On-line determination of serum bactericidal activity using recombinant luminescent bacteria.

Intensity of luminescence quenching in recombinant strains of Escherichia coli with cloned lux-operones by human blood serum is directly proportional to the degree of bactericidal effect assessed by nephelometric and bacteriological methods. This correlation was most characteristic of E. coli with luminescence genes from Photobacterium leiognathi, which substantiates its use in the development of the kinetic bioluminescent method to determine of serum bactericidal activity. The possibility of using this method for evaluation of activity of classic and alternative pathways of compliment activation was demonstrated by using zymosan or EGTA-Mg(2+)-treated sera and C1-C5-deficient sera.