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Faculty

Dong H. Kwon

Associate Professor of Biology

Post-Doc, Baylor College of Medicine Ph.D., Georgia State University

Description

My research interests have centered in pharmaceutical biotechnology focusing on the molecular details of drug susceptibility/resistance mechanisms, finding new drug targets (or a new drug), and novel strategies to treat drug resistant (and susceptible) bacterial human pathogens. My researches have been supported by National Institutes of Health (NIH).

I have been studying one of human pathogens Helicobacter pylori (H. pylori), which is a Gram-negative bacterium infecting more than 50% of the human population. H. pylori infection is etiologically associated with peptic ulcer disease, gastric lymphoma, and gastric cancer. Cure of the infection cures peptic ulcer disease and if done early in the course of the infection will prevent development of the H. pylori-related diseases including gastric cancer. While H. pylori is susceptible to most common antibiotics in vitro, clinically cure of the infection has proven difficult. Current H. pylori eradication therapies consist of combinations of two or more antibiotics including amoxicillin, clarithromycin, metronidazole, or tetracycline and antisecretory drugs. Overall, the cure rate in clinical practice has been in the range of 60 to 80%. Failure of treatment is most frequently due to the presence of antibiotic resistant H. pylori, and acquired-resistance to amoxicillin, clarithromycin, metronidazole, and tetracycline.

Initial studies were focused on the resistance mechanisms in relation to amoxicillin, clarithromycin, metronidazole, and tetracycline. My work was devoted to understanding the molecular details of resistance to these antibiotics. The molecular bases of resistance to these antibiotics relate to chromosomal mutations on the antibiotic-target genes, (e.g., a gene encoding penicillin-binding protein [pbp-1A] for amoxicillin, genes encoding 23S rRNA for clarithromycin, genes encoding 16S rRNA for tetracycline, and inactivation of a gene encoding metronidazole nitroreductase [rdxA] for metronidazole). My studies have moved on finding new drug targets (or a new drug) and a novel strategy to treat the drug resistant (or susceptible) pathogens, in addition to H. pylori, including Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa, which cause a variety of hospital-acquired human diseases.

Specialties

Molecular Genetics of Microorganisms; Antimicrobial Susceptibility/Resistance; Biochemistry

Publications

Co-author, “R-Plasmids in Staphylococcus aureus,” published in J Microbiol

Co-author, “Studies on antibiotics resistance gene in Staphylococcus aureus plasmid: cloning of chloramphenicol resistance determinant,” published in J Microbiol

Co-author, “Cloning of ori region of R-plasmid pSBK203 and construction of new shuttle-vector for E. coli and B. subtilis using cloned fragments,” published in J Microbiol

Co-author, “Nucleotide Sequence and Inducibility Analysis of Chloramphenicol Acetyltransferase Gene from Staphylococcus aureus R-plasmid pSBK203,” published in J Microbiol

Co-author, “Nucleotide sequence and properties of Macrolide-Lincosamide-Streptogramin B resistance gene from Staphylococcus aureus DH1,” published in J Microbiol

Co-author, “Cloning and base sequence determination of replication initiation gene (rep) isolated from Staphylococcus aureus DH1 R-plasmid pSBK203,” published in J Microbiol

Co-author, “Structure and regulation of the carAB operon in Pseudomonas aeruginosa and Pseudomonas stutzeri: no untranslated region exists,” published in J Bacteriol

Co-author, “Identification of greA encoding a transcriptional elongation factor as a member of the carA-orf-carB-greA operon in Pseudomonas aeruginosa PAO1,” published in J Bacteriol

Co-author, “Demonstration of unexpected antibiotic resistance of genotypically identical Helicobacter pylori isolates,” published in Clin Infect Dis

Co-author, “The effect of galE gene inactivation on lipopolysaccharide profile of Helicobacter pylori,” published in Curr Microbiol

Co-author, “REP-PCR fragments as biomarkers for differentiating gastroduodenal disease-specific Helicobacter pylori strains,” published in Dig Dis Sci

Co-author, “Isolation and characterization of tetracycline-resistant clinical isolates of Helicobacter pylori,” published in Antimicrob Agents Chemother

Co-author, “Frameshift mutations in rdxA and metronidazole resistance in North American Helicobacter pylori isolates,” published in J Antimicrob Chemother

Co-author, “A M(r) 34,000 proinflammatory outer membrane protein (oipA) of Helicobacter pylori,” published in Proc Natl Acad Sci USA

Co-author, “Quantitative RT-PCR analysis of multiple genes encoding putative metronidazole nitroreductases from Helicobacter pylori,” published in Int J Antimicrob Agents

Co-author, “Regional differences in metronidazole resistance and increasing clarithromycin resistance among Helicobacter pylori isolates from Japan,” published in Antimicrob Agents Chemother

Co-author, “Analysis of rdxA and involvement of additional genes encoding NAD(P)H flavin oxidoreductase (FrxA) and ferredoxin-like protein (FdxB) in metronidazole resistance of Helicobacter pylori,” published in Antimicrob Agents Chemother

