[Susceptibility to nitrofurantoin, biseptol and nalidixic acid of E. coli strains isolated from urine in the years 1983-1990].

The group of microorganisms causing urinary tract infections includes the Enterobacteriaceae family, particularly E. coli, being the most commonly detected etiologic factor of the above infections. Research was conducted from 1983 to 1990 on 1102 E. coli strains isolated from patients with clinical diagnosis of urinary tract infection. Susceptibility of the bacteria to nitrofurantoin, Biseptol and nalidixic acid was determined by application of the paper-disk- plate technique. The percentage of nitrofurantoin susceptible strains during the time period of research remained on the low level of 6-20%. The susceptibility of the strains isolated from 1983 to 1987 to Biseptol was also low, 0-11%, however, in later years (1988-1990) the gradual increase of susceptibility was observed, reaching the level of 35% in 1990. The most active of the used chemotherapeutics turned out to be nalidixic acid proven to be effective against 34.3-56.3% of E. coli strains.