Mycobacterium avium subsp. paratuberculosis in pasteurised and unpasteurised milk in the Republic of Ireland

Between March and September 1999, 310 milk samples were collected from individual compartments of bulk tankers on their arrival into seven dairy co-operatives. In addition, 77 cartons of pasteurised cows milk from eight dairies and nine cartons of pasteurised goat's milk from two dairies were purchased from retail outlets during the same period. Following decontamination with hexadecyl pyridinium chloride, the samples were cultured for Mycobacterium avium subsp. paratuberculosis (Map) using Bactec B12B and Herrold's Egg Yolk medium. All 396 samples tested negative for culture of Map. Non-mycobactin dependant mycobacteria were isolated from 12 of the unpasteurised samples.