiae contain coronafncate ligase genes (cfl)with identical sequences, whereas their. corR genes exhibited 91% sequence similarity. The production of coronatine, instead of phaseolotoxin, by the Korean strains of P. syringae pv. actinidiae was confirmed by a bioassay using reference pathovars known to produce coronatine and phaseolotoxin. The genes for coronatine biosynthesis in the Korean strains of P. syringae pv. actinidiae were found to be present on plasmids.