The prevalence of ampicillin, cephalosporin and sulphonamide resistance amongst urinary tract pathogens.

A total of 2,031 clinical isolates of Gram negative bacilli was obtained from hospitals in 4 centres and these cultures were tested for resistance to ampicillin, cephazolin and sulphonamide. Ampicillin and sulphonamide resistance in outpatients ranged from 15 to 28 per cent of E. coli strains and 4 to 11 per cent of Proteus mirabilis strains. Resistance to cephazolin in outpatients ranged from 0 to 3 per cent of E. coli and 0 to 6 per cent of Proteus mirabilis. Resistance patterns for E. coli, Proteus mirabilis and Klebsiella strains isolated from inpatients were much higher and varied widely. These patterns are presented and the reasons for these variations discussed.