Effect of antibiotic treatment on the incidence of infectious drug resistance among intestinal lactose-fermenting bacteria isolated from burn patients.

Antibiotic-resistant lactose-fermenting bacteria were recovered from the feces of 20 of 25 burn patients studied. Of the Escherichia coli isolated from patients receiving antibiotic treatment, 81.5% were shown to be infectiously resistant; only 32% of the E. coli recovered from patients not receiving antibiotics were shown to be harboring R factors. Three resistance patterns, ampicillin-chloramphenicol-streptomycin-kanamycin, ampicillin-tetracycline, and ampicillin-streptomycin, accounted for 25.2, 20.3, and 15.4%, respectively, of the total R factors identified.