[Urinary tract infection in an ambulatory population: epidemiological analysis of the etiology and antibiotic resistance of isolated gram-negative strains].

15,892 urinocultures belonging to out-patients admitted to Chieti ULSS 04, from January '85 to December '89 were studied. Among the examined samples, the positive urinocultures were 4255 (26.8%) with a prevalence in the female sex (78.6%). During the year E. coli was the most frequently identified organism (55.8%) without significant changes. 25.7% was the isolation percentage of Morganella-Proteus-Providencia (MPP). In order to plan a right antibiotic-therapy the resistance of isolates to 19 chemo-antibiotics, during five years, was evaluated and compared.