Jonathan completed an MSc in Biomedical Science at the University of Hull in 2007. From there he was awarded an EPSRC CASE (Unilever PLC) PhD studentship in the Department of Chemistry at the University of Hull, under the supervision of Prof Stephen Haswell and Prof Stephen Kelly. The project involved the microfluidic synthesis of deuterium labelled theaflavin and the antimicrobial activity of polyphenols. Upon completing his PhD, Jonathan undertook a fixed term Postdoctoral position with Prof Stephen Kelly to investigate the novel synthesis and antibacterial activity of metal nanoparticles.
In December 2012 he began a Postdoctoral appointment with Dr David Wareham in the Centre for Immunobiology at Queen Mary, University of London (QMUL). Over the next 3 years at QMUL, Jonathan conducted various research projects investigating the in vitro and in vivo activity of novel antimicrobials and antibiotic combinations against multidrug-resistant bacteria. He was also involved with several projects investigating the virulence of Gram-negative bacteria in the Galleria mellonella model. During this period Jonathan continued to collaborate with the University of Hull and also worked with other research groups at the University of Oxford, UCL, Pfizer and Merck.
In October 2015, Jonathan became Postdoctoral Research Fellow at the University of Surrey on a BBSRC funded project with Prof Roberto La Ragione, to study the antibacterial activity and cytotoxicity of carbon monoxide releasing molecules (CORMs) against avian pathogenic Escherichia coli (APEC), Acinetobacter baumannii and Pseudomonas aeruginosa, in collaboration with Prof Robert Poole and his group at the University of Sheffield.
Antimicrobial resistance is a critical global issue and infections resulting from multidrug-resistant (MDR) bacterial strains have become more frequent, leading to longer hospital stays, an increased financial burden to health services and higher rates of morbidity and mortality. This has been compounded by a marked decline in antibiotic development over the past 40 years, and some infections are now untreatable with conventional drugs. By increasing the resources for research into new drug development, improved diagnostics, and educating both clinicians and the public on how to more appropriately use these 'magic bullets', it may be possible to avoid a 'post antibiotic era'.
Jonathan's research interests include the mechanisms of antimicrobial resistance in Gram-negative bacteria and the development of novel antimicrobial chemotherapies. He also has a particular interest in alternatives to traditional antibiotics, including metal nanoparticles and natural compounds such as polyphenols, and their development for clinical use in humans and animals. Other interests also include bacterial virulence and infection control.
Jonathan has previously delivered lectures at the University of Hull on Infection Control, for third year Undergraduate/MSc students and on Nosocomial Infections for second year BSc students at Queen Mary University of London. Jonathan has also been involved in the teaching of Medical Microbiology and Analytical Chemistry laboratory practicals at the University of Hull and more recently at the University of Surrey.
Alongside Jonathan's personal research activities, he is involved in the design and supervision of BSc and MSc projects and the supervision of PhD students. Jonathan is also involved in the day to day management of the bacteriology laboratories at the Veterinary Medicine main academic building.
Member of the British Society for Antimicrobial Chemotherapy (BSAC) Member of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Member of the American Society of Microbiology (ASM) Champion for Antibiotic Action
Peer Reviewer for: RSC advances, Green Chemistry, Journal of Antimicrobial Chemotherapy, Nutrition, Journal of Microbiology and Biochemistry, FEMS Microbiology and the International Journal of Antimicrobial Agents. Review editor for Frontiers in Microbiology.
Green tea catechins have been reported to have multiple health benefits. To understand their metabolic and toxicological interactions in the human body studies need to be undertaken using stable isotope labelled compounds, but they can be time consuming and expensive. Using microreactor technology labelling catechins could be produced more quickly and at a reduced cost. This research reports on a 2-step synthesis of deuteriumlabelledepicatechin developed using microreactor technology for the production.
Stenotrophomonas maltophilia and Acinetobacter baumannii are recognised as important nosocomial pathogens; however, due to their intrinsic resistance to multiple antibiotics, treatment options are limited. Polyphenols from black tea have been shown to possess antibacterial action. In this study, the antibacterial effects of various concentrations of theaflavin as well as combinations of theaflavin and epicatechin were determined using the disk diffusion assay. The results showed strong antibacterial activity of theaflavin against eight clinical isolates of S. maltophilia and A. baumannii. Significant synergy (P≤0.05) was also observed between theaflavin and epicatechin against all isolates. Although the mechanisms for this activity and synergy are not well understood, the clinical potential is clear and further research is recommended to determine the modes of action.
