David C Rowley

David C Rowley
University of Rhode Island | URI · Department of Biomedical and Pharmaceutical Sciences

PhD Oceanography

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174
Publications
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2,116
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Publications

Publications (174)
Preprint
Infections caused by the bacterium Staphylococcus aureus continue to pose threats to human health and put a financial burden on the healthcare system. The overuse of antibiotics has contributed to mutations leading to the emergence of methicillin-resistant Staphylococcus aureus , and there is a critical need for the discovery and development of new...
Article
Full-text available
Myeloid-derived suppressor cells (MDSCs) promote immunosuppressive activities in the tumor microenvironment (TME), resulting in increased tumor burden and diminishing the anti-tumor response of immunotherapies. While primary and metastatic tumors are typically the focal points of therapeutic development, the immune cells of the TME are differential...
Article
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We report the draft genome sequence for Pseudoalteromonas sp. strain JC3, an isolate obtained from an aquaculture facility for whiteleg shrimp ( Litopenaeus vannamei ). The JC3 genome suggests multiple mechanisms for microbial interactions, including a type VI secretion system and potential for antibiotic production.
Preprint
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Vibrio coralliilyticus is an extracellular bacterial pathogen and a causative agent of vibriosis in larval oysters. Host mortality rates can quickly reach 100% during vibriosis outbreaks in oyster hatcheries. Type VI Secretion Systems (T6SS) are rapidly polymerizing, contact dependent injection apparatus for prey cell intoxication and play importan...
Article
Full-text available
The emergence of multi-drug resistant pathogenic bacteria represents a serious and growing threat to national healthcare systems. Most pressing is an immediate need for the development of novel antibacterial agents to treat Gram-negative multi-drug resistant infections, including the opportunistic, hospital-derived pathogen, Acinetobacter baumannii...
Article
Uropathogenic Escherichia coli (UPEC) is the leading cause of urinary tract infections (UTIs). During pathogenesis, UPEC cells adhere to and infiltrate bladder epithelial cells, where they may form intracellular bacterial communities (IBCs) or enter a nongrowing or slowly growing quiescent state. Here, we show in vitro that UPEC strains at low popu...
Article
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Ectoine is widely produced by various bacteria as a natural cell protectant against environment stress, e.g., osmotic and temperature stress. Its protective properties therefore exhibit high commercial value, especially in agriculture, medicine, cosmetics, and biotechnology. Here, we successfully constructed an engineered Escherichia coli for the h...
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Urinary tract infections (UTIs) caused by Escherichia coli create a large burden on healthcare and frequently lead to recurrent infections. Part of the success of E. coli as an uropathogenic bacterium can be attributed to its ability to form quiescent intracellular reservoirs in bladder cells and its persistence after antibiotic treatment. Cranberr...
Preprint
Full-text available
The layer of peptidoglycan surrounding bacteria provides structural integrity for the bacterial cell wall. Many organisms, including human cells and diverse bacteria, detect peptidoglycan fragments that are released as bacteria grow. Uropathogenic Escherichia coli (UPEC) strains are the leading cause of human urinary tract infections (UTIs) and man...
Article
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Quorum sensing (QS) antagonists have been proposed as novel therapeutic agents to combat bacterial infections. We previously reported that the secondary metabolite 3-methyl-N-(2′-phenylethyl)-butyramide, produced by a marine bacterium identified as Halobacillus salinus, inhibits QS controlled phenotypes in multiple Gram-negative reporter strains. H...
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Larval oysters in hatcheries are susceptible to diseases caused by bacterial pathogens, including Vibrio spp. Previous studies have shown that daily addition of the probiotic Bacillus pumilus RI06-95 to water in rearing tanks increases larval survival when challenged with the pathogen Vibrio coralliilyticus. We propose that the presence of probioti...
Article
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Thalassobius sp. I31.1 is a putative pathogen involved in epizootic shell disease in the American lobster ( Homarus americanus ). We report here the draft genome sequence for Thalassobius sp. I31.1 and provide insight into its metabolism and links to environmental pollutant degradation.
