[Frequency of isolation and drug resistance of bacterial strains from urine samples tested in the Bacteriology and Virology Laboratory of the U.S.L. 10/D in Florence].

Two thousand five hundred and sixty-eight positive monomicrobic urine samples (from general practice and hospital wards) were examined and isolated strains were tested against various antimicrobial drugs. Our findings showed that urinary-tract infections caused by Escherichia coli were the most common in females, whereas those by Pseudomonas aeruginosa, Proteus rettgeri, Enterobacter species, other difficult Gram-negative rods and Streptococcus faecalis were in total the most common in males. If we compare the strains isolated from general practice with those from the hospital, no significant differences were observed. E. coli strains were the most susceptible to the tested drugs; cefotaxime, amikacin, cefuroxime and ceftazidime were the most effective drugs against Enterobacter species, Ps. aeruginosa, P. rettgeri and Proteus mirabilis. P. mirabilis and Str. faecalis strains isolated in the hospital were more chemo-resistant than those isolated in general practice. Ampicillin and trimethoprim/sulphamethoxazole were less active against E. coli strains isolated from children's departments in comparison with the others.