[Serum resistance of Escherichia coli and serum bactericidal activity in chronic pyelonephritis]

123 patients with chronic pyelonephritis of the renal dispensary of the clinic of internal medicine of the Department of Medicine Wilhelm Pieck University Rostock were controlled microbiologically for one to four years. Of 59 patients of this group with significant bacteriuria we cultivated 170 strains of E. coli, which were standardised O, K, and H. Of all causative organisms the serum resistance was determined in a human serum pool. All sera of patients were examined for their bactericidal activity to the homologous E. coli urine strain as well as to a serum-sensitive E. coli reference strain (E. coli O 22:K-:H+). In 11.8% we found in the sera investigated at the time of the excretion of causative organisms disturbances of the serum bactericidal action, which rendered possible the survival of the sensitive in the human serum pool causative organism. In 8.82% of the sera of patients at the time of bacteriuria there was a decreased bactericidal action against the E. coli reference strain, only two of these sera did also not kill the urine strain of the patients. In individual cases sera of patients were examined for bactericidal activity with the homologous germ after absorption. By this absorption the antibactericidal activity of the sera could be removed. The proof of a disturbance of a bactericidal action may be an important reference for the course of the chronic pyelonephritis.