Comparison between the conventional methods used for detection of M. bovis in milk and the nested polymerase chain reaction [electronic resource].

Includes references.

The lower sensitivity and specificity, moreover the time required for reporting the results of the traditional methods make them of low value for diagnosis of M bovis. Therefore the purpose of the prospective study was targeted to amplify a 560 bp fragment of the 16s rRNA which is conserved in all Mycobacterium spp. And 270 bp region nested within the first 16srRNA and conserved only in M tuberculosis complex from the extracted DNA of 520 milk samples collected from tuberculin p9sitive and negative animals as well as market milk samples. Amplification of 560 bp fragment was observed with the extracted DNA of 33 (6.35%) out of 520 examined milk samples, of them 23 (4.42%) milk samples were positive by Ziehl-Neelsen stain. Amplification of 270 bp fragment was observed with 22 (4.23%) milk samples, while the other 11 samples were negative. Amplification of 500 bp fragment which is specific for M bovis, revealed positive results with 16 (3.06%) milk samples only. PCR could detect all samples yielding M. bovis with bacteriological examination in addition, 8 milk samples with negative bacteriological examination. The present results concluded that PCR assay could be effectively used as a diagnostic and/or screening test for detection of M bovis in milk.

Summary in Arabic.

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