Genetic variability of Mycobacterium avium subsp. avium of pig isolates

The genetic diversity of 132 pig isolates of Mycobacterium avium subsp. avium (MAA) from the Czech Republic, the Slovak Republic and Slovenia was examined by IS901 restriction fragment length polymorphism (RFLP) analysis with restriction endonuclease PvuII. A total of 18 RFLP types were detected. The occurrence frequency of respective RFLP types varied between respective pig farms, with the exception of one RFLP type F found in 21 (34.4%) of 61 farms and in 10 (55.6%) of 18 farms in the Czech Republic and Slovak Republic, respectively. Two different RFLP types were detected in 5 (33.3%) of the 15 studied farms, from which more than one isolate were examined. These results show the low variability of the MAA isolates among the pig farms and the possibility of various sources of infection for pigs from infected farms.