A 6-year survey of resistance patterns of urinary tract pathogens in general practice.

A survey of resistance patterns of urinary pathogens causing infections in general practice over the period 1964-69, including 3100 cases of which 2718 were caused by species or coliform organisms has been made. The resistance patterns of the enterobacteria have been examined and reveal a rise in incidence of sulphonamide-resistant strains from 1964 to a peak of 61·3% in 1967 followed by a symmetrical fall to return to 24·9% in 1969. Ampicillin and nalidixic acid were the only two drugs of twelve to show a constant rise in incidence of resistant strains although the figures are much lower reaching peaks of 11·1% in 1969 for ampicillin and 3·2% in 1969 for nalidixic acid. The other drugs surveyed show less definite change; tetracycline constantly shows an incidence of about 30% resistance and nitrofurantoin varies between 2·7% and 8·7%. Low incidences of resistance against trimethoprim-sulphonamide mixture are recorded: 1·5% in 1968 and 2·0% in 1969. strains, treated separately, frequently show resistance to tetracycline, 90·3% in 1969, and to nitrofurantoin, 37·8% in 1969. The incidence of multiple resistance is also increasing. Fifty-three percent of strains were resistant to at least one antibiotic and 6% to three or more in the period 1964-67 and 57·3% show resistance to at least one drug and 10·3% to three or more in the period 1967-69.