Drug resistance amongst uropathogens isolated from women in a suburban population: laboratory findings over 7 years.
Urinary tract infections (UTI) are a common reason for patient visits to the family physician. The following study was carried out during one month in 1989 and one month in 1996, whereby urine specimens from adult females (living in suburban areas of Toronto, Canada), with presumed signs and symptoms of UTI, were processed. The pool of 20 infecting uropathogenic species was relatively unaltered over the seven years. Most isolates were Gram negative pathogens (72% in 1989; 76% in 1996), with Escherichia coli the most common (56.5% in 1989; 61.9%, in 1996), followed by Enterococcus faecalis (17.4% in 1989; 9.47% in 1996). The resistance to commonly prescribed trimethoprim-sulfamethoxazole increased during the seven years from 10% to 15%, for E. coli (Table 2) and from 35% to 100% for enterococci (Table 3). In 1996, although there was resistance to norfloxacin, the top five uropathogenic species were highly susceptible. No enterococci were resistant to nitrofurantoin and almost all E. coli (99.2%) were susceptible. Based upon this in-vitro data, nitrofurantoin, and not trimethoprim-sulfamethoxazole, would be the antimicrobial agent of choice for treatment of uncomplicated UTI in adult females.