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Probiotics represent a promising alternative strategy to control infection and disease caused by marine pathogens of aquaculturally important species. Generally, the beneficial effects of probiotics include improved water quality, control of pathogenic bacteria and their virulence, stimulation of the immune system, and improved animal growth. Previ...
Chapter
Marine pathogenic bacteria and toxic phytoplankton species have significant impacts on coastal communities. Acute exposure to these deleterious microbes can result in outbreaks of communicable diseases, for example, cholerae, and poisonings through exposure to toxins. Interactions between phytoplankton and bacteria may influence phytoplankton bloom...
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Marine actinobacteria continue to be a rich source for the discovery of structurally diverse secondary metabolites. Here we present a new hydroxymate siderophore produced by Amycolatopsis albispora, a recently described species of this less explored actinomycete genus. Strain WP1T was isolated from sediments collected at -2945 m in the Indian Ocean...
Article
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Loktanella maritima strain YPC211 was isolated from the American lobster ( Homarus americanus ). We report here the draft genome sequence for L. maritima YPC211 and identify genes of potential importance to its role within the microbial community.
Article
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Aquimarina sp. strain I32.4 (formerly Aquimarina sp. ‘ homaria ’) is a putative pathogen involved in epizootic shell disease in the American lobster ( Homarus americanus ). We report here the draft genome sequence for Aquimarina sp. strain I32.4 and describe virulence factors that may provide insight into its mechanism of pathogenicity.
Article
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Bowmanella denitrificans strain JL63 was isolated from a whiteleg shrimp (Litopenaeus vannamei) and was determined to have antibacterial activity against an acute hepatopancreatic necrosis disease (AHPND) strain ofVibrio parahaemolyticusHere, we report the draft genome sequence of this strain and identify genes that are potentially involved in its...
Article
Commensal bifidobacteria colonize the human gastrointestinal tract and catabolize glycans that are impervious to host digestion. Accordingly, Bifidobacterium longum typically secretes acetate and lactate as fermentative end products. This study tested the hypothesis that B. longum utilizes cranberry-derived xyloglucans in a strain-dependent manner....
Article
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Oxidative stress and free radical generation accelerate the formation of advanced glycation endproducts (AGEs) which are linked to several chronic diseases. Published data suggest that phenolic-rich plant foods, show promise as natural anti-AGEs agents due to their anti-oxidation capacities. A phenolic-enriched maple syrup extract (MSX) has previou...
Article
Maple syrup is a widely consumed plant-derived natural sweetener produced by concentrating xylem sap collected from certain maple (Acer) species. During thermal evaporation of water, natural phytochemical components are concentrated in maple syrup. The polymeric components from maple syrup were isolated by ethanol precipitation, dialysis, and anion...
Article
Bacterial pathogens are a major cause of mortality in bivalve hatcheries, and outbreaks can result in shortages of seed supply to the grow-out industry. The use of probiotic bacteria is a potential preventative measure to limit the impact of bacterial diseases. Previous research showed that the marine bacteria Phaeobacter inhibens S4 (S4) and Bacil...
Article
Hatcheries providing seed for bivalve mollusc aquaculture can suffer from disease outbreaks resulting in high losses of larvae. Previous research demonstrated the effectiveness of candidate probiotics Phaeobacter inhibens S4 (S4) and Bacillus pumilus RI06-95 (RI) in protecting the larvae of eastern oysters Crassostrea virginica, against bacterial c...
Article
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BACKGROUND: The formation and accumulation of advanced glycation end-products (AGEs) are implicated in several chronic human illnesses including type-2 diabetes, renal failure, and neurodegenerative diseases. The cranberry (Vaccinium macrocarpon) fruit has been previously reported to show anti-AGEs effects, attributed primarily to its phenolic cons...
Article
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Aliiroseovarius crassostreae CV919-312 is a marine alphaproteobacterium and the causative agent of Roseovarius oyster disease. We announce here the draft genome sequence of A. crassostreae CV919-312 and identify potential virulence genes involved in pathogenicity.
