Nalidixic Acid in Urinary Tract Infections with Particular Reference to the Emergence of Resistance

Publisher Website
Google Scholar
Abstract
The effect of nalidixic acid-treatment was studied in 100 cases of significant bacteriuria discovered during gynaecological health control. In 70 patients asymptomatic bacteriuria was diagnosed, in 18 acute cystitis, and in 12 chronic non-obstructive pyelonephritis. In view of the past controversy regarding the significance of rapid emergence of resistance with this antibiotic the investigation was designed to distinguish between true emergence of resistance in the original organism and appearance of a different, resistant strain. Most patients were treated for about 3 months. In 86% of the patients a rapid sterilization of the urine was achieved, lasting throughout the treatment. The original organism became resistant to nalidixic acid in 8%. Replacement of the original strain by a different resistant strain occurred in 6%. The emergence of a resistant bacterial population occurred very rapidly, if at all, but not more frequently with nalidixic acid than reported in the literature with other standard antibiotics used in the treatment of urinary tract infections. 66 patients with successful treatment were followed for up to one year. Recurrent bacteriuria was observed in 14 (21%) and was found to be due to reinfection with a new organism in 9 cases whereas the possibility of recrudescence of the original infection could not be excluded in 5 cases.