TABLE 1

Samples included in the feasibility study to compare the ethanol precipitation and optimized magnetic bead DNA isolation methods for MAP in liquid culture

Species of originSample typeStrain of MAP presentNo. of samples and original culture resultNo of samples detected bya:
Positive (wk to GI 999b)NegativeEtOH precip.Mag bead
CattleFecesC302c3c
CattleFecesC4 (4)44
10 (5)1010
5 (6)55
3 (7)33
2 (8)22
SheepFecesS30All negativeAll negative
SheepTissuesS10All negativeAll negative
SheepFecesS10 (4)1010
10 (5)1010
10 (6)1010
10 (7)1010
SheepTissuesS101010
  • a EtOH precip., ethanol precipitation and IS900 qPCR method; Mag bead, optimized magnetic bead DNA isolation and IS900 qPCR method.

  • b Weeks of growth in Bactec 12B liquid culture medium to reach a growth index (GI) of 999.

  • c These samples had a GI of 999, but the original PCR results were negative. Two were positive on secondary testing with both methods, and an additional sample was detected by magnetic bead isolation/qPCR. The remainder of the samples in this group were negative using both methods.