CARRIAGE OF ANTIBIOTIC-RESISTANT ESCHERICHIA-COLI BY HEALTHY-VOLUNTEERS DURING A 15-WEEK PERIOD

Escherichia coli strains (n = 678 and n = 670) isolated from faecal sa mples from 90 and 93 healthy volunteers of two cities, Weert and Roerm ond respectively, were analysed for their susceptibility to 12 antimic robial agents during a 15-week period. Significant differences between both cities in the distribution of the MIC values were observed for a pramycin, chloramphenicol, kanamycin, neomycin, nitrofurantoin, sulfam ethoxazole and trimethoprim. For Weert (n = 678) the antibiotic resist ance percentages varied from 0.4% for nalidixic acid to 26.7% for sulf amethoxazole. For Roermond (n = 670) the figures varied from 0.6% for nitrofurantoin to 37.5% for sulfamethoxazole. Resistance to amoxicilli n/clavulanate was hot found in either city. The most frequent pattern was resistance to sulfamethoxazole only, followed by resistance to oxy tetracycline, streptomycin and sulfamethoxazole. In each individual th ere was only a small variation in resistance patterns of the isolates, i. e. the majority had one (n = 51) or two (n = 63) patterns with a m aximum of five during the 15-week period. A fully susceptible pattern was found in the strains from 38 individuals.