Co-author, “Metronidazole containing quadruple therapy for infection with metronidazole resistant Helicobacter pylori: a prospective study,” published in Aliment Pharmacol Ther

Co-author, “Frame-shift mutations in NAD(P)H flavin oxidoreductase encoding gene (frxA) from metronidazole resistant Helicobacter pylori ATCC43504 and its involvement in metronidazole resistance,” published in FEMS Microbiol Letter

Co-author, “Analysis of metronidazole, clarithromycin and tetracycline resistance of Helicobacter pylori isolates from Korea,” published in J Antimicrob Chemother

Co-author, Stable amoxicillin resistance in Helicobacter pylori.  Helicobacter. 2001;6:79

Co-author, “Nitrofurantoin quadruple therapy for Helicobacter pylori infection: effect of metronidazole resistance,” published in Aliment Pharmacol Ther

Co-author, “Furazolidone- and nitrofurantoin-resistant Helicobacter pylori: prevalence and role of genes involved in metronidazole resistance,” published in Antimicrob Agents Chemother

Co-author, “DNA sequence analysis of rdxA and frxA from 12 pairs of metronidazole-sensitive and -resistant clinical Helicobacter pylori isolates,” published in Antimicrob Agents Chemother

Co-author, “Mixed-infection of antibiotic susceptible and resistant Helicobacter pylori isolates in a single patient and underestimation of antimicrobial susceptibility testing,” published in Helicobacter

Co-author, “Studies of High-Level b-Lactam Antibiotic Resistance Associated with Acquired Multidrug Resistance in Helicobacter pylori,” published in Antimicrob Agents Chemother

Co-author, “The arginine regulatory protein mediates repression by arginine of the operons encoding glutamate synthase and anabolic glutamate dehydrogenase in Pseudomonas aeruginosa,” published in J Bacteriol

Co-author, “Tetracycline-resistant clinical Helicobacter pylori isolates with and without mutations in 16S rRNA-encoding genes,” published in Antimicrob Agents Chemother

Co-author, “In vitro induction of resistance to metronidazole, and analysis of mutations in rdxA and frxA genes from Helicobacter pylori isolates,” published in J Infect Chemother

Co-author, “Isogenic Variation of Helicobacter pylori Strain Resulting in Heteroresistant Antibacterial Phenotypes in a Single Host In Vivo,” published in Helicobacter

Co-author, “Polyamines induce resistance to cationic peptide, aminoglycoside, and quinolone antibiotics in Pseudomonas aeruginosa PAO1,” published in Antimicrob Agents Chemother

Co-author, “Polyamines increase antibiotic susceptibility in Pseudomonas aeruginosa,” published in Antimicrob Agents Chemother

Co-author, “Polyamine effects on antibiotic susceptibility in bacteria,” published in Antimicrob Agents Chemother

Co-author, “Transcriptome Analysis of Agmatine and Putrescine Catabolism in Pseudomonas aeruginosa PAO1,” published in J Bacteriol

Co-author, “Fur-independent induction of Helicobacter pylori flavodoxin-encoding gene (fldA) under iron starvation,” published in Helicobacter

Co-author, “A Single Amino Acid Substitution in PmrB Is Associated with Polymyxin B Resistance in Clinical Isolate of Pseudomonas aeruginosa,” published in FEMS Microbial Letters

Co-author, “Alterations in Two-Component Regulatory Systems of phoPQ and pmrAB Are Associated with Polymyxin B Resistance in Clinical Isolates of Pseudomonas aeruginosa,” published in Antimicrobial Agents and Chemotherapy

Co-author,  “Co-Existence of Multidrug-Resistant and -Susceptible Strains of Pseudomonas aeruginosa from a Single Clinical Isolate,” published in Current Microbiology

Co-author, “Surface Modification of Poly(amidoamine) (PAMAM) Dendrimer as Antimicrobial Agents,” published in Tetrahedron Letters

Co-author, “Differential Role of Two-Component Regulatory Systems (phoPQ and pmrAB) in Polymyxin B Susceptibility of Pseudomonas aeruginosa,” published in Advances in Microbiology

Co-author, “Carbapenem-associated multidrug-resistant Acinetobacter baumannii are sensitized by aztreonam in combination with polyamines,” published in International Journal of Antimicrobial Agents

Co-author, “Homeostasis of Glutathione Is Associated with Polyamine-Mediated beta-Lactam Susceptibility in Acinetobacter baumannii ATCC 19606,” published in Antimicrobial Agents and Chemotherapy

Co-author, “Promoter Deletions of Klebsiella pneumoniae Carbapenemase (KPC)-Encoding Genes (blaKPC-2) and Efflux Pump (AcrAB) on b-Lactam Susceptibility in KPC-Producing Enterobacteriaceae,” published in FEMS Microbiology Letters

     

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