Restriction fragment length polymorphism analysis of Mycobacterium avium isolates from animal and human sources

Restriction fragment length polymorphism (RFLP) analysis using probes deriv ed from the insertion sequences IS901, IS1245 and IS1311, was carried out o n Mycobacterium avium isolates obtained from 18 human patients, 44 deer, 14 pigs and five cattle in the Republic of Ireland. Forty-two of the cervine isolates and two of the bovine isolates contained IS901, while this inserti on sequence was absent from all of the human and porcine isolates. RFLP ana lysis with IS901 probe differentiated the 44 field isolates which contained this element into three types. All of the IS901-positive isolates had a ch aracteristic three-band IS1245 hybridisation pattern and a characteristic s ingle-band IS1311 hybridisation pattern. The IS902-negative isolates exhibi ted highly polymorphic IS1245 and IS1311 hybridisation patterns which diffe rentiated the human and porcine isolates into a wide diversity of strain ty pes.