DISTRIBUTION OF IS901 IN STRAINS OF MYCOBACTERIUM-AVIUM COMPLEX FROM SWINE BY USING IS9O1-DETECTING PRIMERS THAT DISCRIMINATE BETWEEN MYCOBACTERIUM-AVIUM AND MYCOBACTERIUM-INTRACELLULARE

The presence of the mycobacterial insertion sequence IS901 was studied by PCR with reference strains of Mycobacterium avium complex; 122 vet erinary strains of mycobacteria, mainly M. avium complex, isolated fro m swine; and 15 clinical strains. Four kinds of DNA extraction methods for PCR were compared. Use of the commerical extraction matrix allowe d for the faster and easier preparation of PCR-amplifiable DNA than us e of NaOH heating extraction or sodium dodecyl sulfate extraction of p retreated mycobacteria. It also provided more effective protection tha n boiling extraction against the destruction of DNA. Four reference st rains of serovars 1 to 3 possessed IS901. Nine reference strains of se rovars 1, 4 to 6, 8 to 11, and 21 possessed only IS901 insertion sites . A novel PCR product was found in the other reference strains of sero vars 7, 12 to 17, 19, and 20 and two clinical strains of serovar 15. I t is suggested that the primers that amplified the insertion portion o f IS901 divided the M. avium complex into M, avium, Mycobacterium intr acellulare, and other mycobacteria. None of the 110 strains of M. aviu m complex isolated from swine possessed IS901. It is suggested that th e absence of IS901 might be characteristic of swine-derived strains of M. avium complex.