Scanning electron microscopy of P. aeruginosa biofilms (scale bar, 1 μm)—(a) control; (b) 20% Manuka honey; (c) 50% artificial honey (representative images). The control image showed hundreds of bacterial cells connected by a substantial amount of extracellular matrix which appeared stringy and covered most of the cells. The Manuka honey-exposed bacterial cells, in contrast, were spread apart with little apparent matrix. The cells appeared curved and distorted, and the cell density was markedly decreased. The artificial honey-exposed cells had a few connecting strands, but were mainly separate from one another. They less densely covered the disc than the control cells but more densely covered the disc than did the Manuka honey-exposed cells.