IS1311 PCR-REA types, PFGE profiles and estimations of span, K, and plateau for the quantification of each M. avium subsp. paratuberculosis isolate in the Bactec MGIT 960 system.

Growth of all the isolates in the Bactec MGIT 960 system fitted to a one-phase exponential-decay model according to the following equation [log10 inoculum size = span X e (-K X TTD) + plateau]. Span is the difference between TTD at time zero and the plateau, K is the degree of decay for the log10 CFU, and plateau is the value for log10 CFU curve flattening.