Table 3. Isolation and quantification of E. coli strains from either rectal swabs or intestinal contents of weaned pigs before and after the treatments; numerical data are expressed as either average values of CFU/mL or percent values of hemolytic colonies in the isolates for each group of pigs.
Treatment of pigsa | Day of experiment | No. of E. coli positive pigs/total no. of pigs | E. coli isolate | CFU/mL | Hemolytic isolates (%) |
---|---|---|---|---|---|
None | −2 | 3/5 | O8:K87:F4 acc | - | - |
7 | 5/5 | E. colid | - | - | |
10 | 1/5 | E. coli | - | - | |
13 | 4/5 | O138:K81, | 3.0×107 | 10 | |
O149:K91:F4ac | 1.0×106 | 20 | |||
F4ac+ non-ETEC | −2 | 1/5 | E. coli | - | - |
7 | 2/5 | O8:K87:F4ac : | - | 75 | |
O9:K36:H19:F4ac | |||||
10 | 4/5 | O149:K91:F4ac | - | - | |
13 | 2/5 | O149:K91:F4ac | 5.5×106 | 22.5 | |
Levamisole + F4ac+ non-ETEC | −2 | 1/5 | O8:K87:F4ac | - | - |
7 | 3/5 | E. coli | - | - | |
10 | 1/5 | E. coli | - | - | |
13 | 5/5 | O8:K87:F4ac | 3.5×106 | ||
O9:K36:H19:F4ac | 2.5×106 | 15.0 |
Groups comprised five 4-weeks-old pigs each.bControl pigs received saline as a placebo.
“Farm strain”.
Non-pathogenic strain.