TABLE 4.

E. coli O157 in GIT compartments of reinoculated steers

No. of day postinoculationaNo. of E. coli O157 CFU/g of digesta fromb:
RumenDuodenumFeces
A1bA2A1A2A1A2
0000000
0.251.0 × 1031.0 × 1021.0 × 103E+05.0 × 103
1E+c1.0 × 102E+1.0 × 1021.6 × 1045.0 × 104
2E+E+E+E+1.0 × 1035.0 × 102
3E+E+0E+2.0 × 1021.0 × 103
60E+E+01.0 × 1015.0 × 101
9000001.5 × 102
130E+0000
16000000
200000E+0
23000000
270000E+0
300000E+0
3400000E+
41000000
  • a Two steers received 2 × 109 E. coli O157:H7 ATCC 43895 directly into the rumen 132 days after the first inoculation (see Table 3).

  • b A1, A2, etc. identify animals from which samples were taken.

  • c E+, digesta sample culture positive for E. coli O157 after enrichment culture only.