Article
Rhizoleucinoside (1), a unique rhamnolipid-amino alcohol hybrid, was isolated from the rhizobial symbiont bacterium Bradyrhizobium sp. BTAi1. Compound 1 features a rare rhamnolipid core attached to an unprecedented leucinol moiety. Its structure and absolute configuration were determined by spectroscopic analysis, tandem mass spectrometry, chemical...
Article
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Interactions between phytoplankton and bacteria play a central role in mediating biogeochemical cycling and food web structure in the ocean. However, deciphering the chemical drivers of these interspecies interactions remains challenging. Here we report the isolation of 2-heptyl-4-quinolone (HHQ), released by Pseudoalteromonas piscicida, a marine g...
Data
Flow chart detailing the bioassay guided fractionation process that was used to eventually identify HHQ as a causative compound influencing growth of E. huxleyi.
Data
Growth rate (μ d-1) for three species of phytoplankton exposed to the crude extract of the secreted metabolites of P. piscicida. Despite HHQ having little effect on D. tertiolecta and P. tricornutum, toxicity to the crude extract of P. piscicida is observed in all species, indicating that P. piscicida likely produces additional compounds that resul...
Data
Structural identification of 2-heptyl-4-quinolone (HHQ) from P. piscicida. 13C-NMR spectrum (75 MHz, DMSO-d6) of the pure compound isolated from P. piscicida (blue) and the authentic standard HHQ (red).
Data
Genome mining of pqs operon in Pseudoalteromonas sp. (A) The pqs operon from two species of Pseudomonas aeruginosa PAO1 were used to query 67 publically available Pseudoalteromonas sp. genomes. Joint Genome Institute (JGI) genome accession numbers are listed for each isolate in parentheses. Red boxes indicate the presence of a homolog and black box...
Article
Thalassotalic acids A-C and thalassotalamides A and B are new N-acyl dehydrotyrosine derivatives produced by Thalassotalea sp. PP2-459, a Gram-negative bacterium isolated from a marine bivalve aquaculture facility. The structures were elucidated via a combination of spectroscopic analyses emphasizing two-dimensional NMR and high-resolution mass spe...
Article
Full-text available
In the present study, it is shown that although Escherichia coli CFT073, a human uropathogenic (UPEC) strain, grows in liquid glucose M9 minimal medium, it fails to grow on glucose M9 minimal medium agar plates seeded with ≤1⁰6 CFU. The cells on glucose plates appear to be in a "quiescent" state that can be prevented by various combinations of lysi...
Article
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The probiotic bacterium Phaeobacter inhibens strain S4Sm, isolated from the inner shell surface of a healthy oyster, secretes the antibiotic tropodithietic acid (TDA), is an excellent biofilm former, and increases oyster larvae survival when challenged with bacterial pathogens. In this study, we investigated the specific roles of TDA secretion and...
Article
Full-text available
Vibrio coralliilyticus RE22 is a causative agent of vibriosis in larval bivalves. We report here the draft genome sequence of V. coralliilyticus RE22 and describe additional virulence factors that may provide insight into its mechanism of pathogenicity.
Article
Full-text available
Bacillus pumilus RI06-95 is a marine bacterium isolated in Narragansett, Rhode Island, which has shown probiotic activity against marine pathogens in larval shellfish. We report the genome of B. pumilus RI06-95, which provides insight into the microbe's probiotic ability and may be used in future studies of the probiotic mechanism. Copyright © 2015...
Conference Paper
Marine mollusks are filter feeders and thus are continuously exposed to a myriad of microorganisms. While the majority of bacteria likely have no effect on the overall health of the animal, some microbes, including members of the bacteria genus Vibrio, can cause infections that lead to rapid mortality, especially in larval and juvenile bivalves. Fo...
Article
Full-text available
Members of the resistance nodulation cell division (RND) of efflux pumps play essential roles in multidrug resistance (MDR) in Gram-negative bacteria. Here, we describe the search for new small molecules from marine microbial extracts to block efflux and thus restore antibiotic susceptibility in MDR bacterial strains. We report the isolation of 3,4...
