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Professor David Lloyd


David Lloyd2

Studies in Professor Lloyd’s laboratory include the following aspects of studies on parasites:

Biological timekeeping (in the range seconds to hours) in living organisms.
Monitoring intracellular events by non-invasive methods such as mass spectrometry, fluorescence techniques & NMR.
Using these approaches to solve medical, environmental and industrial problems.


Telephone: +44 (0)29 208 74048
Fax: +44 (0)29 208 74305
Location: Cardiff School of Biosciences, Main Building, Museum Avenue, Cardiff, CF10 3AT


Research is aimed at novel therapeutic targets and agents against the following organisms:
Ascaridia galli: a parasite of chickens that we have kept in culture for up to a month: cytochrome b567 is the terminal oxidase of this microaerophilic worm.
Brugia pahangi filarial nematode from the peritoneal cavity of jirds: pathways of alternative respiration and H2O2 production (possible targets)
Tritrichomonas foetus: a micraerophilic cattle and horse parasite, with hydrogenosomes, not mitochondria.
Trichomonas vaginalis: the sexually-transmitted parasite. We identified a major site of action of metronidazole in its hydrogenosomes (still after 54 y use the most effective therapy, but rare resistant forms are incurable.
Acanthamoeba castellanii : causes corneal keratitis: a burgeoning problem especially of contact lens wearers. Often incurable due to impermeability of cysts to drugs. Only remedy then is corneal transplant.
Naegleria grubber : a brain-eating amoeboid protist that can penetrate the blood-brain barrier. This organism killed a swimmer in the Roman Baths at Bath, leading to the closure of the Baths for 15y. We are trying to find new ways of killing the encysted life stage, e.g. by microwave irradiation after feeding of nanoparticles.
Giardia intestinal: a waterborne parasite of the upper intestine, described as early-branching lower eukaryote in textbooks. We were first to reclassify this as belonging to a crown taxa, having been derived from an aerobic flagellate by loss of mitochondria.
Spironucleus vortens: parasite of ornamental fish e.g. Angel fish. Sensitive to metronidazole (now banned from environmental use in US and Europe but also killed by garlic constituents.


Link to ScopusTM Database

Selected publications:

Williams C.F., Cable J., Lloyd D., Schelkle B., Vacca A.R. (2013). Non-invasive estimation of Spironucleus vortens in angelfish provides novel insights on the transmission of this diplomonad parasite. Dis Aquat Org. 105, 211-223.

Williams C.F., Millet C.O., Hayes A.J., Cable J., Lloyd D. (2013). Diversity in mitochondria-derived organelles of the parasitic diplomonads Spironucleus and Giardia. Trends Parasitol, 29, 311-312

Leitsch D., Williams C.F., Lloyd D., Duchêne M. (2013). Unexpected properties of NADP-dependent secondary alcohol dehydrogenase (ADH-1) in Trichomonas vaginalis and other microaerophilic parasites. Exp Parasitol 134, 374-380

Williams C.F., Lloyd D., Kolarich D., Alagesan K., Duchene M., Cable J., Williams D., Leitsch D., (2012). Disrupted intracellular redox balance of the diplomonad fish parasite Spironucleus vortens by 5-nitroimidazoles and garlic-derived compounds. Vet Parasitol 190: 63-73.

Williams C.F., Lloyd D., Poynton S.L., Jorgensen A., Millet C.O.M., Cable J. (2011). Spironucleus species: economically-important fish pathogens and enigmatic single-celled eukaryotes. J Aquacult Res Dev  S2

Millet C.O., Lloyd D., Coogan M.P., Rumsey J., Cable J. (2011). Carbohydrate and amino acid metabolism of Spironucleus vortens. Exp. Parasitol.129, 17-26

Williams C.F., Lloyd D. (2012). Composition and antimicrobial properties of sulphur-containing constituents of garlic (Allium sativum). CF Williams & D Lloyd  Essential Oils as Natural Food additives: Composition, Applications, Antioxidant and Antimicrobial Properties, Ed. Valgimiglia , Nova Science, New York, pp.287-304.

Fernandez-Moreira V., Thorp-Greenwood F.L., Millet C.O., Williams C.F., Cable J., Court L.B., Hayes A.J., Lloyd D., Coogan M.P. (2011). A ‘Sleeping Trojan Horse’ transports metal ions into cells, localioses in nucleoli and has potential for bimodal flourescence /PET imaging. Chem. Commun. 47:3096-3098.

Millet C.O.M., Lloyd D., Williams C.F., Williams D., Evans G., Cable J. (2011). Effect of garlic and allium-derived products on the growth and metabolism of Spironucleus vortens. Exp. Parassitol. 127 (2) 490-499.