Comparison of Mycobacterium avium complex (MAC) strains from pigs and humans in Sweden by random amplified polymorphic DNA (RAPD) using standardized reagents

Infections with atypical mycobacteria belonging to the Mycobacterium avium/ intracellulare complex (MAC) can cause infection in both animals and humans . Using a standardized reagents commercial kit for random amplified polymor phic DNA (RAPD) analysis, 49 MAC strains isolated from 32 slaughter pigs an d 17 humans in Sweden were identified and sorted out, yielding 6 RAPD types . By combining the results of RAPD primers 4 and 5 and the primer IS1245A, we found that pigs and humans may be infected with the same types of MAC st rains, since 14 strains from humans and 8 strains from pigs were essentiall y identical and together, comprised RAPD type 2, the largest group of strai ns (44.8% of strains). With respect to grouping of strains, serotype and RA PD type were uncorrelated, except for serotype 20 and RAPD type 6. Using st andardized beads, RAPD analysis is a reproducible technique for typing MAC strains, as the indistinguishable banding patterns obtained with repeated a nalyses of two isolates from each strain in this study demonstrate. However , primer selection and DNA purity were crucial for differentiating closely related strains. (C) 2001 Elsevier Science B.V. All rights reserved.