The increasing resistance of micro-organisms to antimicrobial agents is a major public health problem. Previously well controlled diseases have become difficult to treat due to the rapid or sustained emergence of bacterial resistance. Dr Stuart Levy from Tufts University, Boston, US, told delegates at the 99th General Meeting of the American Society for Microbiology [Chicago, US; May-June 1999], that overprescribing of antimicrobials, public expectation of the need for antimicrobials for nonbacterial infections, excessive use of antimicrobials in animal food production and the widespread use of cleansing products impregnated with antimicrobials are largely responsible for this problem.