Testing animal fluids.

摘要

A method for testing animal fluids such as milk or blood for the presence of antimicrobial agents. The method relies upon testing for growth in the fluid of an indicator organism which is resistant to the antimicrobial agent. The fluid may be tested for the presence of a range of antimicrobial agents by testing for growth in the fluid of a series of indicator organisms which are selectively resistant to one or more antimicrobial agents. The indicator organism may be one which has been produced by transformation (using genetic engineering techniques) of an organism which is sensitive to the antimicrobial agent. The sensitive organism may be transformed using a plasmid vector into which a gene providing the desired antimicrobial resistance has been cloned. If the sensitive organism is required to be resistant to two or more antimicrobial agents then the organism may be transformed with two or more genes, as required. The introduction of the antimicrobial resistance factor should affect only the host's sensitivity to the corresponding antimicrobial agent or cross-functional class of agents and not the host phenotype with respect to the rest of its antimicrobial sensitivity spectrum.