FIG. 4.

Frequency of antimicrobial drug resistance patterns for all E. coli strains shed from calves for the cured-SSuT group (n = 3,415), “susceptible” wild-type group (n = 3,430), and “medium-only” group (n = 3,448). *, statistically significant (P < 0.05 with Student-Newman-Keuls multiple comparison test for seven tests). Resistance patterns are denoted by letters, where A is ampicillin, Ch is chloramphenicol, S is streptomycin, Su is sulfadiazine, and T is tetracycline. Susceptible isolates were susceptible to all above-mentioned antimicrobial drugs tested.