- ItemGenome mining and characterisation of a novel transaminase with remote stereoselectivity(Springer Nature Switzerland AG, 2019-12-30) Gavin, Declan P.; Reen, F. Jerry; Rocha-Martin, J.; Abreu-Castilla, I.; Woods, David F.; Foley, Aoife M.; Sanchez-Murcia, P. A.; Schwarz, Maria; O'Neill, P.; Maguire, Anita R.; O'Gara, Fergal; Enterprise Ireland; Health Research Board; Irish Thoracic Society; European Commission; Science Foundation Ireland; Irish Research Council for Science, Engineering and Technology; Cystic Fibrosis Foundation; Austrian Science FundMicrobial enzymes from pristine niches can potentially deliver disruptive opportunities in synthetic routes to Active Pharmaceutical Ingredients and intermediates in the Pharmaceutical Industry. Advances in green chemistry technologies and the importance of stereochemical control, further underscores the application of enzyme-based solutions in chemical synthesis. The rich tapestry of microbial diversity in the oceanic ecosystem encodes a capacity for novel biotransformations arising from the chemical complexity of this largely unexplored bioactive reservoir. Here we report a novel omega-transaminase discovered in a marine sponge Pseudovibrio sp. isolate. Remote stereoselection using a transaminase has been demonstrated for the first time using this novel protein. Application to the resolution of an intermediate in the synthesis of sertraline highlights the synthetic potential of this novel biocatalyst discovered through genomic mining. Integrated chemico-genomics revealed a unique substrate profile, while molecular modelling provided structural insights into this 'first in class' selectivity at a remote chiral centre.
- ItemIs there potential for repurposing statins as novel antimicrobials?(American Society for Microbiology, 2016-08-22) Hennessy, Emma; Adams, Claire; Reen, F. Jerry; O'Gara, Fergal; Science Foundation Ireland; Seventh Framework Programme; Health Research Board; Department of Agriculture, Food and the Marine; Food Institutional Research MeasureStatins are members of a class of pharmaceutical widely used to reduce high levels of serum cholesterol. In addition, statins have so-called "pleiotropic effects," which include inflammation reduction, immunomodulation, and antimicrobial effects. An increasing number of studies are emerging which detail the attenuation of bacterial growth and in vitro and in vivo virulence by statin treatment. In this review, we describe the current information available concerning the effects of statins on bacterial infections and provide insight regarding the potential use of these compounds as antimicrobial therapeutic agents.
- ItemSynthesis and electrochemical detection of a thiazolyl-indole natural product isolated from the nosocomial pathogen Pseudomonas aeruginosa(Springer, 2016-09) Buzid, Alyah; Muimhneacháin, Eoin Ó; Reen, F. Jerry; Hayes, Phyllis E.; Pardo, Leticia M.; Shang, Fengjun; O'Gara, Fergal; Sperry, Jonathan; Luong, John H. T.; Glennon, Jeremy D.; McGlacken, Gerard P.; Science Foundation Ireland; Enterprise Ireland; European Commission; Department of Agriculture, Food and the Marine; Irish Research Council for Science, Engineering and Technology; Health Research Board; Irish Thoracic Society, Ireland; Marine Institute; Teagasc; University College CorkPseudomonas aeruginosa is a Gram-negative opportunistic pathogen, capable of surviving in a broad range of natural environments and quickly acquiring resistance. It is associated with hospital-acquired infections, particularly in patients with compromised immunity, and is the primary cause of morbidity and mortality in cystic fibrosis (CF) patients. P. aeruginosa is also of nosocomial importance on dairy farms and veterinary hospitals, where it is a key morbidity factor in bovine mastitis. P. aeruginosa uses a cell-cell communication system consisting of signalling molecules to coordinate bacterial secondary metabolites, biofilm formation, and virulence. Simple and sensitive methods for the detection of biomolecules as indicators of P. aeruginosa infection would be of great clinical importance. Here, we report the synthesis of the P. aeruginosa natural product, barakacin, which was recently isolated from the bovine ruminal strain ZIO. A simple and sensitive electrochemical method was used for barakacin detection using a boron-doped diamond (BDD) and glassy carbon (GC) electrodes, based on cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The influence of electrolyte pH on the peak potential and peak currents was also investigated. At pH 2.0, the peak current was linearly dependent on barakacin concentration (in the range used, 1-10 mu M), with correlation coefficients greater than 0.98 on both electrodes. The detection limit (S/N = 3) on the BDD electrode was 100-fold lower than that obtained on the GC electrode. The optimized method using the BDD electrode was extended to bovine (cow feces) and human (sputum of a CF patient) samples. Spiked barakacin was easily detected in these matrices at a limit of 0.5 and 0.05 mu M, respectively.
