Fig. 1

Percentage of fecal presence of the gene encoding STa enterotoxin in weaned pigs challenged or not with ETEC: F4. Challenge was performed at d0 and treatment with colistin sulfate at the dose of 50,000 IU/kg was started at d1 (24 h post challenge) and administered twice daily for 5 days. At d4 a significant reduction in the fecal presence of the gene encoding STa was found in the unchallenged treated group compared to the challenged untreated and the unchallenged untreated groups (p < 0.0001). At d36, the fecal presence of the gene encoding STa was statistically lower in the challenged untreated group compared with the unchallenged untreated group (p < 0.001). The percentage was calculated by dividing the number of positive pigs by the total number of pigs in each group