The uncontrolled use of large amounts of antibiotics for human and animal therapy has resulted in the selection of pathogenic bacteria resistant to almost all commercially available antibiotics and this problem requires new agents or strategies active against the multidrug resistant (MDR) pathogenic bacteria. Currently, the most problematic MDR Gram-negative pathogens associated healthcare-infections and nosocomial outbreaks are Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii. PI discovered that exogenous polyamines (spermine, spermidine, and putrescine) in combination with 2-lactams sensitized 2- lactam resistance (become 4- to 64-fold sensitive) but in combination with polymyxin B induced resistance to polymyxin B (become 4- to 8-fold resistant) in P. aeruginosa. Molecular mechanism for the polyamine effect on 2-lactam and polymyxin B was unknown. Polyamines are positively charged compounds synthesized in all living organisms. Intracellular concentration of polyamines is strictly regulated by biosynthesis, degradation, and transport. The role of polyamines is primarily for cellular growth, but a variety of other roles has been reported in bacteria. The principal investigator hypothesizes that 1) exogenous polyamines alter the polyamine homeostasis in cells;2) this alteration induces a cellular response to maintain intracellular concentration of polyamines, and 3) the cellular response includes the polyamine effect on 2-lactam and polymyxin B susceptibility. To test the hypothesis following specific aims are proposed:
Specific Aim 1 : Elucidate the polyamine effect on 2-lactam and polymyxin B susceptibility in MDR clinical isolates of P. aeruginosa, K. pneumoniae, and A. baumannii. Standard methods of minimal inhibitory concentration, time-killing, and checkerboard assays will be employed to elucidate the polyamine effect on 2-lactam and polymyxin B susceptibility for MDR clinical isolates of P. aeruginosa, K. pneumoniae, and A. baumannii.
Specific Aim 2 : Determine role of polyamine uptake systems and intracellular polyamine concentration in the polyamine effect on 2-lactam and polymyxin B susceptibility. Mutant P. aeruginosa PAO1 lacking polyamine uptake and biosynthesis will be produced by deletion of two major polyamine uptake systems (potABCD/spuABCDEFGH) and the genes for polyamine biosynthesis (speA/speC) employing gene- replacement techniques. These strains will be used to determine role of polyamine uptake and intracellular polyamine concentration in the polyamine effect on 2-lactam and polymyxin B susceptibility. Long-term goal of this study is to understand molecular details of the polyamine effect on 2-lactam and polymyxin B susceptibility in bacterial pathogens, which will provide the basis for designing a new therapeutic agent or strategy to treat MDR infections.

Public Health Relevance

Infectious diseases caused by multidrug resistant (MDR) pathogens are major public health problems since the limited therapeutic options to combat them. Polyamines have been known as sensitizing 2- lactam resistant pathogens. This study is to elucidate the applicability of the polyamines to treat the MDR pathogens using currently existing 2-lactam antibiotics and to identify genetic determinant associated with the polyamine effect.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Continuance Award (SC3)
Project #
5SC3GM094053-03
Application #
8327204
Study Section
Special Emphasis Panel (ZGM1-MBRS-X (GC))
Program Officer
Krasnewich, Donna M
Project Start
2010-09-01
Project End
2014-08-31
Budget Start
2012-09-01
Budget End
2013-08-31
Support Year
3
Fiscal Year
2012
Total Cost
$84,985
Indirect Cost
$10,735
Name
Long Island University Brooklyn Campus
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
618059232
City
Greenvale
State
NY
Country
United States
Zip Code
11548
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Seecoomar, Gomattie D; Marmol, Brenda C; Kwon, Dong H (2013) Promoter deletions of Klebsiella pneumoniae carbapenemase (KPC)-encoding genes (blaKPC -2) and efflux pump (AcrAB) on *-lactam susceptibility in KPC-producing Enterobacteriaceae. FEMS Microbiol Lett 348:120-6
Binh, Tran Thanh; Suzuki, Rumiko; Shiota, Seiji et al. (2013) Complete Genome Sequences of Helicobacter pylori Clarithromycin-Resistant Strains. Genome Announc 1:
Malone, Louis; Kwon, Dong H (2013) Carbapenem-associated multidrug-resistant Acinetobacter baumannii are sensitised by aztreonam in combination with polyamines. Int J Antimicrob Agents 41:70-4
Kwon, Dong H; Hekmaty, Saboor; Seecoomar, Gomattie (2013) Homeostasis of glutathione is associated with polyamine-mediated β-lactam susceptibility in Acinetobacter baumannii ATCC 19606. Antimicrob Agents Chemother 57:5457-61
Charles, Shakira; Vasanthan, Nadarajah; Kwon, Dong et al. (2012) Surface Modification of Poly(amidoamine) (PAMAM) Dendrimer as Antimicrobial Agents. Tetrahedron Lett 53:6670-6675
Owusu-Anim, Daniel; Kwon, Dong H (2012) Differential Role of Two-Component Regulatory Systems (phoPQ and pmrAB) in Polymyxin B Susceptibility of Pseudomonas aeruginosa. Adv Microbiol 2: