[The biological significance of the anticomplement activity of bacteria]

The occurrence and the average levels of anticomplementary activity among the representatives of bacterial species as Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, mainly reflecting differences between their ecovariants, were established. In connection with the fact that some of E. coli uropathogenic strains with high anticomplementary activity were found to be capable of inhibiting the activity of C5 in a hemolytic system and with the presence of correlation between the property under study and complement resistance, the existence of common mechanisms for the realization of these properties was supposed. Extracellular products of S. aureus were shown to be capable of inhibiting the functional activity and opsonic action of C3 component of the complement, which was related to the presence of anticomplementary activity in these bacteria. Experimental staphylococcal infection in mice revealed the predominant accumulation of bacteria possessing this property. Clinico-bacteriological studies demonstrated that the anticomplementary activity of E. coli contributed to the increased risk of postoperative complications in cholecystitis and to the prolongation of bacteriuria in chronic pyelonephritis.