Evaluation of combined high-efficiency DNA extraction and real-time PCR for detection of Mycobacterium avium subsp. paratuberculosis in subclinically infected dairy cattle: comparison with faecal culture, milk real-time PCR and milk ELISA

Table 1 Efficiencies of the total Mycobacterium avium subsp. paratuberculosis DNA isolation procedure from the faeces

Theoretical input of Map cells per g faeces^a	Experimental mean output of Map cells per g faeces^b	Mean DNA isolation efficiency (%)^c
900,000	586,667	65 ±38
90,000	82,833	92 ±16
9,000	6,747	76 ±3
900	704	78 ±19
90	100	112 ±30

Map, Mycobacterium avium subsp. paratuberculosis.
^aDetermined by OD₆₀₀ of bacterial suspension.
^bCalculated as the mean of the recovered IS900 copy number from IS900 qPCR divided by 15, considering there is on average 15 IS900 copies per single Map cell.
^cCalculated as the mean yield obtained using HYDEqPCR divided by the theoretical number of Map cells added into the faeces, multiplied by 100.

ISSN: 1746-6148