- ItemDissecting the regulation of bile-induced biofilm formation in Staphylococcus aureus(Microbiology Society, 2016-08-01) Ulluwishewa, Dulantha; Wang, Liang; Pereira, Callen; Flynn, Stephanie; Cain, Elizabeth; Stick, Stephen; Reen, F. Jerry; Ramsay, Joshua P.; O'Gara, Fergal; Curtin University, Australia; Seventh Framework Programme; Horizon 2020; Science Foundation Ireland; Department of Agriculture, Food and the Marine; Food Institutional Research Measure; Health Research Board; Irish Thoracic Society; Marine Institute; TeagascAspiration of bile into the cystic fibrosis (CF) lung has emerged as a prognostic factor for reduced microbial lung biodiversity and the establishment of often fatal, chronic pathogen infections. Staphylococcus aureus is one of the earliest pathogens detected in the lungs of children with CF, and once established as a chronic infection, strategies for its eradication become limited. Several lung pathogens are stimulated to produce biofilms in vitro in the presence of bile. In this study, we further investigated the effects of bile on S. aureus biofilm formation. Most clinical S. aureus strains and the laboratory strain RN4220 were stimulated to form biofilms with sub-inhibitory concentrations of bovine bile. Additionally, we observed bile-induced sensitivity to aminoglycosides, which we exploited in a bursa aurealis transposon screen to isolate mutants reduced in aminoglycoside sensitivity and augmented in bile-induced biofilm formation. We identified five mutants that exhibited hypersensitivity to bile with respect to bile-induced biofilm formation, three of which carried transposon insertions within gene clusters involved in wall teichoic acid (WTA) biosynthesis or transport. Strain TM4 carried an insertion between the divergently oriented tagH and tagG genes, which encode the putative WTA membrane translocation apparatus. Ectopic expression of tagG in TM4 restored a wild-type bile-induced biofilm response, suggesting that reduced translocation of WTA in TM4 induced sensitivity to bile and enhanced the bile-induced biofilm formation response. We propose that WTA may be important for protecting S. aureus against exposure to bile and that bile-induced biofilm formation may be an evolved response to protect cells from bile-induced cell lysis.
- ItemIntegrated (meta) genomic and synthetic biology approaches to develop new biocatalysts(MDPI, 2016-03-21) Parages, María L.; Gutiérrez-Barranquero, José A.; Reen, F. Jerry; Dobson, Alan D. W.; O'Gara, Fergal; Seventh Framework Programme; Horizon 2020; Science Foundation Ireland; Department of Agriculture, Food and the Marine; Food Institutional Research Measure; Irish Research Council for Science, Engineering and Technology; Health Research Board; Irish Thoracic Society; Marine Institute; TeagascIn recent years, the marine environment has been the subject of increasing attention from biotechnological and pharmaceutical industries as a valuable and promising source of novel bioactive compounds. Marine biodiscovery programmes have begun to reveal the extent of novel compounds encoded within the enormous bacterial richness and diversity of the marine ecosystem. A combination of unique physicochemical properties and spatial niche-specific substrates, in wide-ranging and extreme habitats, underscores the potential of the marine environment to deliver on functionally novel biocatalytic activities. With the growing need for green alternatives to industrial processes, and the unique transformations which nature is capable of performing, marine biocatalysts have the potential to markedly improve current industrial pipelines. Furthermore, biocatalysts are known to possess chiral selectivity and specificity, a key focus of pharmaceutical drug design. In this review, we discuss how the explosion in genomics based sequence analysis, allied with parallel developments in synthetic and molecular biology, have the potential to fast-track the discovery and subsequent improvement of a new generation of marine biocatalysts.