Concentration in various intestinal segments of total aerobic microorganisms (closed diamonds), total anaerobic microorganisms (open diamonds), total tetracycline-resistant aerobic microorganisms (×), E. coli (+), total enterococci (open circles), recipient bacteria (open squares), and transconjugant bacteria (closed triangles). The figure shows the average values from three mini-pigs, measured at the day of euthanatization. Error bars represent standard errors of the means.