Article
Multidrug resistant pathogens have become a major public health concern. There is a great need for the development of novel antibiotics with alternative mechanisms of action for the treatment of life-threatening bacterial infections. Antimicrobial peptides (AMPs), a major class of antibacterial agents, share amphiphilicity and cationic structural p...
Article
Full-text available
Although human exposure to Gram-negative Vibrio vulnificus (V. vulnificus) lipopolysaccharide (LPS) has been reported to result in septic shock, its impact on the central nervous system's innate immunity remains undetermined. The purpose of this study was to determine whether V. vulnificus MO6-24/O LPS might activate rat microglia in vitro and stim...
Article
Several groups of structurally-related compounds, comprised of either five or six-membered ring structures with attached lipophilic carbon chains and in some cases possessing halogen atoms, have been isolated from various marine algae and filamentous cyanobacteria. The related compounds considered in the present work include the coibacins, laurenci...
Article
Full-text available
Bacterial pathogens, including several Vibrio spp. and Roseovarius crassostreae, cause severe mortality of larval and juvenile eastern oysters. The introduction of beneficial bacterial isolates in oyster hatcheries and nurseries for the biocontrol of bacterial diseases is a good alternative to the use of antibiotics. The goal of this study was to s...
Article
Full-text available
Vibrio cholerae is a human pathogenic marine bacterium inhabiting coastal regions and is vectored into human food and water supplies via attachment to particles including detritus, phytoplankton, and zooplankton. Particle colonization by the pathogen is inhibited by an antagonistic interaction with the particle-associated Vibrionales bacterium SWAT...
Article
Sediment samples collected off the coast of San Diego were analyzed for actinomycete diversity using culture independent techniques. Eight new operational taxonomic units (OTUs) in the Streptomycetaceae were identified as well as new diversity within previously cultured marine OTUs. Sequences belonging to the marine actinomycete genus Salinispora w...
Article
Biofilm producing bacteria such as Staphylococcus species and Escherichia coli are the most common cause of catheter related urinary tract infections (UTIs). The American cranberry (Vaccinium macrocarpon) is utilized widely as a prophylaxis for UTIs due to its prevention of microbial adhesion. Cranberry contains proanthocyanidins (PACs), which have...
Article
Full-text available
Entamoeba histolytica infects 50 million people per year, causing 100,000 deaths worldwide. The primary treatment for amoebiasis is metronidazole. However, increased pathogen resistance combined with the drug's toxic side effects encourages a search for alternative therapeutic agents. Secondary metabolites from marine bacteria are a promising resou...
Article
Biofilm embedded bacterial pathogens such as Staphylococcus spp., Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii are difficult to eradicate and are major sources of bacterial infections. New drugs are needed to combat these pathogens. Hypericum is a plant genus that contains species known to have antimicrobial properties. How...
Article
Honaucins A-C were isolated from the cyanobacterium Leptolyngbya crossbyana which was found overgrowing corals on the Hawaiian coast. Honaucin A consists of (S)-3-hydroxy-γ-butyrolactone and 4-chlorocrotonic acid, which are connected via an ester linkage. Honaucin A and its two natural analogs exhibit potent inhibition of both bioluminescence, a qu...
Article
Inhibitors of bacterial quorum sensing have been proposed as potentially novel therapeutics for the treatment of certain bacterial diseases. We recently reported a marine Halobacillus salinus isolate that secretes secondary metabolites capable of quenching quorum sensing phenotypes in several Gram-negative reporter strains. To investigate how wides...
Article
Three acylphloroglucinol derivatives have been isolated from the hexane and acetone extracts of the aerial parts of Hypericum densiflorum Pursch. The compounds were characterized by NMR spectroscopy and mass spectrometry and identified as 4-geranyloxy-2,6-dihydroxybenzophenone (1), 4-geranyloxy-1-(2-methylpropanoyl)- phloroglucinol (2) and 4-gerany...