Bacterial

The results of MTT assay demonstrate a dose-dependent decrease in mitochondrial activity in Vero cells at all concentrations of Carbadox. Treatment with Carbadox at the highest concentration of 160 μg/mL results in cell viability down to only 12%. Cells following Carbadox treatment show a dose-dependent increase of the DNA migration (p<0.01). The nuclear division index (NDI) reduces markedly with the increase doses of Carbadox.

Alpha diversities (Shannon diversity, Heips evenness, and inverse Simpson indices) of samples from medicated piglets compare to non-medicated piglets are significantly different at 2, 3, and 4 days after continuous Carbadox, but not different in either late Carbadox or at any time during the withdrawal period. Analysis of the community structure of bacteria in animals shows significant differences at days 3 and 4 of early Carbadox treatment ([R=0.32, p=0.015] and [R=0.54, p=0.003], respectively), but not before starting antibiotic treatment (p=0.82). No significant differences in E. coli colony forming units (CFUs) are observed during the Carbadox-treatment period of the study or late in the withdrawal period. E. coli CFUs are significantly different between the medicated and non-medicated groups on day 2 after the withdrawal of Carbadox.