The widespread and common use of antibiotics to treat many infectious diseases has allowed for the selection and continual emergence of multiple-drug resistant pathogens. There is an urgent need for the development of novel antibiotics to target these infections. This research project will focus on finding novel therapies to treat methicillin-resistant Staphylococcus aureus (MRSA). Previous work by William Fenical and Paul Jensen at Scripps Institution of Oceanography showed deep ocean sediments contain actinomycetes that produce a rich and diverse array of natural products. Two new classes of compounds with novel structures, the marinopyrroles and napyradiomycins, have been identified from marine actinomycete bacteria. These compounds exhibit promising preliminary data, showing potent antibiotic activities against drug-resistant MRSA. The overall goal of this project is evaluate the pharmacological and therapeutic potential of these two novel classes of antibiotics in treating infections caused by drug-resistant MRSA. We will investigate and evaluate the marinopyrrole and napyradiomycin classes of compounds as detailed in three specific aims, creating interdisciplinary links between infectious disease microbiology, marine natural product chemistry and pharmacology.
The first aim i s to assess the antimicrobial properties of the marinopyrroles and napyradiomycins isolated from marine actinomycetes by measuring in vitro activity, capacity for resistance development, and synergistic activities with known antibiotics.
The second aim i s to determine the pharmacological characteristics of these novel classes of compounds by testing their in vitro bactericidal activity, post-antibiotic effect and cytotoxic effects. We will study the in vivo pharmacokinetic and pharmacodynamic profiles of the candidate antibiotics in a mouse model.
The third aim i s to define the mechanisms of action of the marinopyrrole and napyradiomycin classes of antibiotics by evaluating bacterial cell wall integrity and using radiolabeled precursors to measure changes in bacterial DNA, RNA and protein syntheses. We will collaborate with other laboratories to employ methods such as mass-spectrometry and structure-activity relationship studies to further understand mechanism of action.
The widespread emergence and increasing prevalence of infections caused by multiple drug-resistant microorganisms, such as methicillin-resistant Staphylococcus aureus (MRSA), is a distinct medical concern. An urgent need exists for the discovery of novel antibiotics to treat these infections. The goal of this project is to discover and develop new antibiotics derived from marine- natural products to target drug-resistant MRSA and address this public health crisis.
|Pence, Morgan A; Haste, Nina M; Meharena, Hiruy S et al. (2015) Beta-Lactamase Repressor BlaI Modulates Staphylococcus aureus Cathelicidin Antimicrobial Peptide Resistance and Virulence. PLoS One 10:e0136605|
|Hensler, Mary E; Jang, Kyoung Hwa; Thienphrapa, Wdee et al. (2014) Anthracimycin activity against contemporary methicillin-resistant Staphylococcus aureus. J Antibiot (Tokyo) 67:549-53|
|Liu, Yan; Haste, Nina M; Thienphrapa, Wdee et al. (2014) Marinopyrrole derivatives as potential antibiotic agents against methicillin-resistant Staphylococcus aureus (III). Mar Drugs 12:2458-70|
|Haste, Nina M; Thienphrapa, Wdee; Tran, Dan N et al. (2012) Activity of the thiopeptide antibiotic nosiheptide against contemporary strains of methicillin-resistant Staphylococcus aureus. J Antibiot (Tokyo) 65:593-8|
|Liu, Yan; Haste, Nina M; Thienphrapa, Wdee et al. (2012) Marinopyrrole derivatives as potential antibiotic agents against methicillin-resistant Staphylococcus aureus (I). Mar Drugs 10:953-62|
|Haste, Nina M; Talabani, Hana; Doo, Alex et al. (2012) Exploring the Plasmodium falciparum cyclic-adenosine monophosphate (cAMP)-dependent protein kinase (PfPKA) as a therapeutic target. Microbes Infect 14:838-50|
|Haste, Nina M; Hughes, Chambers C; Tran, Dan N et al. (2011) Pharmacological properties of the marine natural product marinopyrrole A against methicillin-resistant Staphylococcus aureus. Antimicrob Agents Chemother 55:3305-12|
|Haste, Nina M; Farnaes, Lauge; Perera, Varahenage R et al. (2011) Bactericidal kinetics of marine-derived napyradiomycins against contemporary methicillin-resistant Staphylococcus aureus. Mar Drugs 9:680-9|
|Gonzalez, David J; Haste, Nina M; Hollands, Andrew et al. (2011) Microbial competition between Bacillus subtilis and Staphylococcus aureus monitored by imaging mass spectrometry. Microbiology 157:2485-92|
|Liu, Wei-Ting; Yang, Yu-Liang; Xu, Yuquan et al. (2010) Imaging mass spectrometry of intraspecies metabolic exchange revealed the cannibalistic factors of Bacillus subtilis. Proc Natl Acad Sci U S A 107:16286-90|
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