Stenotrophomonas maltophilia is an important nosocomial pathogen with intrinsic resistance to multiple antibiotics. Previous investigations have shown flavanols from black tea to possess antibacterial activity. This study describes the determination of minimum inhibitory concentrations and minimum bactericidal concentration for theaflavin independently and in formulations with the polyphenols epicatechin and quercetin against nine clinical isolates of Stenotrophomonas maltophilia and the control isolate NCTC 130141 via the microtitre assay. The results demonstrate that theaflavin has strong antibacterial activity and also shows significant synergism with epicatechin and quercetin. The minimum inhibitory concentrations of the isolates range between 200-400 ug/mL for theaflavin and 100-200 ug/mL for both theaflavin:epicatechin and theaflavin:quercetin combinations. The minimum bactericidal concentrations were discovered to be a 2 fold increase on those of the minimum inhibitory concentrations. The research highlights the potential use of polyphenols for the clinical treatment of highly antibiotic resistant bacteria.
Stenotrophomonas maltophilia is an important opportunistic nosocomial pathogen that shows intrinsic resistance to many antibiotics. This often limits treatment options and can cause lengthy hospital stays. Combination treatments are often used to combat resistance and using natural compounds such as polyphenols could give increased treatment options and even the reuse of antibiotics to which high levels of resistance have been observed. A checkerboard assay was used to determine if any synergy exists between ampicillin and the polyphenol theaflavin against 9 clinical isolates and one control isolate (NCTC 13014) of S. maltophilia. It was discovered that significant synergy (P < 0.05) does exist between theaflavin and ampicillin, reducing the mean MIC of ampicillin from 12.5-22.9 μg/mL, in liquid culture, to 3.125-6.25 μg/mL. The FIC index was calculated to be 0.22-0.35 confirming synergy. From these results, significant potential for medical applications can be seen and further investigation is recommended.
A simple, environmentally friendly and cost-effective synthetic method has been developed to prepare highly stable aqueous colloidal solutions of small (2–14 nm) silver nanoparticles using aminocellulose (AMC) as a combined reducing and capping reagent. The effects of temperature, reaction time, the concentration of silver nitrate and AMC are systematically investigated and the reaction conditions optimised. The AMC-stabilized silver nanoparticles can be deposited on the surfaces of cotton fibres and microporous cellulose acetate (CA) filters, without affecting the permeability of the filters. The AMC-stabilized aqueous silver colloidal solutions and silver nanoparticle coated CA filters and cotton fibres all show significant antibacterial action against all the bacterial isolates tested, with the antibacterial levels between “Sufficient” and “Good”, although some of solutions have been stored at room temperature for 18 months.
New antifungal agents are required to compensate for the increase in resistance to standard antifungal agents of C. albicans, which is an important opportunistic fungal pathogen that causes minor infections in many individuals but very serious infections in those who are immune-compromised. In this study, combinations of the theaflavin and epicatechin are investigated as potential antifungal agents and also to establish whether antifungal synergy exists between these two readily accessible and cost-effective polyphenols isolated from black and green tea. The results of disc diffusion assays show stronger antibacterial activity of theaflavin:epicatechin combinations against C. albicans NCTC 3255 and NCTC 3179, than that of theaflavin alone. Minimum inhibitory concentrations (MICs) of theaflavin and the theaflavin:epicatechin combinations of 1024 ㎍/mL with theaflavin and 128-256 ㎍/mL with theaflavin:epicatechin combinations are found. FICIs were calculated and synergy between theaflavin and epicatechin against both isolates of C. albicans confirmed. Theaflavin:epicatechin combinations show real potential for future use as a treatment for infections caused by C. albicans.
Small, carboxymethyl-starch-stabilised zinc oxide nanoparticles with a defined shape, size and morphology were prepared in situ in water at relatively low reaction temperatures using soluble carboxymethyl starch (CMS) as a combined crystallising, stabilising and solubilising agent and triethanolamine as the reducing agent. Aqueous colloidal solutions of these CMS-stabilised ZnO nanoparticles were used to deposit a coating of ZnO nanoparticles on cellulose paper by a wet-chemistry, polyelectrolyte, layer-by-layer approach using water as the only solvent. Such cellulose paper samples, coated with these CMS-stabilised ZnO nanoparticles, show higher brightness and whiteness than that of blank reference paper and are more stable to UV-radiation than the paper reference as well as demonstrating good antibacterial activity against MRSA and A. baumannii.